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consul/website/source/api/agent/service.html.md
Grégoire Seux 4f62a3b528 Implement /v1/agent/health/service/<service name> endpoint (#3551) 
This endpoint aggregates all checks related to <service id> on the agent
and return an appropriate http code + the string describing the worst
check.

This allows to cleanly expose service status to other component, hiding
complexity of multiple checks.
This is especially useful to use consul to feed a load balancer which
would delegate health checking to consul agent.

Exposing this endpoint on the agent is necessary to avoid a hit on
consul servers and avoid decreasing resiliency (this endpoint will work
even if there is no consul leader in the cluster).
2019-01-07 09:39:23 -05:00

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---
layout: api
page_title: Service - Agent - HTTP API
sidebar_current: api-agent-service
description: |-
The /agent/service endpoints interact with services on the local agent in
Consul.
---
# Service - Agent HTTP API
The `/agent/service` endpoints interact with services 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](/docs/internals/anti-entropy.html), 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](/api/index.html#blocking-queries),
[consistency modes](/api/index.html#consistency-modes),
[agent caching](/api/index.html#agent-caching), and
[required ACLs](/api/index.html#acls).
| Blocking Queries | Consistency Modes | Agent Caching | ACL Required |
| ---------------- | ----------------- | ------------- | -------------- |
| `NO` | `none` | `none` | `service:read` |
### Sample Request
```text
$ curl \
http://127.0.0.1:8500/v1/agent/services
```
### Sample Response
```json
{
"redis": {
"ID": "redis",
"Service": "redis",
"Tags": [],
"Meta": {
"redis_version": "4.0"
},
"Port": 8000,
"Address": "",
"EnableTagOverride": false,
"Weights": {
"Passing": 10,
"Warning": 1
}
}
}
```
## Get Service Configuration
This endpoint was added in Consul 1.3.0 and returns the full service definition
for a single service instance registered on the local agent. It is used by
[Connect proxies](/docs/connect/proxies.html) to discover the embedded proxy
configuration that was registered with the instance.
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](/docs/internals/anti-entropy.html), so in most situations
everything will be in sync within a few seconds.
| Method | Path | Produces |
| ------ | ---------------------------- | -------------------------- |
| `GET` | `/agent/service/:service_id` | `application/json` |
The table below shows this endpoint's support for
[blocking queries](/api/index.html#blocking-queries),
[consistency modes](/api/index.html#consistency-modes),
[agent caching](/api/index.html#agent-caching), and
[required ACLs](/api/index.html#acls).
| Blocking Queries | Consistency Modes | Agent Caching | ACL Required |
| ---------------- | ----------------- | ------------- | -------------- |
| `YES`<sup>1</sup>| `none` | `none` | `service:read` |
<sup>1</sup> Supports [hash-based
blocking](/api/index.html#hash-based-blocking-queries) only.
### Parameters
- `service_id` `(string: <required>)` - Specifies the ID of the service to
fetch. This is specified as part of the URL.
### Sample Request
```text
$ curl \
http://127.0.0.1:8500/v1/agent/service/web-sidecar-proxy
```
### Sample Response
```json
{
"Kind": "connect-proxy",
"ID": "web-sidecar-proxy",
"Service": "web-sidecar-proxy",
"Tags": null,
"Meta": null,
"Port": 18080,
"Address": "",
"Weights": {
"Passing": 1,
"Warning": 1
},
"EnableTagOverride": false,
"ContentHash": "4ecd29c7bc647ca8",
"Proxy": {
"DestinationServiceName": "web",
"DestinationServiceID": "web",
"LocalServiceAddress": "127.0.0.1",
"LocalServicePort": 8080,
"Config": {
"foo": "bar"
},
"Upstreams": [
{
"DestinationType": "service",
"DestinationName": "db",
"LocalBindPort": 9191
}
]
}
}
```
The response has the same structure as the [service
definition](/docs/agent/services.html) with one extra field `ContentHash` which
contains the [hash-based blocking
query](/api/index.html#hash-based-blocking-queries) hash for the result. The
same hash is also present in `X-Consul-ContentHash`.
## Get local service health
Retrieve an aggregated state of service(s) on the local agent by name.
