--- stage: Verify group: Continuous Integration info: 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 type: reference --- # Where variables can be used As it's described in the [CI/CD variables](README.md) docs, you can define many different variables. Some of them can be used for all GitLab CI/CD features, but some of them are more or less limited. This document describes where and how the different types of variables can be used. ## Variables usage There are two places defined variables can be used. On the: 1. GitLab side, in `.gitlab-ci.yml`. 1. The runner side, in `config.toml`. ### `.gitlab-ci.yml` file | Definition | Can be expanded? | Expansion place | Description | |:-------------------------------------------|:-----------------|:-----------------------|:----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | `environment:url` | yes | GitLab | The variable expansion is made by GitLab's [internal variable expansion mechanism](#gitlab-internal-variable-expansion-mechanism).

Supported are all variables defined for a job (project/group variables, variables from `.gitlab-ci.yml`, variables from triggers, variables from pipeline schedules).

Not supported are variables defined in Runner's `config.toml` and variables created in job's `script`. | | `environment:name` | yes | GitLab | Similar to `environment:url`, but the variables expansion doesn't support the following:

- Variables that are based on the environment's name (`CI_ENVIRONMENT_NAME`, `CI_ENVIRONMENT_SLUG`).
- Any other variables related to environment (currently only `CI_ENVIRONMENT_URL`).
- [Persisted variables](#persisted-variables). | | `resource_group` | yes | GitLab | Similar to `environment:url`, but the variables expansion doesn't support the following:

- Variables that are based on the environment's name (`CI_ENVIRONMENT_NAME`, `CI_ENVIRONMENT_SLUG`).
- Any other variables related to environment (currently only `CI_ENVIRONMENT_URL`).
- [Persisted variables](#persisted-variables). | | `variables` | yes | Runner | The variable expansion is made by GitLab Runner's [internal variable expansion mechanism](#gitlab-runner-internal-variable-expansion-mechanism) | | `image` | yes | Runner | The variable expansion is made by GitLab Runner's [internal variable expansion mechanism](#gitlab-runner-internal-variable-expansion-mechanism) | | `services:[]` | yes | Runner | The variable expansion is made by GitLab Runner's [internal variable expansion mechanism](#gitlab-runner-internal-variable-expansion-mechanism) | | `services:[]:name` | yes | Runner | The variable expansion is made by GitLab Runner's [internal variable expansion mechanism](#gitlab-runner-internal-variable-expansion-mechanism) | | `cache:key` | yes | Runner | The variable expansion is made by GitLab Runner's [internal variable expansion mechanism](#gitlab-runner-internal-variable-expansion-mechanism) | | `artifacts:name` | yes | Runner | The variable expansion is made by GitLab Runner's shell environment | | `script`, `before_script`, `after_script` | yes | Script execution shell | The variable expansion is made by the [execution shell environment](#execution-shell-environment) | | `only:variables:[]`, `except:variables:[]` | no | n/a | The variable must be in the form of `$variable`. Not supported are the following:

- Variables that are based on the environment's name (`CI_ENVIRONMENT_NAME`, `CI_ENVIRONMENT_SLUG`).
- Any other variables related to environment (currently only `CI_ENVIRONMENT_URL`).
- [Persisted variables](#persisted-variables). | ### `config.toml` file NOTE: **Note:** You can read more about `config.toml` in the [Runner's docs](https://docs.gitlab.com/runner/configuration/advanced-configuration.html). | Definition | Can be expanded? | Description | |:-------------------------------------|:-----------------|:---------------------------------------------------------------------------------------------------------------------------------------------| | `runners.environment` | yes | The variable expansion is made by the Runner's [internal variable expansion mechanism](#gitlab-runner-internal-variable-expansion-mechanism) | | `runners.kubernetes.pod_labels` | yes | The Variable expansion is made by the Runner's [internal variable expansion mechanism](#gitlab-runner-internal-variable-expansion-mechanism) | | `runners.kubernetes.pod_annotations` | yes | The Variable expansion is made by the Runner's [internal variable expansion mechanism](#gitlab-runner-internal-variable-expansion-mechanism) | ## Expansion mechanisms There are three expansion mechanisms: - GitLab - GitLab Runner - Execution shell environment ### GitLab internal variable expansion mechanism The expanded part needs to be in a form of `$variable`, or `${variable}` or `%variable%`. Each form is handled in the same way, no matter which OS/shell will finally handle the job, since the expansion is done in GitLab before any Runner will get the job. ### GitLab Runner internal variable expansion mechanism - Supported: project/group variables, `.gitlab-ci.yml` variables, `config.toml` variables, and variables from triggers, pipeline schedules, and manual pipelines. - Not supported: variables defined inside of scripts (e.g., `export MY_VARIABLE="test"`). The Runner uses Go's `os.Expand()` method for variable expansion. It means that it will handle only variables defined as `$variable` and `${variable}`. What's also important, is that the expansion is done only once, so nested variables may or may not work, depending on the ordering of variables definitions. ### Execution shell environment This is an expansion that takes place during the `script` execution. How it works depends on the used shell (`bash`, `sh`, `cmd`, PowerShell). For example, if the job's `script` contains a line `echo $MY_VARIABLE-${MY_VARIABLE_2}`, it should be properly handled by bash/sh (leaving empty strings or some values depending whether the variables were defined or not), but will not work with Windows' `cmd` or PowerShell, since these shells are using a different variables syntax. Supported: - The `script` may use all available variables that are default for the shell (e.g., `$PATH` which should be present in all bash/sh shells) and all variables defined by GitLab CI/CD (project/group variables, `.gitlab-ci.yml` variables, `config.toml` variables, and variables from triggers and pipeline schedules). - The `script` may also use all variables defined in the lines before. So, for example, if you define a variable `export MY_VARIABLE="test"`: - In `before_script`, it will work in the following lines of `before_script` and all lines of the related `script`. - In `script`, it will work in the following lines of `script`. - In `after_script`, it will work in following lines of `after_script`. In the case of `after_script` scripts, they can: - Only use variables defined before the script within the same `after_script` section. - Not use variables defined in `before_script` and `script`. These restrictions are because `after_script` scripts are executed in a [separated shell context](../yaml/README.md#before_script-and-after_script). ## Persisted variables NOTE: **Note:** Some of the persisted variables contain tokens and cannot be used by some definitions due to security reasons. The following variables are known as "persisted": - `CI_PIPELINE_ID` - `CI_JOB_ID` - `CI_JOB_TOKEN` - `CI_BUILD_ID` - `CI_BUILD_TOKEN` - `CI_REGISTRY_USER` - `CI_REGISTRY_PASSWORD` - `CI_REPOSITORY_URL` - `CI_DEPLOY_USER` - `CI_DEPLOY_PASSWORD` They are: - Supported for definitions where the ["Expansion place"](#gitlab-ciyml-file) is: - Runner. - Script execution shell. - Not supported: - For definitions where the ["Expansion place"](#gitlab-ciyml-file) is GitLab. - In the `only` and `except` [variables expressions](README.md#environment-variables-expressions). ## Variables with an environment scope Variables defined with an environment scope are supported. Given that there is a variable `$STAGING_SECRET` defined in a scope of `review/staging/*`, the following job that is using dynamic environments is going to be created, based on the matching variable expression: ```yaml my-job: stage: staging environment: name: review/$CI_JOB_STAGE/deploy script: - 'deploy staging' only: variables: - $STAGING_SECRET == 'something' ```