Execution environment definition

You define the content of your execution environment in a YAML file. By default, this file is called execution-environment.yml or execution-environment.yaml. This file tells Ansible Builder how to create the build instruction file (Containerfile for Podman, Dockerfile for Docker) and build context for your container image.

Note

This page documents the definition schema for Ansible Builder 3.x. If you are running an older version of Ansible Builder, you need an older schema version. Please consult older versions of the docs for more information. We recommend using version 3, which is more configurable and functional than previous versions.

Overview

The Ansible Builder 3.x execution environment definition file accepts seven top-level sections:

  • additional_build_files

  • additional_build_steps

  • build_arg_defaults

  • dependencies

  • images

  • options

  • version

Version 3 sample file

Here is a sample version 3 EE file. To use Ansible Builder 3.x, you must specify the schema version. If your EE file does not specify version: 3, Ansible Builder will assume you want version 1.

---
version: 3

build_arg_defaults:
  ANSIBLE_GALAXY_CLI_COLLECTION_OPTS: '--pre'

dependencies:
  ansible_core:
    package_pip: ansible-core==2.14.4
  ansible_runner:
    package_pip: ansible-runner
  galaxy: requirements.yml
  python:
    - six
    - psutil
  system: bindep.txt
  exclude:
    python:
      - docker
    system:
      - python3-Cython

images:
  base_image:
    name: docker.io/redhat/ubi9:latest
    # Other available base images:
    #   - quay.io/rockylinux/rockylinux:9
    #   - quay.io/centos/centos:stream9
    #   - registry.fedoraproject.org/fedora:38
    #   - registry.redhat.io/ansible-automation-platform-23/ee-minimal-rhel8:latest
    #     (needs an account)

# Custom package manager path for the RHEL based images
# options:
#  package_manager_path: /usr/bin/microdnf

additional_build_files:
    - src: files/ansible.cfg
      dest: configs

additional_build_steps:
  prepend_base:
    - RUN echo This is a prepend base command!
    # Enable Non-default stream before packages provided by it can be installed. (optional)
    # - RUN $PKGMGR module enable postgresql:15 -y
    # - RUN $PKGMGR install -y postgresql
  prepend_galaxy:
    - COPY _build/configs/ansible.cfg /etc/ansible/ansible.cfg

  prepend_final: |
    RUN whoami
    RUN cat /etc/os-release
  append_final:
    - RUN echo This is a post-install command!
    - RUN ls -la /etc

Configuration options

You may use the configuration YAML keys listed here in your v3 execution environment definition file.

additional_build_files

Specifies files to be added to the build context directory. These can then be referenced or copied by additional_build_steps during any build stage. The format is a list of dictionary values, each with a src and dest key and value.

Each list item must be a dictionary containing the following (non-optional) keys:

src

Specifies the source file(s) to copy into the build context directory. This may either be an absolute path (e.g., /home/user/.ansible.cfg), or a path that is relative to the execution environment file. Relative paths may be a glob expression matching one or more files (e.g. files/*.cfg). Note that an absolute path may not include a regular expression. If src is a directory, the entire contents of that directory are copied to dest.

dest

Specifies a subdirectory path underneath the _build subdirectory of the build context directory that should contain the source file(s) (e.g., files/configs). This may not be an absolute path or contain .. within the path. This directory will be created for you if it does not exist.

additional_build_steps

Specifies custom build commands for any build phase. These commands will be inserted directly into the build instruction file for the container runtime (e.g., Containerfile or Dockerfile). The commands must conform to any rules required by the containerization tool.

You can add build steps before or after any stage of the image creation process. For example, if you need git to be installed before you install your dependencies, you can add a build step at the end of the base build stage.

Below are the valid keys for this section. Each supports either a multi-line string, or a list of strings.

prepend_base

Commands to insert before building of the base image.

append_base

Commands to insert after building of the base image.

prepend_galaxy

Commands to insert before building of the galaxy image.

append_galaxy

Commands to insert after building of the galaxy image.

prepend_builder

Commands to insert before building of the builder image.

append_builder

Commands to insert after building of the builder image.

prepend_final

Commands to insert before building of the final image.

append_final

Commands to insert after building of the final image.

Note

Please make sure that you do not specify USER directives in these build steps. This may lead to failures while building the image. If you want to override the USER setting, consider using the options.user setting mentioned below.

build_arg_defaults

Specifies default values for build args as a dictionary. This is an alternative to using the --build-arg CLI flag.

Build args used by ansible-builder are the following:

ANSIBLE_GALAXY_CLI_COLLECTION_OPTS

This allows the user to pass the –pre flag (or others) to enable the installation of pre-release collections.

ANSIBLE_GALAXY_CLI_ROLE_OPTS

This allows the user to pass any flags, such as –no-deps, to the role installation.

