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api Service - Agent - HTTP API api-agent-service The /agent/service endpoints interact with services on the local agent in Consul.

Service - Agent HTTP API

The /agent/service endpoints interact with checks on the local agent in Consul. These should not be confused with services in the catalog.

List Services

This endpoint returns all the services that are registered with the local agent. These services were either provided through configuration files or added dynamically using the HTTP API.

It is important to note that the services known by the agent may be different from those reported by the catalog. This is usually due to changes being made while there is no leader elected. The agent performs active anti-entropy, so in most situations everything will be in sync within a few seconds.

Method Path Produces
GET /agent/services application/json

The table below shows this endpoint's support for blocking queries, consistency modes, and required ACLs.

Blocking Queries Consistency Modes ACL Required
NO none service:read

Sample Request

$ curl \
    http://127.0.0.1:8500/v1/agent/services

Sample Response

{
  "redis": {
    "ID": "redis",
    "Service": "redis",
    "Tags": [],
    "Address": "",
    "Meta": {
      "redis_version": "4.0"
    },
    "Port": 8000
  }
}

Register Service

This endpoint adds a new service, with an optional health check, to the local agent.

The agent is responsible for managing the status of its local services, and for sending updates about its local services to the servers to keep the global catalog in sync.

For "connect-proxy" kind services, the service:write ACL for the ProxyDestination value is also required to register the service.

Method Path Produces
PUT /agent/service/register application/json

The table below shows this endpoint's support for blocking queries, consistency modes, and required ACLs.

Blocking Queries Consistency Modes ACL Required
NO none service:write

Parameters

  • Name (string: <required>) - Specifies the logical name of the service. Many service instances may share the same logical service name.

  • ID (string: "") - Specifies a unique ID for this service. This must be unique per agent. This defaults to the Name parameter if not provided.

  • Tags (array<string>: nil) - Specifies a list of tags to assign to the service. These tags can be used for later filtering and are exposed via the APIs.

  • Address (string: "") - Specifies the address of the service. If not provided, the agent's address is used as the address for the service during DNS queries.

  • Meta (map<string|string>: nil) - Specifies arbitrary KV metadata linked to the service instance.

  • Port (int: 0) - Specifies the port of the service.

  • Kind (string: "") - The kind of service. Defaults to "" which is a typical Consul service. This value may also be "connect-proxy" for services that are Connect-capable proxies representing another service.

  • ProxyDestination (string: "") - For "connect-proxy" Kind services, this must be set to the name of the service that the proxy represents. This service doesn't need to be registered, but the caller must have an ACL token with permissions for this service.

  • Connect (Connect: nil) - Specifies the configuration for Connect. See the Connect structure section for supported fields.

  • Check (Check: nil) - Specifies a check. Please see the check documentation for more information about the accepted fields. If you don't provide a name or id for the check then they will be generated. To provide a custom id and/or name set the CheckID and/or Name field.

  • Checks (array<Check>: nil) - Specifies a list of checks. Please see the check documentation for more information about the accepted fields. If you don't provide a name or id for the check then they will be generated. To provide a custom id and/or name set the CheckID and/or Name field. The automatically generated Name and CheckID depend on the position of the check within the array, so even though the behavior is deterministic, it is recommended for all checks to either let consul set the CheckID by leaving the field empty/omitting it or to provide a unique value.

  • EnableTagOverride (bool: false) - Specifies to disable the anti-entropy feature for this service's tags. If EnableTagOverride is set to true then external agents can update this service in the catalog and modify the tags. Subsequent local sync operations by this agent will ignore the updated tags. For instance, if an external agent modified both the tags and the port for this service and EnableTagOverride was set to true then after the next sync cycle the service's port would revert to the original value but the tags would maintain the updated value. As a counter example, if an external agent modified both the tags and port for this service and EnableTagOverride was set to false then after the next sync cycle the service's port and the tags would revert to the original value and all modifications would be lost.

    It is important to note that this applies only to the locally registered service. If you have multiple nodes all registering the same service their EnableTagOverride configuration and all other service configuration items are independent of one another. Updating the tags for the service registered on one node is independent of the same service (by name) registered on another node. If EnableTagOverride is not specified the default value is false. See anti-entropy syncs for more info.

Connect Structure

For the Connect field, the parameters are:

  • Native (bool: false) - Specifies whether this service supports the Connect protocol natively. If this is true, then Connect proxies, DNS queries, etc. will be able to service discover this service.

Sample Payload

{
  "ID": "redis1",
  "Name": "redis",
  "Tags": [
    "primary",
    "v1"
  ],
  "Address": "127.0.0.1",
  "Port": 8000,
  "Meta": {
    "redis_version": "4.0"
  },
  "EnableTagOverride": false,
  "Check": {
    "DeregisterCriticalServiceAfter": "90m",
    "Args": ["/usr/local/bin/check_redis.py"],
    "HTTP": "http://localhost:5000/health",
    "Interval": "10s",
    "TTL": "15s"
  }
}

Sample Request

$ curl \
    --request PUT \
    --data @payload.json \
    http://127.0.0.1:8500/v1/agent/service/register

Deregister Service

This endpoint removes a service from the local agent. If the service does not exist, no action is taken.

The agent will take care of deregistering the service with the catalog. If there is an associated check, that is also deregistered.

Method Path Produces
PUT /agent/service/deregister/:service_id application/json

The table below shows this endpoint's support for blocking queries, consistency modes, and required ACLs.

Blocking Queries Consistency Modes ACL Required
NO none service:write

Parameters

  • service_id (string: <required>) - Specifies the ID of the service to deregister. This is specified as part of the URL.

Sample Request

$ curl \
    --request PUT \
    http://127.0.0.1:8500/v1/agent/service/deregister/my-service-id

Enable Maintenance Mode

This endpoint places a given service into "maintenance mode". During maintenance mode, the service will be marked as unavailable and will not be present in DNS or API queries. This API call is idempotent. Maintenance mode is persistent and will be automatically restored on agent restart.

Method Path Produces
PUT /agent/service/maintenance/:service_id application/json

The table below shows this endpoint's support for blocking queries, consistency modes, and required ACLs.

Blocking Queries Consistency Modes ACL Required
NO none service:write

Parameters

  • service_id (string: <required>) - Specifies the ID of the service to put in maintenance mode. This is specified as part of the URL.

  • enable (bool: <required>) - Specifies whether to enable or disable maintenance mode. This is specified as part of the URL as a query string parameter.

  • reason (string: "") - Specifies a text string explaining the reason for placing the node into maintenance mode. This is simply to aid human operators. If no reason is provided, a default value will be used instead. This is specified as part of the URL as a query string parameter, and, as such, must be URI-encoded.

Sample Request

$ curl \
    --request PUT \
    http://127.0.0.1:8500/v1/agent/service/maintenance/my-service-id?enable=true&reason=For+the+docs