chore: update telegraf to 1.21

[swiatekm]

Description

1.14 is pretty old and contains quite a few vulnerabilities. I ran E2E tests on 1.21 and they passed without issue.

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Checklist

Remove items which don't apply to your PR.

• Changelog updated

Testing performed

• Confirm events, logs, and metrics are coming in

[pmalek-sumo]

Are there any breaking changes between 1.14.4 and 1.21.2?

I'd be more inclined to bump the operator version (that handles the image version itself) instead of bumping the image only.

rel: https://github.com/influxdata/telegraf-operator/releases

[swiatekm]

Are there any breaking changes between 1.14.4 and 1.21.2?

I'd be more inclined to bump the operator version (that handles the image version itself) instead of bumping the image only.

rel: https://github.com/influxdata/telegraf-operator/releases

No breaking changes in Telegraf itself: https://github.com/influxdata/telegraf/blob/master/CHANGELOG.md. They seem to be following semantic versioning even if they don't state so explicitly in their documentation.

For Telegraf Operator, we're already running the latest version, and the default Telegraf version in its Helm Chart is 1.19. Since we're hosting the images on our own ECR as a matter of policy, I figured we may as well upgrade to the latest stable version.

[pmalek-sumo]

I believe the changelog would need some rebasing. Wouldn't it? I wonder why github doesn't show it like that.

[swiatekm]

I believe the changelog would need some rebasing. Wouldn't it? I wonder why github doesn't show it like that.

Good catch. Github does the right thing, since from its perspective there's no conflict in the diff, just an unrelated change in a different line (Unreleased -> 2.4.0).

[sumo-backporter]

The backport to release-v2.4 failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-release-v2.4 release-v2.4
# Navigate to the new working tree
cd .worktrees/backport-release-v2.4
# Create a new branch
git switch --create backport-2036-to-release-v2.4
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick --mainline 1 68cfa2d916264441db4a4005e6f892fcd877b576
# Push it to GitHub
git push --set-upstream origin backport-2036-to-release-v2.4
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-release-v2.4

Then, create a pull request where the base branch is release-v2.4 and the compare/head branch is backport-2036-to-release-v2.4.