Merge pull request #21 from hashicorp/f-ssh

Adding "remote-exec" provisioner

builtin/bins/provisioner-remote-exec/main.go

@@ -0,0 +1,10 @@
+package main
+
+import (
+	"github.com/hashicorp/terraform/builtin/provisioners/remote-exec"
+	"github.com/hashicorp/terraform/plugin"
+)
+
+func main() {
+	plugin.Serve(new(remoteexec.ResourceProvisioner))
+}

builtin/bins/provisioner-remote-exec/main_test.go

@@ -0,0 +1 @@
+package main

builtin/providers/aws/resource_aws_instance.go

@@ -88,6 +88,10 @@ func resource_aws_instance_create(
 
 	instance = instanceRaw.(*ec2.Instance)
 
+	// Initialize the connection info
+	rs.ConnInfo["type"] = "ssh"
+	rs.ConnInfo["host"] = instance.PublicIpAddress
+
 	// Set our attributes
 	rs, err = resource_aws_instance_update_state(rs, instance)
 	if err != nil {

builtin/provisioners/remote-exec/resource_provisioner.go

@@ -0,0 +1,359 @@
+package remoteexec
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"os"
+	"strings"
+	"time"
+
+	"code.google.com/p/go.crypto/ssh"
+	helper "github.com/hashicorp/terraform/helper/ssh"
+	"github.com/hashicorp/terraform/terraform"
+	"github.com/mitchellh/mapstructure"
+)
+
+const (
+	// DefaultUser is used if there is no default user given
+	DefaultUser = "root"
+
+	// DefaultPort is used if there is no port given
+	DefaultPort = 22
+
+	// DefaultScriptPath is used as the path to copy the file to
+	// for remote execution if not provided otherwise.
+	DefaultScriptPath = "/tmp/script.sh"
+
+	// DefaultTimeout is used if there is no timeout given
+	DefaultTimeout = 5 * time.Minute
+
+	// DefaultShebang is added at the top of the script file
+	DefaultShebang = "#!/bin/sh"
+)
+
+type ResourceProvisioner struct{}
+
+// SSHConfig is decoded from the ConnInfo of the resource. These
+// are the only keys we look at. If a KeyFile is given, that is used
+// instead of a password.
+type SSHConfig struct {
+	User       string
+	Password   string
+	KeyFile    string `mapstructure:"key_file"`
+	Host       string
+	Port       int
+	Timeout    string
+	ScriptPath string        `mapstructure:"script_path"`
+	TimeoutVal time.Duration `mapstructure:"-"`
+}
+
+func (p *ResourceProvisioner) Apply(s *terraform.ResourceState,
+	c *terraform.ResourceConfig) (*terraform.ResourceState, error) {
+	// Ensure the connection type is SSH
+	if err := p.verifySSH(s); err != nil {
+		return s, err
+	}
+
+	// Get the SSH configuration
+	conf, err := p.sshConfig(s)
+	if err != nil {
+		return s, err
+	}
+
+	// Collect the scripts
+	scripts, err := p.collectScripts(c)
+	if err != nil {
+		return s, err
+	}
+	for _, s := range scripts {
+		defer s.Close()
+	}
+
+	// Copy and execute each script
+	if err := p.runScripts(conf, scripts); err != nil {
+		return s, err
+	}
+	return s, nil
+}
+
+func (p *ResourceProvisioner) Validate(c *terraform.ResourceConfig) (ws []string, es []error) {
+	num := 0
+	for name := range c.Raw {
+		switch name {
+		case "scripts":
+			fallthrough
+		case "script":
+			fallthrough
+		case "inline":
+			num++
+		default:
+			es = append(es, fmt.Errorf("Unknown configuration '%s'", name))
+		}
+	}
+	if num != 1 {
+		es = append(es, fmt.Errorf("Must provide one of 'scripts', 'script' or 'inline' to remote-exec"))
+	}
+	return
+}
+
+// verifySSH is used to verify the ConnInfo is usable by remote-exec
+func (p *ResourceProvisioner) verifySSH(s *terraform.ResourceState) error {
+	connType := s.ConnInfo["type"]
+	switch connType {
+	case "":
+	case "ssh":
+	default:
+		return fmt.Errorf("Connection type '%s' not supported", connType)
+	}
+	return nil
+}
+
+// sshConfig is used to convert the ConnInfo of the ResourceState into
+// a SSHConfig struct
+func (p *ResourceProvisioner) sshConfig(s *terraform.ResourceState) (*SSHConfig, error) {
+	sshConf := &SSHConfig{}
+	decConf := &mapstructure.DecoderConfig{
+		WeaklyTypedInput: true,
+		Result:           sshConf,
+	}
+	dec, err := mapstructure.NewDecoder(decConf)
+	if err != nil {
+		return nil, err
+	}
+	if err := dec.Decode(s.ConnInfo); err != nil {
+		return nil, err
+	}
+	if sshConf.User == "" {
+		sshConf.User = DefaultUser
+	}
+	if sshConf.Port == 0 {
+		sshConf.Port = DefaultPort
+	}
+	if sshConf.ScriptPath == "" {
+		sshConf.ScriptPath = DefaultScriptPath
+	}
+	if sshConf.Timeout != "" {
+		sshConf.TimeoutVal = safeDuration(sshConf.Timeout, DefaultTimeout)
+	} else {
+		sshConf.TimeoutVal = DefaultTimeout
+	}
+	return sshConf, nil
+}
+
+// generateScript takes the configuration and creates a script to be executed
+// from the inline configs
+func (p *ResourceProvisioner) generateScript(c *terraform.ResourceConfig) (string, error) {
+	lines := []string{DefaultShebang}
+	command, ok := c.Config["inline"]
+	if ok {
+		switch cmd := command.(type) {
+		case string:
+			lines = append(lines, cmd)
+		case []string:
+			lines = append(lines, cmd...)
+		case []interface{}:
+			for _, l := range cmd {
+				lStr, ok := l.(string)
+				if ok {
+					lines = append(lines, lStr)
+				} else {
+					return "", fmt.Errorf("Unsupported 'inline' type! Must be string, or list of strings.")
