Sharing Configuration

Learn how to share and reuse configuration pieces in your configuration.


In Mergify, you can leverage certain features like YAML anchors and aliases, the shared key, and the extends key to reduce redundancy, maintain consistency, and increase code reusability.

YAML anchors (&) and aliases (*) are supported in the configuration file. These allow you to reuse configuration sections. For example, you can create a list of continuous integration checks and use it in multiple sections:

queue_rules:
- name: hotfix
queue_conditions:
- and: &CheckRuns
- check-success=linters
- check-success=unit
- check-success=functionnal
- check-success=e2e
- check-success=docker
- name: default
queue_conditions:
- and: *CheckRuns
- schedule=Mon-Fri 09:00-17:30[Europe/Paris]

Sharing Configuration Sections

Section titled Sharing Configuration Sections

You can store anything in the shared key. Its main purpose is to provide a place to put redundant YAML anchors:

shared:
my_ci: &common_checks
- check-success=ci-one
- check-success=ci-two
queue_rules:
- name: hotfix
queue_conditions:
- and: *my_ci
- name: default
queue_conditions:
- and: *my_ci
- schedule=Mon-Fri 09:00-17:30[Europe/Paris]

Mergify lets you extend your configuration file by including the configuration from another repository. This feature is useful when you want to share and reuse configuration rules across multiple repositories, helping maintain consistency and reduce duplication.

To extend a configuration file, use the extends keyword at the top level of your configuration file file and specify the repository name from which you want to include the configuration.

extends: organization/shared-config

The configuration from the specified repository will be loaded and applied before the one in the current repository. Here’s an example:

extends: organization/shared-config
pull_request_rules:
- name: additional rule specific to this repository
conditions:
- base=main
actions:
label:
add: ["repository-specific"]

Mergify, by using the extends feature, also lets you extend the YAML anchors. With the same duplication reduction goal, you can centralize all your anchors inside one unique configuration file, that will be extended to others.

To extend the anchors, you simply have to define them in the configuration file that will be extended to the current configuration file. Then you can simply use the corresponding aliases inside the current configuration file and Mergify will automatically replace them with the anchors defined in the extended file.

The mechanism works as follows:

  • Main configuration file using extends keyword with an undefined YAML alias:
extends: organization/shared-config
pull_request_rules:
- name: additional rule specific to this repository
conditions: *my-extended-yaml-anchor
actions:
label:
add: ["repository-specific"]
  • Extended file containing the YAML anchor definition:
shared:
condition: &my-extended-yaml-anchor
- label=my-label
  • Final main configuration file:
extends: organization/shared-config
pull_request_rules:
- name: additional rule specific to this repository
conditions:
- label=my-label
actions:
label:
add: ["repository-specific"]