Consul

This is a Consul client.

• Documentation
• License

Documentation

See the official HTTP API docs for more information.

• Consul
  • Callback
  • Promise
  • Common Method Call Options
• ACL
• Agent
  • Check
  • Service
• Catalog
  • Connect
  • Node
  • Service
• Event
• Health
• KV
• Lock
• Query
• Session
• Status
• Transaction
• Watch

consul([options])

Initialize a new Consul client.

Options

• host (String, default: 127.0.0.1): agent address
• port (Integer, default: 8500): agent HTTP(S) port
• secure (Boolean, default: false): enable HTTPS
• ca (String[], optional): array of strings or Buffers of trusted certificates in PEM format
• defaults (Object, optional): common method call options that will be included with every call (ex: set default token), these options can be override on a per call basis
• promisify (Boolean|Function, optional): convert callback methods to promises

Usage

var consul = require('consul')();

Callback

All callback methods have the following signature function(err, data, res).

• err (Error, optional): set if there was an error, otherwise falsy
• data (Object, optional): response data if any, otherwise undefined
• res (http.IncomingMessage, optional): HTTP response object with additional body property. This might not exist when err is set. The body property can be a decoded object, string, or Buffer.

Promise

Promise support can be enabled by setting promisify to true in Node >= 0.12 or passing a wrapper (ex: bluebird.fromCallback) in older versions.

If you need access to the res object you can create a custom wrapper (see example below).

Common Method Call Options

These options can be included with any method call, although only certain endpoints support them. See the HTTP API for more information.

• dc (String, optional): datacenter (defaults to local for agent)
• wan (Boolean, default: false): return WAN members instead of LAN members
• consistent (Boolean, default: false): require strong consistency
• stale (Boolean, default: false): use whatever is available, can be arbitrarily stale
• index (String, optional): used with ModifyIndex to block and wait for changes
• wait (String, optional): limit how long to wait for changes (ex: 5m), used with index
• token (String, optional): ACL token
• near (String, optional): used to sort the node list in ascending order based on the estimated round trip time from that node
• node-meta (String[], optional): used to specify a desired node metadata key/value pair of the form key:value
• filter (String, optional): used to refine a data query for some API listing endpoints

These options work for all methods.

• ctx (EventEmitter, optional): emit cancel to abort request
• timeout (Number|String, optional): number of milliseconds before request is aborted (ex: 1000 or 1s)

consul.acl

• bootstrap
• create
• update
• destroy
• get
• clone
• list
• replication

consul.acl.bootstrap(callback)

Creates one-time management token if not configured.

Usage

consul.acl.bootstrap(function(err, result) {
  if (err) throw err;
});

Result

{
  "ID": "adf4238a-882b-9ddc-4a9d-5b6758e4159e"
}

consul.acl.create([options], callback)

Creates a new token with policy.

Options

• name (String, optional): human readable name for the token
• type (String, enum: client, management; default: client): type of token
• rules (String, optional): string encoded HCL or JSON

Usage

consul.acl.create(function(err, result) {
  if (err) throw err;
});

Result

{
  "ID": "b1f4c10e-b61b-e1de-de95-218c9fefdd3e"
}

consul.acl.update(options, callback)

Update the policy of a token.

Options

• id (String): token ID
• name (String, optional): human readable name for the token
• type (String, enum: client, management; default: client): type of token
• rules (String, optional): string encoded HCL or JSON

Usage

consul.acl.update({ id: '63e1d82e-f718-eb92-3b7d-61f0c71d45b4', name: 'test' }, function(err) {
  if (err) throw err;
});

consul.acl.destroy(options, callback)

Destroys a given token.

Options

• id (String): token ID

Usage

consul.acl.destroy('b1f4c10e-b61b-e1de-de95-218c9fefdd3e', function(err) {
  if (err) throw err;
});

consul.acl.get(options, callback)

Queries the policy of a given token.

Options

• id (String): token ID

Usage

consul.acl.get('63e1d82e-f718-eb92-3b7d-61f0c71d45b4', function(err, result) {
  if (err) throw err;
});

Result

{
  "CreateIndex": 7,
  "ModifyIndex": 7,
  "ID": "63e1d82e-f718-eb92-3b7d-61f0c71d45b4",
  "Name": "Read only",
  "Type": "client",
  "Rules": "{\"key\":{\"\":{\"policy\":\"read\"}}}"
}

consul.acl.clone(options, callback)

Creates a new token by cloning an existing token.

Options

• id (String): token ID

Usage

consul.acl.clone('63e1d82e-f718-eb92-3b7d-61f0c71d45b4', function(err) {
  if (err) throw err;
});

Result

{
  "ID": "9fb8b20b-2636-adbb-9b99-d879df3305ec"
}

consul.acl.list([options], callback)

Lists all the active tokens.