This endpoints support JSON format and text/plain formats, JSON being the
default. In order to get the text format, you can append `?format=text` to
the URL or use Mime Content negotiation by specifying a HTTP Header
`Accept` starting with `text/plain`.
| Method | Path | Produces |
| ------ | --------------------------------------------------------- | ------------------ |
| `GET` | `/v1/agent/health/service/name/:service_name` | `application/json` |
| `GET` | `/v1/agent/health/service/name/:service_name?format=text` | `text/plain` |
The table below shows this endpoint's support for
[blocking queries](/api/index.html#blocking-queries),
[consistency modes](/api/index.html#consistency-modes),
[agent caching](/api/index.html#agent-caching), and
[required ACLs](/api/index.html#acls).
| Blocking Queries | Consistency Modes | Agent Caching | ACL Required |
| ---------------- | ----------------- | ------------- | -------------- |
| `NO` | `none` | `none` | `service:read` |
Those endpoints return the aggregated values of all healthchecks for the
service instance(s) and will return the corresponding HTTP codes:
| Result | Meaning |
| ------ | ----------------------------------------------------------------|
| `200` | All healthchecks of every matching service instance are passing |
| `400` | Bad parameter (missing service name of id) |
| `404` | No such service id or name |
| `429` | Some healthchecks are passing, at least one is warning |
| `503` | At least one of the healthchecks is critical |
Those endpoints might be usefull for the following use-cases:
* a load-balancer wants to check IP connectivity with an agent and retrieve
the aggregated status of given service
* create aliases for a given service (thus, the healthcheck of alias uses
http://localhost:8500/v1/agent/service/id/aliased_service_id healthcheck)
##### Note
If you know the ID of service you want to target, it is recommended to use
[`/v1/agent/health/service/id/:service_id`](/api/service.html#get-local-service-health-by-id)
so you have the result for the service only. When requesting
`/v1/agent/health/service/name/:service_name`, the caller will receive the
worst state of all services having the given name.
### Sample Requests
Given 2 services with name `web`, with web2 critical and web1 passing:
#### List worst statuses of all instances of web-demo services (HTTP 503)
##### By Name, Text
```shell
curl http://localhost:8500/v1/agent/health/service/name/web?format=text
critical
```
##### By Name, JSON
In JSON, the detail of passing/warning/critical services is present in output,
in a array.
```shell
curl localhost:8500/v1/agent/health/service/name/web
```
```json
{
"critical": [
{
"ID": "web2",
"Service": "web",
"Tags": [
"rails"
],
"Address": "",
"Meta": null,
"Port": 80,
"EnableTagOverride": false,
"ProxyDestination": "",
"Connect": {
"Native": false,
"Proxy": null
},
"CreateIndex": 0,
"ModifyIndex": 0
}
],
"passing": [
{
"ID": "web1",
"Service": "web",
"Tags": [
"rails"
],
"Address": "",
"Meta": null,
"Port": 80,
"EnableTagOverride": false,
"ProxyDestination": "",
"Connect": {
"Native": false,
"Proxy": null
},
"CreateIndex": 0,
"ModifyIndex": 0
}
]
}
```
#### List status of web2 (HTTP 503)
##### Failure By ID, Text
```shell
curl http://localhost:8500/v1/agent/health/service/id/web2?format=text
critical
```
##### Failure By ID, JSON
In JSON, the output per ID is not an array, but only contains the value
of service.
```shell
curl localhost:8500/v1/agent/health/service/id/web2
```
```json
{
"critical": {
"ID": "web2",
"Service": "web",
"Tags": [
"rails"
],
"Address": "",
"Meta": null,
"Port": 80,
"EnableTagOverride": false,
"ProxyDestination": "",
"Connect": {
"Native": false,
"Proxy": null
},
"CreateIndex": 0,
"ModifyIndex": 0
}
}
```
#### List status of web2 (HTTP 200)
##### Success By ID, Text
```shell
curl localhost:8500/v1/agent/health/service/id/web1?format=text
passing
```
#### Success By ID, JSON
```shell
curl localhost:8500/v1/agent/health/service/id/web1
```
```json
{
"passing": {
"ID": "web1",
"Service": "web",
"Tags": [
"rails"
],
"Address": "",
"Meta": null,
"Port": 80,
"EnableTagOverride": false,
"ProxyDestination": "",
"Connect": {
"Native": false,
"Proxy": null
},
"CreateIndex": 0,
"ModifyIndex": 0
}
}
```
## Get local service health by its ID
Retrive an aggregated state of service(s) on the local agent by ID.
