Prometheus Vendor Update Tracking

[rfratto]

This issue is meant to track new versions of Prometheus and decide whether they introduce new functionality that the Agent would benefit from. We will note each version as:

• vendored in bold
• skipped update in italics.
• planned for vendoring in non-bold, not italicized text

The current vendored version of Prometheus is v2.21.0.

• v.2.17.1
• v2.17.2: Skipping, no fixes related to Agent
• v2.18.0: Skipping, going directly to 2.18.1
• v2.18.1 (Update to Prometheus v2.18.1 #58)
• v2.19.0: Skipping, going directly to 2.20.1
• v2.19.3: Skipping, going directly to 2.20.1
• v2.20.0: Skipping, going directly to 2.20.1
• v2.20.1 (Update to Prometheus v2.20.1 #149, vendored in v0.6.0)
• v2.21.0 (Update to Prometheus v2.21.0 #203, vendored in v0.7.2)

[hardproblems]

@rfratto is a timeline for when the next release containing prometheus updates will land? We're trying to compare the resource usage for grafana-agent and prometheus for a POC and saw a ~30% memory usage reduction between Prometheus 2.18 -> 2.19.3. Would love to be able to pull this into grafana-agent soon if possible.

[rfratto]

@hardproblems The 0.5.0 release tomorrow won't have anything, but we should be able to update the Prometheus vendor to 2.20.1 for the 0.6.0 release. I had a quick chat with the team here and it seems like we'll be able to release 0.6.0 around the week of August 17th at the earliest or the week of August 24th at the latest.

I've opened #149 to track the progress with this.

[rfratto]

@hardproblems Sorry, the release got pushed back a week further than I had expected. We just released v0.6.0 that includes Prometheus 2.20.1.

[rfratto]

I'm going to lock this issue so it's purely for tracking; if anyone has a question about when we're going to update the vendor feel free to open a specific issue for the question or ask me on our public #agent slack channel at https://slack.grafana.com/.

[rfratto]

I'm closing and unpinning this. There's a lot of dependencies in the Agent that need tracking, and that number is just going to keep growing.

There's now a GitHub action that runs every day and will check for updates against an allowlist of dependencies we explicitly want to track; Prometheus is one of them. You can see the results of this action in #267. All of the issues will have the label outdated-dependency. Closing them means that we intend to not update to that version, though if anyone needs a specific feature, please let us know and we can re-open.