diff --git a/Godeps/Godeps.json b/Godeps/Godeps.json
index b1b16df76..a791ad472 100644
--- a/Godeps/Godeps.json
+++ b/Godeps/Godeps.json
@@ -716,6 +716,10 @@
 			"ImportPath": "github.com/hashicorp/go-multierror",
 			"Rev": "d30f09973e19c1dfcd120b2d9c4f168e68d6b5d5"
 		},
+		{
+			"ImportPath": "github.com/hashicorp/go-plugin",
+			"Rev": "cccb4a1328abbb89898f3ecf4311a05bddc4de6d"
+		},
 		{
 			"ImportPath": "github.com/hashicorp/go-retryablehttp",
 			"Rev": "5ec125ef739293cb4d57c3456dd92ba9af29ed6e"
diff --git a/main.go b/main.go
index 806efe7b6..7e47e7875 100644
--- a/main.go
+++ b/main.go
@@ -9,8 +9,8 @@ import (
 	"runtime"
 	"sync"
 
+	"github.com/hashicorp/go-plugin"
 	"github.com/hashicorp/terraform/helper/logging"
-	"github.com/hashicorp/terraform/plugin"
 	"github.com/mattn/go-colorable"
 	"github.com/mitchellh/cli"
 	"github.com/mitchellh/panicwrap"
diff --git a/vendor/github.com/hashicorp/go-plugin/.gitignore b/vendor/github.com/hashicorp/go-plugin/.gitignore
new file mode 100644
index 000000000..e43b0f988
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-plugin/.gitignore
@@ -0,0 +1 @@
+.DS_Store
diff --git a/vendor/github.com/hashicorp/go-plugin/LICENSE b/vendor/github.com/hashicorp/go-plugin/LICENSE
new file mode 100644
index 000000000..82b4de97c
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-plugin/LICENSE
@@ -0,0 +1,353 @@
+Mozilla Public License, version 2.0
+
+1. Definitions
+
+1.1. “Contributor”
+
+     means each individual or legal entity that creates, contributes to the
+     creation of, or owns Covered Software.
+
+1.2. “Contributor Version”
+
+     means the combination of the Contributions of others (if any) used by a
+     Contributor and that particular Contributor’s Contribution.
+
+1.3. “Contribution”
+
+     means Covered Software of a particular Contributor.
+
+1.4. “Covered Software”
+
+     means Source Code Form to which the initial Contributor has attached the
+     notice in Exhibit A, the Executable Form of such Source Code Form, and
+     Modifications of such Source Code Form, in each case including portions
+     thereof.
+
+1.5. “Incompatible With Secondary Licenses”
+     means
+
+     a. that the initial Contributor has attached the notice described in
+        Exhibit B to the Covered Software; or
+
+     b. that the Covered Software was made available under the terms of version
+        1.1 or earlier of the License, but not also under the terms of a
+        Secondary License.
+
+1.6. “Executable Form”
+
+     means any form of the work other than Source Code Form.
+
+1.7. “Larger Work”
+
+     means a work that combines Covered Software with other material, in a separate
+     file or files, that is not Covered Software.
+
+1.8. “License”
+
+     means this document.
+
+1.9. “Licensable”
+
+     means having the right to grant, to the maximum extent possible, whether at the
+     time of the initial grant or subsequently, any and all of the rights conveyed by
+     this License.
+
+1.10. “Modifications”
+
+     means any of the following:
+
+     a. any file in Source Code Form that results from an addition to, deletion
+        from, or modification of the contents of Covered Software; or
+
+     b. any new file in Source Code Form that contains any Covered Software.
+
+1.11. “Patent Claims” of a Contributor
+
+      means any patent claim(s), including without limitation, method, process,
+      and apparatus claims, in any patent Licensable by such Contributor that
+      would be infringed, but for the grant of the License, by the making,
+      using, selling, offering for sale, having made, import, or transfer of
+      either its Contributions or its Contributor Version.
+
+1.12. “Secondary License”
+
+      means either the GNU General Public License, Version 2.0, the GNU Lesser
+      General Public License, Version 2.1, the GNU Affero General Public
+      License, Version 3.0, or any later versions of those licenses.
+
+1.13. “Source Code Form”
+
+      means the form of the work preferred for making modifications.
+
+1.14. “You” (or “Your”)
+
+      means an individual or a legal entity exercising rights under this
+      License. For legal entities, “You” includes any entity that controls, is
+      controlled by, or is under common control with You. For purposes of this
+      definition, “control” means (a) the power, direct or indirect, to cause
+      the direction or management of such entity, whether by contract or
+      otherwise, or (b) ownership of more than fifty percent (50%) of the
+      outstanding shares or beneficial ownership of such entity.
+
+
+2. License Grants and Conditions
+
+2.1. Grants
+
+     Each Contributor hereby grants You a world-wide, royalty-free,
+     non-exclusive license:
+
+     a. under intellectual property rights (other than patent or trademark)
+        Licensable by such Contributor to use, reproduce, make available,
+        modify, display, perform, distribute, and otherwise exploit its
+        Contributions, either on an unmodified basis, with Modifications, or as
+        part of a Larger Work; and
+
+     b. under Patent Claims of such Contributor to make, use, sell, offer for
+        sale, have made, import, and otherwise transfer either its Contributions
+        or its Contributor Version.
+
+2.2. Effective Date
+
+     The licenses granted in Section 2.1 with respect to any Contribution become
+     effective for each Contribution on the date the Contributor first distributes
+     such Contribution.
+
+2.3. Limitations on Grant Scope
+
+     The licenses granted in this Section 2 are the only rights granted under this
+     License. No additional rights or licenses will be implied from the distribution
+     or licensing of Covered Software under this License. Notwithstanding Section
+     2.1(b) above, no patent license is granted by a Contributor:
+
+     a. for any code that a Contributor has removed from Covered Software; or
+
+     b. for infringements caused by: (i) Your and any other third party’s
+        modifications of Covered Software, or (ii) the combination of its
+        Contributions with other software (except as part of its Contributor
+        Version); or
+
+     c. under Patent Claims infringed by Covered Software in the absence of its
+        Contributions.
+
+     This License does not grant any rights in the trademarks, service marks, or
+     logos of any Contributor (except as may be necessary to comply with the
+     notice requirements in Section 3.4).
+
+2.4. Subsequent Licenses
+
+     No Contributor makes additional grants as a result of Your choice to
+     distribute the Covered Software under a subsequent version of this License
+     (see Section 10.2) or under the terms of a Secondary License (if permitted
+     under the terms of Section 3.3).
+
+2.5. Representation
+
+     Each Contributor represents that the Contributor believes its Contributions
+     are its original creation(s) or it has sufficient rights to grant the
+     rights to its Contributions conveyed by this License.
+
+2.6. Fair Use
+
+     This License is not intended to limit any rights You have under applicable
+     copyright doctrines of fair use, fair dealing, or other equivalents.
+
+2.7. Conditions
+
+     Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted in
+     Section 2.1.
+
+
+3. Responsibilities
+
+3.1. Distribution of Source Form
+
+     All distribution of Covered Software in Source Code Form, including any
+     Modifications that You create or to which You contribute, must be under the
+     terms of this License. You must inform recipients that the Source Code Form
+     of the Covered Software is governed by the terms of this License, and how
+     they can obtain a copy of this License. You may not attempt to alter or
+     restrict the recipients’ rights in the Source Code Form.
+
+3.2. Distribution of Executable Form
+
+     If You distribute Covered Software in Executable Form then:
+
+     a. such Covered Software must also be made available in Source Code Form,
+        as described in Section 3.1, and You must inform recipients of the
+        Executable Form how they can obtain a copy of such Source Code Form by
+        reasonable means in a timely manner, at a charge no more than the cost
+        of distribution to the recipient; and
+
+     b. You may distribute such Executable Form under the terms of this License,
+        or sublicense it under different terms, provided that the license for
+        the Executable Form does not attempt to limit or alter the recipients’
+        rights in the Source Code Form under this License.
+
+3.3. Distribution of a Larger Work
+
+     You may create and distribute a Larger Work under terms of Your choice,
+     provided that You also comply with the requirements of this License for the
+     Covered Software. If the Larger Work is a combination of Covered Software
+     with a work governed by one or more Secondary Licenses, and the Covered
+     Software is not Incompatible With Secondary Licenses, this License permits
+     You to additionally distribute such Covered Software under the terms of
+     such Secondary License(s), so that the recipient of the Larger Work may, at
+     their option, further distribute the Covered Software under the terms of
+     either this License or such Secondary License(s).
