4.9 KiB
| stage | group | info | type |
|---|---|---|---|
| none | unassigned | To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#designated-technical-writers | concepts, howto |
Health Check (CORE ONLY)
- Liveness and readiness probes were introduced in GitLab 9.1.
- The
health_checkendpoint was introduced in GitLab 8.8 and was deprecated in GitLab 9.1.- Access token has been deprecated in GitLab 9.4 in favor of IP whitelist.
GitLab provides liveness and readiness probes to indicate service health and reachability to required services. These probes report on the status of the database connection, Redis connection, and access to the filesystem. These endpoints can be provided to schedulers like Kubernetes to hold traffic until the system is ready or restart the container as needed.
IP whitelist
To access monitoring resources, the requesting client IP needs to be included in a whitelist. For details, see how to add IPs to a whitelist for the monitoring endpoints.
Using the endpoints locally
With default whitelist settings, the probes can be accessed from localhost using the following URLs:
GET http://localhost/-/health
GET http://localhost/-/readiness
GET http://localhost/-/liveness
Health
Checks whether the application server is running.
It does not verify the database or other services
are running. This endpoint circumvents Rails Controllers
and is implemented as additional middleware BasicHealthCheck
very early into the request processing lifecycle.
GET /-/health
Example request:
curl 'https://gitlab.example.com/-/health'
Example response:
GitLab OK
Readiness
The readiness probe checks whether the GitLab instance is ready to accept traffic via Rails Controllers. The check by default does validate only instance-checks.
If the all=1 parameter is specified, the check will also validate
the dependent services (Database, Redis, Gitaly etc.)
and gives a status for each.
GET /-/readiness
GET /-/readiness?all=1
Example request:
curl 'https://gitlab.example.com/-/readiness'
Example response:
{
"master_check":[{
"status":"failed",
"message": "unexpected Master check result: false"
}],
...
}
On failure, the endpoint will return a 503 HTTP status code.
This check does hit the database and Redis if authenticated via token.
This check is being exempt from Rack Attack.
Liveness
DANGER: Warning: In GitLab 12.4 the response body of the Liveness check was changed to match the example below.
Checks whether the application server is running. This probe is used to know if Rails Controllers are not deadlocked due to a multi-threading.
GET /-/liveness
Example request:
curl 'https://gitlab.example.com/-/liveness'
Example response:
On success, the endpoint will return a 200 HTTP status code, and a response like below.
{
"status": "ok"
}
On failure, the endpoint will return a 503 HTTP status code.
This check is being exempt from Rack Attack.
Access token (Deprecated)
NOTE: Note: Access token has been deprecated in GitLab 9.4 in favor of IP whitelist.
An access token needs to be provided while accessing the probe endpoints. The current
accepted token can be found under the Admin Area > Monitoring > Health check
(admin/health_check) page of your GitLab instance.
The access token can be passed as a URL parameter:
https://gitlab.example.com/-/readiness?token=ACCESS_TOKEN
NOTE: Note: In case the database or Redis service are inaccessible, the probe endpoints response is not guaranteed to be correct. You should switch to IP whitelist from deprecated access token to avoid it.