System overview

AlmaLinux Test System (ALTS) - is a way to test rpm/deb packages under realistic circumstances, on real systems with installation, launching, integrity checks, etc. If needed, it also supports third-party test scripts.

AlmaLinux Test System is designed to be a fast, scalable and easily maintainable solution for end-to-end packages testing.

The system consists of API and task manager. API accepts a request for testing a package and creates a task on it. The manager picks up as many tasks as possible.

The process of picking up a created task is:

• Starting up a clean environment like Docker or OpenNebula with its initial configurations;
• An attempt to install a package to the system;
• The package integrity check

The system contains several parts:

• RabbitMQ as messaging broker.
• Celery as a task managing environment, using threads pool. Internal data goes through Azure.
• Scheduler web application.
• FastAPI is used as a framework for the API
• Terraform is used as a tool for managing test environments. It allows quickly adding support for new types of environments.

Mentioned tools and libraries are required for ALTS to run in current state:

• Terraform >= 0.13;
• Ansible (current version is 2.9);
• RabbitMQ;
• Celery >= 5.1;
• SQLite;
• Docker (for development purposes);

Test system flow

• Web application receives a POST request with the requirements (test runner type, distribution name, version, architecture, package name, package version, additional repositories);
• Application calculates where the task should go (RabbitMQ queue) and applies the task to it;
• Celery worker that listens to the queue receives the task parameters and starts processing;
• Task executes all needed steps and saves artifacts to Azure/S3;
• Celery will save the task result (summary on the run) to the separate Azure/S3 folder;
• Web application can return task status and result by calling a separate endpoint.

Celery launch command example:

celery -A alts.app worker --pool=threads --concurrency=10 --loglevel=DEBUG

To launch scheduler, apply the following command:

uvicorn scheduler.app:app

For testing purposes, you can add the --reload argument to the scheduler launch command, which will enable live code to reload.

Both Celery worker and scheduler REST API services need YAML-based configs to function. Config examples are provided in the configs folder.

Filling options in the config file

Here is the description of what is necessary to fill in at alts_config.yaml:

rabbitqm_host: 'rabbitmq' # hostname for the message broker
rabbitmq_port: 5672 # unprotected broker port
rabbitmq_ssl_port: 5671 # protected broker port. They are used separetly depending on the flag 'use_ssl'
rabbitmq_user: 'test-system' # the user as message broker for connection
rabbitmq_password: # the user's password
rabbitmq_vhost: 'test_system' # message "base" on broker

Choosing a backend in theresults backend option, you define which parameter S3 or Azure you need: result_backend: 's3' # 'azureblockblob://$connection_string' # a type of results backend - S3 or connection string to Azure

Now a group of S3 options for authorization on S3:

s3_access_key_id:
s3_secret_access_key:
s3_bucket:
s3_base_path: 'celery_result_backend/' # path at S3 where to put artefacts
s3_region:
s3_endpoint_url: # optional, if not S3 is used, but its substitute
result_backend: 's3'

Options to connect to Azure:

azureblockblob_container_name: # container name for Celery on Azure
azureblockblob_base_path: # a directory to store testing results
azure_connection_string: # connection string to Azure
azure_logs_container: # container name for logs

Running using docker-compose

You can start the whole system using the Docker Compose tool.

Pre-requisites:

• docker and docker-compose tools are installed and set up;

Few preparations needed before you start:

• Open docker-compose.yml and set some password in RABBITMQ_DEFAULT_PASS variable;
• Copy configs/example_config.yaml config file to configs/alts_config.yaml;
• Generate JWT secret: openssl rand -hex 32
• Fill config with Azure/AWS credentials, JWT secret and RabbitMQ password;

To start the system, run the following command: docker-compose up -d. This command will pull RabbitMQ image, build docker images for Celery and Scheduler containers and start the containers themselves. To rebuild images after your local changes, just run docker-compose up -d --build.

Running in virtualenv

You can start the application inside virtualenv. Create virtualenv:

python3 -m venv venv

Activate virtualenv:

source venv/bin/activate

Install all needed packages:

pip install -r requirements/scheduler.txt

After that, you can start Celery and scheduler.

Scheduling tasks

Scheduler part provides 2 REST API endpoints:

• POST /tasks/schedule - to schedule package for installation/tests run;
• GET /tasks/{task_id}/result - to get result of the task;

As scheduler uses FastAPI, it has Swagger support built-in. You can open Swagger documentation just by following the http://localhost:8000/docs link.

Authentication is achieved using JWT tokens. For ease of testing, there is a generate_jwt_token.py script. You can either specify a config file to parse the JWT secret and hashing algorithm or provide them via a parameter. For details on all script parameters, run python generate_jwt_token.py --help. Usage example with config:

python generate_jwt_token.py -c configs/alts_config.yaml -e [email protected]

With command line parameters:

python generate_jwt_token.py -s my_very_secret_phrase -a HS256 -e [email protected]

After acquiring the token, you can put it in Authorize section on the http://localhost:8000/docs page. It will open endpoints for further usage.

/tasks/schedule endpoint accepts the following payload:

{
  "runner_type": "string", # the instance backend to use (docker, opennebula, etc.). For now only `docker` and `any` values are supported
  "dist_name": "string", # name of distribution you want to test on (debian, ubuntu, centos, etc.)
  "dist_version": "string", # distribution version (20.04, 8, etc.)
  "dist_arch": "string", # CPU architecture you want to test package for. Supported values - 'x86_64', 'i686', 'amd64', 'aarch64', 'arm64'
  "repositories": [], # a list of repositories to add before attempting package installation. Each repository is a dictionary with `name` and `url` values. name` is optional
  "package_name": "string", # the name of the package to install
  "package_version": "string" # optional, version of the package you want to install
}

/tasks/{task_id}/result endpoint returns the result of task. task_id - task ID string.

Unresolved issues

• Provision for production server is required;
• Only supports Docker containers;
• No basic tests;