+
+3.4. Notices
+
+     You may not remove or alter the substance of any license notices (including
+     copyright notices, patent notices, disclaimers of warranty, or limitations
+     of liability) contained within the Source Code Form of the Covered
+     Software, except that You may alter any license notices to the extent
+     required to remedy known factual inaccuracies.
+
+3.5. Application of Additional Terms
+
+     You may choose to offer, and to charge a fee for, warranty, support,
+     indemnity or liability obligations to one or more recipients of Covered
+     Software. However, You may do so only on Your own behalf, and not on behalf
+     of any Contributor. You must make it absolutely clear that any such
+     warranty, support, indemnity, or liability obligation is offered by You
+     alone, and You hereby agree to indemnify every Contributor for any
+     liability incurred by such Contributor as a result of warranty, support,
+     indemnity or liability terms You offer. You may include additional
+     disclaimers of warranty and limitations of liability specific to any
+     jurisdiction.
+
+4. Inability to Comply Due to Statute or Regulation
+
+   If it is impossible for You to comply with any of the terms of this License
+   with respect to some or all of the Covered Software due to statute, judicial
+   order, or regulation then You must: (a) comply with the terms of this License
+   to the maximum extent possible; and (b) describe the limitations and the code
+   they affect. Such description must be placed in a text file included with all
+   distributions of the Covered Software under this License. Except to the
+   extent prohibited by statute or regulation, such description must be
+   sufficiently detailed for a recipient of ordinary skill to be able to
+   understand it.
+
+5. Termination
+
+5.1. The rights granted under this License will terminate automatically if You
+     fail to comply with any of its terms. However, if You become compliant,
+     then the rights granted under this License from a particular Contributor
+     are reinstated (a) provisionally, unless and until such Contributor
+     explicitly and finally terminates Your grants, and (b) on an ongoing basis,
+     if such Contributor fails to notify You of the non-compliance by some
+     reasonable means prior to 60 days after You have come back into compliance.
+     Moreover, Your grants from a particular Contributor are reinstated on an
+     ongoing basis if such Contributor notifies You of the non-compliance by
+     some reasonable means, this is the first time You have received notice of
+     non-compliance with this License from such Contributor, and You become
+     compliant prior to 30 days after Your receipt of the notice.
+
+5.2. If You initiate litigation against any entity by asserting a patent
+     infringement claim (excluding declaratory judgment actions, counter-claims,
+     and cross-claims) alleging that a Contributor Version directly or
+     indirectly infringes any patent, then the rights granted to You by any and
+     all Contributors for the Covered Software under Section 2.1 of this License
+     shall terminate.
+
+5.3. In the event of termination under Sections 5.1 or 5.2 above, all end user
+     license agreements (excluding distributors and resellers) which have been
+     validly granted by You or Your distributors under this License prior to
+     termination shall survive termination.
+
+6. Disclaimer of Warranty
+
+   Covered Software is provided under this License on an “as is” basis, without
+   warranty of any kind, either expressed, implied, or statutory, including,
+   without limitation, warranties that the Covered Software is free of defects,
+   merchantable, fit for a particular purpose or non-infringing. The entire
+   risk as to the quality and performance of the Covered Software is with You.
+   Should any Covered Software prove defective in any respect, You (not any
+   Contributor) assume the cost of any necessary servicing, repair, or
+   correction. This disclaimer of warranty constitutes an essential part of this
+   License. No use of  any Covered Software is authorized under this License
+   except under this disclaimer.
+
+7. Limitation of Liability
+
+   Under no circumstances and under no legal theory, whether tort (including
+   negligence), contract, or otherwise, shall any Contributor, or anyone who
+   distributes Covered Software as permitted above, be liable to You for any
+   direct, indirect, special, incidental, or consequential damages of any
+   character including, without limitation, damages for lost profits, loss of
+   goodwill, work stoppage, computer failure or malfunction, or any and all
+   other commercial damages or losses, even if such party shall have been
+   informed of the possibility of such damages. This limitation of liability
+   shall not apply to liability for death or personal injury resulting from such
+   party’s negligence to the extent applicable law prohibits such limitation.
+   Some jurisdictions do not allow the exclusion or limitation of incidental or
+   consequential damages, so this exclusion and limitation may not apply to You.
+
+8. Litigation
+
+   Any litigation relating to this License may be brought only in the courts of
+   a jurisdiction where the defendant maintains its principal place of business
+   and such litigation shall be governed by laws of that jurisdiction, without
+   reference to its conflict-of-law provisions. Nothing in this Section shall
+   prevent a party’s ability to bring cross-claims or counter-claims.
+
+9. Miscellaneous
+
+   This License represents the complete agreement concerning the subject matter
+   hereof. If any provision of this License is held to be unenforceable, such
+   provision shall be reformed only to the extent necessary to make it
+   enforceable. Any law or regulation which provides that the language of a
+   contract shall be construed against the drafter shall not be used to construe
+   this License against a Contributor.
+
+
+10. Versions of the License
+
+10.1. New Versions
+
+      Mozilla Foundation is the license steward. Except as provided in Section
+      10.3, no one other than the license steward has the right to modify or
+      publish new versions of this License. Each version will be given a
+      distinguishing version number.
+
+10.2. Effect of New Versions
+
+      You may distribute the Covered Software under the terms of the version of
+      the License under which You originally received the Covered Software, or
+      under the terms of any subsequent version published by the license
+      steward.
+
+10.3. Modified Versions
+
+      If you create software not governed by this License, and you want to
+      create a new license for such software, you may create and use a modified
+      version of this License if you rename the license and remove any
+      references to the name of the license steward (except to note that such
+      modified license differs from this License).
+
+10.4. Distributing Source Code Form that is Incompatible With Secondary Licenses
+      If You choose to distribute Source Code Form that is Incompatible With
+      Secondary Licenses under the terms of this version of the License, the
+      notice described in Exhibit B of this License must be attached.
+
+Exhibit A - Source Code Form License Notice
+
+      This Source Code Form is subject to the
+      terms of the Mozilla Public License, v.
+      2.0. If a copy of the MPL was not
+      distributed with this file, You can
+      obtain one at
+      http://mozilla.org/MPL/2.0/.
+
+If it is not possible or desirable to put the notice in a particular file, then
+You may include the notice in a location (such as a LICENSE file in a relevant
+directory) where a recipient would be likely to look for such a notice.
+
+You may add additional accurate notices of copyright ownership.
+
+Exhibit B - “Incompatible With Secondary Licenses” Notice
+
+      This Source Code Form is “Incompatible
+      With Secondary Licenses”, as defined by
+      the Mozilla Public License, v. 2.0.
diff --git a/vendor/github.com/hashicorp/go-plugin/README.md b/vendor/github.com/hashicorp/go-plugin/README.md
new file mode 100644
index 000000000..2058cfb68
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-plugin/README.md
@@ -0,0 +1,161 @@
+# Go Plugin System over RPC
+
+`go-plugin` is a Go (golang) plugin system over RPC. It is the plugin system
+that has been in use by HashiCorp tooling for over 3 years. While initially
+created for [Packer](https://www.packer.io), it has since been used by
+[Terraform](https://www.terraform.io) and [Otto](https://www.ottoproject.io),
+with plans to also use it for [Nomad](https://www.nomadproject.io) and
+[Vault](https://www.vaultproject.io).
+
+While the plugin system is over RPC, it is currently only designed to work
+over a local [reliable] network. Plugins over a real network are not supported
+and will lead to unexpected behavior.
+
+This plugin system has been used on millions of machines across many different
+projects and has proven to be battle hardened and ready for production use.
+
+## Features
+
+The HashiCorp plugin system supports a number of features:
+
+**Plugins are Go interface implementations.** This makes writing and consuming
+plugins feel very natural. To a plugin author: you just implement an
+interface as if it were going to run in the same process. For a plugin user:
+you just use and call functions on an interface as if it were in the same
+process. This plugin system handles the communication in between.
+
+**Complex arguments and return values are supported.** This library
+provides APIs for handling complex arguments and return values such
+as interfaces, `io.Reader/Writer`, etc. We do this by giving you a library
+(`MuxBroker`) for creating new connections between the client/server to
+serve additional interfaces or transfer raw data.
+
+**Bidirectional communication.** Because the plugin system supports
+complex arguments, the host process can send it interface implementations
+and the plugin can call back into the host process.