PKGMGR_PRESERVE_CACHE

This controls how often the package manager cache is cleared during the image build process. If this value is not set, which is the default, the cache is cleared frequently. If it is set to the string always, the cache is never cleared. Any other value forces the cache to be cleared only after the system dependencies are installed in the final build stage.

Ansible Builder hard-codes values given inside of build_arg_defaults into the build instruction file, so they will persist if you run your container build manually.

If you specify the same variable in the execution environment definition and at the command line with the CLI --build-arg flag, the CLI value will take higher precedence (the CLI value will override the value in the execution environment definition).

dependencies

Specifies dependencies to install into the final image, including ansible-core, ansible-runner, Python packages, system packages, and Ansible Collections. Ansible Builder automatically installs dependencies for any Ansible Collections you install.

In general, you can use standard syntax to constrain package versions. Use the same syntax you would pass to dnf, pip, ansible-galaxy, or any other package management utility. You can also define your packages or collections in separate files and reference those files in the dependencies section of your execution environment definition file.

The following keys are valid for this section:

ansible_core

The version of the ansible-core Python package to be installed. This value is a dictionary with a single key, package_pip. The package_pip value is passed directly to pip for installation and can be in any format that pip supports. Below are some example values:

ansible_core:
    package_pip: ansible-core
ansible_core:
    package_pip: ansible-core==2.14.3
ansible_core:
    package_pip: https://github.com/example_user/ansible/archive/refs/heads/ansible.tar.gz
ansible_runner

The version of the Ansible Runner Python package to be installed. This value is a dictionary with a single key, package_pip. The package_pip value is passed directly to pip for installation and can be in any format that pip supports. Below are some example values:

ansible_runner:
    package_pip: ansible-runner
ansible_runner:
    package_pip: ansible-runner==2.3.2
ansible_runner:
    package_pip: https://github.com/example_user/ansible-runner/archive/refs/heads/ansible-runner.tar.gz
galaxy

Ansible Collections to be installed from Galaxy. This may be a filename, a dictionary, or a multi-line string representation of an Ansible Galaxy requirements.yml file (see below for examples). Read more about the requirements file format in the Galaxy user guide.

python

The Python installation requirements. This may either be a filename, or a list of requirements (see below for an example).

Note

Python requirement specifications are expected to be limited to features defined by PEP 508. Hash tag comments will always be allowed. Any deviation from this specification will be passed through to pip unverified and unaltered, although this is considered undefined and unsupported behavior. It is not recommended that you depend on this behavior.

python_interpreter

A dictionary that defines the Python system package name to be installed by dnf (package_system) and/or a path to the Python interpreter to be used (python_path).

system

The system packages to be installed, in bindep format. This may either be a filename, or a list of requirements (see below for an example).

exclude

A dictionary defining the Python or system requirements to be excluded from the top-level dependency requirements of referenced collections. These exclusions will not apply to the user supplied Python or system dependencies, nor will they apply to dependencies of dependencies (top-level only).

The following keys are valid for this section:

  • python - A list of Python dependencies to be excluded.

  • system - A list of system dependencies to be excluded.

  • all_from_collections - If you want to exclude all Python and system dependencies from one or more collections, supply a list of collection names under this key.

The exclusion feature supports two forms of matching:

  • Simple name matching.

  • Advanced name matching using regular expressions.

For simple name matching, you need only supply the name of the requirement/collection to match. All values will be compared in a case-insensitive manner.

For advanced name matching, begin the exclusion string with the tilde (~) character to indicate that the remaining portion of the string is a regular expression to be used to match a requirement/collection name. The regex should be considered case-insensitive.

Note

The regular expression must match the full requirement/collection name. For example, ~foo. does not fully match the name foobar, but ~foo.+ does.

With both forms of matching, the exclusion string will be compared against the simple name of any Python or system requirement. For example, if you need to exclude the system requirement that appears as foo [!platform:gentoo] within an included collection, then your exclusion string should be foo. To exclude the Python requirement bar == 1.0.0, your exclusion string would be bar.

Example using both simple and advanced matching:

dependencies:
    exclude:
        python:
            - docker
        system:
            - python3-Cython
        all_from_collections:
            # Regular expression to exclude all from community collections
            - ~community\..+

Note

The exclude option requires ansible-builder version 3.1 or newer.

