.. _Member Methods:

==============
Member Methods
==============

They allow an administrator to configure a cluster, by changing the members of a cluster.
The implementation for member methods follows the specification given in the `etcd members Api <https://coreos.com/etcd/docs/latest/v2/members_api.html>`_.

.. _getMembers:

getMembers
----------

Gets a list of members of an etcd cluster and their details::

  getMembers: Future[EtcdGetMembersResult]

Implemented according to etcd Members API: "`List members <https://coreos.com/etcd/docs/latest/v2/members_api.html#list-members>`_".

**Returns** a Future wrapped around either EtcdGetMembersResponse or EtcdStandardError extending EtcdGetMembersResult.
.. _addMembers:

addMembers
----------

Adds a member to an existing etcd cluster::

  addMember(peerURLs: EtcdMemberForm): Future[EtcdAddMemberResult]

Implemented according to etcd Members API: "`Add a member <https://coreos.com/etcd/docs/latest/v2/members_api.html#add-a-member>`_".

Parameters:

  * **peerURLs:** :ref:`EtcdMemberForm <EtcdMemberForm>`  containing a list of strings representing the peer URLs of the new member.

**Returns** a Future wrapped around either EtcdAddMemberResponse or EtcdStandardError extending EtcdAddMemberResult.

.. _deleteMembers:

deleteMembers
-------------

Deletes a member form an etcd cluster::

  deleteMember(peerID: String): Future[EtcdDefaultResult]

Implemented according to etcd Members API: "`Delete a member <https://coreos.com/etcd/docs/latest/v2/members_api.html#delete-a-member>`_".

Parameters:

  * **peerID:** A string identifying another member of the etcd cluster.

**Returns** a Future wrapped around either EtcdConfirmationResponse or EtcdStandardError extending EtcdConfirmationResult.
.. _changePeerURLs:

changePeerURLs
--------------

Updates the peer URLs of a given member of an etcd cluster::

  changePeerURLs(peerID: String, peerURLs: EtcdMemberForm): Future[EtcdDefaultResult]

Implemented according to etcd Members API: "`Change the peer urls of a member <https://coreos.com/etcd/docs/latest/v2/members_api.html#change-the-peer-urls-of-a-member>`_".

Parameters:

  * **peerID:** A string identifying another member of the etcd cluster.

  * **peerURLs:** :ref:`EtcdMemberForm <EtcdMemberForm>` containing a list of strings representing the new peer URLs that will replace the old ones.

**Returns** aFuture wrapped around either EtcdConfirmationResponse or  EtcdStandardError extending EtcdConfirmationResult.

.. _A possible work flow memberDocs:

A possible work flow
--------------------

The following snippets of code are meant to be read linearly.
Each depends on the previous one.
They present subsequent operations using EtcdClient's member methods.

We start by filling a **EtcdMemberForm** containing a list of peer URLs::

    val newMemberForm: EtcdMemberForm =
      EtcdMemberForm(List("http://10.0.0.10:2380", "http://10.0.0.11:2380"))

When an addMember operation is performed using the form from above, we receive an id, which identifies the new member added::

    val member: Future[String] = for {
      EtcdAddMemberResponse(headers, body) <- etcdcli.addMember(newMemberForm)
    } yield body.id

We can verify that the member was added by listing the members of the cluster::

    val getMembersReq: Future[EtcdGetMembersResult] = for {
      memberID <- member
      membersResp <- etcdcli.getMembers
    } yield membersResp
    val memberAdded: Future[Boolean] = member flatMap {member =>
    getMembersReq.map{
      case EtcdGetMembersResponse(clusterId, body) =>
        // should be true
        body.members.contains(
          EtcdMember(member, "", List("http://10.0.0.10:2380", "http://10.0.0.11:2380"), List ())
          )
    }
    }
But now, suppose we want to change the peer URLs of the recently added member.
We need to fill another **EtcdMemberForm** containing a list of peer URLs that will replace the previous peer URLs::

     val changeMemberForm: EtcdMemberForm = EtcdMemberForm(List("http://10.0.0.12:4002"))

Next we perform a changePeerURLs operation.
After that operation we perform a getMembers operation::

     val changePeerURLReq: Future[EtcdGetMembersResult] = for{
       member <- member
       confirmation <- memberAdded
       changeUrls <- etcdcli.changePeerURLs(member, changeMemberForm)
       membersResp <- etcdcli.getMembers
     } yield membersResp

The getMembers operation performed last can help us check that ``member``'s peer URLs have been modified::

    val memberPeerURLsChanged: Future[Boolean] = member flatMap {member =>
      changePeerURLReq.map{
        case EtcdGetMembersResponse(clusterId, body) =>
          // should be true
          body.members.contains(EtcdMember(member, "", List("http://10.0.0.12:4002"), List()))
      }
    }

Finally, suppose we want to delete the recently added ``member``.
In that case we need to perform a deleteMember operation::

    val deleteMemberReq: Future[EtcdConfirmationResult] = for{
      member <- member
      deleteMember <- etcdcli.deleteMember(member)
    } yield deleteMember

    deleteMemberReq onSuccess{
      case EtcdConfirmationResponse(clusterID) =>
        //shouldBe a EtcdClusterId
        clusterID shouldBe a[EtcdClusterId]
    }