+
+**Built-in Logging.** Any plugins that use the `log` standard library
+will have log data automatically sent to the host process. The host
+process will mirror this output prefixed with the path to the plugin
+binary. This makes debugging with plugins simple.
+
+**Protocol Versioning.** A very basic "protocol version" is supported that
+can be incremented to invalidate any previous plugins. This is useful when
+interface signatures are changing, protocol level changes are necessary,
+etc. When a protocol version is incompatible, a human friendly error
+message is shown to the end user.
+
+**Stdout/Stderr Syncing.** While plugins are subprocesses, they can continue
+to use stdout/stderr as usual and the output will get mirrored back to
+the host process. The host process can control what `io.Writer` these
+streams go to to prevent this from happening.
+
+**TTY Preservation.** Plugin subprocesses are connected to the identical
+stdin file descriptor as the host process, allowing software that requires
+a TTY to work. For example, a plugin can execute `ssh` and even though there
+are multiple subprocesses and RPC happening, it will look and act perfectly
+to the end user.
+
+**Host upgrade while a plugin is running.** Plugins can be "reattached"
+so that the host process can be upgraded while the plugin is still running.
+This requires the host/plugin to know this is possible and daemonize
+properly. `NewClient` takes a `ReattachConfig` to determine if and how to
+reattach.
+
+## Architecture
+
+The HashiCorp plugin system works by launching subprocesses and communicating
+over RPC (using standard `net/rpc`). A single connection is made between
+any plugin and the host process, and we use a
+[connection multiplexing](https://github.com/hashicorp/yamux)
+library to multiplex any other connections on top.
+
+This architecture has a number of benefits:
+
+  * Plugins can't crash your host process: A panic in a plugin doesn't
+    panic the plugin user.
+
+  * Plugins are very easy to write: just write a Go application and `go build`.
+    Theoretically you could also use another language as long as it can
+    communicate the Go `net/rpc` protocol but this hasn't yet been tried.
+
+  * Plugins are very easy to install: just put the binary in a location where
+    the host will find it (depends on the host but this library also provides
+    helpers), and the plugin host handles the rest.
+
+  * Plugins can be relatively secure: The plugin only has access to the
+    interfaces and args given to it, not to the entire memory space of the
+    process. More security features are planned (see the coming soon section
+    below).
+
+## Usage
+
+To use the plugin system, you must take the following steps. These are
+high-level steps that must be done. Examples are available in the
+`examples/` directory.
+
+  1. Choose the interface(s) you want to expose for plugins.
+
+  2. For each interface, implement an implementation of that interface
+     that communicates over an `*rpc.Client` (from the standard `net/rpc`
+     package) for every function call. Likewise, implement the RPC server
+     struct this communicates to which is then communicating to a real,
+     concrete implementation.
+
+  3. Create a `Plugin` implementation that knows how to create the RPC
+     client/server for a given plugin type.
+
+  4. Plugin authors call `plugin.Serve` to serve a plugin from the
+     `main` function.
+
+  5. Plugin users use `plugin.Client` to launch a subprocess and request
+     an interface implementation over RPC.
+
+That's it! In practice, step 2 is the most tedious and time consuming step.
+Even so, it isn't very difficult and you can see examples in the `examples/`
+directory as well as throughout our various open source projects.
+
+For complete API documentation, see [GoDoc](https://godoc.org/github.com/hashicorp/go-plugin).
+
+## Roadmap
+
+Our plugin system is constantly evolving. As we use the plugin system for
+new projects or for new features in existing projects, we constantly find
+improvements we can make.
+
+At this point in time, the roadmap for the plugin system is:
+
+**Cryptographically Secure Plugins.** We'll implement signing plugins
+and loading signed plugins in order to allow Vault to make use of multi-process
+in a secure way.
+
+**Semantic Versioning.** Plugins will be able to implement a semantic version.
+This plugin system will give host processes a system for constraining
+versions. This is in addition to the protocol versioning already present
+which is more for larger underlying changes.
+
+**Plugin fetching.** We will integrate with [go-getter](https://github.com/hashicorp/go-getter)
+to support automatic download + install of plugins. Paired with cryptographically
+secure plugins (above), we can make this a safe operation for an amazing
+user experience.
+
+## What About Shared Libraries?
+
+When we started using plugins (late 2012, early 2013), plugins over RPC
+were the only option since Go didn't support dynamic library loading. Today,
+Go still doesn't support dynamic library loading, but they do intend to.
+Since 2012, our plugin system has stabilized from millions of users using it,
+and has many benefits we've come to value greatly.
+
+For example, we intend to use this plugin system in
+[Vault](https://www.vaultproject.io), and dynamic library loading will
+simply never be acceptable in Vault for security reasons. That is an extreme
+example, but we believe our library system has more upsides than downsides
+over dynamic library loading and since we've had it built and tested for years,
+we'll likely continue to use it.
+
+Shared libraries have one major advantage over our system which is much
+higher performance. In real world scenarios across our various tools,
+we've never required any more performance out of our plugin system and it
+has seen very high throughput, so this isn't a concern for us at the moment.
+
diff --git a/vendor/github.com/hashicorp/go-plugin/client.go b/vendor/github.com/hashicorp/go-plugin/client.go
new file mode 100644
index 000000000..e559f713e
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-plugin/client.go
@@ -0,0 +1,533 @@
+package plugin
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"net"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"sync"
+	"sync/atomic"
+	"time"
+	"unicode"
+)
+
+// If this is 1, then we've called CleanupClients. This can be used
+// by plugin RPC implementations to change error behavior since you
+// can expected network connection errors at this point. This should be
+// read by using sync/atomic.
+var Killed uint32 = 0
+
+// This is a slice of the "managed" clients which are cleaned up when
+// calling Cleanup
+var managedClients = make([]*Client, 0, 5)
+
+// Error types
+var (
+	// ErrProcessNotFound is returned when a client is instantiated to
+	// reattach to an existing process and it isn't found.
+	ErrProcessNotFound = errors.New("Reattachment process not found")
+)
+
+// Client handles the lifecycle of a plugin application. It launches
+// plugins, connects to them, dispenses interface implementations, and handles
+// killing the process.
+//
+// Plugin hosts should use one Client for each plugin executable. To
+// dispense a plugin type, use the `Client.Client` function, and then
+// cal `Dispense`. This awkward API is mostly historical but is used to split
+// the client that deals with subprocess management and the client that
+// does RPC management.
+//
+// See NewClient and ClientConfig for using a Client.
+type Client struct {
+	config      *ClientConfig
+	exited      bool
+	doneLogging chan struct{}
+	l           sync.Mutex
+	address     net.Addr
+	process     *os.Process
+	client      *RPCClient
+}
+
+// ClientConfig is the configuration used to initialize a new
+// plugin client. After being used to initialize a plugin client,
+// that configuration must not be modified again.
+type ClientConfig struct {
+	// HandshakeConfig is the configuration that must match servers.
+	HandshakeConfig
+
+	// Plugins are the plugins that can be consumed.
+	Plugins map[string]Plugin
+
+	// One of the following must be set, but not both.
+	//
+	// Cmd is the unstarted subprocess for starting the plugin. If this is
+	// set, then the Client starts the plugin process on its own and connects
+	// to it.
+	//
+	// Reattach is configuration for reattaching to an existing plugin process
+	// that is already running. This isn't common.
+	Cmd      *exec.Cmd
+	Reattach *ReattachConfig
+
+	// Managed represents if the client should be managed by the
+	// plugin package or not. If true, then by calling CleanupClients,
+	// it will automatically be cleaned up. Otherwise, the client
+	// user is fully responsible for making sure to Kill all plugin
+	// clients. By default the client is _not_ managed.
+	Managed bool
+
+	// The minimum and maximum port to use for communicating with
+	// the subprocess. If not set, this defaults to 10,000 and 25,000
+	// respectively.
+	MinPort, MaxPort uint
+
+	// StartTimeout is the timeout to wait for the plugin to say it
+	// has started successfully.
+	StartTimeout time.Duration
+
+	// If non-nil, then the stderr of the client will be written to here
+	// (as well as the log). This is the original os.Stderr of the subprocess.
+	// This isn't the output of synced stderr.
+	Stderr io.Writer
+
+	// SyncStdout, SyncStderr can be set to override the
+	// respective os.Std* values in the plugin. Care should be taken to
+	// avoid races here. If these are nil, then this will automatically be
+	// hooked up to os.Stdin, Stdout, and Stderr, respectively.