The following example uses filenames that contain various dependencies:

dependencies:
    python: requirements.txt
    system: bindep.txt
    galaxy: requirements.yml
    ansible_core:
        package_pip: ansible-core==2.14.2
    ansible_runner:
        package_pip: ansible-runner==2.3.1
    python_interpreter:
        package_system: "python310"
        python_path: "/usr/bin/python3.10"

And this example uses inline values:

dependencies:
    python:
      - pywinrm
    system:
      - iputils [platform:rpm]
    galaxy:
      collections:
        - name: community.windows
        - name: ansible.utils
          version: 2.10.1
    ansible_core:
        package_pip: ansible-core==2.14.2
    ansible_runner:
        package_pip: ansible-runner==2.3.1
    python_interpreter:
        package_system: "python310"
        python_path: "/usr/bin/python3.10"

images

Specifies the base image to be used. At a minimum you MUST specify a source, image, and tag for the base image. The base image provides the operating system and may also provide some packages. We recommend using the standard host/namespace/container:tag syntax to specify images. You may use Podman or Docker shortcut syntax instead, but the full definition is more reliable and portable.

Valid keys for this section are:

base_image

A dictionary defining the parent image for the execution environment. A name key must be supplied with the container image to use. Use the signature_original_name key if the image is mirrored within your repository, but signed with the original image’s signature key.

image verification

You can verify signed container images if you are using the podman container runtime. Set the --container-policy CLI option to control how this data is used with a Podman policy.json file for container image signature validation.

  • ignore_all policy: Generate a policy.json file in the build context directory where no signature validation is performed.

  • system policy: Signature validation is performed using pre-existing policy.json files in standard system locations. ansible-builder assumes no responsibility for the content within these files, and the user has complete control over the content.

  • signature_required policy: ansible-builder will use the container image definitions here to generate a policy.json file in the build context directory that will be used during the build to validate the images.

options

A dictionary of keywords/options that can affect builder runtime functionality. Valid keys for this section are:

container_init

A dictionary with keys that allow for customization of the container ENTRYPOINT and CMD directives (and related behaviors). Customizing these behaviors is an advanced task, and may result in subtle, difficult-to-debug failures. As the provided defaults for this section control several intertwined behaviors, overriding any value will skip all remaining defaults in this dictionary. Valid keys are:

cmd

Literal value for the CMD Containerfile directive. The default value is ["bash"].

entrypoint

Literal value for the ENTRYPOINT Containerfile directive. The default entrypoint behavior handles signal propagation to subprocesses, as well as attempting to ensure at runtime that the container user has a proper environment with a valid writeable home directory, represented in /etc/passwd, with the HOME envvar set to match. The default entrypoint script may emit warnings to stderr in cases where it is unable to suitably adjust the user runtime environment. This behavior can be ignored or elevated to a fatal error; consult the source for the entrypoint target script for more details. The default value is ["/opt/builder/bin/entrypoint", "dumb-init"].

package_pip

Package to install via pip for entrypoint support. This package will be installed in the final build image. The default value is dumb-init==1.2.5.

package_manager_path

A string with the path to the package manager (For example - dnf or microdnf) to use. The default is /usr/bin/dnf. This value will be used to install a Python interpreter, if specified in dependencies, and during the build phase by the assemble script.

skip_ansible_check

This boolean value controls whether or not the check for an installation of Ansible and Ansible Runner is performed on the final image. Set this value to True to not perform this check. The default is False.

skip_pip_install

This boolean value controls whether or not we attempt to install pip into the base image. Pip is necessary for Python requirement installation, among other things. You may choose to disable this step and handle installing pip manually if the current method of pip installation does not work for you. The default is False.

relax_passwd_permissions

This boolean value controls whether the root group (GID 0) is explicitly granted write permission to /etc/passwd in the final container image. The default entrypoint script may attempt to update /etc/passwd under some container runtimes with dynamically created users to ensure a fully functional POSIX user environment and home directory. Disabling this capability can cause failures of software features that require users to be listed in /etc/passwd with a valid and writeable home directory (eg, async in ansible-core, and the ~username shell expansion). The default is True.

workdir

Default current working directory for new processes started under the final container image. Some container runtimes also use this value as HOME for dynamically-created users in the root (GID 0) group. When this value is specified, the directory will be created (if it doesn’t already exist), set to root group ownership, and rwx group permissions recursively applied to it. The default value is /runner.

user

This sets the username or UID to use as the default user for the final container image. The default value 1000.

tags

Specifies the names that are assigned to the resulting image if the build process completes successfully. The default value is ansible-execution-env:latest.

Example options section:

options:
    container_init:
        package_pip: dumb-init>=1.2.5
        entrypoint: '["dumb-init"]'
        cmd: '["csh"]'
    package_manager_path: /usr/bin/microdnf
    relax_passwd_permissions: false
    skip_ansible_check: true
    workdir: /myworkdir
    user: bob
    tags:
      - ee_development:latest

version

An integer value that sets the schema version of the execution environment definition file. Defaults to 1. Must be 3 if you are using Ansible Builder 3.x.