#Next Generation Cloud Servers™ (compute_v2) This document explains how to get started using Next Generation Cloud Servers with Fog. It assumes you have read the [Getting Started with Fog and the Rackspace Open Cloud](getting_started.md) document. **Note**: Fog also provides an interface to First Gen Cloud Servers™ (compute). The compute interface is deprecated and should only be used if you need to interact with our first generation cloud. Fog determines the appropriate interface based on the `:version` parameter. See [Create Service](#create-service) section for more information. ## Starting irb console Start by executing the following command: irb Once `irb` has launched you need to require the Fog library. If using Ruby 1.8.x execute: require 'rubygems' require 'fog' If using Ruby 1.9.x execute: require 'fog' ## Create Service Next, create a connection to the Next Gen Cloud Servers: Using a US-based account: service = Fog::Compute.new({ :provider => 'Rackspace', # Rackspace Fog provider :rackspace_username => RACKSPACE_USER_NAME, # Your Rackspace Username :rackspace_api_key => RACKSPACE_API, # Your Rackspace API key :version => :v2, # Use Next Gen Cloud Servers :rackspace_region => :ord, # Defaults to :dfw :connection_options => {} # Optional }) Using a UK-based account: service = Fog::Compute.new({ :provider => 'Rackspace', # Rackspace Fog provider :rackspace_username => RACKSPACE_USER_NAME, # Your Rackspace Username :rackspace_api_key => RACKSPACE_API, # Your Rackspace API key :version => :v2, # Use Next Gen Cloud Servers :rackspace_auth_url => Fog::Rackspace::UK_AUTH_ENDPOINT, :rackspace_region => :lon, :connection_options => {} # Optional }) To learn more about obtaining cloud credentials refer to the [Getting Started with Fog and the Rackspace Open Cloud](getting_started.md) document. By default `Fog::Compute` will authenticate against the US authentication endpoint and connect to the DFW region. You can specify alternative authentication endpoints using the key `:rackspace_auth_url`. Please refer to [Alternate Authentication Endpoints](http://docs.rackspace.com/auth/api/v2.0/auth-client-devguide/content/Endpoints-d1e180.html) for a list of alternative Rackspace authentication endpoints. Alternative regions are specified using the key `:rackspace_region `. A list of regions available for Cloud Servers can be found by executing the following: identity_service = Fog::Identity({ :provider => 'Rackspace', # Rackspace Fog provider :rackspace_username => RACKSPACE_USER_NAME, # Your Rackspace Username :rackspace_api_key => RACKSPACE_API, # Your Rackspace API key :rackspace_auth_url => Fog::Rackspace::UK_AUTH_ENDPOINT # Not specified for US Cloud }) identity_service.service_catalog.display_service_regions :cloudServersOpenStack Rackspace Private Cloud installations can skip specifying a region and directly specify their custom service endpoints using the key `:rackspace_compute_url`. **Note**: A`Fog::Compute` instance is needed for the desired region. ### Optional Connection Parameters Fog supports passing additional connection parameters to its underlying HTTP library (Excon) using the `:connection_options` parameter.
Key Description
:connect_timeout Connection timeout (default: 60 seconds)
:read_timeout Read timeout for connection (default: 60 seconds)
:write_timeout Write timeout for connection (default: 60 seconds)
:proxy Proxy for HTTP and HTTPS connections
:ssl_ca_path Path to SSL certificate authorities
:ssl_ca_file SSL certificate authority file
:ssl_verify_peer SSL verify peer (default: true)
## Fog Abstractions Fog provides both a **model** and **request** abstraction. The request abstraction provides the most efficient interface and the model abstraction wraps the request abstraction to provide a convenient `ActiveModel` like interface. ### Request Layer The request abstraction maps directly to the [Next Gen Cloud Servers API](http://docs.rackspace.com/servers/api/v2/cs-devguide/content/ch_preface.html). It provides the most efficient interface to the Rackspace Open Cloud. To see a list of requests supported by the service: service.requests This returns: :list_servers, :get_server, :create_server, :update_server, :delete_server, :change_server_password, :reboot_server, :rebuild_server, :resize_server, :confirm_resize_server, :revert_resize_server, :list_images, :get_image, :list_flavors, :get_flavor, :attach_volume, :get_attachment, :list_attachments, :delete_attachment #### Example Request To request a list of flavors: response = service.list_flavors This returns in the following `Excon::Response`: [{"id"=>"2", "links"=>[{"href"=>"https://ord.servers.api.rackspacecloud.com/v2/772045/flavors/2", "rel"=>"self"}, {"href"=>"https://ord.servers.api.rackspacecloud.com/772045/flavors/2", "rel"=>"bookmark"}], "name"=>"512MB Standard Instance"}, {"id"=>"3", "links"=>[{"href"=>"https://ord.servers.api.rackspacecloud.com/v2/772045/flavors/3", "rel"=>"self"}, {"href"=>"https://ord.servers.api.rackspacecloud.com/772045/flavors/3", "rel"=>"bookmark"}], "name"=>"1GB Standard Instance"}, {"id"=>"4", "links"=>[{"href"=>"https://ord.servers.api.rackspacecloud.com/v2/772045/flavors/4", "rel"=>"self"}, {"href"=>"https://ord.servers.api.rackspacecloud.com/772045/flavors/4", "rel"=>"bookmark"}], "name"=>"2GB Standard Instance"}, {"id"=>"5", "links"=>[{"href"=>"https://ord.servers.api.rackspacecloud.com/v2/772045/flavors/5", "rel"=>"self"}, {"href"=>"https://ord.servers.api.rackspacecloud.com/772045/flavors/5", "rel"=>"bookmark"}], "name"=>"4GB Standard Instance"}, {"id"=>"6", "links"=>[{"href"=>"https://ord.servers.api.rackspacecloud.com/v2/772045/flavors/6", "rel"=>"self"}, {"href"=>"https://ord.servers.api.rackspacecloud.com/772045/flavors/6", "rel"=>"bookmark"}], "name"=>"8GB Standard Instance"}, {"id"=>"7", "links"=>[{"href"=>"https://ord.servers.api.rackspacecloud.com/v2/772045/flavors/7", "rel"=>"self"}, {"href"=>"https://ord.servers.api.rackspacecloud.com/772045/flavors/7", "rel"=>"bookmark"}], "name"=>"15GB Standard Instance"}, {"id"=>"8", "links"=>[{"href"=>"https://ord.servers.api.rackspacecloud.com/v2/772045/flavors/8", "rel"=>"self"}, {"href"=>"https://ord.servers.api.rackspacecloud.com/772045/flavors/8", "rel"=>"bookmark"}], "name"=>"30GB Standard Instance"}]}, @headers={"Date"=>"Mon, 21 Jan 2013 16:14:45 GMT", "Content-Length"=>"1697", "Content-Type"=>"application/json", "X-Compute-Request-Id"=>"req-0a1e8532-19b3-4993-8b48-cf2d9efe078c", "Server"=>"Jetty(8.0.y.z-SNAPSHOT)"}, @status=200> To view the status of the response: response.status **Note**: Fog is aware of valid HTTP response statuses for each request type. If an unexpected HTTP response status occurs, Fog will raise an exception. To view response body: response.body This will return: {"flavors"=>[{"id"=>"2", "links"=>[{"href"=>"https://ord.servers.api.rackspacecloud.com/v2/772045/flavors/2", "rel"=>"self"}, {"href"=>"https://ord.servers.api.rackspacecloud.com/772045/flavors/2", "rel"=>"bookmark"}], "name"=>"512MB Standard Instance"}, {"id"=>"3", "links"=>[{"href"=>"https://ord.servers.api.rackspacecloud.com/v2/772045/flavors/3", "rel"=>"self"}, {"href"=>"https://ord.servers.api.rackspacecloud.com/772045/flavors/3", "rel"=>"bookmark"}], "name"=>"1GB Standard Instance"}, {"id"=>"4", "links"=>[{"href"=>"https://ord.servers.api.rackspacecloud.com/v2/772045/flavors/4", "rel"=>"self"}, {"href"=>"https://ord.servers.api.rackspacecloud.com/772045/flavors/4", "rel"=>"bookmark"}], "name"=>"2GB Standard Instance"}, {"id"=>"5", "links"=>[{"href"=>"https://ord.servers.api.rackspacecloud.com/v2/772045/flavors/5", "rel"=>"self"}, {"href"=>"https://ord.servers.api.rackspacecloud.com/772045/flavors/5", "rel"=>"bookmark"}], "name"=>"4GB Standard Instance"}, {"id"=>"6", "links"=>[{"href"=>"https://ord.servers.api.rackspacecloud.com/v2/772045/flavors/6", "rel"=>"self"}, {"href"=>"https://ord.servers.api.rackspacecloud.com/772045/flavors/6", "rel"=>"bookmark"}], "name"=>"8GB Standard Instance"}, {"id"=>"7", "links"=>[{"href"=>"https://ord.servers.api.rackspacecloud.com/v2/772045/flavors/7", "rel"=>"self"}, {"href"=>"https://ord.servers.api.rackspacecloud.com/772045/flavors/7", "rel"=>"bookmark"}], "name"=>"15GB Standard Instance"}, {"id"=>"8", "links"=>[{"href"=>"https://ord.servers.api.rackspacecloud.com/v2/772045/flavors/8", "rel"=>"self"}, {"href"=>"https://ord.servers.api.rackspacecloud.com/772045/flavors/8", "rel"=>"bookmark"}], "name"=>"30GB Standard Instance"}]} To learn more about Compute request methods refer to [rdoc](http://rubydoc.info/gems/fog/Fog/Compute/Rackspace/Real). To learn more about Excon refer to [Excon GitHub repo](https://github.com/geemus/excon). ### Model Layer Fog models behave in a manner similar to `ActiveModel`. Models will generally respond to `create`, `save`, `persisted?`, `destroy`, `reload` and `attributes` methods. Additionally, fog will automatically create attribute accessors. Here is a summary of common model methods:
Method Description
create Accepts hash of attributes and creates object.