+				}
+			}
+		default:
+			return "", fmt.Errorf("Unsupported 'inline' type! Must be string, or list of strings.")
+		}
+	}
+	lines = append(lines, "")
+	return strings.Join(lines, "\n"), nil
+}
+
+// collectScripts is used to collect all the scripts we need
+// to execute in preperation for copying them.
+func (p *ResourceProvisioner) collectScripts(c *terraform.ResourceConfig) ([]io.ReadCloser, error) {
+	// Check if inline
+	_, ok := c.Config["inline"]
+	if ok {
+		script, err := p.generateScript(c)
+		if err != nil {
+			return nil, err
+		}
+		rc := ioutil.NopCloser(bytes.NewReader([]byte(script)))
+		return []io.ReadCloser{rc}, nil
+	}
+
+	// Collect scripts
+	var scripts []string
+	s, ok := c.Config["script"]
+	if ok {
+		sStr, ok := s.(string)
+		if !ok {
+			return nil, fmt.Errorf("Unsupported 'script' type! Must be a string.")
+		}
+		scripts = append(scripts, sStr)
+	}
+
+	sl, ok := c.Config["scripts"]
+	if ok {
+		switch slt := sl.(type) {
+		case []string:
+			scripts = append(scripts, slt...)
+		case []interface{}:
+			for _, l := range slt {
+				lStr, ok := l.(string)
+				if ok {
+					scripts = append(scripts, lStr)
+				} else {
+					return nil, fmt.Errorf("Unsupported 'scripts' type! Must be list of strings.")
+				}
+			}
+		default:
+			return nil, fmt.Errorf("Unsupported 'scripts' type! Must be list of strings.")
+		}
+	}
+
+	// Open all the scripts
+	var fhs []io.ReadCloser
+	for _, s := range scripts {
+		fh, err := os.Open(s)
+		if err != nil {
+			for _, fh := range fhs {
+				fh.Close()
+			}
+			return nil, fmt.Errorf("Failed to open script '%s': %v", s, err)
+		}
+		fhs = append(fhs, fh)
+	}
+
+	// Done, return the file handles
+	return fhs, nil
+}
+
+// runScripts is used to copy and execute a set of scripts
+func (p *ResourceProvisioner) runScripts(conf *SSHConfig, scripts []io.ReadCloser) error {
+	sshConf := &ssh.ClientConfig{
+		User: conf.User,
+	}
+	if conf.KeyFile != "" {
+		key, err := ioutil.ReadFile(conf.KeyFile)
+		if err != nil {
+			return fmt.Errorf("Failed to read key file '%s': %v", conf.KeyFile, err)
+		}
+		signer, err := ssh.ParsePrivateKey(key)
+		if err != nil {
+			return fmt.Errorf("Failed to parse key file '%s': %v", conf.KeyFile, err)
+		}
+		sshConf.Auth = append(sshConf.Auth, ssh.PublicKeys(signer))
+	}
+	if conf.Password != "" {
+		sshConf.Auth = append(sshConf.Auth,
+			ssh.Password(conf.Password))
+		sshConf.Auth = append(sshConf.Auth,
+			ssh.KeyboardInteractive(helper.PasswordKeyboardInteractive(conf.Password)))
+	}
+	host := fmt.Sprintf("%s:%d", conf.Host, conf.Port)
+	config := &helper.Config{
+		SSHConfig:  sshConf,
+		Connection: helper.ConnectFunc("tcp", host),
+	}
+
+	// Wait and retry until we establish the SSH connection
+	var comm *helper.SSHCommunicator
+	err := retryFunc(conf.TimeoutVal, func() error {
+		var err error
+		comm, err = helper.New(host, config)
+		return err
+	})
+	if err != nil {
+		return err
+	}
+
+	for _, script := range scripts {
+		var cmd *helper.RemoteCmd
+		err := retryFunc(conf.TimeoutVal, func() error {
+			if err := comm.Upload(conf.ScriptPath, script); err != nil {
+				return fmt.Errorf("Failed to upload script: %v", err)
+			}
+			cmd = &helper.RemoteCmd{
+				Command: fmt.Sprintf("chmod 0777 %s", conf.ScriptPath),
+			}
+			if err := comm.Start(cmd); err != nil {
+				return fmt.Errorf(
+					"Error chmodding script file to 0777 in remote "+
+						"machine: %s", err)
+			}
+			cmd.Wait()
+
+			rPipe1, wPipe1 := io.Pipe()
+			rPipe2, wPipe2 := io.Pipe()
+			go streamLogs(rPipe1, "stdout")
+			go streamLogs(rPipe2, "stderr")
+
+			cmd = &helper.RemoteCmd{
+				Command: conf.ScriptPath,
+				Stdout:  wPipe1,
+				Stderr:  wPipe2,
+			}
+			if err := comm.Start(cmd); err != nil {
+				return fmt.Errorf("Error starting script: %v", err)
+			}
+			return nil
+		})
+		if err != nil {
+			return err
+		}
+
+		cmd.Wait()
+		if cmd.ExitStatus != 0 {
+			return fmt.Errorf("Script exited with non-zero exit status: %d", cmd.ExitStatus)
+		}
+	}
+
+	return nil
+}
+
+// retryFunc is used to retry a function for a given duration
+func retryFunc(timeout time.Duration, f func() error) error {
+	finish := time.After(timeout)
+	for {
+		err := f()
+		if err == nil {
+			return nil
+		}
+		log.Printf("Retryable error: %v", err)
+
+		select {
+		case <-finish:
+			return err
+		case <-time.After(3 * time.Second):
+		}
+	}
+}
+
+// safeDuration returns either the parsed duration or a default value
+func safeDuration(dur string, defaultDur time.Duration) time.Duration {
+	d, err := time.ParseDuration(dur)
+	if err != nil {
+		log.Printf("Invalid duration '%s' for remote-exec, using default", dur)
+		return defaultDur
+	}
+	return d
+}
+
+// streamLogs is used to stream lines from stdout/stderr
+// of a remote command to log output for users.
+func streamLogs(r io.ReadCloser, name string) {
+	defer r.Close()
+	bufR := bufio.NewReader(r)
+	for {
+		line, err := bufR.ReadString('\n')
+		if err != nil {
+			return
+		}
+		log.Printf("remote-exec: %s: %s", name, line)
+	}
+}

