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Creating and managing your build definition file

An important element of the pipelines feature is the build definition file. This is a YAML format file (named acquia-pipelines.yaml) that you create in your workspace. The build definition file contains all of the information that is required to perform the build, including any variables that are required and the instructions used to perform the build. The components of the build process can be broken into individual steps in the build definition file, and each step will be executed in order. Each step corresponds to the keys at the top level in the steps section of the build definition file.

Pipeline builds will time out after 60 minutes. Unless all steps and processes used during the build are closed before the timeout, the build job will fail.

Example build definition files are available at Example pipelines build definition files.

Example build definition files

For examples of build definition files you can customize for your application’s needs, see Example pipelines build definition files.

Build definition file structure

The build definition file must be named acquia-pipelines.yaml and must exist in the root directory in the branch you wish to build.

The file will have the following approximate key/value structure. Click a key for additional information.

You can use pipelines environment variables and pipelines commands in your build steps.

You can also use the pipelines_metadata command in any of the previously mentioned sections of your build definition file to send build or container information back for use in other steps.

version key

This required key must have a value of at least 1.0.0 for use with the pipelines feature. The following version keys enable additional features:

Version key Features
1.1.0 or greater Enables PHP 7. For more information about using PHP 7 in your build definition file, see the services: php section on this page.
1.2.0 or greater Adds support for the cde-databases key in your YAML file.
1.3.0 or greater Adds memcached support. For more information, see the services: memcached section on this page.

variables key

The variables key of the build definition file provides a means of setting environment variables that are needed for your build. The environment variables are defined for all commands run during the job.

Here is an example of the variables key:

variables:
  global:
    ADMIN_USERNAME: admin
    ADMIN_PASSWORD:
      secure: 2aciWcRBNXrG/KcWG1bb0uSRTOVoiDl+h+QRi$. . .

For details about including secure (encrypted) variables in the variables key, see Encrypting keys and variables.

For information about the default environment variables provided by the pipelines feature, see Default environment variables in pipelines.

cde-databases

This key, available to version 1.2.0 and higher, enables you to specify which database schemas in a multisite configuration will be used to build this application. You can select a maximum of three databases.

cde-databases:
  - my-first-database
  - my-second-database

This definition has one of the following results, depending on its settings:

Definition value Result
Undefined / empty All of the databases that are available for the application will be deployed to environment
null (~) All of the databases that are available for the application will be deployed to environment
array Only the specified databases will be included in the environment created by the job
database name not defined on the application The job will fail
any other value The job will display an error

For information about copying databases, see Copying a database into a Acquia Cloud CD environment.

services key

The services key allows you to enable one or more services to be available during the execution of your pipelines job, including:

services: mysql

If your build process requires the use of MySQL, be sure to include the services: mysql key in your build definition file.

The mysql service starts a MySQL database server on 127.0.0.1 port 3306 for the duration of the job. This database is configured with only one user configured, which has the username root and the password root.

Note

You must use the services: mysql key to start MySQL in your build definition file. The Acquia Cloud pipelines feature does not support sudo mysql commands.

services: php

If your build process requires PHP 7, be sure to both set your version key to 1.1.0 and include the services: php key in your build definition file. For a services: php example, see the following:

services:
  - php:
      version: 7.1

services: memcached

If your build process requires memcached, ensure you set your version key to at least 1.3.0 and include the services: memcached key in your build definition file, as in the following example:

version: 1.3.0

services:
  - memcached

It will start the Memcached service on 127.0.0.1 port 11211 for the duration of the job, but does not support sudo memcached commands.

events key

The required events key is the parent of the following keys:

Key Required Description
build Yes Describes how the workspace will be built
fail-on-build No Executes only if the build fails
post-deploy No The post-deploy event is triggered after the build event
pr-merged No Steps taken if a pull request is merged to its base branch
pr-closed No Steps taken if a pull request is closed without being merged to its base branch

Each of these keys can contain a steps key.

build key

The build key is required in the events top-level key. The build event is triggered by the pipelines start command. The contents of the build key describe how the workspace is to be built. It must contain a single steps key, with values describing the actual process of the build.

fail-on-build key

The fail-on-build key is optional in the events top-level key, and will execute only if the build event fails. The fail-on-build must contain a single steps key, which may have multiple values. For example:

fail-on-build:
    steps:
      - runonfailure:
          type: script
          script:
            - "echo 'This is simple echo from fail-on-build event'"

post-deploy key

The post-deploy key is optional in the events top-level key, and executes after the build event. This key must contain a single steps key, with a value describing the actual process.