Note: creation is a non-blocking call and you will be required to wait for a valid state before using resulting object.
save Saves object.
Note: not all objects support updating object.
persisted? Returns true if the object has been persisted.
destroy Destroys object.
Note: this is a non-blocking call and object deletion might not be instantaneous.
reload Updates object with latest state from service.
ready? Returns true if object is in a ready state and able to perform actions. This method will raise an exception if object is in an error state.
attributes Returns a hash containing the list of model attributes and values.
identity Returns the identity of the object.
Note: This might not always be equal to object.id.
wait_for This method periodically reloads model and then yields to specified block until block returns true or a timeout occurs.
The remainder of this document details the model abstraction. ## List Images To retrieve a list of available images: service.images This returns a collection of `Fog::Compute::RackspaceV2::Image` models: "https://ord.servers.api.rackspacecloud.com/v2/772045/images/8a3a9f96-b997-46fd-b7a8-a9e740796ffd", "rel"=>"self"}, {"href"=>"https://ord.servers.api.rackspacecloud.com/772045/images/8a3a9f96-b997-46fd-b7a8-a9e740796ffd", "rel"=>"bookmark"}, {"href"=>"https://ord.images.api.rackspacecloud.com/772045/images/8a3a9f96-b997-46fd-b7a8-a9e740796ffd", "type"=>"application/vnd.openstack.image", "rel"=>"alternate"}] >, "https://ord.servers.api.rackspacecloud.com/v2/772045/images/992ba82c-083b-4eed-9c26-c54473686466", "rel"=>"self"}, {"href"=>"https://ord.servers.api.rackspacecloud.com/772045/images/992ba82c-083b-4eed-9c26-c54473686466", "rel"=>"bookmark"}, {"href"=>"https://ord.images.api.rackspacecloud.com/772045/images/992ba82c-083b-4eed-9c26-c54473686466", "type"=>"application/vnd.openstack.image", "rel"=>"alternate"}] >, … **Note**: In order to speed up access `service.images` does not retrieve all attribute values. To retrieve additional details you will either need to `reload` each individual image or use the request abstraction. ## Get Image To retrieve individual image: service.images.get "8a3a9f96-b997-46fd-b7a8-a9e740796ffd" This returns an `Fog::Compute::RackspaceV2::Image` instance: "ubuntu", "com.rackspace__1__visible_core"=>"1", "com.rackspace__1__build_rackconnect"=>"1", "auto_disk_config"=>"True", "com.rackspace__1__options"=>"0", "image_type"=>"base", "org.openstack__1__os_version"=>"12.10", "os_version"=>"12.10", "rax_options"=>"0", "com.rackspace__1__visible_rackconnect"=>"1", "org.openstack__1__os_distro"=>"org.ubuntu", "com.rackspace__1__visible_managed"=>"1", "com.rackspace__1__build_core"=>"1", "arch"=>"x86-64", "os_type"=>"linux", "org.openstack__1__architecture"=>"x64", "com.rackspace__1__build_managed"=>"1"}, disk_config="AUTO", links=[{"href"=>"https://ord.servers.api.rackspacecloud.com/v2/772045/images/8a3a9f96-b997-46fd-b7a8-a9e740796ffd", "rel"=>"self"}, {"href"=>"https://ord.servers.api.rackspacecloud.com/772045/images/8a3a9f96-b997-46fd-b7a8-a9e740796ffd", "rel"=>"bookmark"}, {"href"=>"https://ord.images.api.rackspacecloud.com/772045/images/8a3a9f96-b997-46fd-b7a8-a9e740796ffd", "type"=>"application/vnd.openstack.image", "rel"=>"alternate"}] > **Note**: This request populates all Image attributes. ## List Flavors To retrieve a list of available flavors: service.images This returns a collection of `Fog::Compute::RackspaceV2::Flavor` models: "https://dfw.servers.api.rackspacecloud.com/v2/772045/flavors/2", "rel"=>"self"}, {"href"=>"https://dfw.servers.api.rackspacecloud.com/772045/flavors/2", "rel"=>"bookmark"}] >, "https://dfw.servers.api.rackspacecloud.com/v2/772045/flavors/3", "rel"=>"self"}, {"href"=>"https://dfw.servers.api.rackspacecloud.com/772045/flavors/3", "rel"=>"bookmark"}] >, … **Note**: In order to speed up access `service.flavors` does not retrieve all attribute values. To retrieve additional details you will either need to `reload` each individual flavor or use the request abstraction. ## Get Flavor To retrieve individual flavor: service.flavor.get 