+	//
+	// If the default values (nil) are used, then this package will not
+	// sync any of these streams.
+	SyncStdout io.Writer
+	SyncStderr io.Writer
+}
+
+// ReattachConfig is used to configure a client to reattach to an
+// already-running plugin process. You can retrieve this information by
+// calling ReattachConfig on Client.
+type ReattachConfig struct {
+	Addr net.Addr
+	Pid  int
+}
+
+// This makes sure all the managed subprocesses are killed and properly
+// logged. This should be called before the parent process running the
+// plugins exits.
+//
+// This must only be called _once_.
+func CleanupClients() {
+	// Set the killed to true so that we don't get unexpected panics
+	atomic.StoreUint32(&Killed, 1)
+
+	// Kill all the managed clients in parallel and use a WaitGroup
+	// to wait for them all to finish up.
+	var wg sync.WaitGroup
+	for _, client := range managedClients {
+		wg.Add(1)
+
+		go func(client *Client) {
+			client.Kill()
+			wg.Done()
+		}(client)
+	}
+
+	log.Println("[DEBUG] plugin: waiting for all plugin processes to complete...")
+	wg.Wait()
+}
+
+// Creates a new plugin client which manages the lifecycle of an external
+// plugin and gets the address for the RPC connection.
+//
+// The client must be cleaned up at some point by calling Kill(). If
+// the client is a managed client (created with NewManagedClient) you
+// can just call CleanupClients at the end of your program and they will
+// be properly cleaned.
+func NewClient(config *ClientConfig) (c *Client) {
+	if config.MinPort == 0 && config.MaxPort == 0 {
+		config.MinPort = 10000
+		config.MaxPort = 25000
+	}
+
+	if config.StartTimeout == 0 {
+		config.StartTimeout = 1 * time.Minute
+	}
+
+	if config.Stderr == nil {
+		config.Stderr = ioutil.Discard
+	}
+
+	if config.SyncStdout == nil {
+		config.SyncStdout = ioutil.Discard
+	}
+	if config.SyncStderr == nil {
+		config.SyncStderr = ioutil.Discard
+	}
+
+	c = &Client{config: config}
+	if config.Managed {
+		managedClients = append(managedClients, c)
+	}
+
+	return
+}
+
+// Client returns an RPC client for the plugin.
+//
+// Subsequent calls to this will return the same RPC client.
+func (c *Client) Client() (*RPCClient, error) {
+	addr, err := c.Start()
+	if err != nil {
+		return nil, err
+	}
+
+	c.l.Lock()
+	defer c.l.Unlock()
+
+	if c.client != nil {
+		return c.client, nil
+	}
+
+	// Connect to the client
+	conn, err := net.Dial(addr.Network(), addr.String())
+	if err != nil {
+		return nil, err
+	}
+	if tcpConn, ok := conn.(*net.TCPConn); ok {
+		// Make sure to set keep alive so that the connection doesn't die
+		tcpConn.SetKeepAlive(true)
+	}
+
+	// Create the actual RPC client
+	c.client, err = NewRPCClient(conn, c.config.Plugins)
+	if err != nil {
+		conn.Close()
+		return nil, err
+	}
+
+	// Begin the stream syncing so that stdin, out, err work properly
+	err = c.client.SyncStreams(
+		c.config.SyncStdout,
+		c.config.SyncStderr)
+	if err != nil {
+		c.client.Close()
+		c.client = nil
+		return nil, err
+	}
+
+	return c.client, nil
+}
+
+// Tells whether or not the underlying process has exited.
+func (c *Client) Exited() bool {
+	c.l.Lock()
+	defer c.l.Unlock()
+	return c.exited
+}
+
+// End the executing subprocess (if it is running) and perform any cleanup
+// tasks necessary such as capturing any remaining logs and so on.
+//
+// This method blocks until the process successfully exits.
+//
+// This method can safely be called multiple times.
+func (c *Client) Kill() {
+	if c.process == nil {
+		return
+	}
+
+	// Kill the process
+	c.process.Kill()
+
+	// Wait for the client to finish logging so we have a complete log
+	<-c.doneLogging
+}
+
+// Starts the underlying subprocess, communicating with it to negotiate
+// a port for RPC connections, and returning the address to connect via RPC.
+//
+// This method is safe to call multiple times. Subsequent calls have no effect.
+// Once a client has been started once, it cannot be started again, even if
+// it was killed.
+func (c *Client) Start() (addr net.Addr, err error) {
+	c.l.Lock()
+	defer c.l.Unlock()
+
+	if c.address != nil {
+		return c.address, nil
+	}
+
+	// If one of cmd or reattach isn't set, then it is an error. We wrap
+	// this in a {} for scoping reasons, and hopeful that the escape
+	// analysis will pop the stock here.
+	{
+		cmdSet := c.config.Cmd != nil
+		attachSet := c.config.Reattach != nil
+		if cmdSet == attachSet {
+			return nil, fmt.Errorf("Only one of Cmd or Reattach must be set")
+		}
+	}
+
+	// Create the logging channel for when we kill
+	c.doneLogging = make(chan struct{})
+
+	if c.config.Reattach != nil {
+		// Verify the process still exists. If not, then it is an error
+		p, err := os.FindProcess(c.config.Reattach.Pid)
+		if err != nil {
+			return nil, err
+		}
+
+		// Attempt to connect to the addr since on Unix systems FindProcess
+		// doesn't actually return an error if it can't find the process.
+		conn, err := net.Dial(
+			c.config.Reattach.Addr.Network(),
+			c.config.Reattach.Addr.String())
+		if err != nil {
+			p.Kill()
+			return nil, ErrProcessNotFound
+		}
+		conn.Close()
+
+		// Goroutine to mark exit status
+		go func(pid int) {
+			// Wait for the process to die
+			pidWait(pid)
+
+			// Log so we can see it
+			log.Printf("[DEBUG] plugin: reattached plugin process exited\n")
+
+			// Mark it
+			c.l.Lock()
+			defer c.l.Unlock()
+			c.exited = true
+
+			// Close the logging channel since that doesn't work on reattach
+			close(c.doneLogging)
+		}(p.Pid)
+
+		// Set the address and process
+		c.address = c.config.Reattach.Addr
+		c.process = p
+
+		return c.address, nil
+	}
+
+	env := []string{
+		fmt.Sprintf("%s=%s", c.config.MagicCookieKey, c.config.MagicCookieValue),
+		fmt.Sprintf("PLUGIN_MIN_PORT=%d", c.config.MinPort),
+		fmt.Sprintf("PLUGIN_MAX_PORT=%d", c.config.MaxPort),
+	}
+
+	stdout_r, stdout_w := io.Pipe()
+	stderr_r, stderr_w := io.Pipe()
+
+	cmd := c.config.Cmd
+	cmd.Env = append(cmd.Env, os.Environ()...)
+	cmd.Env = append(cmd.Env, env...)
+	cmd.Stdin = os.Stdin
+	cmd.Stderr = stderr_w
+	cmd.Stdout = stdout_w
+
+	log.Printf("[DEBUG] plugin: starting plugin: %s %#v", cmd.Path, cmd.Args)
+	err = cmd.Start()
+	if err != nil {
+		return
+	}
+
+	// Set the process
+	c.process = cmd.Process
+
+	// Make sure the command is properly cleaned up if there is an error
+	defer func() {
+		r := recover()
+
+		if err != nil || r != nil {
+			cmd.Process.Kill()
+		}
+
+		if r != nil {
+			panic(r)
+		}
+	}()
+
+	// Start goroutine to wait for process to exit
+	exitCh := make(chan struct{})
+	go func() {
+		// Make sure we close the write end of our stderr/stdout so
+		// that the readers send EOF properly.
+		defer stderr_w.Close()
+		defer stdout_w.Close()
+
+		// Wait for the command to end.
