Analysis

When a service has a metadata resource it typically takes the form of

{
  "metadata": {
    "key1": "value1",
    "key2": "value2"
  }
}

There doesn't seem to be a strong consensus about how the metadata is CRUDed.

The outliers are Orchestration's Software Configuration metadata which seems to describe a concept different from the other services notion of metadata and Object Storage's metadata which does everything with headers.

Current Design

Server

http://developer.openstack.org/api-ref-compute-v2.html#compute_server_metadata

{
  "metadata": {
    "name": "test_server",
    "server_type": "test"
  }
}

Method	Path	Description
GET	/v2/{tenant_id}/servers/{server_id}/metadata	Show server metadata
PUT	/v2/{tenant_id}/servers/{server_id}/metadata	Create or replace server metadata items
POST	/v2/{tenant_id}/servers/{server_id}/metadata	Update server metadata items
GET	/v2/{tenant_id}/servers/{server_id}/metadata/{key}	Show server metadata item details
PUT	/v2/{tenant_id}/servers/{server_id}/metadata/{key}	Create or update server metadata item
DELETE	/v2/{tenant_id}/servers/{server_id}/metadata/{key}	Delete server metadata item

Snapshot

http://developer.openstack.org/api-ref-blockstorage-v2.html#snapshots-v2

{
  "metadata": {
    "key": "v2"
  }
}

Method	Path	Description
GET	/v2/{tenant_id}/snapshots/{snapshot_id}/metadata	Show snapshot metadata
PUT	/v2/{tenant_id}/snapshots/{snapshot_id}/metadata	Update snapshot metadata One or more metadata key and value pairs to set or unset for the snapshot. To unset a metadata key value, specify only the key name. To set a metadata key value, specify the key and value pair.

Stack

http://developer.openstack.org/api-ref-orchestration-v1.html#stack-resources

{
  "metadata": {
    "some_key": "some_value",
    "some_other_key": "some_other_value"
  }
}

Method	Path	Description
GET	/v1/{tenant_id}/stacks/{stack_name}/{stack_id}/resources/{resource_name}/metadata	Show resource metadata

Software Configuration

http://developer.openstack.org/api-ref-orchestration-v1.html#software-config

{
  "metadata": [
    {
      "inputs": [
        {
          "default": null,
          "type": "String",
          "name": "foo",
          "value": "fooooo",
          "description": null
        },
        {
          "default": null,
          "type": "String",
          "name": "bar",
          "value": "baaaaa",
          "description": null
        },
        {
          "type": "String",
          "name": "deploy_server_id",
          "value": "ec14c864-096e-4e27-bb8a-2c2b4dc6f3f5",
          "description": "ID of the server being deployed to"
        },
        {
          "type": "String",
          "name": "deploy_action",
          "value": "CREATE",
          "description": "Name of the current action being deployed"
        },
        {
          "type": "String",
          "name": "deploy_stack_id",
          "value": "a/9bd57090-8954-48ab-bab9-adf9e1ac70fc",
          "description": "ID of the stack this deployment belongs to"
        },
        {
          "type": "String",
          "name": "deploy_resource_name",
          "value": "deployment",
          "description": "Name of this deployment resource in the stack"
        },
        {
          "type": "String",
          "name": "deploy_signal_id",
          "value": "http://192.168.20.103:8000/v1/signal/arn%3Aopenstack%3Aheat%3A%3Ae2a84fbdaeb047ae8da4b503f3b69f1f%3Astacks%2Fa%2F9bd57090-8954-48ab-bab9-adf9e1ac70fc%2Fresources%2Fdeployment?Timestamp=2014-03-19T20%3A30%3A59Z&SignatureMethod=HmacSHA256&AWSAccessKeyId=ca3571413e4a49998d580215517b3685&SignatureVersion=2&Signature=w6Iu%2BNbg86mqwSOUf1GLuKPO7KaD82PiGpL4ig9Q1l4%3D",
          "description": "ID of signal to use for signalling output values"
        }
      ],
      "group": "script",
      "name": "a-config-we5zpvyu7b5o",
      "outputs": [
        {
          "type": "String",
          "name": "result",
          "error_output": false,
          "description": null
        }
      ],
      "options": null,
      "config": "#!/bin/sh -x\necho \"Writing to /tmp/$bar\"\necho $foo > /tmp/$bar\necho -n \"The file /tmp/$bar contains `cat /tmp/$bar` for server $deploy_server_id during $deploy_action\" > $heat_outputs_path.result\necho \"Written to /tmp/$bar\"\necho \"Output to stderr\" 1>&2",
      "id": "3d5ec2a8-7004-43b6-a7f6-542bdbe9d434"
    },
    {
      "inputs": [
        {
          "default": null,
          "type": "String",
          "name": "foo",
          "value": "fu",
          "description": null
        },
        {
          "default": null,
          "type": "String",
          "name": "bar",
          "value": "barmy",
          "description": null
        },
        {
          "type": "String",
          "name": "deploy_server_id",
          "value": "ec14c864-096e-4e27-bb8a-2c2b4dc6f3f5",
          "description": "ID of the server being deployed to"
        },
        {
          "type": "String",
          "name": "deploy_action",
          "value": "CREATE",
          "description": "Name of the current action being deployed"
        },
        {
          "type": "String",
          "name": "deploy_stack_id",
          "value": "a/9bd57090-8954-48ab-bab9-adf9e1ac70fc",
          "description": "ID of the stack this deployment belongs to"
        },
        {
          "type": "String",
          "name": "deploy_resource_name",
          "value": "other_deployment",
          "description": "Name of this deployment resource in the stack"
        },
        {
          "type": "String",
          "name": "deploy_signal_id",
          "value": "http://192.168.20.103:8000/v1/signal/arn%3Aopenstack%3Aheat%3A%3Ae2a84fbdaeb047ae8da4b503f3b69f1f%3Astacks%2Fa%2F9bd57090-8954-48ab-bab9-adf9e1ac70fc%2Fresources%2Fother_deployment?Timestamp=2014-03-19T20%3A30%3A59Z&SignatureMethod=HmacSHA256&AWSAccessKeyId=7b761482f8254946bcd3d5ccb36fe939&SignatureVersion=2&Signature=giMfv%2BhrAw6y%2FCMKQIQz2IhO5PkAj5%2BfP5YsL6rul3o%3D",
          "description": "ID of signal to use for signalling output values"
        }
      ],
      "group": "script",
      "name": "a-config-we5zpvyu7b5o",
      "outputs": [
        {
          "type": "String",
          "name": "result",
          "error_output": false,
          "description": null
        }
      ],
      "options": null,
      "config": "#!/bin/sh -x\necho \"Writing to /tmp/$bar\"\necho $foo > /tmp/$bar\necho -n \"The file /tmp/$bar contains `cat /tmp/$bar` for server $deploy_server_id during $deploy_action\" > $heat_outputs_path.result\necho \"Written to /tmp/$bar\"\necho \"Output to stderr\" 1>&2",
      "id": "8da95794-2ad9-4979-8ae5-739ce314c5cd"
    }
  ]
}

Method	Path	Description
GET	/v1/{tenant_id}/software_deployments/metadata/{server_id}	Show server configuration metadata

Container

http://developer.openstack.org/api-ref-objectstorage-v1.html#storage_container_services

HTTP/1.1 204 No Content
X-Container-Meta-Author: SamuelClemens

Method	Path	Description
POST	/v1/{account}/{container}	Create, update, or delete container metadata
HEAD	/v1/{account}/{container}	Show container metadata

API Special Interest Group/Current Design/Metadata

Contents