Usage

consul.acl.list(function(err, result) {
  if (err) throw err;
});

Result

[
  {
    "CreateIndex": 2,
    "ModifyIndex": 2,
    "ID": "anonymous",
    "Name": "Anonymous Token",
    "Type": "client",
    "Rules": ""
  }
  {
    "CreateIndex": 3,
    "ModifyIndex": 3,
    "ID": "root",
    "Name": "Master Token",
    "Type": "management",
    "Rules": ""
  }
]

consul.acl.replication([options], callback)

Get the status of the ACL replication process in the datacenter.

Usage

consul.acl.replication(function(err, result) {
  if (err) throw err;
});

Result

{
  "Enabled": true,
  "Running": true,
  "SourceDatacenter": "dc1",
  "ReplicatedIndex": 1976,
  "LastSuccess": "2016-08-05T06:28:58Z",
  "LastError": "2016-08-05T06:28:28Z"
}

consul.agent

• check
• service
• members
• reload
• self
• maintenance
• join
• forceLeave

consul.agent.members([options], callback)

Returns the members as seen by the consul agent.

Options

• wan (Boolean, default: false): return WAN members instead of LAN members

Usage

consul.agent.members(function(err, result) {
  if (err) throw err;
});

Result

[
  {
    "Name": "node1",
    "Addr": "127.0.0.1",
    "Port": 8301,
    "Tags": {
      "bootstrap": "1",
      "build": "0.3.0:441d613e",
      "dc": "dc1",
      "port": "8300",
      "role": "consul",
      "vsn": "2",
      "vsn_max": "2",
      "vsn_min": "1"
    },
    "Status": 1,
    "ProtocolMin": 1,
    "ProtocolMax": 2,
    "ProtocolCur": 2,
    "DelegateMin": 2,
    "DelegateMax": 4,
    "DelegateCur": 4
  }
]

consul.agent.reload([options], callback)

Reload agent configuration.

Usage

consul.agent.reload(function(err, result) {
  if (err) throw err;
});

consul.agent.self(callback)

Returns the agent node configuration.

Usage

consul.agent.self(function(err, result) {
  if (err) throw err;
});

Result

{
  "Config": {
    "Bootstrap": true,
    "Server": true,
    "Datacenter": "dc1",
    "DataDir": "/tmp/node1/data",
    "DNSRecursor": "",
    "DNSConfig": {
      "NodeTTL": 0,
      "ServiceTTL": null,
      "AllowStale": false,
      "MaxStale": 5000000000
    },
    "Domain": "consul.",
    "LogLevel": "INFO",
    "NodeName": "node1",
    "ClientAddr": "127.0.0.1",
    "BindAddr": "127.0.0.1",
    "AdvertiseAddr": "127.0.0.1",
    "Ports": {
      "DNS": 8600,
      "HTTP": 8500,
      "RPC": 8400,
      "SerfLan": 8301,
      "SerfWan": 8302,
      "Server": 8300
    },
    "LeaveOnTerm": false,
    "SkipLeaveOnInt": false,
    "StatsiteAddr": "",
    "Protocol": 2,
    "EnableDebug": false,
    "VerifyIncoming": false,
    "VerifyOutgoing": false,
    "CAFile": "",
    "CertFile": "",
    "KeyFile": "",
    "ServerName": "",
    "StartJoin": [],
    "UiDir": "",
    "PidFile": "/tmp/node1/pid",
    "EnableSyslog": false,
    "SyslogFacility": "LOCAL0",
    "RejoinAfterLeave": false,
    "CheckUpdateInterval": 300000000000,
    "Revision": "441d613e1bd96254c78c46ee7c1b35c161fc7295+CHANGES",
    "Version": "0.3.0",
    "VersionPrerelease": ""
  },
  "Member": {
    "Name": "node1",
    "Addr": "127.0.0.1",
    "Port": 8301,
    "Tags": {
      "bootstrap": "1",
      "build": "0.3.0:441d613e",
      "dc": "dc1",
      "port": "8300",
      "role": "consul",
      "vsn": "2",
      "vsn_max": "2",
      "vsn_min": "1"
    },
    "Status": 1,
    "ProtocolMin": 1,
    "ProtocolMax": 2,
    "ProtocolCur": 2,
    "DelegateMin": 2,
    "DelegateMax": 4,
    "DelegateCur": 4
  }
}

consul.agent.maintenance(options, callback)

Set node maintenance mode.

Options

• enable (Boolean): maintenance mode enabled
• reason (String, optional): human readable reason for maintenance

Usage

consul.agent.maintenance(true, function(err) {
  if (err) throw err;
});

consul.agent.join(options, callback)

Trigger agent to join a node.

