Infrastructure 2020/Fedora Messaging

This is a shorthand list of items we are needing to cover for migrating from fedmsg to fedora-messaging in Fedora Infrastructure for the Fiscal Year 2020.

Point of contact: Aurelien Bompard

Why?

Fedmsg has a number of issues but the main one is that it is unreliable. Since critical elements of our CI pipeline (and general infrastructure) are depending on it, it is important to migrate to fedora-messaging to solve that issue.

This is also why the migration to fedora-messaging needs to happen before the Gating Rawhide initiative goes to production (development can start, though).

What?

About 30+ apps require changes. The most critical ones are:

1. bodhi
2. koji
3. greenwave
4. waiverdb
5. pagure
6. centos infrastructure CI
7. anitya & the-new-hotness

Migrating to fedora-messaging will also allow us to define schemas for our data, use versions on the topic to avoid breakage in the message consumers, and rethink the topic to make them more useful with the routing capabilities we have. However, these tasks are out of scope for this initiative, for time/resources reasons.

The other applications will be migrated at a slower pace throughout FY20.

When?

• Critical applications: by 2019-06-01
• Other applications: 2020-03-31

Who?

The people involved will be abompard and the owner of each app (be it for writing the migration or for reviewing and testing it).

How?

We will start with the application that are most critical (see above).

The changes from fedmsg to fedora-messaging are usually similar in each application, so it can be a great opportunity for pair programming between abompard and the app owners.

The staging and production networks are ready for fedora-messaging, so the migration and testing can start immediately.

Since this is a significant change from a deployment point of view, app owners may decide to change their major version number, but this decision is left to them.

Status

The migration status can be:

1. todo: no step has been taken yet
2. date set: a date has been decided for the pair programming session
3. in dev: a branch has been made and the code migration is in progress
4. PR ready: the code migration is done and under review
5. merged: the main branch is migrated
6. staging: the new code is deployed to staging and under test
7. production: the migrated app is running in production

• Bodhi: PR ready
• koji: todo
• greenwave: todo
• waiverdb: todo
• resultsdb todo
• pagure: todo
• centos infrastructure CI: todo
• anitya: PR ready
• the-new-hotness: in dev

Details per-app

Bodhi

The producing side on the server is already migrated to fedora-messaging. Some PRs are left to merge: consumers , message schemas.

The migration to Fedora Messaging should be available in Bodhi 4.0

Koji

Koji sends fedmsgs via a plugin, this plugin should be migrated. I did not find any upstream source control for the koji plugin, unless I'm mistaken it only lives in the Infra Ansible repository. Ideally, we would create an upstream project for that with its proper git, tracker, releases, tags, etc.

Greenwave

Source code: https://pagure.io/greenwave

Greenwave has 2 consumers (ResultsDB and WaiverDB) and produces one message topic.

WaiverDB

Source code: https://pagure.io/waiverdb

WaiverDB only produces one message topic.

ResultsDB

Source code: https://pagure.io/resultsdb

ResultsDB only produces one message topic.