+		cmd.Wait()
+
+		// Log and make sure to flush the logs write away
+		log.Printf("[DEBUG] plugin: %s: plugin process exited\n", cmd.Path)
+		os.Stderr.Sync()
+
+		// Mark that we exited
+		close(exitCh)
+
+		// Set that we exited, which takes a lock
+		c.l.Lock()
+		defer c.l.Unlock()
+		c.exited = true
+	}()
+
+	// Start goroutine that logs the stderr
+	go c.logStderr(stderr_r)
+
+	// Start a goroutine that is going to be reading the lines
+	// out of stdout
+	linesCh := make(chan []byte)
+	go func() {
+		defer close(linesCh)
+
+		buf := bufio.NewReader(stdout_r)
+		for {
+			line, err := buf.ReadBytes('\n')
+			if line != nil {
+				linesCh <- line
+			}
+
+			if err == io.EOF {
+				return
+			}
+		}
+	}()
+
+	// Make sure after we exit we read the lines from stdout forever
+	// so they don't block since it is an io.Pipe
+	defer func() {
+		go func() {
+			for _ = range linesCh {
+			}
+		}()
+	}()
+
+	// Some channels for the next step
+	timeout := time.After(c.config.StartTimeout)
+
+	// Start looking for the address
+	log.Printf("[DEBUG] plugin: waiting for RPC address for: %s", cmd.Path)
+	select {
+	case <-timeout:
+		err = errors.New("timeout while waiting for plugin to start")
+	case <-exitCh:
+		err = errors.New("plugin exited before we could connect")
+	case lineBytes := <-linesCh:
+		// Trim the line and split by "|" in order to get the parts of
+		// the output.
+		line := strings.TrimSpace(string(lineBytes))
+		parts := strings.SplitN(line, "|", 4)
+		if len(parts) < 4 {
+			err = fmt.Errorf(
+				"Unrecognized remote plugin message: %s\n\n"+
+					"This usually means that the plugin is either invalid or simply\n"+
+					"needs to be recompiled to support the latest protocol.", line)
+			return
+		}
+
+		// Check the core protocol. Wrapped in a {} for scoping.
+		{
+			var coreProtocol int64
+			coreProtocol, err = strconv.ParseInt(parts[0], 10, 0)
+			if err != nil {
+				err = fmt.Errorf("Error parsing core protocol version: %s", err)
+				return
+			}
+
+			if int(coreProtocol) != CoreProtocolVersion {
+				err = fmt.Errorf("Incompatible core API version with plugin. "+
+					"Plugin version: %s, Ours: %d\n\n"+
+					"To fix this, the plugin usually only needs to be recompiled.\n"+
+					"Please report this to the plugin author.", parts[0], CoreProtocolVersion)
+				return
+			}
+		}
+
+		// Parse the protocol version
+		var protocol int64
+		protocol, err = strconv.ParseInt(parts[1], 10, 0)
+		if err != nil {
+			err = fmt.Errorf("Error parsing protocol version: %s", err)
+			return
+		}
+
+		// Test the API version
+		if uint(protocol) != c.config.ProtocolVersion {
+			err = fmt.Errorf("Incompatible API version with plugin. "+
+				"Plugin version: %s, Ours: %d", parts[1], c.config.ProtocolVersion)
+			return
+		}
+
+		switch parts[2] {
+		case "tcp":
+			addr, err = net.ResolveTCPAddr("tcp", parts[3])
+		case "unix":
+			addr, err = net.ResolveUnixAddr("unix", parts[3])
+		default:
+			err = fmt.Errorf("Unknown address type: %s", parts[3])
+		}
+	}
+
+	c.address = addr
+	return
+}
+
+// ReattachConfig returns the information that must be provided to NewClient
+// to reattach to the plugin process that this client started. This is
+// useful for plugins that detach from their parent process.
+//
+// If this returns nil then the process hasn't been started yet. Please
+// call Start or Client before calling this.
+func (c *Client) ReattachConfig() *ReattachConfig {
+	c.l.Lock()
+	defer c.l.Unlock()
+
+	if c.address == nil {
+		return nil
+	}
+
+	if c.config.Cmd != nil && c.config.Cmd.Process == nil {
+		return nil
+	}
+
+	// If we connected via reattach, just return the information as-is
+	if c.config.Reattach != nil {
+		return c.config.Reattach
+	}
+
+	return &ReattachConfig{
+		Addr: c.address,
+		Pid:  c.config.Cmd.Process.Pid,
+	}
+}
+
+func (c *Client) logStderr(r io.Reader) {
+	bufR := bufio.NewReader(r)
+	for {
+		line, err := bufR.ReadString('\n')
+		if line != "" {
+			c.config.Stderr.Write([]byte(line))
+
+			line = strings.TrimRightFunc(line, unicode.IsSpace)
+			log.Printf("[DEBUG] plugin: %s: %s", filepath.Base(c.config.Cmd.Path), line)
+		}
+
+		if err == io.EOF {
+			break
+		}
+	}
+
+	// Flag that we've completed logging for others
+	close(c.doneLogging)
+}
diff --git a/vendor/github.com/hashicorp/go-plugin/discover.go b/vendor/github.com/hashicorp/go-plugin/discover.go
new file mode 100644
index 000000000..d22c566ed
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-plugin/discover.go
@@ -0,0 +1,28 @@
+package plugin
+
+import (
+	"path/filepath"
+)
+
+// Discover discovers plugins that are in a given directory.
+//
+// The directory doesn't need to be absolute. For example, "." will work fine.
+//
+// This currently assumes any file matching the glob is a plugin.
+// In the future this may be smarter about checking that a file is
+// executable and so on.
+//
+// TODO: test
+func Discover(glob, dir string) ([]string, error) {
+	var err error
+
+	// Make the directory absolute if it isn't already
+	if !filepath.IsAbs(dir) {
+		dir, err = filepath.Abs(dir)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return filepath.Glob(filepath.Join(dir, glob))
+}
diff --git a/vendor/github.com/hashicorp/go-plugin/error.go b/vendor/github.com/hashicorp/go-plugin/error.go
new file mode 100644
index 000000000..22a7baa6a
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-plugin/error.go
@@ -0,0 +1,24 @@
+package plugin
+
+// This is a type that wraps error types so that they can be messaged
+// across RPC channels. Since "error" is an interface, we can't always
+// gob-encode the underlying structure. This is a valid error interface
+// implementer that we will push across.
+type BasicError struct {
+	Message string
+}
+
+// NewBasicError is used to create a BasicError.
+//
+// err is allowed to be nil.
+func NewBasicError(err error) *BasicError {
+	if err == nil {
+		return nil
+	}
+
+	return &BasicError{err.Error()}
+}
+
+func (e *BasicError) Error() string {
+	return e.Message
+}
diff --git a/vendor/github.com/hashicorp/go-plugin/mux_broker.go b/vendor/github.com/hashicorp/go-plugin/mux_broker.go
new file mode 100644
index 000000000..01c45ad7c
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-plugin/mux_broker.go
@@ -0,0 +1,204 @@
+package plugin
+
+import (
+	"encoding/binary"
+	"fmt"
+	"log"
+	"net"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/hashicorp/yamux"
+)
+
+// MuxBroker is responsible for brokering multiplexed connections by unique ID.
+//
+// It is used by plugins to multiplex multiple RPC connections and data
+// streams on top of a single connection between the plugin process and the
+// host process.
+//
+// This allows a plugin to request a channel with a specific ID to connect to
+// or accept a connection from, and the broker handles the details of
+// holding these channels open while they're being negotiated.
+//
+// The Plugin interface has access to these for both Server and Client.
+// The broker can be used by either (optionally) to reserve and connect to
+// new multiplexed streams. This is useful for complex args and return values,
+// or anything else you might need a data stream for.
+type MuxBroker struct {
+	nextId  uint32
+	session *yamux.Session
+	streams map[uint32]*muxBrokerPending
+
+	sync.Mutex
+}
+
+type muxBrokerPending struct {
+	ch     chan net.Conn
+	doneCh chan struct{}
+}
+
+func newMuxBroker(s *yamux.Session) *MuxBroker {
+	return &MuxBroker{
+		session: s,
+		streams: make(map[uint32]*muxBrokerPending),
+	}
+}
+
+// Accept accepts a connection by ID.
+//
+// This should not be called multiple times with the same ID at one time.
+func (m *MuxBroker) Accept(id uint32) (net.Conn, error) {
+	var c net.Conn
+	p := m.getStream(id)
+	select {
+	case c = <-p.ch:
+		close(p.doneCh)
+	case <-time.After(5 * time.Second):
+		m.Lock()
+		defer m.Unlock()
+		delete(m.streams, id)
+
+		return nil, fmt.Errorf("timeout waiting for accept")
+	}
+
+	// Ack our connection
+	if err := binary.Write(c, binary.LittleEndian, id); err != nil {
+		c.Close()
+		return nil, err
+	}
+
+	return c, nil
+}
+
+// AcceptAndServe is used to accept a specific stream ID and immediately
+// serve an RPC server on that stream ID. This is used to easily serve
+// complex arguments.