Options

• address (String): node IP address to join
• wan (Boolean, default false): attempt to join using the WAN pool

Usage

consul.agent.join('127.0.0.2', function(err) {
  if (err) throw err;
});

consul.agent.forceLeave(options, callback)

Force remove node.

Options

• node (String): node name to remove

Usage

consul.agent.forceLeave('node2', function(err) {
  if (err) throw err;
});

consul.agent.check

• list
• register
• deregister
• pass
• warn
• fail

consul.agent.check.list(callback)

Returns the checks the agent is managing.

Usage

consul.agent.check.list(function(err, result) {
  if (err) throw err;
});

Result

{
  "example": {
    "Node": "node1",
    "CheckID": "example",
    "Name": "example",
    "Status": "passing",
    "Notes": "This is an example check.",
    "Output": "",
    "ServiceID": "",
    "ServiceName": ""
  }
}

consul.agent.check.register(options, callback)

Registers a new check.

Options

• name (String): check name
• id (String, optional): check ID
• serviceid (String, optional): service ID, associate check with existing service
• http (String): url to test, 2xx passes, 429 warns, and all others fail
• tlsskipverify (Boolean, default: false): skip HTTPS verification
• tcp (String): host:port to test, passes if connection is established, fails otherwise
• args (String[]): path to check script, requires interval
• script (String): path to check script, requires interval (DEPRECATED)
• dockercontainerid (String, optional): Docker container ID to run script
• grpc (String, optional): gRPC endpoint (ex: 127.0.0.1:12345)
• grpcusetls (Boolean, optional): enable TLS for gRPC check
• shell (String, optional): shell in which to run script (currently only supported with Docker)
• interval (String): interval to run check, requires script (ex: 15s)
• timeout (String, optional): timeout for the check (ex: 10s)
• ttl (String): time to live before check must be updated (ex: 60s)
• aliasnode (String): ID of a node for an alias check (ex: web1)
• aliasservice (String): ID of a service for an alias check (ex: web)
• notes (String, optional): human readable description of check
• status (String, optional): initial service status
• deregistercriticalserviceafter (String, optional, Consul 0.7+): timeout after which to automatically deregister service if check remains in critical state

Usage

var check = {
  name: 'example',
  ttl: '15s',
  notes: 'This is an example check.',
};

consul.agent.check.register(check, function(err) {
  if (err) throw err;
});

consul.agent.check.deregister(options, callback)

Deregister a check.

Options

• id (String): check ID

Usage

consul.agent.check.deregister('example', function(err) {
  if (err) throw err;
});

consul.agent.check.pass(options, callback)

Mark a test as passing.

Options

• id (String): check ID
• note (String, optional): human readable message

Usage

consul.agent.check.pass('example', function(err) {
  if (err) throw err;
});

consul.agent.check.warn(options, callback)

Mark a test as warning.

Options

• id (String): check ID
• note (String, optional): human readable message

Usage

consul.agent.check.warn('example', function(err) {
  if (err) throw err;
});

consul.agent.check.fail(options, callback)

Mark a test as critical.

Options

• id (String): check ID
• note (String, optional): human readable message

Usage

consul.agent.check.fail('example', function(err) {
  if (err) throw err;
});

consul.agent.service

• list
• register
• deregister
• maintenance

consul.agent.service.list(callback)

Returns the services the agent is managing.

Usage

consul.agent.service.list(function(err, result) {
  if (err) throw err;
});

Result

{
  "example": {
    "ID": "example",
    "Service": "example",
    "Tags": [
      "dev",
      "web"
    ],
    "Port": 80
  }
}

consul.agent.service.register(options, callback)

Registers a new service.

Options

• name (String): service name
• id (String, optional): service ID
• tags (String[], optional): service tags
• address (String, optional): service IP address
• port (Integer, optional): service port
• meta (Object, optional): metadata linked to the service instance
• check (Object, optional): service check
  • http (String): URL endpoint, requires interval
  • tcp (String): host:port to test, passes if connection is established, fails otherwise
  • script (String): path to check script, requires interval
  • dockercontainerid (String, optional): Docker container ID to run script
  • shell (String, optional): shell in which to run script (currently only supported with Docker)
  • interval (String): interval to run check, requires script (ex: 15s)
  • timeout (String, optional): timeout for the check (ex: 10s)
  • ttl (String): time to live before check must be updated, instead of http/tcp/script and interval (ex: 60s)
  • notes (String, optional): human readable description of check
  • status (String, optional): initial service status
  • deregistercriticalserviceafter (String, optional, Consul 0.7+): timeout after which to automatically deregister service if check remains in critical state
• checks (Object[], optional): service checks (see check above)
• connect (Object, optional): specifies the configuration for Connect
• proxy (Object, optional): specifies the configuration for a Connect proxy instance
• taggedAddresses (Object, optional): specifies a map of explicit LAN and WAN addresses for the service instance

Usage

consul.agent.service.register('example', function(err) {
  if (err) throw err;
});

consul.agent.service.deregister(options, callback)

Deregister a service.

