Mongo Charms Single Kernel library

Library containing shared code for MongoDB operators (mongodb, mongos, VM and k8s).

The goal of this library is to provide reusable and shared code for the four mongo charms:

• MongoDB VM
• MongoDB Kubernetes
• Mongos VM
• Mongos Kubernetes

Code layout

The source code can be found in single_kernel_mongo/ The layout is organised as so:

• configurations
• core services
• events handlers
• event managers
• charm state
• charm workloads
• utils and helpers
• abstract charm skeleton
• exceptions

Charm Structure

This single kernel library aims at providing a clear and reliable structure, following the single responsibility principle. All the logic is expected to happen in this library and a charm should be no more than a few lines defining the substrate, the operator type and the config.

class MongoTestCharm(AbstractMongoCharm[MongoDBCharmConfig, MongoDBOperator]):
    config_type = MongoDBCharmConfig
    operator_type = MongoDBOperator
    substrate = Substrates.VM
    peer_rel_name = PeerRelationNames.PEERS
    name = "mongodb-test"

Contributing

You can have longer explanations in ./CONTRIBUTING.md but for a quick start:

# Install poetry and tox
pipx install tox
pipx install poetry

poetry install

Code quality is enforced using pre-commit hooks. They will run before each commit and also at other stages.

# Install the first time
pre-commit install

# Run it manually with
pre-commit run --all-files

Once a PR is opened, it's possible to trigger integration testing on the charms with a comment on the PR. This can be run only by members of the Data and AI team

Use the following syntax:

* /test to run on 4 charms.
* /test/<mongodb | mongos>/<vm | k8s> to run on a specific charm.
* /test/*/<vm | k8s> to run for both charms on a specific substrate.

This will create a PR with an updated version of the library on the selected charms.

Project and community

Mongo Charms Single Kernel library is an open source project that warmly welcomes community contributions, suggestions, fixes, and constructive feedback.

• Check our Code of Conduct
• Raise software issues or feature requests on GitHub
• Report security issues through LaunchPad.
• Meet the community and chat with us on Matrix
• Contribute to the code

License

The Mongo Single Library is free software, distributed under the Apache Software License, version 2.0. See LICENSE for more information.