+//
+// The served interface is always registered to the "Plugin" name.
+func (m *MuxBroker) AcceptAndServe(id uint32, v interface{}) {
+	conn, err := m.Accept(id)
+	if err != nil {
+		log.Printf("[ERR] plugin: plugin acceptAndServe error: %s", err)
+		return
+	}
+
+	serve(conn, "Plugin", v)
+}
+
+// Close closes the connection and all sub-connections.
+func (m *MuxBroker) Close() error {
+	return m.session.Close()
+}
+
+// Dial opens a connection by ID.
+func (m *MuxBroker) Dial(id uint32) (net.Conn, error) {
+	// Open the stream
+	stream, err := m.session.OpenStream()
+	if err != nil {
+		return nil, err
+	}
+
+	// Write the stream ID onto the wire.
+	if err := binary.Write(stream, binary.LittleEndian, id); err != nil {
+		stream.Close()
+		return nil, err
+	}
+
+	// Read the ack that we connected. Then we're off!
+	var ack uint32
+	if err := binary.Read(stream, binary.LittleEndian, &ack); err != nil {
+		stream.Close()
+		return nil, err
+	}
+	if ack != id {
+		stream.Close()
+		return nil, fmt.Errorf("bad ack: %d (expected %d)", ack, id)
+	}
+
+	return stream, nil
+}
+
+// NextId returns a unique ID to use next.
+//
+// It is possible for very long-running plugin hosts to wrap this value,
+// though it would require a very large amount of RPC calls. In practice
+// we've never seen it happen.
+func (m *MuxBroker) NextId() uint32 {
+	return atomic.AddUint32(&m.nextId, 1)
+}
+
+// Run starts the brokering and should be executed in a goroutine, since it
+// blocks forever, or until the session closes.
+//
+// Uses of MuxBroker never need to call this. It is called internally by
+// the plugin host/client.
+func (m *MuxBroker) Run() {
+	for {
+		stream, err := m.session.AcceptStream()
+		if err != nil {
+			// Once we receive an error, just exit
+			break
+		}
+
+		// Read the stream ID from the stream
+		var id uint32
+		if err := binary.Read(stream, binary.LittleEndian, &id); err != nil {
+			stream.Close()
+			continue
+		}
+
+		// Initialize the waiter
+		p := m.getStream(id)
+		select {
+		case p.ch <- stream:
+		default:
+		}
+
+		// Wait for a timeout
+		go m.timeoutWait(id, p)
+	}
+}
+
+func (m *MuxBroker) getStream(id uint32) *muxBrokerPending {
+	m.Lock()
+	defer m.Unlock()
+
+	p, ok := m.streams[id]
+	if ok {
+		return p
+	}
+
+	m.streams[id] = &muxBrokerPending{
+		ch:     make(chan net.Conn, 1),
+		doneCh: make(chan struct{}),
+	}
+	return m.streams[id]
+}
+
+func (m *MuxBroker) timeoutWait(id uint32, p *muxBrokerPending) {
+	// Wait for the stream to either be picked up and connected, or
+	// for a timeout.
+	timeout := false
+	select {
+	case <-p.doneCh:
+	case <-time.After(5 * time.Second):
+		timeout = true
+	}
+
+	m.Lock()
+	defer m.Unlock()
+
+	// Delete the stream so no one else can grab it
+	delete(m.streams, id)
+
+	// If we timed out, then check if we have a channel in the buffer,
+	// and if so, close it.
+	if timeout {
+		select {
+		case s := <-p.ch:
+			s.Close()
+		}
+	}
+}
diff --git a/vendor/github.com/hashicorp/go-plugin/plugin.go b/vendor/github.com/hashicorp/go-plugin/plugin.go
new file mode 100644
index 000000000..37c8fd653
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-plugin/plugin.go
@@ -0,0 +1,25 @@
+// The plugin package exposes functions and helpers for communicating to
+// plugins which are implemented as standalone binary applications.
+//
+// plugin.Client fully manages the lifecycle of executing the application,
+// connecting to it, and returning the RPC client for dispensing plugins.
+//
+// plugin.Serve fully manages listeners to expose an RPC server from a binary
+// that plugin.Client can connect to.
+package plugin
+
+import (
+	"net/rpc"
+)
+
+// Plugin is the interface that is implemented to serve/connect to an
+// inteface implementation.
+type Plugin interface {
+	// Server should return the RPC server compatible struct to serve
+	// the methods that the Client calls over net/rpc.
+	Server(*MuxBroker) (interface{}, error)
+
+	// Client returns an interface implementation for the plugin you're
+	// serving that communicates to the server end of the plugin.
+	Client(*MuxBroker, *rpc.Client) (interface{}, error)
+}
diff --git a/vendor/github.com/hashicorp/go-plugin/process.go b/vendor/github.com/hashicorp/go-plugin/process.go
new file mode 100644
index 000000000..88c999a58
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-plugin/process.go
@@ -0,0 +1,24 @@
+package plugin
+
+import (
+	"time"
+)
+
+// pidAlive checks whether a pid is alive.
+func pidAlive(pid int) bool {
+	return _pidAlive(pid)
+}
+
+// pidWait blocks for a process to exit.
+func pidWait(pid int) error {
+	ticker := time.NewTicker(1 * time.Second)
+	defer ticker.Stop()
+
+	for range ticker.C {
+		if !pidAlive(pid) {
+			break
+		}
+	}
+
+	return nil
+}
diff --git a/vendor/github.com/hashicorp/go-plugin/process_posix.go b/vendor/github.com/hashicorp/go-plugin/process_posix.go
new file mode 100644
index 000000000..70ba546bf
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-plugin/process_posix.go
@@ -0,0 +1,19 @@
+// +build !windows
+
+package plugin
+
+import (
+	"os"
+	"syscall"
+)
+
+// _pidAlive tests whether a process is alive or not by sending it Signal 0,
+// since Go otherwise has no way to test this.
+func _pidAlive(pid int) bool {
+	proc, err := os.FindProcess(pid)
+	if err == nil {
+		err = proc.Signal(syscall.Signal(0))
+	}
+
+	return err == nil
+}
diff --git a/vendor/github.com/hashicorp/go-plugin/process_windows.go b/vendor/github.com/hashicorp/go-plugin/process_windows.go
new file mode 100644
index 000000000..9f7b01809
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-plugin/process_windows.go
@@ -0,0 +1,29 @@
+package plugin
+
+import (
+	"syscall"
+)
+
+const (
+	// Weird name but matches the MSDN docs
+	exit_STILL_ACTIVE = 259
+
+	processDesiredAccess = syscall.STANDARD_RIGHTS_READ |
+		syscall.PROCESS_QUERY_INFORMATION |
+		syscall.SYNCHRONIZE
+)
+
+// _pidAlive tests whether a process is alive or not
+func _pidAlive(pid int) bool {
+	h, err := syscall.OpenProcess(processDesiredAccess, false, uint32(pid))
+	if err != nil {
+		return false
+	}
+
+	var ec uint32
+	if e := syscall.GetExitCodeProcess(h, &ec); e != nil {
+		return false
+	}
+
+	return ec == exit_STILL_ACTIVE
+}
diff --git a/vendor/github.com/hashicorp/go-plugin/rpc_client.go b/vendor/github.com/hashicorp/go-plugin/rpc_client.go
new file mode 100644
index 000000000..e6d613bc6
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-plugin/rpc_client.go
@@ -0,0 +1,110 @@
+package plugin
+
+import (
+	"fmt"
+	"io"
+	"net"
+	"net/rpc"
+
+	"github.com/hashicorp/yamux"
+)
+
+// RPCClient connects to an RPCServer over net/rpc to dispense plugin types.
+type RPCClient struct {
+	broker  *MuxBroker
+	control *rpc.Client
+	plugins map[string]Plugin
+
+	// These are the streams used for the various stdout/err overrides
+	stdout, stderr net.Conn
+}
+
+// NewRPCClient creates a client from an already-open connection-like value.
+// Dial is typically used instead.
+func NewRPCClient(conn io.ReadWriteCloser, plugins map[string]Plugin) (*RPCClient, error) {
+	// Create the yamux client so we can multiplex
+	mux, err := yamux.Client(conn, nil)
+	if err != nil {
+		conn.Close()
+		return nil, err
+	}
+
+	// Connect to the control stream.