Options

• id (String): service ID

Usage

consul.agent.service.deregister('example', function(err) {
  if (err) throw err;
});

consul.agent.service.maintenance(options, callback)

Set service maintenance mode.

Options

• id (String): service ID
• enable (Boolean): maintenance mode enabled
• reason (String, optional): human readable reason for maintenance

Usage

consul.agent.service.maintenance({ id: 'example', enable: true }, function(err) {
  if (err) throw err;
});

consul.catalog

• datacenters
• connect
• node
• service

consul.catalog.datacenters(callback)

Lists known datacenters.

Usage

consul.catalog.datacenters(function(err, result) {
  if (err) throw err;
});

Result

[
  "dc1"
]

consul.catalog.connect

• nodes

consul.catalog.connect.nodes(options, callback)

Lists the nodes for a given Connect-capable service.

Options

• service (String): service name
• dc (String, optional): datacenter (defaults to local for agent)

Usage

consul.catalog.connect.nodes('example', function(err, result) {
  if (err) throw err;
});

Result

[
  {
    "ID": "40e4a748-2192-161a-0510-9bf59fe950b5",
    "Node": "foobar",
    "Address": "192.168.10.10",
    "Datacenter": "dc1",
    "TaggedAddresses": {
      "lan": "192.168.10.10",
      "wan": "10.0.10.10"
    },
    "NodeMeta": {
      "somekey": "somevalue"
    },
    "CreateIndex": 51,
    "ModifyIndex": 51,
    "ServiceAddress": "172.17.0.3",
    "ServiceEnableTagOverride": false,
    "ServiceID": "32a2a47f7992:nodea:5000",
    "ServiceName": "foobar",
    "ServiceKind": "connect-proxy",
    "ServiceProxyDestination": "my-service",
    "ServicePort": 5000,
    "ServiceMeta": {
        "foobar_meta_value": "baz"
    },
    "ServiceTags": [
      "tacos"
    ]
  }
]

consul.catalog.node

• list
• services

consul.catalog.node.list([options], callback)

Lists nodes in a given datacenter.

Options

• dc (String, optional): datacenter (defaults to local for agent)

Usage

consul.catalog.node.list(function(err, result) {
  if (err) throw err;
});

Result

[
  {
    "Node": "node1",
    "Address": "127.0.0.1"
  }
]

consul.catalog.node.services(options, callback)

Lists the services provided by a node.

Options

• node (String): node ID

Usage

consul.catalog.node.services('node1', function(err, result) {
  if (err) throw err;
});

Result

{
  "Node": {
    "Node": "node1",
    "Address": "127.0.0.1"
  },
  "Services": {
    "consul": {
      "ID": "consul",
      "Service": "consul",
      "Tags": [],
      "Port": 8300
    },
    "example": {
      "ID": "example",
      "Service": "example",
      "Tags": [
        "dev",
        "web"
      ],
      "Port": 80
    }
  }
}

consul.catalog.service

• list
• nodes

consul.catalog.service.list([options], callback)

Lists services in a given datacenter.

Options

• dc (String): datacenter (defaults to local for agent)

Usage

consul.catalog.service.list(function(err, result) {
  if (err) throw err;
});

Result

{
  "consul": [],
  "example": [
    "dev",
    "web"
  ]
}

consul.catalog.service.nodes(options, callback)

Lists the nodes for a given service.

Options

• service (String): service name
• dc (String, optional): datacenter (defaults to local for agent)
• tag (String, optional): filter by tag

Usage

consul.catalog.service.nodes('example', function(err, result) {
  if (err) throw err;
});

Result

[
  {
    "Node": "node1",
    "Address": "127.0.0.1",
    "ServiceID": "example",
    "ServiceName": "example",
    "ServiceTags": [
      "dev",
      "web"
    ],
    "ServicePort": 80
  }
]

consul.event

• fire
• list

consul.event.fire(options, callback)

Fires a new user event.

Options

• name (String): event name
• payload (String|Buffer): payload
• node (String, optional): regular expression to filter by node
• service (String, optional): regular expression to filter by service
• tag (String, optional): regular expression to filter by tag

Usage

consul.event.fire('deploy', '53', function(err, result) {
  if (err) throw err;
});

Result

{
  "ID": "4730953b-3135-7ff2-47a7-9d9fc9c4e5a2",
  "Name": "deploy",
  "Payload": "53",
  "NodeFilter": "",
  "ServiceFilter": "",
  "TagFilter": "",
  "Version": 1,
  "LTime": 0
}

consul.event.list([options], callback)

Lists the most recent events an agent has seen.

