• Use cases
  • Commit messages with a specific reference
  • Restrict branch names
    • Default restricted branch names
  • Custom Push Rules
• Enabling push rules
  • Caveat to “Reject unsigned commits” push rule
    • “Reject unsigned commits” push rule disables Web IDE
• Prevent pushing secrets to the repository
• Prohibited file names

Push Rules

Gain additional control over what can and can’t be pushed to your repository by using regular expressions to reject pushes based on commit contents, branch names or file details.

GitLab already offers protected branches, but there are cases when you need some specific rules. Some common scenarios: preventing Git tag removal, or enforcing a special format for commit messages.

Push rules are pre-receive Git hooks you can enable in a user-friendly interface. They are defined either:

• Globally if you are an administrator.
• Per project, so you can have different rules applied to different projects depending on your needs.

Use cases

Every push rule could have its own use case, but let’s consider some examples.

Commit messages with a specific reference

Let’s assume you have the following requirements for your workflow:

• every commit should reference a Jira issue, for example: Refactored css. Fixes JIRA-123.
• users should not be able to remove Git tags with git push

Write a regular expression that requires the mention of a Jira issue in the commit message, like JIRA\-\d+.

Now when a user tries to push a commit with a message Bugfix, their push is declined. Only pushing commits with messages like Bugfix according to JIRA-123 is accepted.

Restrict branch names

If your company has a strict policy for branch names, you may want the branches to start with a certain name. This approach enables different GitLab CI/CD jobs (such as feature, hotfix, docker, android) that rely on the branch name.

Your developers may not remember that policy, so they might push to various branches, and CI pipelines might not work as expected. By restricting the branch names globally in Push Rules, such mistakes are prevented. Any branch name that doesn’t match your push rule is rejected.

Note that the name of your default branch is always allowed, regardless of the branch naming regular expression (regex) specified. GitLab is configured this way because merges typically have the default branch as their target. If you have other target branches, include them in your regex. (See Enabling push rules).

The default branch also defaults to being a protected branch, which already limits users from pushing directly.

Some example regular expressions you can use in push rules:

• ^JIRA- Branches must start with JIRA-.
• -JIRA$ Branches must end with -JIRA.
• ^[a-z0-9\\-]{4,15}$ Branches must be between 4 and 15 characters long, accepting only lowercase letters, numbers and dashes.

Default restricted branch names

By default, GitLab restricts certain formats of branch names for security purposes. 40-character hexadecimal names, similar to Git commit hashes, are prohibited.

Custom Push Rules

It’s possible to create custom push rules rather than the push rules available in Admin Area > Push Rules by using more advanced server hooks.

See server hooks for more information.

Enabling push rules

You can create push rules for all new projects to inherit, but they can be overridden at the project level or the group level.

To create global push rules:

1. On the top bar, select Menu > Admin.
2. In the left sidebar, select Push rules.

To override global push rules in a project’s settings:

1. Navigate to your project’s Settings > Repository and expand Push rules.
2. Set the rule you want.
3. Select Save Push Rules for the changes to take effect.

The following options are available:

Caveat to “Reject unsigned commits” push rule

This push rule ignores commits that are authenticated and created by GitLab (either through the UI or API). When the Reject unsigned commits push rule is enabled, unsigned commits may still show up in the commit history if a commit was created within GitLab itself. As expected, commits created outside GitLab and pushed to the repository are rejected. For more information about how GitLab plans to fix this issue, read issue #19185.

“Reject unsigned commits” push rule disables Web IDE

In 13.10, if a project has the “Reject unsigned commits” push rule, the user will not be allowed to commit through GitLab Web IDE.

To allow committing through the Web IDE on a project with this push rule, a GitLab administrator will need to disable the feature flag reject_unsigned_commits_by_gitlab. This can be done through a rails console and running:

Feature.disable(:reject_unsigned_commits_by_gitlab)

Prevent pushing secrets to the repository

Secrets such as credential files, SSH private keys, and other files containing secrets should never be committed to source control. GitLab enables you to turn on a predefined denylist of files which can’t be pushed to a repository. The list stops those commits from reaching the remote repository.

By selecting the checkbox Prevent committing secrets to Git, GitLab prevents pushes to the repository when a file matches a regular expression as read from files_denylist.yml (make sure you are at the right branch as your GitLab version when viewing this file).

Below is an example list of what GitLab rejects with these regular expressions:

#####################
# AWS CLI credential blobs
#####################
.aws/credentials
aws/credentials
homefolder/aws/credentials

#####################
# Private RSA SSH keys
#####################
/ssh/id_rsa
/.ssh/personal_rsa
/config/server_rsa
id_rsa
.id_rsa

#####################
# Private DSA SSH keys
#####################
/ssh/id_dsa
/.ssh/personal_dsa
/config/server_dsa
id_dsa
.id_dsa

#####################
# Private ed25519 SSH keys
#####################
/ssh/id_ed25519
/.ssh/personal_ed25519
/config/server_ed25519
id_ed25519
.id_ed25519

#####################
# Private ECDSA SSH keys
#####################
/ssh/id_ecdsa
/.ssh/personal_ecdsa
/config/server_ecdsa
id_ecdsa
.id_ecdsa

#####################
# Any file with .pem or .key extensions
#####################
*.pem
*.key

#####################
# Any file ending with _history or .history extension
#####################
*.history
*_history

Prohibited file names

Each filename contained in a Git push is compared to the regular expression in this field. Filenames in Git consist of both the file’s name and any directory that may precede it. A singular regular expression can contain multiple independent matches used as exclusions. File names can be broadly matched to any location in the repository, or restricted to specific locations. Filenames can also be partial matches used to exclude file types by extension.

The following examples make use of regex string boundary characters which match the beginning of a string (^), and the end ($). They also include instances where either the directory path or the filename can include . or /. Both of these special regex characters have to be escaped with a backslash \\ to be used as normal characters in a match condition.

Example: prevent pushing any .exe files to any location in the repository. This is an example of a partial match, which can match any filename that contains .exe at the end:

\.exe$

Example: prevent a specific configuration file in the repository root from being pushed:

^config\.yml$

Example: prevent a specific configuration file in a known directory from being pushed:

^directory-name\/config\.yml$

Example: prevent the specific file named install.exe from being pushed to any location in the repository. The parenthesized expression (^|\/) matches either a file following a directory separator or a file in the root directory of the repository:

(^|\/)install\.exe$

Example: combining all of the above in a single expression. The preceding expressions rely on the end-of-string character $. We can move that part of each expression to the end of the grouped collection of match conditions where it is appended to all matches:

(\.exe|^config\.yml|^directory-name\/config\.yml|(^|\/)install\.exe)$