+	control, err := mux.Open()
+	if err != nil {
+		mux.Close()
+		return nil, err
+	}
+
+	// Connect stdout, stderr streams
+	stdstream := make([]net.Conn, 2)
+	for i, _ := range stdstream {
+		stdstream[i], err = mux.Open()
+		if err != nil {
+			mux.Close()
+			return nil, err
+		}
+	}
+
+	// Create the broker and start it up
+	broker := newMuxBroker(mux)
+	go broker.Run()
+
+	// Build the client using our broker and control channel.
+	return &RPCClient{
+		broker:  broker,
+		control: rpc.NewClient(control),
+		plugins: plugins,
+		stdout:  stdstream[0],
+		stderr:  stdstream[1],
+	}, nil
+}
+
+// SyncStreams should be called to enable syncing of stdout,
+// stderr with the plugin.
+//
+// This will return immediately and the syncing will continue to happen
+// in the background. You do not need to launch this in a goroutine itself.
+//
+// This should never be called multiple times.
+func (c *RPCClient) SyncStreams(stdout io.Writer, stderr io.Writer) error {
+	go copyStream("stdout", stdout, c.stdout)
+	go copyStream("stderr", stderr, c.stderr)
+	return nil
+}
+
+// Close closes the connection. The client is no longer usable after this
+// is called.
+func (c *RPCClient) Close() error {
+	if err := c.control.Close(); err != nil {
+		return err
+	}
+	if err := c.stdout.Close(); err != nil {
+		return err
+	}
+	if err := c.stderr.Close(); err != nil {
+		return err
+	}
+
+	return c.broker.Close()
+}
+
+func (c *RPCClient) Dispense(name string) (interface{}, error) {
+	p, ok := c.plugins[name]
+	if !ok {
+		return nil, fmt.Errorf("unknown plugin type: %s", name)
+	}
+
+	var id uint32
+	if err := c.control.Call(
+		"Dispenser.Dispense", name, &id); err != nil {
+		return nil, err
+	}
+
+	conn, err := c.broker.Dial(id)
+	if err != nil {
+		return nil, err
+	}
+
+	return p.Client(c.broker, rpc.NewClient(conn))
+}
diff --git a/vendor/github.com/hashicorp/go-plugin/rpc_server.go b/vendor/github.com/hashicorp/go-plugin/rpc_server.go
new file mode 100644
index 000000000..714b047dc
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-plugin/rpc_server.go
@@ -0,0 +1,143 @@
+package plugin
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"net"
+	"net/rpc"
+
+	"github.com/hashicorp/yamux"
+)
+
+// RPCServer listens for network connections and then dispenses interface
+// implementations over net/rpc.
+type RPCServer struct {
+	Plugins map[string]Plugin
+
+	// Stdout, Stderr are what this server will use instead of the
+	// normal stdin/out/err. This is because due to the multi-process nature
+	// of our plugin system, we can't use the normal process values so we
+	// make our own custom one we pipe across.
+	Stdout io.Reader
+	Stderr io.Reader
+}
+
+// Accept accepts connections on a listener and serves requests for
+// each incoming connection. Accept blocks; the caller typically invokes
+// it in a go statement.
+func (s *RPCServer) Accept(lis net.Listener) {
+	for {
+		conn, err := lis.Accept()
+		if err != nil {
+			log.Printf("[ERR] plugin: plugin server: %s", err)
+			return
+		}
+
+		go s.ServeConn(conn)
+	}
+}
+
+// ServeConn runs a single connection.
+//
+// ServeConn blocks, serving the connection until the client hangs up.
+func (s *RPCServer) ServeConn(conn io.ReadWriteCloser) {
+	// First create the yamux server to wrap this connection
+	mux, err := yamux.Server(conn, nil)
+	if err != nil {
+		conn.Close()
+		log.Printf("[ERR] plugin: error creating yamux server: %s", err)
+		return
+	}
+
+	// Accept the control connection
+	control, err := mux.Accept()
+	if err != nil {
+		mux.Close()
+		if err != io.EOF {
+			log.Printf("[ERR] plugin: error accepting control connection: %s", err)
+		}
+
+		return
+	}
+
+	// Connect the stdstreams (in, out, err)
+	stdstream := make([]net.Conn, 2)
+	for i, _ := range stdstream {
+		stdstream[i], err = mux.Accept()
+		if err != nil {
+			mux.Close()
+			log.Printf("[ERR] plugin: accepting stream %d: %s", i, err)
+			return
+		}
+	}
+
+	// Copy std streams out to the proper place
+	go copyStream("stdout", stdstream[0], s.Stdout)
+	go copyStream("stderr", stdstream[1], s.Stderr)
+
+	// Create the broker and start it up
+	broker := newMuxBroker(mux)
+	go broker.Run()
+
+	// Use the control connection to build the dispenser and serve the
+	// connection.
+	server := rpc.NewServer()
+	server.RegisterName("Dispenser", &dispenseServer{
+		broker:  broker,
+		plugins: s.Plugins,
+	})
+	server.ServeConn(control)
+}
+
+// dispenseServer dispenses variousinterface implementations for Terraform.
+type dispenseServer struct {
+	broker  *MuxBroker
+	plugins map[string]Plugin
+}
+
+func (d *dispenseServer) Dispense(
+	name string, response *uint32) error {
+	// Find the function to create this implementation
+	p, ok := d.plugins[name]
+	if !ok {
+		return fmt.Errorf("unknown plugin type: %s", name)
+	}
+
+	// Create the implementation first so we know if there is an error.
+	impl, err := p.Server(d.broker)
+	if err != nil {
+		// We turn the error into an errors error so that it works across RPC
+		return errors.New(err.Error())
+	}
+
+	// Reserve an ID for our implementation
+	id := d.broker.NextId()
+	*response = id
+
+	// Run the rest in a goroutine since it can only happen once this RPC
+	// call returns. We wait for a connection for the plugin implementation
+	// and serve it.
+	go func() {
+		conn, err := d.broker.Accept(id)
+		if err != nil {
+			log.Printf("[ERR] go-plugin: plugin dispense error: %s: %s", name, err)
+			return
+		}
+
+		serve(conn, "Plugin", impl)
+	}()
+
+	return nil
+}
+
+func serve(conn io.ReadWriteCloser, name string, v interface{}) {
+	server := rpc.NewServer()
+	if err := server.RegisterName(name, v); err != nil {
+		log.Printf("[ERR] go-plugin: plugin dispense error: %s", err)
+		return
+	}
+
+	server.ServeConn(conn)
+}
diff --git a/vendor/github.com/hashicorp/go-plugin/server.go b/vendor/github.com/hashicorp/go-plugin/server.go
new file mode 100644
index 000000000..4e3a552c5
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-plugin/server.go
@@ -0,0 +1,187 @@
+package plugin
+
+import (
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net"
+	"os"
+	"os/signal"
+	"runtime"
+	"strconv"
+	"sync/atomic"
+)
+
+// CoreProtocolVersion is the ProtocolVersion of the plugin system itself.
+// We will increment this whenever we change any protocol behavior. This
+// will invalidate any prior plugins but will at least allow us to iterate
+// on the core in a safe way. We will do our best to do this very
+// infrequently.
+const CoreProtocolVersion = 1
+
+// HandshakeConfig is the configuration used by client and servers to
+// handshake before starting a plugin connection. This is embedded by
+// both ServeConfig and ClientConfig.
+//
+// In practice, the plugin host creates a HandshakeConfig that is exported
+// and plugins then can easily consume it.
+type HandshakeConfig struct {
+	// ProtocolVersion is the version that clients must match on to
+	// agree they can communicate. This should match the ProtocolVersion
+	// set on ClientConfig when using a plugin.
+	ProtocolVersion uint
+
+	// MagicCookieKey and value are used as a very basic verification
+	// that a plugin is intended to be launched. This is not a security
+	// measure, just a UX feature. If the magic cookie doesn't match,
+	// we show human-friendly output.
+	MagicCookieKey   string
+	MagicCookieValue string
+}
+
+// ServeConfig configures what sorts of plugins are served.
+type ServeConfig struct {
+	// HandshakeConfig is the configuration that must match clients.
+	HandshakeConfig
+
+	// Plugins are the plugins that are served.
+	Plugins map[string]Plugin
+}
+
+// Serve serves the plugins given by ServeConfig.