builtin/provisioners/remote-exec/resource_provisioner_test.go

@@ -0,0 +1,224 @@
+package remoteexec
+
+import (
+	"bytes"
+	"io"
+	"testing"
+
+	"github.com/hashicorp/terraform/config"
+	"github.com/hashicorp/terraform/terraform"
+)
+
+func TestResourceProvisioner_impl(t *testing.T) {
+	var _ terraform.ResourceProvisioner = new(ResourceProvisioner)
+}
+
+func TestResourceProvider_Validate_good(t *testing.T) {
+	c := testConfig(t, map[string]interface{}{
+		"inline": "echo foo",
+	})
+	p := new(ResourceProvisioner)
+	warn, errs := p.Validate(c)
+	if len(warn) > 0 {
+		t.Fatalf("Warnings: %v", warn)
+	}
+	if len(errs) > 0 {
+		t.Fatalf("Errors: %v", errs)
+	}
+}
+
+func TestResourceProvider_Validate_bad(t *testing.T) {
+	c := testConfig(t, map[string]interface{}{
+		"invalid": "nope",
+	})
+	p := new(ResourceProvisioner)
+	warn, errs := p.Validate(c)
+	if len(warn) > 0 {
+		t.Fatalf("Warnings: %v", warn)
+	}
+	if len(errs) == 0 {
+		t.Fatalf("Should have errors")
+	}
+}
+
+func TestResourceProvider_verifySSH(t *testing.T) {
+	p := new(ResourceProvisioner)
+	r := &terraform.ResourceState{
+		ConnInfo: map[string]string{
+			"type": "telnet",
+		},
+	}
+	if err := p.verifySSH(r); err == nil {
+		t.Fatalf("expected error with telnet")
+	}
+	r.ConnInfo["type"] = "ssh"
+	if err := p.verifySSH(r); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+}
+
+func TestResourceProvider_sshConfig(t *testing.T) {
+	p := new(ResourceProvisioner)
+	r := &terraform.ResourceState{
+		ConnInfo: map[string]string{
+			"type":     "ssh",
+			"user":     "root",
+			"password": "supersecret",
+			"key_file": "/my/key/file.pem",
+			"host":     "127.0.0.1",
+			"port":     "22",
+			"timeout":  "30s",
+		},
+	}
+
+	conf, err := p.sshConfig(r)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if conf.User != "root" {
+		t.Fatalf("bad: %v", conf)
+	}
+	if conf.Password != "supersecret" {
+		t.Fatalf("bad: %v", conf)
+	}
+	if conf.KeyFile != "/my/key/file.pem" {
+		t.Fatalf("bad: %v", conf)
+	}
+	if conf.Host != "127.0.0.1" {
+		t.Fatalf("bad: %v", conf)
+	}
+	if conf.Port != 22 {
+		t.Fatalf("bad: %v", conf)
+	}
+	if conf.Timeout != "30s" {
+		t.Fatalf("bad: %v", conf)
+	}
+	if conf.ScriptPath != DefaultScriptPath {
+		t.Fatalf("bad: %v", conf)
+	}
+}
+
+func TestResourceProvider_generateScript(t *testing.T) {
+	p := new(ResourceProvisioner)
+	conf := testConfig(t, map[string]interface{}{
+		"inline": []string{
+			"cd /tmp",
+			"wget http://foobar",
+			"exit 0",
+		},
+	})
+	out, err := p.generateScript(conf)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if out != expectedScriptOut {
+		t.Fatalf("bad: %v", out)
+	}
+}
+
+var expectedScriptOut = `#!/bin/sh
+cd /tmp
+wget http://foobar
+exit 0
+`
+
+func TestResourceProvider_CollectScripts_inline(t *testing.T) {
+	p := new(ResourceProvisioner)
+	conf := testConfig(t, map[string]interface{}{
+		"inline": []string{
+			"cd /tmp",
+			"wget http://foobar",
+			"exit 0",
+		},
+	})
+
+	scripts, err := p.collectScripts(conf)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if len(scripts) != 1 {
+		t.Fatalf("bad: %v", scripts)
+	}
+
+	var out bytes.Buffer
+	_, err = io.Copy(&out, scripts[0])
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if string(out.Bytes()) != expectedScriptOut {
+		t.Fatalf("bad: %v", out.Bytes())
+	}
+}
+
+func TestResourceProvider_CollectScripts_script(t *testing.T) {
+	p := new(ResourceProvisioner)
+	conf := testConfig(t, map[string]interface{}{
+		"script": "test-fixtures/script1.sh",
+	})
+
+	scripts, err := p.collectScripts(conf)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if len(scripts) != 1 {
+		t.Fatalf("bad: %v", scripts)
+	}
+
+	var out bytes.Buffer
+	_, err = io.Copy(&out, scripts[0])
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if string(out.Bytes()) != expectedScriptOut {
+		t.Fatalf("bad: %v", out.Bytes())
+	}
+}
+
+func TestResourceProvider_CollectScripts_scripts(t *testing.T) {
+	p := new(ResourceProvisioner)
+	conf := testConfig(t, map[string]interface{}{
+		"scripts": []interface{}{
+			"test-fixtures/script1.sh",
+			"test-fixtures/script1.sh",
+			"test-fixtures/script1.sh",
+		},
+	})
+
+	scripts, err := p.collectScripts(conf)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if len(scripts) != 3 {
+		t.Fatalf("bad: %v", scripts)
+	}
+
+	for idx := range scripts {
+		var out bytes.Buffer
+		_, err = io.Copy(&out, scripts[idx])
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		if string(out.Bytes()) != expectedScriptOut {
+			t.Fatalf("bad: %v", out.Bytes())
+		}
+	}
+}
+
+func testConfig(
+	t *testing.T,
+	c map[string]interface{}) *terraform.ResourceConfig {
+	r, err := config.NewRawConfig(c)
+	if err != nil {
+		t.Fatalf("bad: %s", err)
+	}
+
+	return terraform.NewResourceConfig(r)
+}

builtin/provisioners/remote-exec/test-fixtures/script1.sh

@@ -0,0 +1,4 @@
+#!/bin/sh
+cd /tmp
+wget http://foobar
+exit 0

command/apply_test.go

@@ -383,8 +383,9 @@ func TestApply_state(t *testing.T) {
 	originalState := &terraform.State{
 		Resources: map[string]*terraform.ResourceState{
 			"test_instance.foo": &terraform.ResourceState{
-				ID:   "bar",
+				ID:       "bar",
-				Type: "test_instance",
+				Type:     "test_instance",
+				ConnInfo: make(map[string]string),
 			},
 		},
 	}

config.go

@@ -36,7 +36,8 @@ func init() {
 		"aws": "terraform-provider-aws",
 	}
 	BuiltinConfig.Provisioners = map[string]string{
-		"local-exec": "terraform-provisioner-local-exec",
+		"local-exec":  "terraform-provisioner-local-exec",
+		"remote-exec": "terraform-provisioner-remote-exec",
 	}
 }
 

config/config.go

@@ -42,6 +42,7 @@ type Resource struct {
 type Provisioner struct {
 	Type      string
 	RawConfig *RawConfig
+	ConnInfo  *RawConfig
 }
 
 // Variable is a variable defined within the configuration.

config/loader_libucl.go

@@ -316,6 +316,10 @@ func loadResourcesLibucl(o *libucl.Object) ([]*Resource, error) {
 			// that is treated specially.
 			delete(config, "provisioner")
 
+			// Delete the "connection" section since we handle that
+			// seperately
+			delete(config, "connection")
+
 			rawConfig, err := NewRawConfig(config)
 			if err != nil {
 				return nil, fmt.Errorf(
@@ -339,11 +343,26 @@ func loadResourcesLibucl(o *libucl.Object) ([]*Resource, error) {
 				}
 			}
 
+			// If we have connection info, then parse those out
+			var connInfo map[string]interface{}
+			if conn := r.Get("connection"); conn != nil {
+				var err error
+				connInfo, err = loadConnInfoLibucl(conn)
+				conn.Close()
+				if err != nil {
+					return nil, fmt.Errorf(
+						"Error reading connection info for %s[%s]: %s",
+						t.Key(),
+						r.Key(),
+						err)
+				}
+			}
+
 			// If we have provisioners, then parse those out
 			var provisioners []*Provisioner
 			if po := r.Get("provisioner"); po != nil {
 				var err error
-				provisioners, err = loadProvisionersLibucl(po)
+				provisioners, err = loadProvisionersLibucl(po, connInfo)
 				po.Close()
 				if err != nil {
 					return nil, fmt.Errorf(
@@ -367,7 +386,7 @@ func loadResourcesLibucl(o *libucl.Object) ([]*Resource, error) {
 	return result, nil
 }
 
-func loadProvisionersLibucl(o *libucl.Object) ([]*Provisioner, error) {
+func loadProvisionersLibucl(o *libucl.Object, connInfo map[string]interface{}) ([]*Provisioner, error) {
 	pos := make([]*libucl.Object, 0, int(o.Len()))
 
 	// Accumulate all the actual provisioner configuration objects. We
@@ -409,16 +428,58 @@ func loadProvisionersLibucl(o *libucl.Object) ([]*Provisioner, error) {
 			return nil, err
 		}
 
