Environments

Tier: Free, Premium, Ultimate Offering: GitLab.com, Self-managed, GitLab Dedicated

Environments connect GitLab to your infrastructure. An environment:

  • Can monitor and deploy to its target infrastructure.
  • Has its own variables.
  • Can be long-lived or ephemeral, depending on its use case.

In addition, access to an environment can be controlled.

View environments and deployments

Prerequisites:

There are a few ways to view a list of environments for a given project:

  • On the project’s overview page, if at least one environment is available (that is, not stopped). Number of Environments

  • On the left sidebar, select Operate > Environments. The environments are displayed.

    Environments list

  • To view a list of deployments for an environment, select the environment name, for example, staging.

    Deployments list

Deployments show up in this list only after a deployment job has created them.

Environment URL

History

The environment URL is displayed in a few places in GitLab:

  • In a merge request as a link: Environment URL in merge request
  • In the Environments view as a button: Open live environment from environments view
  • In the Deployments view as a button: Environment URL in deployments

You can see this information in a merge request if:

  • The merge request is eventually merged to the default branch (usually main).
  • That branch also deploys to an environment (for example, staging or production).

For example:

Environment URLs in merge request

Go from source files to public pages

With GitLab Route Maps, you can go directly from source files to public pages in the environment set for review apps.

Types of environments

An environment is either static or dynamic.

Static environments:

  • Are usually reused by successive deployments.
  • Have static names. For example, staging or production.
  • Are created manually or as part of a CI/CD pipeline.

Dynamic environments:

  • Are usually created in a CI/CD pipeline and are used by only a single deployment, then either stopped or deleted.
  • Have dynamic names, usually based on the value of a CI/CD variable.
  • Are a feature of review apps.

An environment has one of three states, depending on whether its stop job has run:

  • available: The environment exists. There might be a deployment.
  • stopping: The on stop job has started. This state does not apply when there is no on stop job defined.
  • stopped: Either the on stop job has run, or a user manually stopped the job.

Create a static environment

You can create a static environment in the UI or in your .gitlab-ci.yml file.

In the UI

Prerequisites:

  • You must have at least the Developer role.

To create a static environment in the UI:

  1. On the left sidebar, select Search or go to and find your project.
  2. Select Operate > Environments.
  3. Select Create an environment.
  4. Complete the fields.
  5. Select Save.

In your .gitlab-ci.yml file

Prerequisites:

  • You must have at least the Developer role.

To create a static environment, in your .gitlab-ci.yml file:

  1. Define a job in the deploy stage.
  2. In the job, define the environment name and url. If an environment of that name doesn’t exist when the pipeline runs, it is created.
note
Some characters cannot be used in environment names. For more information about the environment keywords, see the .gitlab-ci.yml keyword reference.

For example, to create an environment named staging, with URL https://staging.example.com:

deploy_staging:
  stage: deploy
  script:
    - echo "Deploy to staging server"
  environment:
    name: staging
    url: https://staging.example.com

Create a dynamic environment

To create a dynamic environment, you use CI/CD variables that are unique to each pipeline.

Prerequisites:

  • You must have at least the Developer role.

To create a dynamic environment, in your .gitlab-ci.yml file:

  1. Define a job in the deploy stage.
  2. In the job, define the following environment attributes:
    • name: Use a related CI/CD variable like $CI_COMMIT_REF_SLUG. Optionally, add a static prefix to the environment’s name, which groups in the UI all environments with the same prefix.
    • url: Optional. Prefix the hostname with a related CI/CD variable like $CI_ENVIRONMENT_SLUG.
note
Some characters cannot be used in environment names. For more information about the environment keywords, see the .gitlab-ci.yml keyword reference.

In the following example, every time the deploy_review_app job runs the environment’s name and URL are defined using unique values.

deploy_review_app:
  stage: deploy
  script: make deploy
  environment:
    name: review/$CI_COMMIT_REF_SLUG
    url: https://$CI_ENVIRONMENT_SLUG.example.com
  rules:
    - if: $CI_COMMIT_BRANCH == "main"
      when: never
    - if: $CI_COMMIT_BRANCH

Set a dynamic environment URL

Some external hosting platforms generate a random URL for each deployment, for example: https://94dd65b.amazonaws.com/qa-lambda-1234567. That makes it difficult to reference the URL in the .gitlab-ci.yml file.

