2015-08-26 01:42:46 +00:00
|
|
|
# Runners
|
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
In GitLab CI, Runners run the code defined in [`.gitlab-ci.yml`](../yaml/README.md).
|
|
|
|
They are isolated (virtual) machines that pick up jobs through the coordinator
|
|
|
|
API of GitLab CI.
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-02-13 16:59:57 +00:00
|
|
|
A Runner can be specific to a certain project or serve any project
|
|
|
|
in GitLab CI. A Runner that serves all projects is called a shared Runner.
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
Ideally, the GitLab Runner should not be installed on the same machine as GitLab.
|
2017-02-15 18:27:40 +00:00
|
|
|
Read the [requirements documentation](../../install/requirements.md#gitlab-runner)
|
2016-04-11 09:41:27 +00:00
|
|
|
for more information.
|
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
## Shared vs specific Runners
|
|
|
|
|
|
|
|
After [installing the Runner][install], you can either register it as shared or
|
|
|
|
specific. You can only register a shared Runner if you have admin access to
|
|
|
|
the GitLab instance. The main differences between a shared and a specific Runner
|
|
|
|
are:
|
|
|
|
|
|
|
|
- **Shared Runners** are useful for jobs that have similar requirements,
|
|
|
|
between multiple projects. Rather than having multiple Runners idling for
|
|
|
|
many projects, you can have a single or a small number of Runners that handle
|
|
|
|
multiple projects. This makes it easier to maintain and update them.
|
|
|
|
Shared Runners process jobs using a [fair usage queue](#how-shared-runners-pick-jobs).
|
|
|
|
In contrast to specific Runners that use a FIFO queue, this prevents
|
|
|
|
cases where projects create hundreds of jobs which can lead to eating all
|
|
|
|
available shared Runners resources.
|
|
|
|
- **Specific Runners** are useful for jobs that have special requirements or for
|
|
|
|
projects with a specific demand. If a job has certain requirements, you can set
|
|
|
|
up the specific Runner with this in mind, while not having to do this for all
|
|
|
|
Runners. For example, if you want to deploy a certain project, you can setup
|
|
|
|
a specific Runner to have the right credentials for this. The [usage of tags](#using-tags)
|
|
|
|
may be useful in this case. Specific Runners process jobs using a [FIFO] queue.
|
|
|
|
|
|
|
|
A Runner that is specific only runs for the specified project(s). A shared Runner
|
|
|
|
can run jobs for every project that has enabled the option **Allow shared Runners**
|
|
|
|
under **Settings ➔ Pipelines**.
|
|
|
|
|
|
|
|
Projects with high demand of CI activity can also benefit from using specific
|
|
|
|
Runners. By having dedicated Runners you are guaranteed that the Runner is not
|
|
|
|
being held up by another project's jobs.
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-02-13 16:59:57 +00:00
|
|
|
You can set up a specific Runner to be used by multiple projects. The difference
|
|
|
|
with a shared Runner is that you have to enable each project explicitly for
|
|
|
|
the Runner to be able to run its jobs.
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-02-13 16:59:57 +00:00
|
|
|
Specific Runners do not get shared with forked projects automatically.
|
2017-06-06 16:56:30 +00:00
|
|
|
A fork does copy the CI settings (jobs, allow shared, etc) of the cloned
|
|
|
|
repository.
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
## Registering a shared Runner
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
You can only register a shared Runner if you are an admin of the GitLab instance.
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
1. Grab the shared-Runner token on the `admin/runners` page
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
![Shared Runners admin area](img/shared_runners_admin.png)
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
1. [Register the Runner][register]
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
Shared Runners are enabled by default as of GitLab 8.2, but can be disabled
|
|
|
|
with the **Disable shared Runners** button which is present under each project's
|
|
|
|
**Settings ➔ Pipelines** page. Previous versions of GitLab defaulted shared
|
|
|
|
Runners to disabled.
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
## Registering a specific Runner
|
2015-08-26 01:42:46 +00:00
|
|
|
|
|
|
|
Registering a specific can be done in two ways:
|
|
|
|
|
2017-02-13 16:59:57 +00:00
|
|
|
1. Creating a Runner with the project registration token
|
|
|
|
1. Converting a shared Runner into a specific Runner (one-way, admin only)
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
### Registering a specific Runner with a project registration token
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-02-13 16:59:57 +00:00
|
|
|
To create a specific Runner without having admin rights to the GitLab instance,
|
2017-06-06 16:56:30 +00:00
|
|
|
visit the project you want to make the Runner work for in GitLab:
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
1. Go to **Settings ➔ Pipelines** to obtain the token
|
|
|
|
1. [Register the Runner][register]
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
### Making an existing shared Runner specific
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
If you are an admin on your GitLab instance, you can turn any shared Runner into
|
|
|
|
a specific one, but not the other way around. Keep in mind that this is a one
|
|
|
|
way transition.