+		// Delete the "connection" section, handle seperately
+		delete(config, "connection")
+
 		rawConfig, err := NewRawConfig(config)
 		if err != nil {
 			return nil, err
 		}
 
+		// Check if we have a provisioner-level connection
+		// block that overrides the resource-level
+		var subConnInfo map[string]interface{}
+		if conn := po.Get("connection"); conn != nil {
+			var err error
+			subConnInfo, err = loadConnInfoLibucl(conn)
+			conn.Close()
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		// Inherit from the resource connInfo any keys
+		// that are not explicitly overriden.
+		if connInfo != nil && subConnInfo != nil {
+			for k, v := range connInfo {
+				if _, ok := subConnInfo[k]; !ok {
+					subConnInfo[k] = v
+				}
+			}
+		} else if subConnInfo == nil {
+			subConnInfo = connInfo
+		}
+
+		// Parse the connInfo
+		connRaw, err := NewRawConfig(subConnInfo)
+		if err != nil {
+			return nil, err
+		}
+
 		result = append(result, &Provisioner{
 			Type:      po.Key(),
 			RawConfig: rawConfig,
+			ConnInfo:  connRaw,
 		})
 	}
 
 	return result, nil
 }
+
+func loadConnInfoLibucl(o *libucl.Object) (map[string]interface{}, error) {
+	var config map[string]interface{}
+	if err := o.Decode(&config); err != nil {
+		return nil, err
+	}
+	return config, nil
+}

config/loader_test.go

@@ -185,6 +185,44 @@ func TestLoad_provisioners(t *testing.T) {
 	}
 }
 
+func TestLoad_connections(t *testing.T) {
+	c, err := Load(filepath.Join(fixtureDir, "connection.tf"))
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	if c == nil {
+		t.Fatal("config should not be nil")
+	}
+
+	actual := resourcesStr(c.Resources)
+	if actual != strings.TrimSpace(connectionResourcesStr) {
+		t.Fatalf("bad:\n%s", actual)
+	}
+
+	// Check for the connection info
+	r := c.Resources[0]
+	if r.Name != "web" && r.Type != "aws_instance" {
+		t.Fatalf("Bad: %#v", r)
+	}
+
+	p1 := r.Provisioners[0]
+	if p1.ConnInfo == nil || len(p1.ConnInfo.Raw) != 2 {
+		t.Fatalf("Bad: %#v", p1.ConnInfo)
+	}
+	if p1.ConnInfo.Raw["user"] != "nobody" {
+		t.Fatalf("Bad: %#v", p1.ConnInfo)
+	}
+
+	p2 := r.Provisioners[1]
+	if p2.ConnInfo == nil || len(p2.ConnInfo.Raw) != 2 {
+		t.Fatalf("Bad: %#v", p2.ConnInfo)
+	}
+	if p2.ConnInfo.Raw["user"] != "root" {
+		t.Fatalf("Bad: %#v", p2.ConnInfo)
+	}
+}
+
 // This helper turns a provider configs field into a deterministic
 // string value for comparison in tests.
 func providerConfigsStr(pcs map[string]*ProviderConfig) string {
@@ -448,6 +486,20 @@ aws_instance[web] (x1)
     user: var.foo
 `
 
+const connectionResourcesStr = `
+aws_instance[web] (x1)
+  ami
+  security_groups
+  provisioners
+    shell
+      path
+    shell
+      path
+  vars
+    resource: aws_security_group.firewall.foo
+    user: var.foo
+`
+
 const variablesVariablesStr = `
 bar
   <>

config/test-fixtures/connection.tf

@@ -0,0 +1,23 @@
+resource "aws_instance" "web" {
+    ami = "${var.foo}"
+    security_groups = [
+        "foo",
+        "${aws_security_group.firewall.foo}"
+    ]
+
+    connection {
+        type = "ssh"
+        user = "root"
+    }
+
+    provisioner "shell" {
+        path = "foo"
+        connection {
+            user = "nobody"
+        }
+    }
+
+    provisioner "shell" {
+        path = "bar"
+    }
+}