To address this problem, you can configure a deployment job to report back a set of variables. These variables include the URL that was dynamically generated by the external service. GitLab supports the dotenv (.env) file format, and expands the environment:url value with variables defined in the .env file.

To use this feature, specify the artifacts:reports:dotenv keyword in .gitlab-ci.yml.

You can also specify a static part of the URL at environment:url, such as https://$DYNAMIC_ENVIRONMENT_URL. If the value of DYNAMIC_ENVIRONMENT_URL is example.com, the final result is https://example.com.

The assigned URL for the review/your-branch-name environment is visible in the UI.

For an overview, see Set dynamic URLs after a job finished.

In the following example a review app creates a new environment for each merge request:

  • The review job is triggered by every push, and creates or updates an environment named review/your-branch-name. The environment URL is set to $DYNAMIC_ENVIRONMENT_URL.
  • When the review job finishes, GitLab updates the review/your-branch-name environment’s URL. It parses the deploy.env report artifact, registers a list of variables as runtime-created, expands the environment:url: $DYNAMIC_ENVIRONMENT_URL and sets it to the environment URL.
review:
  script:
    - DYNAMIC_ENVIRONMENT_URL=$(deploy-script)                                 # In script, get the environment URL.
    - echo "DYNAMIC_ENVIRONMENT_URL=$DYNAMIC_ENVIRONMENT_URL" >> deploy.env    # Add the value to a dotenv file.
  artifacts:
    reports:
      dotenv: deploy.env                                                       # Report back dotenv file to rails.
  environment:
    name: review/$CI_COMMIT_REF_SLUG
    url: $DYNAMIC_ENVIRONMENT_URL                                              # and set the variable produced in script to `environment:url`
    on_stop: stop_review

stop_review:
  script:
    - ./teardown-environment
  when: manual
  environment:
    name: review/$CI_COMMIT_REF_SLUG
    action: stop

Note the following:

  • stop_review doesn’t generate a dotenv report artifact, so it doesn’t recognize the DYNAMIC_ENVIRONMENT_URL environment variable. Therefore you shouldn’t set environment:url in the stop_review job.
  • If the environment URL isn’t valid (for example, the URL is malformed), the system doesn’t update the environment URL.
  • If the script that runs in stop_review exists only in your repository and therefore can’t use GIT_STRATEGY: none or GIT_STRATEGY: empty, configure merge request pipelines for these jobs. This ensures that runners can fetch the repository even after a feature branch is deleted. For more information, see Ref Specs for Runners.
note
For Windows runners, you should use the PowerShell Add-Content command to write to .env files.
Add-Content -Path deploy.env -Value "DYNAMIC_ENVIRONMENT_URL=$DYNAMIC_ENVIRONMENT_URL"

Deployment tier of environments

Sometimes, instead of using an industry standard environment name, like production, you might want to use a code name, like customer-portal. While there is no technical reason not to use a name like customer-portal, the name no longer indicates that the environment is used for production. This can affect how metrics like deployment frequency are calculated.

To indicate that a specific environment is for a specific use, you can use tiers:

Environment tier Environment name examples
production Production, Live
staging Staging, Model, Demo
testing Test, QC
development Dev, Review apps, Trunk
other  

By default, GitLab assumes a tier based on the environment name. You cannot set an environment tier using the UI. Instead, you can use the deployment_tier keyword to specify a tier.

Rename an environment

History
  • Renaming an environment by using the API was deprecated in GitLab 15.9.
  • Renaming an environment with the API removed in GitLab 16.0.

You cannot rename an environment.

To achieve the same result as renaming an environment:

  1. Stop the existing environment.
  2. Delete the existing environment.
  3. Create a new environment with the desired name.

CI/CD variables

To customize your environments and deployments, you can use any of the predefined CI/CD variables, and define custom CI/CD variables.

Limit the environment scope of a CI/CD variable

By default, all CI/CD variables are available to all jobs in a pipeline. If a test tool in a job becomes compromised, the tool could attempt to retrieve all CI/CD variables available to the job. To help mitigate this kind of supply chain attack, you should limit the environment scope of sensitive variables to only the jobs that require them.

Limit the environment scope of a CI/CD variable by defining which environments it can be available for. The default environment scope is the * wildcard, so any job can access the variable.

You can use specific matching to select a particular environment. For example, set the variable’s environment scope to production to only allow jobs with an environment of production to access the variable.

