docker-py/docs/swarm.md

275 lines
9.2 KiB
Markdown

# Swarm management
Starting with Engine version 1.12 (API 1.24), it is possible to manage the
engine's associated Swarm cluster using the API.
## Initializing a new Swarm
You can initialize a new Swarm by calling `Client.init_swarm`. An advertising
address needs to be provided, usually simply by indicating which network
interface needs to be used. Advanced options are provided using the
`swarm_spec` parameter, which can easily be created using
`Client.create_swarm_spec`.
```python
spec = client.create_swarm_spec(
snapshot_interval=5000, log_entries_for_slow_followers=1200
)
client.init_swarm(
advertise_addr='eth0', listen_addr='0.0.0.0:5000', force_new_cluster=False,
swarm_spec=spec
)
```
## Joining an existing Swarm
If you're looking to have the engine your client is connected to join an
existing Swarm, this can be accomplished by using the `Client.join_swarm`
method. You will need to provide a list of at least one remote address
corresponding to other machines already part of the swarm as well as the
`join_token`. In most cases, a `listen_addr` and `advertise_addr` for your
node are also required.
```python
client.join_swarm(
remote_addrs=['192.168.14.221:2377'], join_token='SWMTKN-1-redacted',
listen_addr='0.0.0.0:5000', advertise_addr='eth0:5000'
)
```
## Leaving the Swarm
To leave the swarm you are currently a member of, simply use
`Client.leave_swarm`. Note that if your engine is the Swarm's manager,
you will need to specify `force=True` to be able to leave.
```python
client.leave_swarm(force=False)
```
## Retrieving Swarm status
You can retrieve information about your current Swarm status by calling
`Client.inspect_swarm`. This method takes no arguments.
```python
client.inspect_swarm()
```
## Listing Swarm nodes
List all nodes that are part of the current Swarm using `Client.nodes`.
The `filters` argument allows to filter the results.
```python
client.nodes(filters={'role': 'manager'})
```
## Swarm API documentation
### Client.init_swarm
Initialize a new Swarm using the current connected engine as the first node.
**Params:**
* advertise_addr (string): Externally reachable address advertised to other
nodes. This can either be an address/port combination in the form
`192.168.1.1:4567`, or an interface followed by a port number, like
`eth0:4567`. If the port number is omitted, the port number from the listen
address is used. If `advertise_addr` is not specified, it will be
automatically detected when possible. Default: None
* listen_addr (string): Listen address used for inter-manager communication,
as well as determining the networking interface used for the VXLAN Tunnel
Endpoint (VTEP). This can either be an address/port combination in the form
`192.168.1.1:4567`, or an interface followed by a port number, like
`eth0:4567`. If the port number is omitted, the default swarm listening port
is used. Default: '0.0.0.0:2377'
* force_new_cluster (bool): Force creating a new Swarm, even if already part of
one. Default: False
* swarm_spec (dict): Configuration settings of the new Swarm. Use
`Client.create_swarm_spec` to generate a valid configuration. Default: None
**Returns:** `True` if the request went through. Raises an `APIError` if it
fails.
#### Client.create_swarm_spec
Create a `docker.types.SwarmSpec` instance that can be used as the `swarm_spec`
argument in `Client.init_swarm`.
**Params:**
* task_history_retention_limit (int): Maximum number of tasks history stored.
* snapshot_interval (int): Number of logs entries between snapshot.
* keep_old_snapshots (int): Number of snapshots to keep beyond the current
snapshot.
* log_entries_for_slow_followers (int): Number of log entries to keep around
to sync up slow followers after a snapshot is created.
* heartbeat_tick (int): Amount of ticks (in seconds) between each heartbeat.
* election_tick (int): Amount of ticks (in seconds) needed without a leader to
trigger a new election.
* dispatcher_heartbeat_period (int): The delay for an agent to send a
heartbeat to the dispatcher.
* node_cert_expiry (int): Automatic expiry for nodes certificates.
* external_ca (dict): Configuration for forwarding signing requests to an
external certificate authority. Use `docker.types.SwarmExternalCA`.
* name (string): Swarm's name
**Returns:** `docker.types.SwarmSpec` instance.
#### docker.types.SwarmExternalCA
Create a configuration dictionary for the `external_ca` argument in a
`SwarmSpec`.
**Params:**
* protocol (string): Protocol for communication with the external CA (currently
only “cfssl” is supported).
* url (string): URL where certificate signing requests should be sent.
* options (dict): An object with key/value pairs that are interpreted as
protocol-specific options for the external CA driver.
### Client.inspect_node
Retrieve low-level information about a Swarm node
**Params:**
* node_id (string): ID of the node to be inspected.
