Node aggregates

This spec introduces aggregate concept to Mogan.

Change-Id: I371605d56dc41a39f56dad060f640dad6bf0c6b7
Implements: bp node-aggregate

specs/pike/approved/node-aggregate.rst

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+..
+ This work is licensed under a Creative Commons Attribution 3.0 Unported
+ License.
+
+ http://creativecommons.org/licenses/by/3.0/legalcode
+
+===============
+Node Aggregates
+===============
+
+https://blueprints.launchpad.net/mogan/+spec/node-aggregate
+
+This introduces the concept of aggregate into Mogan, which is quite like Nova
+host aggregate, but we are based on baremetal nodes. Node aggregate allows the
+partition of baremetal nodes into logical groups for server distribution.
+
+
+Problem description
+===================
+
+Currently Mogan only have a concept of availability zones which is for
+providing isolation and redundancy from other availability zones. We need a
+mechanism to further partitioning baremetal nodes.
+
+Use Cases
+---------
+
+* As a cloud operator, I want to classify baremetal nodes based on the
+  location like rack, row, cage, zone, DC.
+
+* As a cloud operator, I want to classify baremetal nodes based on the
+  hardware specs like with GPU, FPGA, ceph storage backend.
+
+
+Proposed change
+===============
+
+* A new mogan.objects.aggregate.Aggregate object would be added to the object
+model.
+
+* Add a set of API that only allow admins to create, delete, and list
+aggregates, also admins should be able to add nodes to the specific aggregate
+and remove nodes from it.
+
+* When do resources update we will cache the resource providers and the map of
+aggregates with resource providers. Add a node list API for admins which will
+derive resource providers from the cache.
+
+* Before scheduling, mogan will handle the flavor resource_aggregates matching
+with node aggregate metadata, then got a list of aggregates, and pass it to
+placement with `member_of` parameter when listing resource providers::
+
+    /resource_providers?member_of=in:{agg1_uuid},{agg2_uuid},{agg3_uuid}
+
+Alternatives
+------------
+
+None
+
+Data model impact
+-----------------
+
+The proposed change will be adding the following fields to the aggregate
+object with their data type and default value for migrations.
+
++-----------------------+--------------+
+| Field Name            | Field Type   |
++=======================+==============+
+|          id           | Integer      |
++-----------------------+--------------+
+|         uuid          | UUID         |
++-----------------------+--------------+
+|         name          | String       |
++-----------------------+--------------+
+|        metadata       | DictOfStrings|
++-----------------------+--------------+
+
+For the database schema, the following table constructs would suffice ::
+
+    op.create_table(
+        'aggregates',
+        sa.Column('created_at', sa.DateTime(), nullable=True),
+        sa.Column('updated_at', sa.DateTime(), nullable=True),
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('uuid', sa.String(length=36), nullable=False),
+        sa.Column('name', sa.String(length=255), nullable=False),
+        sa.PrimaryKeyConstraint('id'),
+        mysql_ENGINE='InnoDB',
+        mysql_DEFAULT_CHARSET='UTF8'
+    )
+
+    op.create_table(
+        'aggregate_metadata',
+        sa.Column('created_at', sa.DateTime(), nullable=True),
+        sa.Column('updated_at', sa.DateTime(), nullable=True),
+        sa.Column('id', sa.Integer(), primary_key=True, nullable=False),
+        sa.Column('key', sa.String(length=255), nullable=False),
+        sa.Column('value', sa.String(length=255), nullable=False),
+        sa.Column('aggregate_id', sa.Integer(), nullable=False),
+        sa.PrimaryKeyConstraint('id'),
+        sa.ForeignKeyConstraint(['aggregate_id'],
+                                ['aggregate.id']),
+        mysql_ENGINE='InnoDB',
+        mysql_DEFAULT_CHARSET='UTF8'
+    )
+
+REST API impact
+---------------
+
+- To create a new aggregate, a user will ::
+
+    POST /v1/aggregates
+
+  With a body containing the JSON description of the aggregate.
+
+  JSON Schema::
+
+    {
+        "type": "object",
+        "properties": {
+            "name": {"type": "string", "minLength": 1, "maxLength": 255},
+            "metadata": {
+                'type': 'object',
+                'patternProperties': {
+                    '^[a-zA-Z0-9-_:. ]{1,255}$': {
+                        'type': 'string', 'maxLength': 255
+                    }
+                },
+                'additionalProperties': False
+            },
+        },
+        "required": ["name"],
+        "additionalProperties": False,
+    }
+
+- To list aggregates, a user will ::
+
+    GET /v1/aggregates
+
+- To show aggregate details, a user will ::
+
+    GET /v1/aggregates/{aggregate_id}
+
+- To update aggregate, a user will ::
+
+    PATCH /v1/aggregates/{aggregate_id}
+
+  With a body containing the JSON description of the fileds to be updated.
+
+  Example Update Aggregate: JSON request::
+
+  [
+      {
+          "op": "replace",
+          "path": "/name",
+          "value": "foo"
+      },
+      {
+          "op": "add",
+          "path": "/metadata/k1",
+          "value": "v1"
+      }
+  ]
+
+- To delete an aggregate, a user will ::
+
+    DELETE /v1/aggregates/{aggregate_id}
+
+- To add nodes to an aggregate, a user will ::
+
+    POST /v1/aggregates/{aggregate_id}/nodes
+
+  With a body containing a list of node uuid to be added to the aggregate.
+
+- To remove node from an aggregate, a user will ::
+
+    DELETE /v1/aggregates/{aggregate_id}/nodes/{node}
+
+- To get nodes from an aggregate, a user will ::
+
+    GET /v1/aggregates/{aggregate_id}/nodes
+
+Security impact
+---------------
+
+None
+
+Notifications impact
+--------------------
+
+None
+
+Other end user impact
+---------------------
+
+None
+
+Performance Impact
+------------------
+
+None
+
+Other deployer impact
+---------------------
+
+None
+
+Developer impact
+----------------
+
+None
+
+Implementation
+==============
+
+Assignee(s)
+-----------
+
+Primary assignee:
+  <niu-zglinux>
+
+Work Items
+----------
+
+* Add aggregate object.
+* Add APIs that allows an admin to add, remove, and list node aggregates.
+* Add APIs that allows an admin to add/remove nodes to an aggregate.
+* Add new CLIs to manage node aggregates.
+
+Dependencies
+============
+
+None
+
+Testing
+=======
+
+Unit Testing will be added.
+
+Documentation Impact
+====================
+
+Docs about node aggregates will be added.
+
+References
+==========
+
+None