# Environment Variables

Nix GitLab CI is mostly controlled using environment variables.
This page outlines all the variables and their use case.

## `NIX_CI_IMAGE`

|             |                                                                            |
| ----------- | -------------------------------------------------------------------------- |
| Default     | `registry.gitlab.com/technofab/nix-gitlab-ci/nix-ci@$[[ inputs.version ]]` |
| Description | Image to use for the jobs                                                  |

## `NIX_CI_PIPELINE_NAME`

|             |                                                   |
| ----------- | ------------------------------------------------- |
| Default     | N/A                                               |
| Description | Explicitly request a pipeline to be built and ran |
| See also    | [Multi Pipeline](./multi_pipeline.md)             |

## `NIX_CI_DEFAULT_SOURCES`

|             |                                                                                                                                  |
| ----------- | -------------------------------------------------------------------------------------------------------------------------------- |
| Default     | `.*`                                                                                                                             |
| Description | Regex to match `$CI_PIPELINE_SOURCE` against. If it matches, the `default` pipeline will be ran, otherwise `$CI_PIPELINE_SOURCE` |
| See also    | [Multi Pipeline](./multi_pipeline.md)                                                                                            |

## `NIX_CI_FORCE_BUILD`

|             |                                                                                        |
| ----------- | -------------------------------------------------------------------------------------- |
| Default     | N/A                                                                                    |
| Description | Set to any non-empty value to force the `nix-ci:build` job to freshly build the config |
| See also    | [Caching](./caching.md)                                                                |

## `NIX_CI_DISABLE_CACHE`

|             |                                                        |
| ----------- | ------------------------------------------------------ |
| Default     | N/A                                                    |
| Description | Set to any non-empty value to disable caching for jobs |
| See also    | [Caching](./caching.md)                                |

## `NIX_CI_CACHE_STRATEGY`

|             |                                                                                   |
| ----------- | --------------------------------------------------------------------------------- |
| Default     | `$[[ inputs.cache_strategy ]]` -> defaults to `auto`                              |
| Description | Caching strategy to use. `auto` will select the strategy based on runner settings |
| See also    | [Caching](./caching.md)                                                           |

## `NIX_CI_RUNNER_CACHE_STRATEGY`

|             |                                                                  |
| ----------- | ---------------------------------------------------------------- |
| Default     | N/A                                                              |
| Description | Every runner can set it's own preferred cache strategy with this |
| See also    | [Caching](./caching.md)                                          |

## `NIX_CI_DEFAULT_CACHE_STRATEGY`

|             |                                                                                                   |
| ----------- | ------------------------------------------------------------------------------------------------- |
| Default     | `none`                                                                                            |
| Description | If no runner cache strategy is set and the main strategy is set to auto, this will be the default |
| See also    | [Caching](./caching.md)                                                                           |

## `RUNNER_CACHE`

|             |                                        |
| ----------- | -------------------------------------- |
| Default     | `.nix-cache`                           |
| Description | Path to directory for the runner cache |
| See also    | [Caching](./caching.md)                |

## `CACHIX_CACHE`

|             |                                 |
| ----------- | ------------------------------- |
| Default     | N/A                             |
| Description | Name of the cachix cache to use |
| See also    | [Caching](./caching.md)         |

## `ATTIC_CACHE`

|             |                                |
| ----------- | ------------------------------ |
| Default     | N/A                            |
| Description | Name of the attic cache to use |
| See also    | [Caching](./caching.md)        |

## `ATTIC_SERVER`

|             |                         |
| ----------- | ----------------------- |
| Default     | N/A                     |
| Description | URL of the attic server |
| See also    | [Caching](./caching.md) |

## `ATTIC_TOKEN`

|             |                                 |
| ----------- | ------------------------------- |
| Default     | N/A                             |
| Description | API token from the attic server |
| See also    | [Caching](./caching.md)         |