Backport of fix panic from keyring raft entries being written during upgrade into release/1.4.x #14829
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Backport
This PR is auto-generated from #14821 to be assessed for backporting due to the inclusion of the label backport/1.4.x.
The below text is copied from the body of the original PR.
Fixes #14819
During an upgrade to Nomad 1.4.0, if a server running 1.4.0 becomes the leader before one of the 1.3.x servers, the old server will crash because the keyring is initialized and writes a raft entry.
Wait until all members are on a version that supports the keyring before initializing it.