You can also use wildcard matching (*) to select a particular environment group, like all review apps with review/*.

For example, with these four environments:

  • production
  • staging
  • review/feature-1
  • review/feature-2

These environment scopes match as follows:

↓ Scope / Environment → production staging review/feature-1 review/feature-2
* Match Match Match Match
production Match      
staging   Match    
review/*     Match Match
review/feature-1     Match  

You should not use environment-scoped variables with rules or include. The variables might not be defined when GitLab validates the pipeline configuration at pipeline creation.

Search environments

History

To search environments by name:

  1. On the left sidebar, select Search or go to and find your project.
  2. Select Operate > Environments.
  3. In the search bar, enter your search term.
    • The length of your search term should be 3 or more characters.
    • Matching applies from the beginning of the environment name.
      • For example, devel matches the environment name development, but elop does not.
    • For environments with a folder name format, matching applies after the base folder name.
      • For example when the name is review/test-app, search term test matches review/test-app.
      • Also searching with the folder name prefixed like review/test matches review/test-app.

Group similar environments

You can group environments into collapsible sections in the UI.

For example, if all of your environments start with the name review, then in the UI, the environments are grouped under that heading:

Environment groups

The following example shows how to start your environment names with review. The $CI_COMMIT_REF_SLUG variable is populated with the branch name at runtime:

deploy_review:
  stage: deploy
  script:
    - echo "Deploy a review app"
  environment:
    name: review/$CI_COMMIT_REF_SLUG

Stopping an environment

Stopping an environment means its deployments are not accessible on the target server. You must stop an environment before it can be deleted.

Stop an environment by using the UI

note
To trigger an on_stop action and manually stop an environment from the Environments view, the stop and deploy jobs must be in the same resource_group.

To stop an environment in the GitLab UI:

  1. On the left sidebar, select Search or go to and find your project.
  2. Select Operate > Environments.
  3. Next to the environment you want to stop, select Stop.
  4. On the confirmation dialog, select Stop environment.

Stop an environment when a branch is deleted

You can configure environments to stop when a branch is deleted.

In the following example, a deploy_review job calls a stop_review job to clean up and stop the environment.

  • Both jobs must have the same rules or only/except configuration. Otherwise, the stop_review job might not be included in all pipelines that include the deploy_review job, and you cannot trigger action: stop to stop the environment automatically.
  • The job with action: stop might not run if it’s in a later stage than the job that started the environment.
  • If you can’t use merge request pipelines, set GIT_STRATEGY to none or empty in the stop_review job. Then, the runner doesn’t try to check out the code after the branch is deleted.
deploy_review:
  stage: deploy
  script:
    - echo "Deploy a review app"
  environment:
    name: review/$CI_COMMIT_REF_SLUG
    url: https://$CI_ENVIRONMENT_SLUG.example.com
    on_stop: stop_review

stop_review:
  stage: deploy
  script:
    - echo "Remove review app"
  environment:
    name: review/$CI_COMMIT_REF_SLUG
    action: stop
  when: manual

Stop an environment when a merge request is merged or closed

When you use the merge request pipelines configuration, the stop trigger is automatically enabled.

In the following example, the deploy_review job calls a stop_review job to clean up and stop the environment.

deploy_review:
  stage: deploy
  script:
    - echo "Deploy a review app"
  environment:
    name: review/$CI_COMMIT_REF_SLUG
    on_stop: stop_review
  rules:
    - if: $CI_MERGE_REQUEST_ID

stop_review:
  stage: deploy
  script:
    - echo "Remove review app"
  environment:
    name: review/$CI_COMMIT_REF_SLUG
    action: stop
  rules:
    - if: $CI_MERGE_REQUEST_ID
      when: manual

Stop an environment after a certain time period

You can set an environment to stop automatically after a certain time period.

note
Due to resource limitations, a background worker for stopping environments runs only once every hour. This means that environments may not be stopped after the exact time period specified, but are instead stopped when the background worker detects expired environments.

In your .gitlab-ci.yml file, specify the environment:auto_stop_in keyword. Specify the time period in natural language, such as 1 hour and 30 minutes or 1 day. After the time period passes, GitLab automatically triggers a job to stop the environment.

