GoogleCloudPlatform/testgrid

Config Merger only reads configuration on startup; should be more often

Open

#517 opened on Jun 23, 2021

View on GitHub
 (0 comments) (1 reaction) (0 assignees)Go (72 forks)auto 404
good first issuehelp wanted

Repository metrics

Stars
 (205 stars)
PR merge metrics
 (PR metrics pending)

Description

The Config Merger is a controller that takes multiple configurations and merges them together. It requires a list of configurations to merge together.

https://github.com/GoogleCloudPlatform/testgrid/blob/651499da486f08c6ba6fcfa7efb1535318c22fa5/cmd/config_merger/main.go#L93

It then periodically reads those configs and merges them together. Changes in the config are picked up in this loop, but changes to the config list are not.

https://github.com/GoogleCloudPlatform/testgrid/blob/651499da486f08c6ba6fcfa7efb1535318c22fa5/cmd/config_merger/main.go#L111-L125

This has caused issues when the config is changed, and Config Merger silently ignores those changes until it's rebooted. See https://github.com/GoogleCloudPlatform/oss-test-infra/issues/919

Additional logic to determine if the config list has changed and to either log this event or do less work if it hasn't changed would also be nice.

Contributor guide

Research direction
Examine the current loop in config merger/main.go that reads configs periodically. Add logic to detect changes in the config list (e.g., by storing a hash of the list and comparing on each iteration). If changed, log the event or update the merge accordingly. Implement a periodic check or watch mechanism for the config list source.
Tech stack
go
Domain
backenddevops
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Go
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60