2 This returns a `Fog::Compute::RackspaceV2::Flavor` instance: "https://dfw.servers.api.rackspacecloud.com/v2/772045/flavors/2", "rel"=>"self"}, {"href"=>"https://dfw.servers.api.rackspacecloud.com/772045/flavors/2", "rel"=>"bookmark"}] > **Note**: This request populates all Flavor attributes. ## List Servers To retrieve a list of available servers: service.servers This returns a collection of `Fog::Compute::RackspaceV2::Servers` models: "https://dfw.servers.api.rackspacecloud.com/v2/772045/servers/6a273531-8ee4-4bef-ad1a-baca963f8bbb", "rel"=>"self"}, {"href"=>"https://dfw.servers.api.rackspacecloud.com/772045/servers/6a273531-8ee4-4bef-ad1a-baca963f8bbb", "rel"=>"bookmark"}], metadata={}, personality=nil, ipv4_address="198.101.255.186", ipv6_address="2001:4800:780e:0510:0fe1:75e8:ff04:c4a0", disk_config="AUTO", bandwidth=[], addresses={"public"=>[{"version"=>4, "addr"=>"198.101.255.186"}, {"version"=>6, "addr"=>"2001:4800:780e:0510:0fe1:75e8:ff04:c4a0"}], "private"=>[{"version"=>4, "addr"=>"10.180.22.165"}]}, flavor_id="2", image_id="33e21646-43ed-407e-9dbf-7c7873fccd9a" >, … ## Get Server To return an individual server: service.servers.get "6a273531-8ee4-4bef-ad1a-baca963f8bbb" This returns a `Fog::Compute::RackspaceV2::Server` instance: "https://dfw.servers.api.rackspacecloud.com/v2/772045/servers/6a273531-8ee4-4bef-ad1a-baca963f8bbb", "rel"=>"self"}, {"href"=>"https://dfw.servers.api.rackspacecloud.com/772045/servers/6a273531-8ee4-4bef-ad1a-baca963f8bbb", "rel"=>"bookmark"}], metadata={}, personality=nil, ipv4_address="198.101.255.186", ipv6_address="2001:4800:780e:0510:0fe1:75e8:ff04:c4a0", disk_config="AUTO", bandwidth=[], addresses={"public"=>[{"version"=>4, "addr"=>"198.101.255.186"}, {"version"=>6, "addr"=>"2001:4800:780e:0510:0fe1:75e8:ff04:c4a0"}], "private"=>[{"version"=>4, "addr"=>"10.180.22.165"}]}, flavor_id="2", image_id="33e21646-43ed-407e-9dbf-7c7873fccd9a" >, ... ## Create Server To create a server: flavor = service.flavors.first image = service.images.first server = service.servers.create(:name => 'fog-doc', :flavor_id => flavor.id, :image_id => image.id) This will return a `Fog::Compute::RackspaceV2::Server` instance: "https://dfw.servers.api.rackspacecloud.com/v2/772045/servers/8ff308a6-e04a-4602-b991-ed526ab3b6be", "rel"=>"self"}, {"href"=>"https://dfw.servers.api.rackspacecloud.com/772045/servers/8ff308a6-e04a-4602-b991-ed526ab3b6be", "rel"=>"bookmark"}], metadata=nil, personality=nil, ipv4_address=nil, ipv6_address=nil, disk_config="AUTO", bandwidth=nil, addresses=nil, flavor_id=2, image_id="3afe97b2-26dc-49c5-a2cc-a2fc8d80c001" > Notice that your server contains several `nil` attributes. To see the latest status, reload the instance like so: server.reload You can see that the server is currently 17% built: Fog::Compute::RackspaceV2::Server id="8ff308a6-e04a-4602-b991-ed526ab3b6be", name="fog-server", created="2013-01-18T16:15:41Z", updated="2013-01-18T16:16:14Z", host_id="775837108e45aa3f2a58527c9c3b6160838078e83148f07906c933ca", state="BUILD", progress=17, user_id="296063", tenant_id="772045", links=[{"href"=>"https://dfw.servers.api.rackspacecloud.com/v2/772045/servers/8ff308a6-e04a-4602-b991-ed526ab3b6be", "rel"=>"self"}, {"href"=>"https://dfw.servers.api.rackspacecloud.com/772045/servers/8ff308a6-e04a-4602-b991-ed526ab3b6be", "rel"=>"bookmark"}], metadata={}, personality=nil, ipv4_address="", ipv6_address="", disk_config="AUTO", bandwidth=[], addresses={"public"=>[{"version"=>4, "addr"=>"198.61.209.78"}, {"version"=>6, "addr"=>"2001:4800:7810:0512:0fe1:75e8:ff04:94e4"}], "private"=>[{"version"=>4, "addr"=>"10.181.13.198"}]}, flavor_id="2", image_id="3afe97b2-26dc-49c5-a2cc-a2fc8d80c001" > You will be unable to perform any actions to this server until it reaches an `ACTIVE` state. Since this is true for most server actions, Fog provides the convenience method `wait_for`. Fog can wait for the server to become ready as follows: server.wait_for { ready? } **Note**: The `Fog::Compute::RackspaceV2::Server` instance returned from the create method contains a `password` attribute. The `password` attribute will NOT be present in subsequent retrievals either through `service.servers` or `server.servers.get my_server_id`. ### Additional Parameters The `create` method also supports the following key values:
Key Description
:disk_config The disk configuration value (AUTO or MANUAL). Refer to Next Gen Server API documentation - Disk Configuration Extension.
:metadata Hash containing server metadata.
:personality File path and contents. Refer to Next Gen Server API documentation - Server Personality.
## Bootstrap In addition to the `create` method, fog provides a method called `bootstrap`. This method creates a server and then performs the following actions via ssh: 1. Create `ROOT_USER/.ssh/authorized_keys` using the specified `:public_key`. 2. Lock password for root user using `passwd -l root`. 3. Create `ROOT_USER/attributes.json` with the server's attributes. 4. Create `ROOT_USER/metadata.json` with the server's metadata **Note**: The `bootstrap` method is a blocking call unlike `create` method. The following example demonstrates bootstraping a server: service.servers.bootstrap :name => 'bootstrap-server', :flavor_id => service.flavors.first.id, :image_id => service.images.find {|img| img.name =~ /Ubuntu/}.id, :public_key_path => '~/.ssh/fog_rsa.pub', :private_key_path => '~/.ssh/fog_rsa' **Note**: The `create` method provides an option called `:personality` that allows developers to populate files on the server without using ssh. ## SSH Once a server has been created and setup for ssh key authentication, fog can execute remote commands as follows: result = server.ssh ['pwd'] This will return the following: [#] **Note**: SSH key authentication can be setup using `bootstrap` method or by using the `:personality` attribute on the `:create` method. See [Bootstrap](#bootstrap) or [Create Server](#create-server) for more information. ## Update Server Next Gen Cloud Servers support updating the following attributes `name`, `access_ipv4_address`, and `access_ipv6_address`. To update these attributes: server.name = "batman" server.access_ipv4_address = "10.0.0.1" server.access_ipv6_address = "fdbb:1717:4533:7c89:0:0:0:1" server.save Additional information about server access addresses can be found [here](http://docs.rackspace.com/servers/api/v2/cs-devguide/content/Server_Primary_Addresses-d1e2558.html). **Note**: Updating the server name does not change the host name. Names are not guaranteed to be unique. ## Delete Server To delete a server: server.destroy **Note**: The server is not immediately destroyed, but it does occur shortly there after. ## Metadata You can access metadata as an attribute on both `Fog::Compute::RackspaceV2::Server` and `Fog::Compute::RackspaceV2::Metadata::Image`. You can specify metadata during creation of a server or an image. Please refer to [Create Server](#create-server) or [Create Image](#create-image) sections for more information. This example demonstrates how to iterate through a server's metadata: server.metadata.each {|metadatum| puts "#{metadatum.key}: #{metadatum.value}" } You can update and retrieve metadata in a manner similar to a hash: server.metadata["os_type"] server.metadata["installed_ruby"] = "MRI 1.9.3" Metadata also responds to `save` and `reload` as follows: server.metadata.save server.metadata.reload ## Change Admin Password To change the administrator password: server.change_admin_password "superSecure" ## Reboot To perform a soft reboot: server.reboot To perform a hard reboot: server.reboot 'HARD' ## Rebuild Rebuild removes all data on the server and replaces it with the specified image. The id and all IP addresses remain the same. To rebuild a server: image = service.images.first server.rebuild image.id Additionally, the `rebuild` method will take a second parameter containing a hash with the following values:
Key Description
:name Name of Server
:flavorRef Flavor id
:accessIPv4 IPv4 access address
:accessIPv6 IPv6 access address
:metadata Hash containing server metadata
:personality File path and contents. Refer to Next Gen Server API documentation - Server Personality.