In the following example:

  • Each commit on a merge request triggers a review_app job that deploys the latest change to the environment and resets its expiry period.
  • If the environment is inactive for more than a week, GitLab automatically triggers the stop_review_app job to stop the environment.
review_app:
  script: deploy-review-app
  environment:
    name: review/$CI_COMMIT_REF_SLUG
    on_stop: stop_review_app
    auto_stop_in: 1 week
  rules:
    - if: $CI_MERGE_REQUEST_ID

stop_review_app:
  script: stop-review-app
  environment:
    name: review/$CI_COMMIT_REF_SLUG
    action: stop
  rules:
    - if: $CI_MERGE_REQUEST_ID
      when: manual

View an environment’s scheduled stop date and time

When a environment has been scheduled to stop after a specified time period, you can view its expiration date and time.

To view an environment’s expiration date and time:

  1. On the left sidebar, select Search or go to and find your project.
  2. Select Operate > Environments.
  3. Select the name of the environment.

The expiration date and time is displayed in the upper-left corner, next to the environment’s name.

Override an environment’s scheduled stop date and time

When a environment has been scheduled to stop after a specified time period, you can override its expiration.

To override an environment’s expiration in the UI:

  1. On the left sidebar, select Search or go to and find your project.
  2. Select Operate > Environments.
  3. Select the deployment name.
  4. in the upper-right corner, select the thumbtack ().

To override an environment’s expiration in the .gitlab-ci.yml:

  1. Open the project’s .gitlab-ci.yml.
  2. Update the auto_stop_in setting of the corresponding deploy job to auto_stop_in: never.

The auto_stop_in setting is overridden and the environment remains active until it’s stopped manually.

Clean up stale environments

History

Clean up stale environments when you want to stop old environments in a project.

Prerequisites:

  • You must have at least the Maintainer role.

To clean up stale environments:

  1. On the left sidebar, select Search or go to and find your project.
  2. Select Operate > Environments.
  3. Select Clean up environments.
  4. Select the date to use for determining which environments to consider stale.
  5. Select Clean up.

Active environments that haven’t been updated after the specified date are stopped. Protected environments are ignored and not stopped.

Run a pipeline job when environment is stopped

History
  • Feature flag environment_stop_actions_include_all_finished_deployments introduced in GitLab 16.9. Disabled by default.
  • Feature flag environment_stop_actions_include_all_finished_deployments removed in GitLab 17.0.

You can define a stop job for the environment with an on_stop action in the environment’s deploy job.

The stop jobs of finished deployments in the latest finished pipeline are run when an environment is stopped. A deployment or pipeline is finished if it has the successful, canceled, or failed status.

Prerequisites:

  • Both the deploy and stop jobs must have the same rules or only/except configuration.
  • The stop job must have the following keywords defined:

In the following example:

  • A review_app job calls a stop_review_app job after the first job is finished.
  • The stop_review_app is triggered based on what is defined under when. In this case, it is set to manual, so it needs a manual action from the GitLab UI to run.
  • The GIT_STRATEGY is set to none. If the stop_review_app job is automatically triggered, the runner doesn’t try to check out the code after the branch is deleted.
review_app:
  stage: deploy
  script: make deploy-app
  environment:
    name: review/$CI_COMMIT_REF_SLUG
    url: https://$CI_ENVIRONMENT_SLUG.example.com
    on_stop: stop_review_app

stop_review_app:
  stage: deploy
  variables:
    GIT_STRATEGY: none
  script: make delete-app
  when: manual
  environment:
    name: review/$CI_COMMIT_REF_SLUG
    action: stop

Multiple stop actions for an environment

To configure multiple parallel stop actions on an environment, specify the on_stop keyword across multiple deployment jobs for the same environment, as defined in the .gitlab-ci.yml file.

When an environment is stopped, the matching on_stop actions from only successful deployment jobs are run in parallel, in no particular order.

note
All on_stop actions for an environment must belong to the same pipeline. To use multiple on_stop actions in downstream pipelines, you must configure the environment actions in the parent pipeline. For more information, see downstream pipelines for deployments.

