gitlab-job-exec 1.1.91

Execute GitLab-CI docker jobs

GitLab-CI Job Executor

This is a simple tool to parse and expand a .gitlab-ci.yml file to then execute GitLab-CI jobs in a docker container. It can be used either as a library or an command line executable.

Note

This tool was made to fit the needs of the authors first. Suggestions on what should be implemented next are welcomed.

Requirements

• Python 3

Main features

• No need to commit before running a job since it mounts the working directory in the job's container.
• extends support for jobs templates.
• include support to import jobs and templates from other files. Its behavior is as close as possible to how GitLab does it (https://docs.gitlab.com/ee/ci/yaml/README.html#include).
  • Supports local, remote, project and template includes.
• For include:project type includes:
  • The included file needs to be accessible by a HTTP GET request made using the URL pattern.
  • The pattern (which can be passed as an argument) has 2 variables possible to place in it: 'group' and 'project'
    • The values will correspond to the 'project' key of the include ({group}/{project})
    • This will follow defaults GitLab Pages URL with subgroup being part of {project}.
  • Supported schemes are http://, https:// and file://
  • You can look at the setup used by our projects in https://gitlab.com/uncrns for a setup that is compatible with gitlab-job-exec.
• Possibility for extra volumes to mount to the container running the job.
• Possibility to pass extra/overrides environment variables to the job.
• Configuration file for the command line interface.

Command line interface

For the command line executable, we suggest using gitlab-job-exec --help to get detailed usage information.

Library

class GitlabCI(filename, include_pattern, template_url)

The constructor will do the parsing and expansion of the .gitlab-ci.yml file.

• filename: the path to the .gitlab-ci.yml file to read and parse.
• include_pattern: The pattern to use for include:project file includes. Defaults to https://{group}.gitlab.io/{project} which is the default URL for GitLab Pages.
• template_url: Base URL to use to fetch GitLab templates for include:template.

GitlabCI.defaults: Contains the details of the default job (if defined) to define global defaults.

GitlabCI.include_pattern: The include pattern passed to the constructor.

GitlabCI.jobs: Dictionary representing the different jobs available to execute, excluding jobs starting with . or global attributes not representing a complete job. Keys are the jobs' names and the values are instances of gitlab_job_exec.GitlabJobs.

GitlabCI.stages: The list of stages defined in the pipeline definition.

GitlabCI.template_url: The template base URL passed to the constructor.

GitlabCI.variables: Dictionary containing the global variables defined by the variables keyword in the pipeline definition.

class GitlabJob(name, parameters, defaults, global_variables)

• name: Name of the job.
• parameters: Other job parameters.
• defaults: Values in the GitlabCI.defaults dict.
• global_variables: Values in the GitlabCI.variables dict.

The keys before_script, image, name, script, services, stage and variables are available members with values equal to the job's definition.

classmethod GitlabJobs.run(extra_variables, extra_volumes, pull_image, user): Runs a job in a docker container and returns the exit code of the script.

• extra_variables: Environment variables to pass to the job. They will override existing values defined in the job.
• extra_volumes: Extra volumes to mount in the job's container. The format is the one used by docker.DockerClient.containers.run() for volumes.
• pull_image: Boolean indicating if the docker image should be pulled or not before starting the job.
• user: The user to use in the container. The format used is the same as the docker.DockerClient.containers.run().

Predefined GitLab environment variables

GitLab-CI is defining a lot of environment variables that can be used in a pipeline. We have implemented the following variables that will be passed to the jobs:

Variable	Value
CI_PIPELINE_ID	Current date and time (ex:202102190830)
CI_PIPELINE_IID	Current date and time (ex:202102190830)
CI_PIPELINE_SOURCE	"local"
CI_PROJECT_DIR	The current working directory
CI_PROJECT_NAME	The base name of the current working directory
CI_PROJECT_NAMESPACE	The directory in which the cwd is located (dirname of ../). Prefixed with ${CI_PROJECT_ROOT_NAMESPACE}/ if defined
CI_PROJECT_PATH	"local/${CI_PROJECT_NAME}"
CI_PROJECT_ROOT_NAMESPACE	Empty by defaults
CI_PROJECT_URL	"https://localhost/${CI_PROJECT_NAME}"
CI_REGISTRY	"registry.gitlab.com"
CI_REGISTRY_IMAGE	"registry.gitlab.com/local/${CI_PROJECT_NAME}"
CI_SERVER_URL	"https://gitlab.com"

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Main unsupported features/current limitation

• after_script is not being read. (See #8)
• Override of Docker entrypoint and command for services containers.
• Health check on services/wait for services to be ready before starting the job.
• Have an array of extends in a job. (See #23)
• Envrionment variables regarding the namespace of a project only supports 1 level of dynamic value. (See #27)