For an example of copying files to an on-demand environment as part of a pipelines job, see Copying files to an on-demand environment.

pr-merged key

The pr-merged key is triggered when a GitHub pull request is merged to its base branch. This key must contain a single steps key, with a value describing the actual process.

pr-closed key

The pr-closed key is triggered when a GitHub pull request is closed without being merged to its base branch. This key must contain a single steps key key, with values describing the actual process.

steps key

The steps key describes the steps to accomplish the build. Each step will be executed in the order it appears in the steps key of the build definition file.

Each steps key has a type property that indicates how the step will be executed.

Note

When creating your build definition file, the final action in the steps key should move the directory to the docroot. If you do not do this, your build cannot be used on Acquia Cloud.

type: script

Steps of type: script let you specify arbitrary shell commands to be executed by Bash. Each type: script step must include a script key whose value is a list of shell commands, each listed on a separate line starting with a dash (-). When the script step runs, the lines are all combined into a single Bash script and executed.

By default, the pipelines feature prepends scripts with set -e, which causes the script to exit immediately if any command has a non-zero exit code. You can override this behavior by including set +e in your build script. Be aware that if you use set +e, the script does not fail when a command fails, and so it is the responsibility of the script to manage its own exit strategy and exit codes.

If a script step runs a program in the background (such as an HTTP server), the backgrounded program is terminated at the end of the step that it was started in. This means that a backgrounded program that started in one script step will not be present and available in a subsequent steps.

ssh-keys key

The ssh-keys key enables you to add SSH keys that may be required to access private resources. These keys are encrypted and can be generated using the pipelines encrypt command. Here is an example ssh-keys key:

ssh-keys:
  mykey:
     secure: 2aciWcRBNXrG/KcABCOvoIDTDG1bboUsVjDl+h+QRi$

Any number of keys can be added in the ssh-keys key. The value of the ssh-keys key (mykey in this example) is the name of the key. When the pipelines feature reads the build definition file, it attempts to decrypt the SSH keys. If the decryption is successful for one or more keys, Acquia Cloud writes those keys into the ~/.ssh directory, making them available for use when accessing private resources from the build script.

Important

  • Acquia recommends you generate a unique SSH key for each application, as the contents of your key are available during runtime. Any access you allow to this key should be based on the principle of least privilege.
  • The default format of SSH keys generated by OpenSSH version 7.8 or greater is incompatible with the pipelines feature. For more information, see this known issue.

Linking to specific SSH keys with a variable

To specify which SSH key will be used in a script, set the PIPELINE_SSH_KEY environment variable with the correct key, as in the following example:

version: 1.1.0
events:
  build:
    steps:
      - welcome:
          script:
            - echo 'STARTED'
            - export PIPELINE_SSH_KEY=~/.ssh/ssh-key-1
            - git ls-remote [email protected]:username/repo-dependent-on-ssh-key-1.git
            - echo 'Steps (git operations) will be successful which are dependent on ssh-key-1'
            - unset PIPELINE_SSH_KEY
            - echo 'Step executed with default ssh keys'
            - export PIPELINE_SSH_KEY=~/.ssh/ssh-key-2
            - git ls-remote [email protected]:username/repo-dependent-on-ssh-key-2.git
            - - echo 'Steps (git operations) will be successful which are dependent on ssh-key-2'
            - unset PIPELINE_SSH_KEY
            - echo 'FINISHED'
ssh-keys:
  ssh-key-1:
    secure: REDACTED
  ssh-key-2:
    secure: REDACTED

When a specified SSH key is no longer required in a step, use unset PIPELINES_SSH_KEY to switch back to the default key.