See:
| Method | Path | Produces |
| ------ | ------------------------------------------------------ | ------------------ |
| `GET` | `/v1/agent/health/service/id/:service_id` | `application/json` |
| `GET` | `/v1/agent/health/service/id/:service_id?format=text` | `text/plain` |
Parameters and response format are the same as
[`/v1/agent/health/service/name/:service_name`](/api/service.html#get-local-service-health).
## 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
`Proxy.DestinationServiceName` 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](/api/index.html#blocking-queries),
[consistency modes](/api/index.html#consistency-modes),
[agent caching](/api/index.html#agent-caching), and
[required ACLs](/api/index.html#acls).
| Blocking Queries | Consistency Modes | Agent Caching | ACL Required |
| ---------------- | ----------------- | ------------- | --------------- |
| `NO` | `none` | `none` | `service:write` |
### Parameters
Note that this endpoint, unlike most also [supports `snake_case`](/docs/agent/services.html#service-definition-parameter-case)
service definition keys for compatibility with the config file format.
- `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](/docs/connect/index.html)
proxies representing another service.
- `ProxyDestination` `(string: "")` - **Deprecated** From 1.2.0 to 1.2.3 this
was used for "connect-proxy" `Kind` services however the equivalent field is
now in `Proxy.DestinationServiceName`. Registrations using this field will
continue to work until some later major version where this will be removed
entirely. It's strongly recommended to switch to using the new field.
- `Proxy` `(Proxy: nil)` - From 1.2.3 on, specifies the configuration for a
Connect proxy instance. This is only valid if `Kind == "connect-proxy"`. See
the [Proxy documentation](/docs/connect/proxies.html) for full details.
- `Connect` `(Connect: nil)` - Specifies the
[configuration for Connect](/docs/connect/configuration.html). See the
[Connect Structure](#connect-structure) section below for supported fields.
- `Check` `(Check: nil)` - Specifies a check. Please see the
[check documentation](/api/agent/check.html) 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](/api/agent/check.html) 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](/api/catalog.html)
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.
- `Weights` `(Weights: nil)` - Specifies weights for the service. Please see the
[service documentation](/docs/agent/services.html) for more information about
weights. If this field is not provided weights will default to
`{"Passing": 1, "Warning": 1}`.
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](/docs/internals/anti-entropy.html) for
more info.
#### Connect Structure
For the `Connect` field, the parameters are:
- `Native` `(bool: false)` - Specifies whether this service supports
the [Connect](/docs/connect/index.html) protocol [natively](/docs/connect/native.html).
If this is true, then Connect proxies, DNS queries, etc. will be able to
service discover this service.
- `Proxy` `(Proxy: nil)` -
[**Deprecated**](/docs/connect/proxies/managed-deprecated.html) Specifies that
a managed Connect proxy should be started for this service instance, and
optionally provides configuration for the proxy. The format is as documented
in [Managed Proxy Deprecation](/docs/connect/proxies/managed-deprecated.html).
- `SidecarService` `(ServiceDefinition: nil)` - Specifies an optional nested
service definition to register. For more information see
[Sidecar Service Registration](/docs/connect/proxies/sidecar-service.html).
### Sample Payload
```json
{
"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"
},
"Weights": {
"Passing": 10,
"Warning": 1
}
}
```
### Sample Request
```text
$ 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](/api/index.html#blocking-queries),
[consistency modes](/api/index.html#consistency-modes),
[agent caching](/api/index.html#agent-caching), and
[required ACLs](/api/index.html#acls).
| Blocking Queries | Consistency Modes | Agent Caching | ACL Required |
| ---------------- | ----------------- | ------------- | --------------- |
| `NO` | `none` | `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
```text
$ 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](/api/index.html#blocking-queries),
[consistency modes](/api/index.html#consistency-modes),
[agent caching](/api/index.html#agent-caching), and
[required ACLs](/api/index.html#acls).
| Blocking Queries | Consistency Modes | Agent Caching | ACL Required |
| ---------------- | ----------------- | ------------- | --------------- |
| `NO` | `none` | `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
```text
$ curl \
--request PUT \
http://127.0.0.1:8500/v1/agent/service/maintenance/my-service-id?enable=true&reason=For+the+docs
```
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