:disk_config The disk configuration value (AUTO or MANUAL). Refer to Next Gen Server API documentation - Disk Configuration Extension.
## Resize Resizing a server allows you to change the resources dedicated to the server. To resize a server: flavor_id = service.flavor[2].id server.resize flavor_id #flavor_id should be your desired flavor During the resize process the server will have a state of `RESIZE`. Once a server has completed resizing it will be in a `VERIFY_RESIZE` state. You can use Fog's `wait_for` method to wait for this state as follows: server.wait_for { ready?('VERIFY_RESIZE', ['ACTIVE', 'ERROR']) } In this case, `wait_for` is waiting for the server to become `VERIFY_READY` and will raise an exception if we enter an `ACTIVE` or `ERROR` state. Once a server enters the `VERIFY_RESIZE` we will need to call `confirm_resize` to confirm the server was properly resized or `revert_resize` to rollback to the old size/flavor. **Note:** A server will automatically confirm resize after 24 hours. To confirm resize: server.confirm_resize To revert to previous size/flavor: server.revert_resize ## Create Image To create an image of your server: image = server.create_image "back-image-#{server.name}", :metadata => { :environment => 'development' } You can use the second parameter to specify image metadata. This is an optional parameter. During the imaging process, the image state will be `SAVING`. The image is ready for use when when state `ACTIVE` is reached. Fog can use `wait_for` to wait for an active state as follows: image.wait_for { ready? } ## List Attached Volumes To list Cloud Block Volumes attached to server: server.attachments ## Attach Volume To attach volume using the volume id: server.attach_volume "0e7a706c-340d-48b3-802d-192850387f93" If the volume id is unknown you can look it up using the Cloud Block Storage service. Start by creating a `cbs_service` similar to our Compute Service: cbs_service = Fog::Rackspace::BlockStorage.new({ :rackspace_username => RACKSPACE_USER_NAME, # Your Rackspace Username :rackspace_api_key => RACKSPACE_API # Your Rackspace API key }) volume = cbs_service.volumes.first server.attach_volume volume, "/dev/xvdb" # name of device on server is optional The `attach_volume` method accepts a volume id `String` or `Fog::Rackspace::BlockStorage::Volume` instance. This example also demonstrates passing in the optional device name. Valid device names are `/dev/xvd[a-p]`. ## Detach Volume To detach a volume: server.attachments.first.detach ## Examples Example code using Next Gen Cloud Servers can be found [here](https://github.com/fog/fog/tree/master/lib/fog/rackspace/examples). ## Additional Resources * [fog.io](http://fog.io/) * [Fog rdoc](http://rubydoc.info/gems/fog/) * [Fog Github repo](https://github.com/fog/fog) * [Fog Github Issues](https://github.com/fog/fog/issues) * [Excon Github repo](https://github.com/geemus/excon) * [Next Gen Cloud Servers API](http://docs.rackspace.com/servers/api/v2/cs-devguide/content/ch_preface.html) ## Support and Feedback Your feedback is appreciated! If you have specific issues with the **fog** SDK, you should file an [issue via Github](https://github.com/fog/fog/issues). For general feedback and support requests, send an email to: .