161 lines
6.2 KiB
Markdown
161 lines
6.2 KiB
Markdown
# Gophercloud: an OpenStack SDK for Go
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[](https://travis-ci.org/rackspace/gophercloud) [](https://coveralls.io/r/rackspace/gophercloud)
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Gophercloud is a flexible SDK that allows you to consume and work with OpenStack
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clouds in a simple and idiomatic way using golang. Many services are supported,
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including Compute, Block Storage, Object Storage, Networking, and Identity.
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Each service API is backed with getting started guides, code samples, reference
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documentation, unit tests and acceptance tests.
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## Useful links
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* [Gophercloud homepage](http://gophercloud.io)
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* [Reference documentation](http://godoc.org/github.com/rackspace/gophercloud)
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* [Getting started guides](http://gophercloud.io/docs)
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* [Effective Go](https://golang.org/doc/effective_go.html)
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## How to install
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Before installing, you need to ensure that your [GOPATH environment variable](https://golang.org/doc/code.html#GOPATH)
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is pointing to an appropriate directory where you want to install Gophercloud:
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```bash
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mkdir $HOME/go
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export GOPATH=$HOME/go
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```
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To protect yourself against changes in your dependencies, we highly recommend choosing a
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[dependency management solution](https://github.com/golang/go/wiki/PackageManagementTools) for
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your projects, such as [godep](https://github.com/tools/godep). Once this is set up, you can install
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Gophercloud as a dependency like so:
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```bash
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go get github.com/rackspace/gophercloud
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# Edit your code to import relevant packages from "github.com/rackspace/gophercloud"
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godep save ./...
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```
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This will install all the source files you need into a `Godeps/_workspace` directory, which is
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referenceable from your own source files when you use the `godep go` command.
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## Getting started
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### Credentials
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Because you'll be hitting an API, you will need to retrieve your OpenStack
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credentials and either store them as environment variables or in your local Go
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files. The first method is recommended because it decouples credential
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information from source code, allowing you to push the latter to your version
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control system without any security risk.
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You will need to retrieve the following:
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* username
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* password
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* tenant name or tenant ID
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* a valid Keystone identity URL
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For users that have the OpenStack dashboard installed, there's a shortcut. If
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you visit the `project/access_and_security` path in Horizon and click on the
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"Download OpenStack RC File" button at the top right hand corner, you will
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download a bash file that exports all of your access details to environment
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variables. To execute the file, run `source admin-openrc.sh` and you will be
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prompted for your password.
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### Authentication
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Once you have access to your credentials, you can begin plugging them into
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Gophercloud. The next step is authentication, and this is handled by a base
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"Provider" struct. To get one, you can either pass in your credentials
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explicitly, or tell Gophercloud to use environment variables:
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```go
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import (
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"github.com/rackspace/gophercloud"
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"github.com/rackspace/gophercloud/openstack"
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"github.com/rackspace/gophercloud/openstack/utils"
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)
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// Option 1: Pass in the values yourself
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opts := gophercloud.AuthOptions{
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IdentityEndpoint: "https://my-openstack.com:5000/v2.0",
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Username: "{username}",
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Password: "{password}",
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TenantID: "{tenant_id}",
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}
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// Option 2: Use a utility function to retrieve all your environment variables
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opts, err := openstack.AuthOptionsFromEnv()
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```
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Once you have the `opts` variable, you can pass it in and get back a
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`ProviderClient` struct:
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```go
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provider, err := openstack.AuthenticatedClient(opts)
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```
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The `ProviderClient` is the top-level client that all of your OpenStack services
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derive from. The provider contains all of the authentication details that allow
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your Go code to access the API - such as the base URL and token ID.
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### Provision a server
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Once we have a base Provider, we inject it as a dependency into each OpenStack
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service. In order to work with the Compute API, we need a Compute service
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client; which can be created like so:
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```go
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client, err := openstack.NewComputeV2(provider, gophercloud.EndpointOpts{
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Region: os.Getenv("OS_REGION_NAME"),
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})
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```
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We then use this `client` for any Compute API operation we want. In our case,
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we want to provision a new server - so we invoke the `Create` method and pass
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in the flavor ID (hardware specification) and image ID (operating system) we're
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interested in:
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```go
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import "github.com/rackspace/gophercloud/openstack/compute/v2/servers"
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server, err := servers.Create(client, servers.CreateOpts{
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Name: "My new server!",
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FlavorRef: "flavor_id",
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ImageRef: "image_id",
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}).Extract()
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```
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If you are unsure about what images and flavors are, you can read our [Compute
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Getting Started guide](http://gophercloud.io/docs/compute). The above code
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sample creates a new server with the parameters, and embodies the new resource
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in the `server` variable (a
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[`servers.Server`](http://godoc.org/github.com/rackspace/gophercloud) struct).
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### Next steps
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Cool! You've handled authentication, got your `ProviderClient` and provisioned
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a new server. You're now ready to use more OpenStack services.
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* [Getting started with Compute](http://gophercloud.io/docs/compute)
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* [Getting started with Object Storage](http://gophercloud.io/docs/object-storage)
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* [Getting started with Networking](http://gophercloud.io/docs/networking)
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* [Getting started with Block Storage](http://gophercloud.io/docs/block-storage)
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* [Getting started with Identity](http://gophercloud.io/docs/identity)
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## Contributing
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Engaging the community and lowering barriers for contributors is something we
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care a lot about. For this reason, we've taken the time to write a [contributing
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guide](./CONTRIBUTING.md) for folks interested in getting involved in our project.
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If you're not sure how you can get involved, feel free to submit an issue or
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[contact us](https://developer.rackspace.com/support/). You don't need to be a
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Go expert - all members of the community are welcome!
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## Help and feedback
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If you're struggling with something or have spotted a potential bug, feel free
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to submit an issue to our [bug tracker](/issues) or [contact us directly](https://developer.rackspace.com/support/).
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