helper/ssh/communicator.go

@@ -0,0 +1,543 @@
+package ssh
+
+import (
+	"bufio"
+	"bytes"
+	"code.google.com/p/go.crypto/ssh"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"net"
+	"os"
+	"path/filepath"
+	"sync"
+	"time"
+)
+
+// RemoteCmd represents a remote command being prepared or run.
+type RemoteCmd struct {
+	// Command is the command to run remotely. This is executed as if
+	// it were a shell command, so you are expected to do any shell escaping
+	// necessary.
+	Command string
+
+	// Stdin specifies the process's standard input. If Stdin is
+	// nil, the process reads from an empty bytes.Buffer.
+	Stdin io.Reader
+
+	// Stdout and Stderr represent the process's standard output and
+	// error.
+	//
+	// If either is nil, it will be set to ioutil.Discard.
+	Stdout io.Writer
+	Stderr io.Writer
+
+	// This will be set to true when the remote command has exited. It
+	// shouldn't be set manually by the user, but there is no harm in
+	// doing so.
+	Exited bool
+
+	// Once Exited is true, this will contain the exit code of the process.
+	ExitStatus int
+
+	// Internal fields
+	exitCh chan struct{}
+
+	// This thing is a mutex, lock when making modifications concurrently
+	sync.Mutex
+}
+
+// SetExited is a helper for setting that this process is exited. This
+// should be called by communicators who are running a remote command in
+// order to set that the command is done.
+func (r *RemoteCmd) SetExited(status int) {
+	r.Lock()
+	defer r.Unlock()
+
+	if r.exitCh == nil {
+		r.exitCh = make(chan struct{})
+	}
+
+	r.Exited = true
+	r.ExitStatus = status
+	close(r.exitCh)
+}
+
+// Wait waits for the remote command to complete.
+func (r *RemoteCmd) Wait() {
+	// Make sure our condition variable is initialized.
+	r.Lock()
+	if r.exitCh == nil {
+		r.exitCh = make(chan struct{})
+	}
+	r.Unlock()
+
+	<-r.exitCh
+}
+
+type SSHCommunicator struct {
+	client  *ssh.Client
+	config  *Config
+	conn    net.Conn
+	address string
+}
+
+// Config is the structure used to configure the SSH communicator.
+type Config struct {
+	// The configuration of the Go SSH connection
+	SSHConfig *ssh.ClientConfig
+
+	// Connection returns a new connection. The current connection
+	// in use will be closed as part of the Close method, or in the
+	// case an error occurs.
+	Connection func() (net.Conn, error)
+
+	// NoPty, if true, will not request a pty from the remote end.
+	NoPty bool
+}
+
+// Creates a new packer.Communicator implementation over SSH. This takes
+// an already existing TCP connection and SSH configuration.
+func New(address string, config *Config) (result *SSHCommunicator, err error) {
+	// Establish an initial connection and connect
+	result = &SSHCommunicator{
+		config:  config,
+		address: address,
+	}
+
+	if err = result.reconnect(); err != nil {
+		result = nil
+		return
+	}
+
+	return
+}
+
+func (c *SSHCommunicator) Start(cmd *RemoteCmd) (err error) {
+	session, err := c.newSession()
+	if err != nil {
+		return
+	}
+
+	// Setup our session
+	session.Stdin = cmd.Stdin
+	session.Stdout = cmd.Stdout
+	session.Stderr = cmd.Stderr
+
+	if !c.config.NoPty {
+		// Request a PTY
+		termModes := ssh.TerminalModes{
+			ssh.ECHO:          0,     // do not echo
+			ssh.TTY_OP_ISPEED: 14400, // input speed = 14.4kbaud
+			ssh.TTY_OP_OSPEED: 14400, // output speed = 14.4kbaud
+		}
+
+		if err = session.RequestPty("xterm", 80, 40, termModes); err != nil {
+			return
+		}
+	}
+
+	log.Printf("starting remote command: %s", cmd.Command)
+	err = session.Start(cmd.Command + "\n")
+	if err != nil {
+		return
+	}
+
+	// A channel to keep track of our done state
+	doneCh := make(chan struct{})
+	sessionLock := new(sync.Mutex)
+	timedOut := false
+
+	// Start a goroutine to wait for the session to end and set the
+	// exit boolean and status.
+	go func() {
+		defer session.Close()
+
+		err := session.Wait()
+		exitStatus := 0
+		if err != nil {
+			exitErr, ok := err.(*ssh.ExitError)
+			if ok {
+				exitStatus = exitErr.ExitStatus()
+			}
+		}
+
+		sessionLock.Lock()
+		defer sessionLock.Unlock()
+
+		if timedOut {
+			// We timed out, so set the exit status to -1
+			exitStatus = -1
+		}
+
+		log.Printf("remote command exited with '%d': %s", exitStatus, cmd.Command)
+		cmd.SetExited(exitStatus)
+		close(doneCh)
+	}()
+
+	return
+}
+
+func (c *SSHCommunicator) Upload(path string, input io.Reader) error {
+	// The target directory and file for talking the SCP protocol
+	target_dir := filepath.Dir(path)
+	target_file := filepath.Base(path)
+
+	// On windows, filepath.Dir uses backslash seperators (ie. "\tmp").
+	// This does not work when the target host is unix.  Switch to forward slash
+	// which works for unix and windows
+	target_dir = filepath.ToSlash(target_dir)
+
+	scpFunc := func(w io.Writer, stdoutR *bufio.Reader) error {
+		return scpUploadFile(target_file, input, w, stdoutR)
+	}
+
+	return c.scpSession("scp -vt "+target_dir, scpFunc)
+}
+
+func (c *SSHCommunicator) UploadDir(dst string, src string, excl []string) error {
+	log.Printf("Upload dir '%s' to '%s'", src, dst)
+	scpFunc := func(w io.Writer, r *bufio.Reader) error {
+		uploadEntries := func() error {
+			f, err := os.Open(src)
+			if err != nil {
+				return err
+			}
+			defer f.Close()
+
+			entries, err := f.Readdir(-1)
+			if err != nil {
+				return err
+			}
+
+			return scpUploadDir(src, entries, w, r)
+		}
+
+		if src[len(src)-1] != '/' {
+			log.Printf("No trailing slash, creating the source directory name")
+			return scpUploadDirProtocol(filepath.Base(src), w, r, uploadEntries)
+		} else {
+			// Trailing slash, so only upload the contents
+			return uploadEntries()
+		}
+	}
+
+	return c.scpSession("scp -rvt "+dst, scpFunc)
+}
+
+func (c *SSHCommunicator) Download(string, io.Writer) error {
+	panic("not implemented yet")
+}
+
+func (c *SSHCommunicator) newSession() (session *ssh.Session, err error) {
+	log.Println("opening new ssh session")
+	if c.client == nil {
+		err = errors.New("client not available")
+	} else {
+		session, err = c.client.NewSession()
+	}
+
+	if err != nil {
+		log.Printf("ssh session open error: '%s', attempting reconnect", err)
+		if err := c.reconnect(); err != nil {
+			return nil, err
+		}
+
+		return c.client.NewSession()
+	}
+
+	return session, nil
+}
+
+func (c *SSHCommunicator) reconnect() (err error) {
+	if c.conn != nil {
+		c.conn.Close()
+	}
+
+	// Set the conn and client to nil since we'll recreate it
+	c.conn = nil
+	c.client = nil
+
+	log.Printf("reconnecting to TCP connection for SSH")
+	c.conn, err = c.config.Connection()
+	if err != nil {
+		// Explicitly set this to the REAL nil. Connection() can return
+		// a nil implementation of net.Conn which will make the
+		// "if c.conn == nil" check fail above. Read here for more information
+		// on this psychotic language feature:
+		//
+		// http://golang.org/doc/faq#nil_error
+		c.conn = nil
+
+		log.Printf("reconnection error: %s", err)
+		return
+	}
+
+	log.Printf("handshaking with SSH")