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
1. Go to the Runners in the admin area **Overview ➔ Runners** (`/admin/runners`)
|
|
|
|
and find your Runner
|
|
|
|
1. Enable any projects under **Restrict projects for this Runner** to be used
|
|
|
|
with the Runner
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
From now on, the shared Runner will be specific to those projects.
|
|
|
|
|
|
|
|
## Locking a specific Runner from being enabled for other projects
|
2016-06-07 14:48:16 +00:00
|
|
|
|
2017-02-13 16:59:57 +00:00
|
|
|
You can configure a Runner to assign it exclusively to a project. When a
|
|
|
|
Runner is locked this way, it can no longer be enabled for other projects.
|
2017-06-06 16:56:30 +00:00
|
|
|
This setting can be enabled the first time you [register a Runner][register] and
|
|
|
|
can be changed afterwards under each Runner's settings.
|
|
|
|
|
|
|
|
To lock/unlock a Runner:
|
|
|
|
|
|
|
|
1. Visit your project's **Settings ➔ Pipelines**
|
|
|
|
1. Find the Runner you wish to lock/unlock and make sure it's enabled
|
|
|
|
1. Click the pencil button
|
|
|
|
1. Check the **Lock to current projects** option
|
|
|
|
1. Click **Save changes** for the changes to take effect
|
2016-06-07 14:48:16 +00:00
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
## How shared Runners pick jobs
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
Shared Runners abide to a process queue we call fair usage. The fair usage
|
|
|
|
algorithm tries to assign jobs to shared Runners from projects that have the
|
|
|
|
lowest number of jobs currently running on shared Runners.
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
**Example 1**
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
We have following jobs in queue:
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-06-15 19:53:44 +00:00
|
|
|
- Job 1 for Project 1
|
|
|
|
- Job 2 for Project 1
|
|
|
|
- Job 3 for Project 1
|
|
|
|
- Job 4 for Project 2
|
|
|
|
- Job 5 for Project 2
|
|
|
|
- Job 6 for Project 3
|
2017-06-06 16:56:30 +00:00
|
|
|
|
|
|
|
With the fair usage algorithm jobs are assigned in following order:
|
|
|
|
|
2017-06-15 19:53:44 +00:00
|
|
|
1. Job 1 is chosen first, because it has the lowest job number from projects with no running jobs (i.e. all projects)
|
|
|
|
1. Job 4 is next, because 4 is now the lowest job number from projects with no running jobs (Project 1 has a job running)
|
|
|
|
1. Job 6 is next, because 6 is now the lowest job number from projects with no running jobs (Projects 1 and 2 have jobs running)
|
|
|
|
1. Job 2 is next, because, of projects with the lowest number of jobs running (each has 1), it is the lowest job number
|
|
|
|
1. Job 5 is next, because Project 1 now has 2 jobs running, and between Projects 2 and 3, Job 5 is the lowest remaining job number
|
|
|
|
1. Lastly we choose Job 3... because it's the only job left
|
2017-06-06 16:56:30 +00:00
|
|
|
|
|
|
|
---
|
|
|
|
|
|
|
|
**Example 2**
|
|
|
|
|
|
|
|
We have following jobs in queue:
|
|
|
|
|
2017-06-15 19:53:44 +00:00
|
|
|
- Job 1 for project 1
|
|
|
|
- Job 2 for project 1
|
|
|
|
- Job 3 for project 1
|
|
|
|
- Job 4 for project 2
|
|
|
|
- Job 5 for project 2
|
|
|
|
- Job 6 for project 3
|
2017-06-06 16:56:30 +00:00
|
|
|
|
|
|
|
With the fair usage algorithm jobs are assigned in following order:
|
|
|
|
|
2017-06-15 19:53:44 +00:00
|
|
|
1. Job 1 is chosen first, because it has the lowest job number from projects with no running jobs (i.e. all projects)
|
2017-06-06 16:56:30 +00:00
|
|
|
1. We finish job 1
|
2017-06-15 19:53:44 +00:00
|
|
|
1. Job 2 is next, because, having finished Job 1, all projects have 0 jobs running again, and 2 is the lowest available job number
|
|
|
|
1. Job 4 is next, because with Project 1 running a job, 4 is the lowest number from projects running no jobs (Projects 2 and 3)
|
2017-06-06 16:56:30 +00:00
|
|
|
1. We finish job 4
|
2017-06-15 19:53:44 +00:00
|
|
|
1. Job 5 is next, because having finished Job 4, Project 2 has no jobs running again
|
|
|
|
1. Job 6 is next, because Project 3 is the only project left with no running jobs
|
|
|
|
1. Lastly we choose Job 3... because, again, it's the only job left (who says 1 is the loneliest number?)
|
2017-06-06 16:56:30 +00:00
|
|
|
|
|
|
|
## Using shared Runners effectively
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-02-13 16:59:57 +00:00
|
|
|
If you are planning to use shared Runners, there are several things you
|
2015-08-26 01:42:46 +00:00
|
|
|
should keep in mind.