Options

• name (String, optional): filter by event name

Usage

consul.event.list('deploy', function(err, result) {
  if (err) throw err;
});

Result

[
  {
    "ID": "4730953b-3135-7ff2-47a7-9d9fc9c4e5a2",
    "Name": "deploy",
    "Payload": "53",
    "NodeFilter": "",
    "ServiceFilter": "",
    "TagFilter": "",
    "Version": 1,
    "LTime": 2
  }
]

consul.health

• node
• checks
• service
• state

consul.health.node(options, callback)

Returns the health info of a node.

Options

• node (String): node
• dc (String, optional): datacenter (defaults to local for agent)

Usage

consul.health.node('node1', function(err, result) {
  if (err) throw err;
});

Result

[
  {
    "Node": "node1",
    "CheckID": "serfHealth",
    "Name": "Serf Health Status",
    "Status": "passing",
    "Notes": "",
    "Output": "Agent alive and reachable",
    "ServiceID": "",
    "ServiceName": ""
  },
  {
    "Node": "node1",
    "CheckID": "service:example",
    "Name": "Service 'example' check",
    "Status": "critical",
    "Notes": "",
    "Output": "",
    "ServiceID": "example",
    "ServiceName": "example"
  }
]

consul.health.checks(options, callback)

Returns the checks of a service.

Options

• service (String): service name
• dc (String, optional): datacenter (defaults to local for agent)

Usage

consul.health.checks('example', function(err, result) {
  if (err) throw err;
});

Result

[
  {
    "Node": "node1",
    "CheckID": "service:example",
    "Name": "Service 'example' check",
    "Status": "critical",
    "Notes": "",
    "Output": "",
    "ServiceID": "example",
    "ServiceName": "example"
  }
]

consul.health.service(options, callback)

Returns the nodes and health info of a service.

Options

• service (String): service name
• dc (String, optional): datacenter (defaults to local for agent)
• tag (String, optional): filter by tag
• passing (Boolean, optional): restrict to passing checks

Usage

consul.health.service('example', function(err, result) {
  if (err) throw err;
});

Result

[
  {
    "Node": {
      "Node": "node1",
      "Address": "127.0.0.1"
    },
    "Service": {
      "ID": "example",
      "Service": "example",
      "Tags": [],
      "Port": 0
    },
    "Checks": [
      {
        "Node": "node1",
        "CheckID": "service:example",
        "Name": "Service 'example' check",
        "Status": "critical",
        "Notes": "",
        "Output": "",
        "ServiceID": "example",
        "ServiceName": "example"
      },
      {
        "Node": "node1",
        "CheckID": "serfHealth",
        "Name": "Serf Health Status",
        "Status": "passing",
        "Notes": "",
        "Output": "Agent alive and reachable",
        "ServiceID": "",
        "ServiceName": ""
      }
    ]
  }
]

consul.health.state(options, callback)

Returns the checks in a given state.

Options

• state (String, enum: any, passing, warning, critical): state
• dc (String, optional): datacenter (defaults to local for agent)

Usage

consul.health.state('critical', function(err, result) {
  if (err) throw err;
});

Result

[
  {
    "Node": "node1",
    "CheckID": "service:example",
    "Name": "Service 'example' check",
    "Status": "critical",
    "Notes": "",
    "Output": "",
    "ServiceID": "example",
    "ServiceName": "example"
  }
]

consul.kv

• get
• keys
• set
• del

consul.kv.get(options, callback)

Return key/value (kv) pair(s) or undefined if key not found.

Options

• key (String): path to value
• dc (String, optional): datacenter (defaults to local for agent)
• recurse (Boolean, default: false): return all keys with given key prefix
• index (String, optional): used with ModifyIndex to block and wait for changes
• wait (String, optional): limit how long to wait for changes (ex: 5m), used with index
• raw (Boolean, optional): return raw value (can't be used with recursive, implies buffer)
• buffer (Boolean, default: false): decode value into Buffer instead of String

Usage

consul.kv.get('hello', function(err, result) {
  if (err) throw err;
  if (result === undefined) throw new Error('key not found');
});

Result

{
  "CreateIndex": 6,
  "ModifyIndex": 6,
  "LockIndex": 0,
  "Key": "hello",
  "Flags": 0,
  "Value": "world"
}

consul.kv.keys(options, callback)

Return keys for a given prefix.

Options

• key (String): path prefix
• dc (String, optional): datacenter (defaults to local for agent)
• separator (String, optional): list keys up to a given separator

Usage

consul.kv.keys('a/', function(err, result) {
  if (err) throw err;
});

Result

[
  "a/b",
  "a/c"
]

consul.kv.set(options, callback)

Set key/value (kv) pair.