+	sshConn, sshChan, req, err := ssh.NewClientConn(c.conn, c.address, c.config.SSHConfig)
+	if err != nil {
+		log.Printf("handshake error: %s", err)
+	}
+	if sshConn != nil {
+		c.client = ssh.NewClient(sshConn, sshChan, req)
+	}
+
+	return
+}
+
+func (c *SSHCommunicator) scpSession(scpCommand string, f func(io.Writer, *bufio.Reader) error) error {
+	session, err := c.newSession()
+	if err != nil {
+		return err
+	}
+	defer session.Close()
+
+	// Get a pipe to stdin so that we can send data down
+	stdinW, err := session.StdinPipe()
+	if err != nil {
+		return err
+	}
+
+	// We only want to close once, so we nil w after we close it,
+	// and only close in the defer if it hasn't been closed already.
+	defer func() {
+		if stdinW != nil {
+			stdinW.Close()
+		}
+	}()
+
+	// Get a pipe to stdout so that we can get responses back
+	stdoutPipe, err := session.StdoutPipe()
+	if err != nil {
+		return err
+	}
+	stdoutR := bufio.NewReader(stdoutPipe)
+
+	// Set stderr to a bytes buffer
+	stderr := new(bytes.Buffer)
+	session.Stderr = stderr
+
+	// Start the sink mode on the other side
+	// TODO(mitchellh): There are probably issues with shell escaping the path
+	log.Println("Starting remote scp process: ", scpCommand)
+	if err := session.Start(scpCommand); err != nil {
+		return err
+	}
+
+	// Call our callback that executes in the context of SCP. We ignore
+	// EOF errors if they occur because it usually means that SCP prematurely
+	// ended on the other side.
+	log.Println("Started SCP session, beginning transfers...")
+	if err := f(stdinW, stdoutR); err != nil && err != io.EOF {
+		return err
+	}
+
+	// Close the stdin, which sends an EOF, and then set w to nil so that
+	// our defer func doesn't close it again since that is unsafe with
+	// the Go SSH package.
+	log.Println("SCP session complete, closing stdin pipe.")
+	stdinW.Close()
+	stdinW = nil
+
+	// Wait for the SCP connection to close, meaning it has consumed all
+	// our data and has completed. Or has errored.
+	log.Println("Waiting for SSH session to complete.")
+	err = session.Wait()
+	if err != nil {
+		if exitErr, ok := err.(*ssh.ExitError); ok {
+			// Otherwise, we have an ExitErorr, meaning we can just read
+			// the exit status
+			log.Printf("non-zero exit status: %d", exitErr.ExitStatus())
+
+			// If we exited with status 127, it means SCP isn't available.
+			// Return a more descriptive error for that.
+			if exitErr.ExitStatus() == 127 {
+				return errors.New(
+					"SCP failed to start. This usually means that SCP is not\n" +
+						"properly installed on the remote system.")
+			}
+		}
+
+		return err
+	}
+
+	log.Printf("scp stderr (length %d): %s", stderr.Len(), stderr.String())
+	return nil
+}
+
+// checkSCPStatus checks that a prior command sent to SCP completed
+// successfully. If it did not complete successfully, an error will
+// be returned.
+func checkSCPStatus(r *bufio.Reader) error {
+	code, err := r.ReadByte()
+	if err != nil {
+		return err
+	}
+
+	if code != 0 {
+		// Treat any non-zero (really 1 and 2) as fatal errors
+		message, _, err := r.ReadLine()
+		if err != nil {
+			return fmt.Errorf("Error reading error message: %s", err)
+		}
+
+		return errors.New(string(message))
+	}
+
+	return nil
+}
+
+func scpUploadFile(dst string, src io.Reader, w io.Writer, r *bufio.Reader) error {
+	// Create a temporary file where we can copy the contents of the src
+	// so that we can determine the length, since SCP is length-prefixed.
+	tf, err := ioutil.TempFile("", "packer-upload")
+	if err != nil {
+		return fmt.Errorf("Error creating temporary file for upload: %s", err)
+	}
+	defer os.Remove(tf.Name())
+	defer tf.Close()
+
+	log.Println("Copying input data into temporary file so we can read the length")
+	if _, err := io.Copy(tf, src); err != nil {
+		return err
+	}
+
+	// Sync the file so that the contents are definitely on disk, then
+	// read the length of it.
+	if err := tf.Sync(); err != nil {
+		return fmt.Errorf("Error creating temporary file for upload: %s", err)
+	}
+
+	// Seek the file to the beginning so we can re-read all of it
+	if _, err := tf.Seek(0, 0); err != nil {
+		return fmt.Errorf("Error creating temporary file for upload: %s", err)
+	}
+
+	fi, err := tf.Stat()
+	if err != nil {
+		return fmt.Errorf("Error creating temporary file for upload: %s", err)
+	}
+
+	// Start the protocol
+	log.Println("Beginning file upload...")
+	fmt.Fprintln(w, "C0644", fi.Size(), dst)
+	if err := checkSCPStatus(r); err != nil {
+		return err
+	}
+
+	if _, err := io.Copy(w, tf); err != nil {
+		return err
+	}
+
+	fmt.Fprint(w, "\x00")
+	if err := checkSCPStatus(r); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func scpUploadDirProtocol(name string, w io.Writer, r *bufio.Reader, f func() error) error {
+	log.Printf("SCP: starting directory upload: %s", name)
+	fmt.Fprintln(w, "D0755 0", name)
+	err := checkSCPStatus(r)
+	if err != nil {
+		return err
+	}
+
+	if err := f(); err != nil {
+		return err
+	}
+
+	fmt.Fprintln(w, "E")
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func scpUploadDir(root string, fs []os.FileInfo, w io.Writer, r *bufio.Reader) error {
+	for _, fi := range fs {
+		realPath := filepath.Join(root, fi.Name())
+
+		// Track if this is actually a symlink to a directory. If it is
+		// a symlink to a file we don't do any special behavior because uploading
+		// a file just works. If it is a directory, we need to know so we
+		// treat it as such.
+		isSymlinkToDir := false
+		if fi.Mode()&os.ModeSymlink == os.ModeSymlink {
+			symPath, err := filepath.EvalSymlinks(realPath)
+			if err != nil {
+				return err
+			}
+
+			symFi, err := os.Lstat(symPath)
+			if err != nil {
+				return err
+			}
+
+			isSymlinkToDir = symFi.IsDir()
+		}
+
+		if !fi.IsDir() && !isSymlinkToDir {
+			// It is a regular file (or symlink to a file), just upload it
+			f, err := os.Open(realPath)
+			if err != nil {
+				return err
+			}
+
+			err = func() error {
+				defer f.Close()
+				return scpUploadFile(fi.Name(), f, w, r)
+			}()
+
+			if err != nil {
+				return err
+			}
+
+			continue
+		}
+
+		// It is a directory, recursively upload
+		err := scpUploadDirProtocol(fi.Name(), w, r, func() error {
+			f, err := os.Open(realPath)
+			if err != nil {
+				return err
+			}
+			defer f.Close()
+
+			entries, err := f.Readdir(-1)
+			if err != nil {
+				return err
+			}
+
+			return scpUploadDir(realPath, entries, w, r)
+		})
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// ConnectFunc is a convenience method for returning a function
+// that just uses net.Dial to communicate with the remote end that
+// is suitable for use with the SSH communicator configuration.
+func ConnectFunc(network, addr string) func() (net.Conn, error) {
+	return func() (net.Conn, error) {
+		c, err := net.DialTimeout(network, addr, 15*time.Second)
+		if err != nil {
+			return nil, err
+		}
+
+		if tcpConn, ok := c.(*net.TCPConn); ok {
+			tcpConn.SetKeepAlive(true)
+		}
+
+		return c, nil
+	}
+}