**Returns:** A dictionary containing data about this node. See sample below.
```python
{u'CreatedAt': u'2016-08-11T23:28:39.695834296Z',
u'Description': {u'Engine': {u'EngineVersion': u'1.12.0',
u'Plugins': [{u'Name': u'bridge', u'Type': u'Network'},
{u'Name': u'host', u'Type': u'Network'},
{u'Name': u'null', u'Type': u'Network'},
{u'Name': u'overlay', u'Type': u'Network'},
{u'Name': u'local', u'Type': u'Volume'}]},
u'Hostname': u'dockerserv-1.local.net',
u'Platform': {u'Architecture': u'x86_64', u'OS': u'linux'},
u'Resources': {u'MemoryBytes': 8052109312, u'NanoCPUs': 4000000000}},
u'ID': u'1kqami616p23dz4hd7km35w63',
u'ManagerStatus': {u'Addr': u'10.0.131.127:2377',
u'Leader': True,
u'Reachability': u'reachable'},
u'Spec': {u'Availability': u'active', u'Role': u'manager'},
u'Status': {u'State': u'ready'},
u'UpdatedAt': u'2016-08-11T23:28:39.979829529Z',
u'Version': {u'Index': 9}}
```
### Client.inspect_swarm
Retrieve information about the current Swarm.
**Returns:** A dictionary containing information about the Swarm. See sample
below.
```python
{u'CreatedAt': u'2016-08-04T21:26:18.779800579Z',
u'ID': u'8hk6e9wh4iq214qtbgvbp84a9',
u'JoinTokens': {u'Manager': u'SWMTKN-1-redacted-1',
u'Worker': u'SWMTKN-1-redacted-2'},
u'Spec': {u'CAConfig': {u'NodeCertExpiry': 7776000000000000},
u'Dispatcher': {u'HeartbeatPeriod': 5000000000},
u'Name': u'default',
u'Orchestration': {u'TaskHistoryRetentionLimit': 10},
u'Raft': {u'ElectionTick': 3,
u'HeartbeatTick': 1,
u'LogEntriesForSlowFollowers': 500,
u'SnapshotInterval': 10000},
u'TaskDefaults': {}},
u'UpdatedAt': u'2016-08-04T21:26:19.391623265Z',
u'Version': {u'Index': 11}}
```
### Client.join_swarm
Join an existing Swarm.
**Params:**
* remote_addrs (list): Addresses of one or more manager nodes already
participating in the Swarm to join.
* join_token (string): Secret token for joining this Swarm.
* listen_addr (string): Listen address used for inter-manager communication
if the node gets promoted to manager, as well as determining the networking
interface used for the VXLAN Tunnel Endpoint (VTEP). Default: `None`
* advertise_addr (string): Externally reachable address advertised to other
nodes. This can either be an address/port combination in the form
`192.168.1.1:4567`, or an interface followed by a port number, like
`eth0:4567`. If the port number is omitted, the port number from the listen
address is used. If AdvertiseAddr is not specified, it will be automatically
detected when possible. Default: `None`
**Returns:** `True` if the request went through. Raises an `APIError` if it
fails.
### Client.leave_swarm
Leave a Swarm.
**Params:**
* force (bool): Leave the Swarm even if this node is a manager.
Default: `False`
**Returns:** `True` if the request went through. Raises an `APIError` if it
fails.
### Client.nodes
List Swarm nodes
**Params:**
* filters (dict): Filters to process on the nodes list. Valid filters:
`id`, `name`, `membership` and `role`. Default: `None`
**Returns:** A list of dictionaries containing data about each swarm node.
### Client.update_node
Update the Node's configuration
**Params:**
* version (int): The version number of the node object being updated. This
is required to avoid conflicting writes.
* node_spec (dict): Configuration settings to update. Any values not provided
will be removed. See the official [Docker API documentation](https://docs.docker.com/engine/reference/api/docker_remote_api_v1.24/#/update-a-node) for more details.
Default: `None`.
**Returns:** `True` if the request went through. Raises an `APIError` if it
fails.
```python
node_spec = {'Availability': 'active',
'Name': 'node-name',
'Role': 'manager',
'Labels': {'foo': 'bar'}
}
client.update_node(node_id='24ifsmvkjbyhk', version=8, node_spec=node_spec)
```
### Client.update_swarm
Update the Swarm's configuration
**Params:**
* version (int): The version number of the swarm object being updated. This
is required to avoid conflicting writes.
* swarm_spec (dict): Configuration settings to update. Use
`Client.create_swarm_spec` to generate a valid configuration.
Default: `None`.
* rotate_worker_token (bool): Rotate the worker join token. Default: `False`.
* rotate_manager_token (bool): Rotate the manager join token. Default: `False`.
**Returns:** `True` if the request went through. Raises an `APIError` if it
fails.