Options

• key (String): key
• value (String|Buffer): value
• dc (String, optional): datacenter (defaults to local for agent)
• flags (Number, optional): unsigned integer opaque to user, can be used by application
• cas (String, optional): use with ModifyIndex to do a check-and-set operation
• acquire (String, optional): session ID, lock acquisition operation
• release (String, optional): session ID, lock release operation

Usage

consul.kv.set('hello', 'world', function(err, result) {
  if (err) throw err;
});

Result

true

consul.kv.del(options, callback)

Delete key/value (kv) pair(s).

Options

• key (String): key
• dc (String, optional): datacenter (defaults to local for agent)
• recurse (Boolean, default: false): delete all keys with given key prefix
• cas (String, optional): use with ModifyIndex to do a check-and-set operation (must be greater than 0)

Usage

consul.kv.del('hello', function(err) {
  if (err) throw err;
});

consul.lock(options)

Experimental

Lock a key using the method described in the leader election guide.

Options

• key (String): lock key
• value (String|Buffer, optional): lock value
• session (Object|String, optional): session options

Events

• acquire: lock successfully acquired
• error: lock related error
• retry: lock retry attempt
• release: lock gracefully released (not always emitted)
• end: lock ended (always emitted)

Usage

var lock = consul.lock({ key: 'test' });

lock.on('acquire', function() {
  console.log('lock acquired');

  lock.release();
});

lock.on('release', function() {
  console.log('lock released');
});

lock.on('error', function() {
  console.log('lock error:', err);
});

lock.on('end', function(err) {
  console.log('lock released or there was a permanent failure');
});

lock.acquire();

Result

lock acquired
lock released
lock released or there was a permanent failure

consul.query

• list
• create
• update
• get
• destroy
• execute
• explain

consul.query.list(callback)

List prepared query.

Usage

consul.query.list(function(err, result) {
  if (err) throw err;
});

Result

[
  {
    "ID": "422b14b9-874b-4520-bd2e-e149a42b0066",
    "Name": "redis",
    "Session": "",
    "Token": "",
    "Template": {
      "Type": "",
      "Regexp":""
    },
    "Service": {
      "Service": "redis",
      "Failover": {
        "NearestN": 3,
        "Datacenters": [
          "dc1",
          "dc2"
        ]
      },
      "OnlyPassing": false,
      "Tags": [
        "master",
        "!experimental"
      ]
    },
    "DNS": {
      "TTL": "10s"
    },
    "RaftIndex": {
      "CreateIndex": 23,
      "ModifyIndex": 42
    }
  }
]

consul.query.create(options, callback)

Create a new prepared query.

Options

• name (String, optional): name that can be used to execute a query instead of using its ID
• session (String, optional): provides a way to automatically remove a prepared query when the given session is invalidated
• token (String, optional): captured ACL Token that is reused as the ACL Token every time the query is executed
• near (String, optional): allows specifying a particular node to sort near based on distance sorting using Network Coordinates
• service.service (String, required): name of the service to query
• service.failover.nearestn (Number, optional): when set the query will be forwarded to up to nearest N other datacenters based on their estimated network round trip time using Network Coordinates from the WAN gossip pool
• service.failover.datacenters (String[], optional): fixed list of remote datacenters to forward the query to if there are no healthy nodes in the local datacenter
• service.onlypassing (Boolean, default: false): filter results to only nodes with a passing state
• service.tags (String[], optional): list of service tags to filter the query results
• ttl.dns (String, optional, ex: 10s): controls how the TTL is set when query results are served over DNS

Usage

var opts = {
  name: 'redis',
  service: {
    service: 'redis'
    onlypassing: true
  },
};

consul.query.create(opts, function(err, result) {
  if (err) throw err;
});

Result

{
  "ID": "422b14b9-874b-4520-bd2e-e149a42b0066"
}

consul.query.update(options, callback)

Update existing prepared query.

Options

• query (String, required): ID of the query

And all [create options][query-create].

Usage

var opts = {
  query: '422b14b9-874b-4520-bd2e-e149a42b0066',
  name: 'redis',
  service: {
    service: 'redis'
    onlypassing: false
  },
};

consul.query.update(opts, function(err, result) {
  if (err) throw err;
});

consul.query.get(options, callback)

Get prepared query.