helper/ssh/communicator_test.go

@@ -0,0 +1,157 @@
+// +build !race
+
+package ssh
+
+import (
+	"bytes"
+	"code.google.com/p/go.crypto/ssh"
+	"fmt"
+	"net"
+	"testing"
+)
+
+// private key for mock server
+const testServerPrivateKey = `-----BEGIN RSA PRIVATE KEY-----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+-----END RSA PRIVATE KEY-----`
+
+var serverConfig = &ssh.ServerConfig{
+	PasswordCallback: func(c ssh.ConnMetadata, pass []byte) (*ssh.Permissions, error) {
+		if c.User() == "user" && string(pass) == "pass" {
+			return nil, nil
+		}
+		return nil, fmt.Errorf("password rejected for %q", c.User())
+	},
+}
+
+func init() {
+	// Parse and set the private key of the server, required to accept connections
+	signer, err := ssh.ParsePrivateKey([]byte(testServerPrivateKey))
+	if err != nil {
+		panic("unable to parse private key: " + err.Error())
+	}
+	serverConfig.AddHostKey(signer)
+}
+
+func newMockLineServer(t *testing.T) string {
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("Unable to listen for connection: %s", err)
+	}
+
+	go func() {
+		defer l.Close()
+		c, err := l.Accept()
+		if err != nil {
+			t.Errorf("Unable to accept incoming connection: %s", err)
+		}
+		defer c.Close()
+		conn, chans, _, err := ssh.NewServerConn(c, serverConfig)
+		if err != nil {
+			t.Logf("Handshaking error: %v", err)
+		}
+		t.Log("Accepted SSH connection")
+		for newChannel := range chans {
+			channel, _, err := newChannel.Accept()
+			if err != nil {
+				t.Errorf("Unable to accept channel.")
+			}
+			t.Log("Accepted channel")
+
+			go func() {
+				defer channel.Close()
+				conn.OpenChannel(newChannel.ChannelType(), nil)
+			}()
+		}
+		conn.Close()
+	}()
+
+	return l.Addr().String()
+}
+
+func TestNew_Invalid(t *testing.T) {
+	clientConfig := &ssh.ClientConfig{
+		User: "user",
+		Auth: []ssh.AuthMethod{
+			ssh.Password("i-am-invalid"),
+		},
+	}
+
+	address := newMockLineServer(t)
+	conn := func() (net.Conn, error) {
+		conn, err := net.Dial("tcp", address)
+		if err != nil {
+			t.Errorf("Unable to accept incoming connection: %v", err)
+		}
+		return conn, err
+	}
+
+	config := &Config{
+		Connection: conn,
+		SSHConfig:  clientConfig,
+	}
+
+	_, err := New(address, config)
+	if err == nil {
+		t.Fatal("should have had an error connecting")
+	}
+}
+
+func TestStart(t *testing.T) {
+	clientConfig := &ssh.ClientConfig{
+		User: "user",
+		Auth: []ssh.AuthMethod{
+			ssh.Password("pass"),
+		},
+	}
+
+	address := newMockLineServer(t)
+	conn := func() (net.Conn, error) {
+		conn, err := net.Dial("tcp", address)
+		if err != nil {
+			t.Fatalf("unable to dial to remote side: %s", err)
+		}
+		return conn, err
+	}
+
+	config := &Config{
+		Connection: conn,
+		SSHConfig:  clientConfig,
+	}
+
+	client, err := New(address, config)
+	if err != nil {
+		t.Fatalf("error connecting to SSH: %s", err)
+	}
+
+	var cmd RemoteCmd
+	stdout := new(bytes.Buffer)
+	cmd.Command = "echo foo"
+	cmd.Stdout = stdout
+
+	client.Start(&cmd)
+}

helper/ssh/password.go

@@ -0,0 +1,27 @@
+package ssh
+
+import (
+	"code.google.com/p/go.crypto/ssh"
+	"log"
+)
+
+// An implementation of ssh.KeyboardInteractiveChallenge that simply sends
+// back the password for all questions. The questions are logged.
+func PasswordKeyboardInteractive(password string) ssh.KeyboardInteractiveChallenge {
+	return func(user, instruction string, questions []string, echos []bool) ([]string, error) {
+		log.Printf("Keyboard interactive challenge: ")
+		log.Printf("-- User: %s", user)
+		log.Printf("-- Instructions: %s", instruction)
+		for i, question := range questions {
+			log.Printf("-- Question %d: %s", i+1, question)
+		}
+
+		// Just send the password back for all questions
+		answers := make([]string, len(questions))
+		for i, _ := range answers {
+			answers[i] = string(password)
+		}
+
+		return answers, nil
+	}
+}

helper/ssh/password_test.go

@@ -0,0 +1,27 @@
+package ssh
+
+import (
+	"code.google.com/p/go.crypto/ssh"
+	"reflect"
+	"testing"
+)
+
+func TestPasswordKeyboardInteractive_Impl(t *testing.T) {
+	var raw interface{}
+	raw = PasswordKeyboardInteractive("foo")
+	if _, ok := raw.(ssh.KeyboardInteractiveChallenge); !ok {
+		t.Fatal("PasswordKeyboardInteractive must implement KeyboardInteractiveChallenge")
+	}
+}
+
+func TestPasswordKeybardInteractive_Challenge(t *testing.T) {
+	p := PasswordKeyboardInteractive("foo")
+	result, err := p("foo", "bar", []string{"one", "two"}, nil)
+	if err != nil {
+		t.Fatalf("err not nil: %s", err)
+	}
+
+	if !reflect.DeepEqual(result, []string{"foo", "foo"}) {
+		t.Fatalf("invalid password: %#v", result)
+	}
+}

terraform/context.go

@@ -3,6 +3,7 @@ package terraform
 import (
 	"fmt"
 	"log"
+	"strconv"
 	"strings"
 	"sync"
 	"sync/atomic"
@@ -467,6 +468,11 @@ func (c *Context) applyWalkFn() depgraph.WalkFunc {
 			diff.init()
 		}
 
+		// If we do not have any connection info, initialize
+		if r.State.ConnInfo == nil {
+			r.State.ConnInfo = make(map[string]string)
+		}
+
 		// Remove any output values from the diff
 		for k, ad := range diff.Attributes {
 			if ad.Type == DiffAttrOutput {
@@ -555,6 +561,13 @@ func (c *Context) applyWalkFn() depgraph.WalkFunc {
 // defined after the resource creation has already completed.
 func (c *Context) applyProvisioners(r *Resource, rs *ResourceState) (*ResourceState, error) {
 	var err error
+
+	// Store the original connection info, restore later
+	origConnInfo := rs.ConnInfo
+	defer func() {
+		rs.ConnInfo = origConnInfo
+	}()
+
 	for _, prov := range r.Provisioners {
 		// Interpolate since we may have variables that depend on the
 		// local resource.
@@ -562,6 +575,41 @@ func (c *Context) applyProvisioners(r *Resource, rs *ResourceState) (*ResourceSt
 			return rs, err
 		}
 
+		// Interpolate the conn info, since it may contain variables
+		connInfo := NewResourceConfig(prov.ConnInfo)
+		if err := connInfo.interpolate(c); err != nil {
+			return rs, err
+		}
+
+		// Merge the connection information
+		overlay := make(map[string]string)
+		if origConnInfo != nil {
+			for k, v := range origConnInfo {
+				overlay[k] = v
+			}
+		}
+		for k, v := range connInfo.Config {
+			switch vt := v.(type) {
+			case string:
+				overlay[k] = vt
+			case int64:
+				overlay[k] = strconv.FormatInt(vt, 10)
+			case int32:
+				overlay[k] = strconv.FormatInt(int64(vt), 10)
+			case int:
+				overlay[k] = strconv.FormatInt(int64(vt), 10)
+			case float32:
+				overlay[k] = strconv.FormatFloat(float64(vt), 'f', 3, 32)
+			case float64:
+				overlay[k] = strconv.FormatFloat(vt, 'f', 3, 64)
+			case bool:
+				overlay[k] = strconv.FormatBool(vt)
+			default:
+				overlay[k] = fmt.Sprintf("%v", vt)
+			}
+		}
+		rs.ConnInfo = overlay
+
 		// Invoke the Provisioner
 		rs, err = prov.Provisioner.Apply(rs, prov.Config)
 		if err != nil {