In the following example, for the test environment there are two deployment jobs:

  • deploy-to-cloud-a
  • deploy-to-cloud-b

When the environment is stopped, the system runs on_stop actions teardown-cloud-a and teardown-cloud-b in parallel.

deploy-to-cloud-a:
  script: echo "Deploy to cloud a"
  environment:
    name: test
    on_stop: teardown-cloud-a

deploy-to-cloud-b:
  script: echo "Deploy to cloud b"
  environment:
    name: test
    on_stop: teardown-cloud-b

teardown-cloud-a:
  script: echo "Delete the resources in cloud a"
  environment:
    name: test
    action: stop
  when: manual

teardown-cloud-b:
  script: echo "Delete the resources in cloud b"
  environment:
    name: test
    action: stop
  when: manual

Stop an environment without running the on_stop action

There may be times when you want to stop an environment without running the defined on_stop action. For example, you want to delete many environments without using compute quota.

To stop an environment without running the defined on_stop action, execute the Stop an environment API with the parameter force=true.

Delete an environment

Delete an environment when you want to remove it and all its deployments.

Prerequisites:

  • You must have at least the Developer role.
  • You must stop the environment before it can be deleted.

To delete an environment:

  1. On the left sidebar, select Search or go to and find your project.
  2. Select Operate > Environments.
  3. Select the Stopped tab.
  4. Next to the environment you want to delete, select Delete environment.
  5. On the confirmation dialog, select Delete environment.

Access an environment for preparation or verification purposes

You can define a job that accesses an environment for various purposes, such as verification or preparation. This effectively bypasses deployment creation, so that you can adjust your CD workflow more accurately.

To do so, add either action: prepare, action: verify, or action: access to the environment section of your job:

build:
  stage: build
  script:
    - echo "Building the app"
  environment:
    name: staging
    action: prepare
    url: https://staging.example.com

This gives you access to environment-scoped variables, and can be used to protect builds from unauthorized access. Also, it’s effective to avoid the prevent outdated deployment jobs feature.

Environment incident management

Production environments can go down unexpectedly, including for reasons outside of your control. For example, issues with external dependencies, infrastructure, or human error can cause major issues with an environment. Things like:

  • A dependent cloud service goes down.
  • A 3rd party library is updated and it’s not compatible with your application.
  • Someone performs a DDoS attack to a vulnerable endpoint in your server.
  • An operator misconfigures infrastructure.
  • A bug is introduced into the production application code.

You can use incident management to get alerts when there are critical issues that need immediate attention.

View the latest alerts for environments

Tier: Ultimate Offering: GitLab.com, Self-managed, GitLab Dedicated

If you set up an alert integration, alerts for environments are shown on the environments page. The alert with the highest severity is shown, so you can identify which environments need immediate attention.

Environment alert

When the issue that triggered the alert is resolved, it is removed and is no longer visible on the environments page.

If the alert requires a rollback, you can select the deployment tab from the environment page and select which deployment to roll back to.

Auto Rollback

Tier: Ultimate Offering: GitLab.com, Self-managed, GitLab Dedicated

In a typical Continuous Deployment workflow, the CI pipeline tests every commit before deploying to production. However, problematic code can still make it to production. For example, inefficient code that is logically correct can pass tests even though it causes severe performance degradation. Operators and SREs monitor the system to catch these problems as soon as possible. If they find a problematic deployment, they can roll back to a previous stable version.

GitLab Auto Rollback eases this workflow by automatically triggering a rollback when a critical alert is detected. For GitLab to select the appropriate environment for the rollback, the alert should contain a gitlab_environment_name key with the name of the environment. GitLab selects and redeploys the most recent successful deployment.

Limitations of GitLab Auto Rollback:

  • The rollback is skipped if a deployment is running when the alert is detected.
  • A rollback can happen only once in three minutes. If multiple alerts are detected at once, only one rollback is performed.

GitLab Auto Rollback is turned off by default. To turn it on:

  1. On the left sidebar, select Search or go to and find your project.
  2. Select Settings > CI/CD.
  3. Expand Automatic deployment rollbacks.
  4. Select the checkbox for Enable automatic rollbacks.
  5. Select Save changes.

Environment permissions

Depending on your role, you can interact with environments in public and private projects.

View environments

  • In public projects, anyone can view a list of environments, including non-members.
  • In private projects, you must have at least the Reporter role to view a list of environments.

Create and update environments

  • You must have at least the Developer role to create a new environment, or update an existing unprotected environment.
  • If an existing environment is protected and you don’t have access to it, you cannot update the environment.

Stop and delete environments

  • You must have at least the Developer role to stop or delete an unprotected environment.
  • If an environment is protected and you don’t have access to it, you cannot stop or delete the environment.

