rapi.rst

Ganeti remote API
=================

Documents Ganeti version |version|

.. contents::

Introduction
------------

Ganeti supports a remote API for enable external tools to easily
retrieve information about a cluster's state. The remote API daemon,
*ganeti-rapi*, is automatically started on the master node. By default
it runs on TCP port 5080, but this can be changed either in
``.../constants.py`` or via the command line parameter *-p*. SSL mode,
which is used by default, can also be disabled by passing command line
parameters.

Protocol
--------

The protocol used is JSON_ over HTTP designed after the REST_
principle.

.. _JSON: http://www.json.org/
.. _REST: http://en.wikipedia.org/wiki/Representational_State_Transfer

Generic parameters
------------------

A few parameter mean the same thing across all resources which implement it.

``bulk``
++++++++

Bulk-mode means that for the resources which usually return just a
list of child resources (e.g. ``/2/instances`` which returns just
instance names), the output will instead contain detailed data for all
these subresources. This is more efficient than query-ing the
sub-resources themselves.

``dry-run``
+++++++++++

The optional *dry-run* argument, if provided and set to a positive
integer value (e.g. ``?dry-run=1``), signals to Ganeti that the job
should not be executed, only the pre-execution checks will be done.

This is useful in trying to determine (without guarantees though, as
in the meantime the cluster state could have changed) if the operation
is likely to succeed or at least start executing.

``force``
+++++++++++

Force operation to continue even if it will cause the cluster to become
inconsistent (e.g. because there are not enough master candidates).

Usage examples
--------------

You can access the API using your favorite programming language as
long as it supports network connections.

Shell
+++++

.. highlight:: sh

Using wget::

   wget -q -O - https://CLUSTERNAME:5080/2/info

or curl::

  curl https://CLUSTERNAME:5080/2/info


Python
++++++

.. highlight: python

  import urllib2
  f = urllib2.urlopen('https://CLUSTERNAME:5080/2/info')
  print f.read()


JavaScript
++++++++++

.. warning:: While it's possible to use JavaScript, it poses several
  potential problems, including browser blocking request due to
  non-standard ports or different domain names. Fetching the data on
  the webserver is easier.

.. highlight:: javascript

::

  var url = 'https://CLUSTERNAME:5080/2/info';
  var info;
  var xmlreq = new XMLHttpRequest();
  xmlreq.onreadystatechange = function () {
    if (xmlreq.readyState != 4) return;
    if (xmlreq.status == 200) {
      info = eval("(" + xmlreq.responseText + ")");
      alert(info);
    } else {
      alert('Error fetching cluster info');
    }
    xmlreq = null;
  };
  xmlreq.open('GET', url, true);
  xmlreq.send(null);

Resources
---------

.. highlight:: javascript

``/``
+++++

The root resource.

It supports the following commands: ``GET``.

``GET``
~~~~~~~

Shows the list of mapped resources.

Returns: a dictionary with 'name' and 'uri' keys for each of them.

``/2``
++++++

The ``/2`` resource, the root of the version 2 API.

It supports the following commands: ``GET``.

``GET``
~~~~~~~

Show the list of mapped resources.

Returns: a dictionary with ``name`` and ``uri`` keys for each of them.

``/2/info``
+++++++++++

Cluster information resource.

It supports the following commands: ``GET``.

``GET``
~~~~~~~

Returns cluster information.

Example::

  {
    "config_version": 2000000,
    "name": "cluster",
    "software_version": "2.0.0~beta2",
    "os_api_version": 10,
    "export_version": 0,
    "candidate_pool_size": 10,
    "enabled_hypervisors": [
      "fake"
    ],
    "hvparams": {
      "fake": {}
     },
    "default_hypervisor": "fake",
    "master": "node1.example.com",
    "architecture": [
      "64bit",
      "x86_64"
    ],
    "protocol_version": 20,
    "beparams": {
      "default": {
        "auto_balance": true,
        "vcpus": 1,
        "memory": 128
       }
      }
    }

``/2/instances``
++++++++++++++++

The instances resource.

It supports the following commands: ``GET``, ``POST``.

``GET``
~~~~~~~

Returns a list of all available instances.

Example::

    [
      {
        "name": "web.example.com",
        "uri": "\/instances\/web.example.com"
      },
      {
        "name": "mail.example.com",
        "uri": "\/instances\/mail.example.com"
      }
    ]

If the optional *bulk* argument is provided and set to a true value
(i.e ``?bulk=1``), the output contains detailed information about
instances as a list.

Example::

    [
      {
         "status": "running",
         "disk_usage": 20480,
         "nic.bridges": [
           "xen-br0"
          ],
         "name": "web.example.com",
         "tags": ["tag1", "tag2"],
         "beparams": {
           "vcpus": 2,
           "memory": 512
         },
         "disk.sizes": [
             20480
         ],
         "pnode": "node1.example.com",
         "nic.macs": ["01:23:45:67:89:01"],
         "snodes": ["node2.example.com"],
         "disk_template": "drbd",
         "admin_state": true,
         "os": "debian-etch",
         "oper_state": true
      },
      ...
    ]


``POST``
~~~~~~~~

Creates an instance.

If the optional *dry-run* argument is provided and set to a positive
integer valu (e.g. ``?dry-run=1``), the job will not be actually
executed, only the pre-execution checks will be done. Query-ing the
job result will return, in both dry-run and normal case, the list of
nodes selected for the instance.

Returns: a job ID that can be used later for polling.

``/2/instances/[instance_name]``
++++++++++++++++++++++++++++++++

Instance-specific resource.

It supports the following commands: ``GET``, ``DELETE``.

``GET``
~~~~~~~

Returns information about an instance, similar to the bulk output from
the instance list.