+//
+// Serve doesn't return until the plugin is done being executed. Any
+// errors will be outputted to the log.
+//
+// This is the method that plugins should call in their main() functions.
+func Serve(opts *ServeConfig) {
+	// Validate the handshake config
+	if opts.MagicCookieKey == "" || opts.MagicCookieValue == "" {
+		fmt.Fprintf(os.Stderr,
+			"Misconfigured ServeConfig given to serve this plugin: no magic cookie\n"+
+				"key or value was set. Please notify the plugin author and report\n"+
+				"this as a bug.\n")
+		os.Exit(1)
+	}
+
+	// First check the cookie
+	if os.Getenv(opts.MagicCookieKey) != opts.MagicCookieValue {
+		fmt.Fprintf(os.Stderr,
+			"This binary is a plugin. These are not meant to be executed directly.\n"+
+				"Please execute the program that consumes these plugins, which will\n"+
+				"load any plugins automatically\n")
+		os.Exit(1)
+	}
+
+	// Logging goes to the original stderr
+	log.SetOutput(os.Stderr)
+
+	// Create our new stdout, stderr files. These will override our built-in
+	// stdout/stderr so that it works across the stream boundary.
+	stdout_r, stdout_w, err := os.Pipe()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error preparing plugin: %s\n", err)
+		os.Exit(1)
+	}
+	stderr_r, stderr_w, err := os.Pipe()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error preparing plugin: %s\n", err)
+		os.Exit(1)
+	}
+
+	// Register a listener so we can accept a connection
+	listener, err := serverListener()
+	if err != nil {
+		log.Printf("[ERR] plugin: plugin init: %s", err)
+		return
+	}
+	defer listener.Close()
+
+	// Create the RPC server to dispense
+	server := &RPCServer{
+		Plugins: opts.Plugins,
+		Stdout:  stdout_r,
+		Stderr:  stderr_r,
+	}
+
+	// Output the address and service name to stdout so that core can bring it up.
+	log.Printf("[DEBUG] plugin: plugin address: %s %s\n",
+		listener.Addr().Network(), listener.Addr().String())
+	fmt.Printf("%d|%d|%s|%s\n",
+		CoreProtocolVersion,
+		opts.ProtocolVersion,
+		listener.Addr().Network(),
+		listener.Addr().String())
+	os.Stdout.Sync()
+
+	// Eat the interrupts
+	ch := make(chan os.Signal, 1)
+	signal.Notify(ch, os.Interrupt)
+	go func() {
+		var count int32 = 0
+		for {
+			<-ch
+			newCount := atomic.AddInt32(&count, 1)
+			log.Printf(
+				"[DEBUG] plugin: received interrupt signal (count: %d). Ignoring.",
+				newCount)
+		}
+	}()
+
+	// Set our new out, err
+	os.Stdout = stdout_w
+	os.Stderr = stderr_w
+
+	// Serve
+	server.Accept(listener)
+}
+
+func serverListener() (net.Listener, error) {
+	if runtime.GOOS == "windows" {
+		return serverListener_tcp()
+	}
+
+	return serverListener_unix()
+}
+
+func serverListener_tcp() (net.Listener, error) {
+	minPort, err := strconv.ParseInt(os.Getenv("PLUGIN_MIN_PORT"), 10, 32)
+	if err != nil {
+		return nil, err
+	}
+
+	maxPort, err := strconv.ParseInt(os.Getenv("PLUGIN_MAX_PORT"), 10, 32)
+	if err != nil {
+		return nil, err
+	}
+
+	for port := minPort; port <= maxPort; port++ {
+		address := fmt.Sprintf("127.0.0.1:%d", port)
+		listener, err := net.Listen("tcp", address)
+		if err == nil {
+			return listener, nil
+		}
+	}
+
+	return nil, errors.New("Couldn't bind plugin TCP listener")
+}
+
+func serverListener_unix() (net.Listener, error) {
+	tf, err := ioutil.TempFile("", "plugin")
+	if err != nil {
+		return nil, err
+	}
+	path := tf.Name()
+
+	// Close the file and remove it because it has to not exist for
+	// the domain socket.
+	if err := tf.Close(); err != nil {
+		return nil, err
+	}
+	if err := os.Remove(path); err != nil {
+		return nil, err
+	}
+
+	return net.Listen("unix", path)
+}
diff --git a/vendor/github.com/hashicorp/go-plugin/server_mux.go b/vendor/github.com/hashicorp/go-plugin/server_mux.go
new file mode 100644
index 000000000..033079ea0
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-plugin/server_mux.go
@@ -0,0 +1,31 @@
+package plugin
+
+import (
+	"fmt"
+	"os"
+)
+
+// ServeMuxMap is the type that is used to configure ServeMux
+type ServeMuxMap map[string]*ServeConfig
+
+// ServeMux is like Serve, but serves multiple types of plugins determined
+// by the argument given on the command-line.
+//
+// This command doesn't return until the plugin is done being executed. Any
+// errors are logged or output to stderr.
+func ServeMux(m ServeMuxMap) {
+	if len(os.Args) != 2 {
+		fmt.Fprintf(os.Stderr,
+			"Invoked improperly. This is an internal command that shouldn't\n"+
+				"be manually invoked.\n")
+		os.Exit(1)
+	}
+
+	opts, ok := m[os.Args[1]]
+	if !ok {
+		fmt.Fprintf(os.Stderr, "Unknown plugin: %s\n", os.Args[1])
+		os.Exit(1)
+	}
+
+	Serve(opts)
+}
diff --git a/vendor/github.com/hashicorp/go-plugin/stream.go b/vendor/github.com/hashicorp/go-plugin/stream.go
new file mode 100644
index 000000000..1d547aaaa
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-plugin/stream.go
@@ -0,0 +1,18 @@
+package plugin
+
+import (
+	"io"
+	"log"
+)
+
+func copyStream(name string, dst io.Writer, src io.Reader) {
+	if src == nil {
+		panic(name + ": src is nil")
+	}
+	if dst == nil {
+		panic(name + ": dst is nil")
+	}
+	if _, err := io.Copy(dst, src); err != nil && err != io.EOF {
+		log.Printf("[ERR] plugin: stream copy '%s' error: %s", name, err)
+	}
+}
diff --git a/vendor/github.com/hashicorp/go-plugin/testing.go b/vendor/github.com/hashicorp/go-plugin/testing.go
new file mode 100644
index 000000000..9086a1b45
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-plugin/testing.go
@@ -0,0 +1,76 @@
+package plugin
+
+import (
+	"bytes"
+	"net"
+	"net/rpc"
+	"testing"
+)
+
+// The testing file contains test helpers that you can use outside of
+// this package for making it easier to test plugins themselves.
+
+// TestConn is a helper function for returning a client and server
+// net.Conn connected to each other.
+func TestConn(t *testing.T) (net.Conn, net.Conn) {
+	// Listen to any local port. This listener will be closed
+	// after a single connection is established.
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	// Start a goroutine to accept our client connection
+	var serverConn net.Conn
+	doneCh := make(chan struct{})
+	go func() {
+		defer close(doneCh)
+		defer l.Close()
+		var err error
+		serverConn, err = l.Accept()
+		if err != nil {
+			t.Fatalf("err: %s", err)
+		}
+	}()
+
+	// Connect to the server
+	clientConn, err := net.Dial("tcp", l.Addr().String())
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	// Wait for the server side to acknowledge it has connected
+	<-doneCh
+
+	return clientConn, serverConn
+}
+
+// TestRPCConn returns a rpc client and server connected to each other.
+func TestRPCConn(t *testing.T) (*rpc.Client, *rpc.Server) {
+	clientConn, serverConn := TestConn(t)
+
+	server := rpc.NewServer()
+	go server.ServeConn(serverConn)
+
+	client := rpc.NewClient(clientConn)
+	return client, server
+}
+
+// TestPluginRPCConn returns a plugin RPC client and server that are connected
+// together and configured.
+func TestPluginRPCConn(t *testing.T, ps map[string]Plugin) (*RPCClient, *RPCServer) {
+	// Create two net.Conns we can use to shuttle our control connection
+	clientConn, serverConn := TestConn(t)
+
+	// Start up the server
+	server := &RPCServer{Plugins: ps, Stdout: new(bytes.Buffer), Stderr: new(bytes.Buffer)}
+	go server.ServeConn(serverConn)
+
+	// Connect the client to the server
+	client, err := NewRPCClient(clientConn, ps)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	return client, server
+}