Run deployment jobs in protected environments

If you can push or merge to the protected branch:

  • You must have at least the Reporter role.

If you can’t push to the protected branch:

  • You must be a part of a group with the Reporter role.

See Deployment-only access to protected environments.

Web terminals (deprecated)

caution
This feature was deprecated in GitLab 14.5.

If you deploy to your environments with the help of a deployment service (for example, the Kubernetes integration), GitLab can open a terminal session to your environment. You can then debug issues without leaving your web browser.

The Web terminal is a container-based deployment, which often lack basic tools (like an editor), and can be stopped or restarted at any time. If this happens, you lose all your changes. Treat the Web terminal as a debugging tool, not a comprehensive online IDE.

Web terminals:

  • Are available to project Maintainers and Owners only.
  • Must be enabled.

In the UI, you can view the Web terminal by selecting Terminal from the actions menu:

Terminal button on environment index

You can also access the terminal button from the page for a specific environment:

Terminal button for an environment

Select the button to establish the terminal session:

Terminal page

This works like any other terminal. You’re in the container created by your deployment so you can:

  • Run shell commands and get responses in real time.
  • Check the logs.
  • Try out configuration or code tweaks.

You can open multiple terminals to the same environment. They each get their own shell session and even a multiplexer like screen or tmux.

Troubleshooting

The job with action: stop doesn’t run

In some cases, environments do not stop despite an on_stop job being configured. This happens when the job with the action: stop is not in a runnable state due to its stages: or needs: configuration.

For example:

  • The environment might start in a stage that also has a job that failed. Then the jobs in later stages job don’t start. If the job with the action: stop for the environment is also in a later stage, it can’t start and the environment isn’t deleted.
  • The job with the action: stop might have a dependency on a job that has not yet completed.

To ensure the action: stop can always run when needed, you can:

  • Put both jobs in the same stage:

    stages:
      - build
      - test
      - deploy
    
    ...
    
    deploy_review:
      stage: deploy
      environment:
        name: review/$CI_COMMIT_REF_SLUG
        url: https://$CI_ENVIRONMENT_SLUG.example.com
        on_stop: stop_review
    
    stop_review:
      stage: deploy
      environment:
        name: review/$CI_COMMIT_REF_SLUG
        action: stop
      when: manual
    
  • Add a needs entry to the action: stop job so the job can start out of stage order:

    stages:
      - build
      - test
      - deploy
      - cleanup
    
    ...
    
    deploy_review:
      stage: deploy
      environment:
        name: review/$CI_COMMIT_REF_SLUG
        url: https://$CI_ENVIRONMENT_SLUG.example.com
        on_stop: stop_review
    
    stop_review:
      stage: cleanup
      needs:
        - deploy_review
      environment:
        name: review/$CI_COMMIT_REF_SLUG
        action: stop
      when: manual
    

Error: job would create an environment with an invalid parameter

If your project is configured to create a dynamic environment, you might encounter this error in a deployment job because the dynamically generated parameter can’t be used for creating an environment:

This job could not be executed because it would create an environment with an invalid parameter.

For example, your project has the following .gitlab-ci.yml:

deploy:
  script: echo
  environment: production/$ENVIRONMENT

Since $ENVIRONMENT variable does not exist in the pipeline, GitLab tries to create an environment with a name production/, which is invalid in the environment name constraint.

To fix this, use one of the following solutions:

  • Remove environment keyword from the deployment job. GitLab has already been ignoring the invalid keyword, therefore your deployment pipelines stay intact even after the keyword removal.
  • Ensure the variable exists in the pipeline. Review the limitation on supported variables.

If you get this error on review apps

For example, if you have the following in your .gitlab-ci.yml:

review:
  script: deploy review app
  environment: review/$CI_COMMIT_REF_NAME

When you create a new merge request with a branch name bug-fix!, the review job tries to create an environment with review/bug-fix!. However, the ! is an invalid character for environments, so the deployment job fails since it was about to run without an environment.

To fix this, use one of the following solutions:

  • Re-create your feature branch without the invalid characters, such as bug-fix.
  • Replace the CI_COMMIT_REF_NAME predefined variable with CI_COMMIT_REF_SLUG which strips any invalid characters:

    review:
      script: deploy review app
      environment: review/$CI_COMMIT_REF_SLUG