``DELETE``
~~~~~~~~~~

Deletes an instance.

It supports the ``dry-run`` argument.


``/2/instances/[instance_name]/reboot``
+++++++++++++++++++++++++++++++++++++++

Reboots URI for an instance.

It supports the following commands: ``POST``.

``POST``
~~~~~~~~

Reboots the instance.

The URI takes optional ``type=hard|soft|full`` and
``ignore_secondaries=False|True`` parameters.

It supports the ``dry-run`` argument.


``/2/instances/[instance_name]/shutdown``
+++++++++++++++++++++++++++++++++++++++++

Instance shutdown URI.

It supports the following commands: ``PUT``.

``PUT``
~~~~~~~

Shutdowns an instance.

It supports the ``dry-run`` argument.


``/2/instances/[instance_name]/startup``
++++++++++++++++++++++++++++++++++++++++

Instance startup URI.

It supports the following commands: ``PUT``.

``PUT``
~~~~~~~

Startup an instance.

The URI takes an optional ``force=False|True`` parameter to start the
instance if even if secondary disks are failing.

It supports the ``dry-run`` argument.


``/2/instances/[instance_name]/tags``
+++++++++++++++++++++++++++++++++++++

Manages per-instance tags.

It supports the following commands: ``GET``, ``PUT``, ``DELETE``.

``GET``
~~~~~~~

Returns a list of tags.

Example::

    ["tag1", "tag2", "tag3"]

``PUT``
~~~~~~~

Add a set of tags.

The request as a list of strings should be ``PUT`` to this URI. The
result willl be a job id.

It supports the ``dry-run`` argument.


``DELETE``
~~~~~~~~~~

Delete a tag.

In order to delete a set of tags, the DELETE request should be
addressed to URI like::

    /tags?tag=[tag]&tag=[tag]

It supports the ``dry-run`` argument.


``/2/jobs``
+++++++++++

The ``/2/jobs`` resource.

It supports the following commands: ``GET``.

``GET``
~~~~~~~

Returns a dictionary of jobs.

Returns: a dictionary with jobs id and uri.

``/2/jobs/[job_id]``
++++++++++++++++++++


Individual job URI.

It supports the following commands: ``GET``, ``DELETE``.

``GET``
~~~~~~~

Returns a job status.

Returns: a dictionary with job parameters.

The result includes:

- id: job ID as a number
- status: current job status as a string
- ops: involved OpCodes as a list of dictionaries for each
  opcodes in the job
- opstatus: OpCodes status as a list
- opresult: OpCodes results as a list of lists

``DELETE``
~~~~~~~~~~

Cancel a not-yet-started job.

``/2/nodes``
++++++++++++

Nodes resource.

It supports the following commands: ``GET``.

``GET``
~~~~~~~

Returns a list of all nodes.

Example::

    [
      {
        "id": "node1.example.com",
        "uri": "\/instances\/node1.example.com"
      },
      {
        "id": "node2.example.com",
        "uri": "\/instances\/node2.example.com"
      }
    ]

If the optional 'bulk' argument is provided and set to 'true' value
(i.e '?bulk=1'), the output contains detailed information about nodes
as a list.

Example::

    [
      {
        "pinst_cnt": 1,
        "mfree": 31280,
        "mtotal": 32763,
        "name": "www.example.com",
        "tags": [],
        "mnode": 512,
        "dtotal": 5246208,
        "sinst_cnt": 2,
        "dfree": 5171712,
        "offline": false
      },
      ...
    ]

``/2/nodes/[node_name]/tags``
+++++++++++++++++++++++++++++

Manages per-node tags.

It supports the following commands: ``GET``, ``PUT``, ``DELETE``.

``GET``
~~~~~~~

Returns a list of tags.

Example::

    ["tag1", "tag2", "tag3"]

``PUT``
~~~~~~~

Add a set of tags.

The request as a list of strings should be PUT to this URI. The result
will be a job id.

It supports the ``dry-run`` argument.

``DELETE``
~~~~~~~~~~

Deletes tags.

In order to delete a set of tags, the DELETE request should be
addressed to URI like::

    /tags?tag=[tag]&tag=[tag]

It supports the ``dry-run`` argument.


``/2/os``
+++++++++

OS resource.

It supports the following commands: ``GET``.

``GET``
~~~~~~~

Return a list of all OSes.

Can return error 500 in case of a problem. Since this is a costly
operation for Ganeti 2.0, it is not recommended to execute it too
often.

Example::

    ["debian-etch"]

``/2/tags``
+++++++++++

Manages cluster tags.

It supports the following commands: ``GET``, ``PUT``, ``DELETE``.

``GET``
~~~~~~~

Returns the cluster tags.

Example::

    ["tag1", "tag2", "tag3"]

``PUT``
~~~~~~~

Adds a set of tags.

The request as a list of strings should be PUT to this URI. The result
will be a job id.

It supports the ``dry-run`` argument.


``DELETE``
~~~~~~~~~~

Deletes tags.

In order to delete a set of tags, the DELETE request should be
addressed to URI like::

    /tags?tag=[tag]&tag=[tag]

It supports the ``dry-run`` argument.


``/version``
++++++++++++

The version resource.

This resource should be used to determine the remote API version and
to adapt clients accordingly.

It supports the following commands: ``GET``.

``GET``
~~~~~~~

Returns the remote API version. Ganeti 1.2 returned ``1`` and Ganeti
2.0 returns ``2``.