terraform/context_test.go

@@ -507,6 +507,81 @@ func TestContextApply_outputDiffVars(t *testing.T) {
 	}
 }
 
+func TestContextApply_Provisioner_ConnInfo(t *testing.T) {
+	c := testConfig(t, "apply-provisioner-conninfo")
+	p := testProvider("aws")
+	pr := testProvisioner()
+
+	p.ApplyFn = func(s *ResourceState, d *ResourceDiff) (*ResourceState, error) {
+		if s.ConnInfo == nil {
+			t.Fatalf("ConnInfo not initialized")
+		}
+
+		result, _ := testApplyFn(s, d)
+		result.ConnInfo = map[string]string{
+			"type": "ssh",
+			"host": "127.0.0.1",
+			"port": "22",
+		}
+		return result, nil
+	}
+	p.DiffFn = testDiffFn
+
+	pr.ApplyFn = func(rs *ResourceState, c *ResourceConfig) (*ResourceState, error) {
+		conn := rs.ConnInfo
+		if conn["type"] != "telnet" {
+			t.Fatalf("Bad: %#v", conn)
+		}
+		if conn["host"] != "127.0.0.1" {
+			t.Fatalf("Bad: %#v", conn)
+		}
+		if conn["port"] != "2222" {
+			t.Fatalf("Bad: %#v", conn)
+		}
+		if conn["user"] != "superuser" {
+			t.Fatalf("Bad: %#v", conn)
+		}
+		if conn["pass"] != "test" {
+			t.Fatalf("Bad: %#v", conn)
+		}
+		return rs, nil
+	}
+
+	ctx := testContext(t, &ContextOpts{
+		Config: c,
+		Providers: map[string]ResourceProviderFactory{
+			"aws": testProviderFuncFixed(p),
+		},
+		Provisioners: map[string]ResourceProvisionerFactory{
+			"shell": testProvisionerFuncFixed(pr),
+		},
+		Variables: map[string]string{
+			"value": "1",
+			"pass":  "test",
+		},
+	})
+
+	if _, err := ctx.Plan(nil); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	state, err := ctx.Apply()
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	actual := strings.TrimSpace(state.String())
+	expected := strings.TrimSpace(testTerraformApplyProvisionerStr)
+	if actual != expected {
+		t.Fatalf("bad: \n%s", actual)
+	}
+
+	// Verify apply was invoked
+	if !pr.ApplyCalled {
+		t.Fatalf("provisioner not invoked")
+	}
+}
+
 func TestContextApply_destroy(t *testing.T) {
 	c := testConfig(t, "apply-destroy")
 	h := new(HookRecordApplyOrder)

terraform/graph.go

@@ -546,6 +546,9 @@ func graphAddVariableDeps(g *depgraph.Graph) {
 			for _, p := range m.Resource.Provisioners {
 				vars = p.RawConfig.Variables
 				nounAddVariableDeps(g, n, vars)
+
+				vars = p.ConnInfo.Variables
+				nounAddVariableDeps(g, n, vars)
 			}
 
 		case *GraphNodeResourceProvider:
@@ -774,6 +777,7 @@ func graphMapResourceProvisioners(g *depgraph.Graph,
 				Provisioner: provisioner,
 				Config:      NewResourceConfig(p.RawConfig),
 				RawConfig:   p.RawConfig,
+				ConnInfo:    p.ConnInfo,
 			})
 		}
 	}

terraform/graph_test.go

@@ -195,11 +195,19 @@ func TestGraphProvisioners(t *testing.T) {
 	if prov.RawConfig.Config()["cmd"] != "add ${aws_instance.web.id}" {
 		t.Fatalf("bad: %#v", prov)
 	}
+	if prov.ConnInfo == nil || len(prov.ConnInfo.Raw) != 2 {
+		t.Fatalf("bad: %#v", prov)
+	}
 
 	// Check that the variable dependency is handled
 	if !depends("aws_load_balancer.weblb", "aws_instance.web") {
 		t.Fatalf("missing dependency from provisioner variable")
 	}
+
+	// Check that the connection variable dependency is handled
+	if !depends("aws_load_balancer.weblb", "aws_security_group.firewall") {
+		t.Fatalf("missing dependency from provisioner connection")
+	}
 }
 
 func TestGraphAddDiff(t *testing.T) {

terraform/resource.go

@@ -18,6 +18,7 @@ type ResourceProvisionerConfig struct {
 	Provisioner ResourceProvisioner
 	Config      *ResourceConfig
 	RawConfig   *config.RawConfig
+	ConnInfo    *config.RawConfig
 }
 
 // Resource encapsulates a resource, its configuration, its provider,

terraform/state.go

@@ -145,14 +145,14 @@ func (s *State) String() string {
 // that should not be serialized. This is only used temporarily
 // and is restored into the state.
 type sensitiveState struct {
-	ConnInfo map[string]*ResourceConnectionInfo
+	ConnInfo map[string]map[string]string
 
 	once sync.Once
 }
 
 func (s *sensitiveState) init() {
 	s.once.Do(func() {
-		s.ConnInfo = make(map[string]*ResourceConnectionInfo)
+		s.ConnInfo = make(map[string]map[string]string)
 	})
 }
 
@@ -245,21 +245,6 @@ func WriteState(d *State, dst io.Writer) error {
 	return err
 }
 
-// ResourceConnectionInfo holds addresses, credentials and configuration
-// information require to connect to a resource. This is populated
-// by a provider so that provisioners can connect and run on the
-// resource.
-type ResourceConnectionInfo struct {
-	// Type is set so that an appropriate connection can be formed.
-	// As an example, for a Linux machine, the Type may be "ssh"
-	Type string
-
-	// Raw is used to store any relevant keys for the given Type
-	// so that a provisioner can connect to the resource. This could
-	// contain credentials or address information.
-	Raw map[string]string
-}
-
 // ResourceState holds the state of a resource that is used so that
 // a provider can find and manage an existing resource as well as for
 // storing attributes that are uesd to populate variables of child
@@ -292,7 +277,7 @@ type ResourceState struct {
 	// ConnInfo is used for the providers to export information which is
 	// used to connect to the resource for provisioning. For example,
 	// this could contain SSH or WinRM credentials.
-	ConnInfo *ResourceConnectionInfo
+	ConnInfo map[string]string
 
 	// Extra information that the provider can store about a resource.
 	// This data is opaque, never shown to the user, and is sent back to

terraform/state_test.go

@@ -98,12 +98,10 @@ func TestReadWriteState(t *testing.T) {
 		Resources: map[string]*ResourceState{
 			"foo": &ResourceState{
 				ID: "bar",
-				ConnInfo: &ResourceConnectionInfo{
+				ConnInfo: map[string]string{
-					Type: "ssh",
+					"type":     "ssh",
-					Raw: map[string]string{
+					"user":     "root",
-						"user":     "root",
+					"password": "supersecret",
-						"password": "supersecret",
-					},
 				},
 			},
 		},

terraform/test-fixtures/apply-provisioner-conninfo/main.tf

@@ -0,0 +1,20 @@
+resource "aws_instance" "foo" {
+    num = "2"
+    compute = "dynamical"
+    compute_value = "${var.value}"
+}
+
+resource "aws_instance" "bar" {
+    connection {
+        type = "telnet"
+    }
+
+    provisioner "shell" {
+        foo = "${aws_instance.foo.dynamical}"
+        connection {
+            user = "superuser"
+            port = 2222
+            pass = "${var.pass}"
+        }
+    }
+}

terraform/test-fixtures/graph-provisioners/main.tf

@@ -24,5 +24,9 @@ resource "aws_instance" "web" {
 resource "aws_load_balancer" "weblb" {
     provisioner "shell" {
         cmd = "add ${aws_instance.web.id}"
+        connection {
+            type = "magic"
+            user = "${aws_security_group.firewall.id}"
+        }
     }
 }