Options

• query (String, required): ID of the query

Usage

consul.query.get('6119cabf-c052-48fe-9f07-711762e52931', function(err, result) {
  if (err) throw err;
});

Result

{
  "ID": "6119cabf-c052-48fe-9f07-711762e52931",
  "Name": "redis",
  "Session": "",
  "Token": "",
  "Template": {
    "Type": "",
    "Regexp":""
  },
  "Service": {
    "Service": "redis",
    "Failover": {
      "NearestN": 3,
      "Datacenters": [
        "dc1",
        "dc2"
      ]
    },
    "OnlyPassing": false,
    "Tags": [
      "master",
      "!experimental"
    ]
  },
  "DNS": {
    "TTL": "10s"
  },
  "RaftIndex": {
    "CreateIndex": 23,
    "ModifyIndex": 42
  }
}

consul.query.destroy(options, callback)

Delete prepared query.

Options

• query (String, required): ID of the query

Usage

consul.query.destroy('422b14b9-874b-4520-bd2e-e149a42b0066', function(err) {
  if (err) throw err;
});

consul.query.execute(options, callback)

Execute prepared query.

Options

• query (String, required): ID of the query

Usage

consul.query.execute('6119cabf-c052-48fe-9f07-711762e52931', function(err) {
  if (err) throw err;
});

Result

{
  "Service": "redis",
  "Nodes": [
    {
      "Node": {
        "Node": "foobar",
        "Address": "10.1.10.12",
        "TaggedAddresses": {
          "lan": "10.1.10.12",
          "wan": "10.1.10.12"
        }
      },
      "Service": {
        "ID": "redis",
        "Service": "redis",
        "Tags": null,
        "Port": 8000
      },
      "Checks": [
        {
          "Node": "foobar",
          "CheckID": "service:redis",
          "Name": "Service 'redis' check",
          "Status": "passing",
          "Notes": "",
          "Output": "",
          "ServiceID": "redis",
          "ServiceName": "redis"
        },
        {
          "Node": "foobar",
          "CheckID": "serfHealth",
          "Name": "Serf Health Status",
          "Status": "passing",
          "Notes": "",
          "Output": "",
          "ServiceID": "",
          "ServiceName": ""
        }
      ],
      "DNS": {
        "TTL": "10s"
      },
      "Datacenter": "dc3",
      "Failovers": 2
    }
  ]
}

consul.query.explain(options, callback)

Explain prepared query.

Options

• query (String, required): ID of the query

Usage

consul.query.explain('422b14b9-874b-4520-bd2e-e149a42b0066', function(err, result) {
  if (err) throw err;
  console.log(result);
});

Result

{
  "Query": {
    "ID": "422b14b9-874b-4520-bd2e-e149a42b0066",
    "Name": "redis",
    "Session": "",
    "Token": "",
    "Template": {
      "Type": "",
      "Regexp":""
    },
    "Service": {
      "Service": "redis",
      "Failover": {
        "NearestN": 3,
        "Datacenters": [
          "dc1",
          "dc2"
        ]
      },
      "OnlyPassing": false,
      "Tags": [
        "master",
        "!experimental"
      ]
    },
    "DNS": {
      "TTL": "10s"
    },
    "RaftIndex": {
      "CreateIndex": 23,
      "ModifyIndex": 42
    }
  }
}

consul.session

• create
• destroy
• get
• node
• list
• renew

consul.session.create([options], callback)

Create a new session.

Options

• dc (String, optional): datacenter (defaults to local for agent)
• lockdelay (String, range: 1s-60s, default: 15s): the time consul prevents locks held by the session from being acquired after a session has been invalidated
• name (String, optional): human readable name for the session
• node (String, optional): node with which to associate session (defaults to connected agent)
• checks (String[], optional): checks to associate with session
• behavior (String, enum: release, delete; default: release): controls the behavior when a session is invalidated
• ttl (String, optional, valid: 10s-86400s): interval session must be renewed

Usage

consul.session.create(function(err, result) {
  if (err) throw err;
});

Result

{
  "ID": "a0f5dc05-84c3-5f5a-1d88-05b875e524e1"
}

consul.session.destroy(options, callback)

Destroy a given session.

Options

• id (String): session ID
• dc (String, optional): datacenter (defaults to local for agent)

Usage

consul.session.destroy('a0f5dc05-84c3-5f5a-1d88-05b875e524e1', function(err) {
  if (err) throw err;
});

consul.session.get(options, callback)

Queries a given session.

Options

• id (String): session ID
• dc (String, optional): datacenter (defaults to local for agent)

Usage

consul.session.get('a0f5dc05-84c3-5f5a-1d88-05b875e524e1', function(err, result) {
  if (err) throw err;
});

Result

{
  "CreateIndex": 11,
  "ID": "a0f5dc05-84c3-5f5a-1d88-05b875e524e1",
  "Name": "",
  "Node": "node1",
  "Checks": [
    "serfHealth"
  ],
  "LockDelay": 15000000000
}

consul.session.node(options, callback)

Lists sessions belonging to a node.