|
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
### Using tags
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-02-13 16:59:57 +00:00
|
|
|
You must setup a Runner to be able to run all the different types of jobs
|
2015-08-26 01:42:46 +00:00
|
|
|
that it may encounter on the projects it's shared over. This would be
|
|
|
|
problematic for large amounts of projects, if it wasn't for tags.
|
|
|
|
|
|
|
|
By tagging a Runner for the types of jobs it can handle, you can make sure
|
2017-02-13 16:59:57 +00:00
|
|
|
shared Runners will only run the jobs they are equipped to run.
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-02-13 16:59:57 +00:00
|
|
|
For instance, at GitLab we have Runners tagged with "rails" if they contain
|
2015-08-26 01:42:46 +00:00
|
|
|
the appropriate dependencies to run Rails test suites.
|
|
|
|
|
2017-06-06 16:56:30 +00:00
|
|
|
### Preventing Runners with tags from picking jobs without tags
|
2016-05-06 10:44:20 +00:00
|
|
|
|
2017-02-13 16:59:57 +00:00
|
|
|
You can configure a Runner to prevent it from picking jobs with tags when
|
2017-06-06 16:56:30 +00:00
|
|
|
the Runner does not have tags assigned. This setting can be enabled the first
|
|
|
|
time you [register a Runner][register] and can be changed afterwards under
|
|
|
|
each Runner's settings.
|
|
|
|
|
|
|
|
To make a Runner pick tagged/untagged jobs:
|
|
|
|
|
|
|
|
1. Visit your project's **Settings ➔ Pipelines**
|
|
|
|
1. Find the Runner you wish and make sure it's enabled
|
|
|
|
1. Click the pencil button
|
|
|
|
1. Check the **Run untagged jobs** option
|
|
|
|
1. Click **Save changes** for the changes to take effect
|
2016-05-06 10:44:20 +00:00
|
|
|
|
|
|
|
### Be careful with sensitive information
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-02-13 16:59:57 +00:00
|
|
|
If you can run a job on a Runner, you can get access to any code it runs
|
|
|
|
and get the token of the Runner. With shared Runners, this means that anyone
|
2017-06-06 16:56:30 +00:00
|
|
|
that runs jobs on the Runner, can access anyone else's code that runs on the
|
|
|
|
Runner.
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-02-13 16:59:57 +00:00
|
|
|
In addition, because you can get access to the Runner token, it is possible
|
|
|
|
to create a clone of a Runner and submit false jobs, for example.
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-02-13 16:59:57 +00:00
|
|
|
The above is easily avoided by restricting the usage of shared Runners
|
2015-08-26 01:42:46 +00:00
|
|
|
on large public GitLab instances and controlling access to your GitLab instance.
|
|
|
|
|
|
|
|
### Forks
|
|
|
|
|
|
|
|
Whenever a project is forked, it copies the settings of the jobs that relate
|
2017-02-13 16:59:57 +00:00
|
|
|
to it. This means that if you have shared Runners setup for a project and
|
|
|
|
someone forks that project, the shared Runners will also serve jobs of this
|
2015-08-26 01:42:46 +00:00
|
|
|
project.
|
|
|
|
|
2016-04-11 09:41:27 +00:00
|
|
|
## Attack vectors in Runners
|
2015-08-26 01:42:46 +00:00
|
|
|
|
2017-02-13 16:59:57 +00:00
|
|
|
Mentioned briefly earlier, but the following things of Runners can be exploited.
|
|
|
|
We're always looking for contributions that can mitigate these
|
|
|
|
[Security Considerations](https://docs.gitlab.com/runner/security/).
|
2017-06-06 16:56:30 +00:00
|
|
|
|
|
|
|
[install]: http://docs.gitlab.com/runner/install/
|
|
|
|
[fifo]: https://en.wikipedia.org/wiki/FIFO_(computing_and_electronics)
|
|
|
|
[register]: http://docs.gitlab.com/runner/register/
|