Options

• node (String): node
• dc (String, optional): datacenter (defaults to local for agent)

Usage

consul.session.node('node1', function(err, result) {
  if (err) throw err;
});

Result

[
  {
    "CreateIndex": 13,
    "ID": "a0f5dc05-84c3-5f5a-1d88-05b875e524e1",
    "Name": "",
    "Node": "node1",
    "Checks": [
      "serfHealth"
    ],
    "LockDelay": 15000000000
  }
]

consul.session.list([options], callback)

Lists all the active sessions.

Options

• dc (String, optional): datacenter (defaults to local for agent)

Usage

consul.session.list(function(err, result) {
  if (err) throw err;
});

Result

[
  {
    "CreateIndex": 15,
    "ID": "a0f5dc05-84c3-5f5a-1d88-05b875e524e1",
    "Name": "",
    "Node": "node1",
    "Checks": [
      "serfHealth"
    ],
    "LockDelay": 15000000000
  }
]

consul.session.renew(options, callback)

Renew a given session.

Options

• id (String): session ID
• dc (String, optional): datacenter (defaults to local for agent)

Usage

consul.session.renew('a0f5dc05-84c3-5f5a-1d88-05b875e524e1', function(err, renew) {
  if (err) throw err;
});

Result

[
  {
    "CreateIndex": 15,
    "ID": "a0f5dc05-84c3-5f5a-1d88-05b875e524e1",
    "Name": "",
    "Node": "node1",
    "Checks": [
      "serfHealth"
    ],
    "LockDelay": 15000000000,
    "Behavior": "release",
    "TTL": ""
  }
]

consul.status

• leader
• peers

consul.status.leader(callback)

Returns the current Raft leader.

Usage

consul.status.leader(function(err, result) {
  if (err) throw err;
});

Result

"127.0.0.1:8300"

consul.status.peers(callback)

Returns the current Raft peer set.

Usage

consul.status.peers(function(err, result) {
  if (err) throw err;
});

Result

[
  "127.0.0.1:8300"
]

consul.transaction.create(operations, callback)

operations: The body of the request should be a list of operations to perform inside the atomic transaction. Up to 64 operations may be present in a single transaction.

Usage

consul.transaction.create([
  {
    {
      KV: {
        Verb: 'set',
        Key: 'key1',
        Value: Buffer.from('value1').toString('base64')
      }
    },{
      KV: {
        Verb: 'delete',
        Key: 'key2'
      }
    }
  }
]);

consul.watch(options)

Watch an endpoint for changes.

The watch relies on blocking queries, adding the index and wait parameters as per Consul's documentation

If a blocking query is dropped due to a Consul crash or disconnect, watch will attempt to reinitiate the blocking query with logarithmic backoff.

Upon reconnect, unlike the first call to watch() in which the latest x-consul-index is unknown, the last known x-consul-index will be reused, thus not emitting the change event unless it has been incremented since.

NOTE: If you specify an alternative options.timeout keep in mind that a small random amount of additional wait is added to all requests (wait / 16). The default timeout is currently set to (wait + wait * 0.1), you should use something similar to avoid issues.

Options

• method (Function): method to watch
• options (Object): method options
• backoffFactor (Integer, default: 100): backoff factor in milliseconds to apply between attempts (backoffFactor * (2 ^ retry attempt))
• backoffMax (Integer, default: 30000): maximum backoff time in milliseconds to wait between attempts
• maxAttempts (Integer): maximum number of retry attempts to make before giving up

Usage

var watch = consul.watch({
  method: consul.kv.get,
  options: { key: 'test' },
  backoffFactor: 1000,
});

watch.on('change', function(data, res) {
  console.log('data:', data);
});

watch.on('error', function(err) {
  console.log('error:', err);
});

setTimeout(function() { watch.end(); }, 30 * 1000);

Promise Wrapper

var Bluebird = require('bluebird');

function fromCallback(fn) {
  return new Bluebird(function(resolve, reject) {
    try {
      return fn(function(err, data, res) {
        if (err) {
          err.res = res;
          return reject(err);
        }
        return resolve([data, res]);
      });
    } catch (err) {
      return reject(err);
    }
  });
}

var consul = require('consul')({ promisify: fromCallback });

consul.kv.set('test', 'hello world').then(function() {
  consul.kv.keys().spread(function(data, res) {
    console.log('data:', data);
    console.log('headers:', res.headers);
  });
});

Acceptance Tests

1. Install Consul into your PATH

   $ brew install consul

2. Attach required IPs

   $ sudo ifconfig lo0 alias 127.0.0.2 up
   $ sudo ifconfig lo0 alias 127.0.0.3 up

3. Install client dependencies

   $ npm install

4. Run tests

   $ npm run acceptance

License

This work is licensed under the MIT License (see the LICENSE file).

Parts of the Documentation were copied from the official Consul website, see the NOTICE file for license information.