metropolis/curator: report leader based on ledership election status

This makes GetCurrentLeader calls respond to cluster/leader changes
instead of relying on connections getting closed on time when a leader
changes, or when a node gets elected as a leader.

This leads to less churn when cluster leadership status changes (no need
for every RPC client to re-establish connectivity to get the new
leader). It should also be faster to respond to cluster leader changes,
as it doesn't rely on the the RPC client detecting that the node it
connected to has stopped responding / disconnected.

Change-Id: I9de12286530226b3832d2ae07cb7d943ca537d3f
Reviewed-on: https://review.monogon.dev/c/monogon/+/2069
Tested-by: Jenkins CI
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
3 files changed
tree: 2c0247c43643cea03672b12d47247acfd4f6d320
  1. .github/
  2. build/
  3. cloud/
  4. go/
  5. intellij/
  6. metropolis/
  7. net/
  8. third_party/
  9. tools/
  10. .bazelignore
  11. .bazelproject
  12. .bazelrc
  13. .bazelrc.sandboxroot
  14. .bazelversion
  15. .git-ignore-revs
  16. .gitignore
  17. BUILD.bazel
  18. CODING_STANDARDS.md
  19. go.mod
  20. go.sum
  21. LICENSE
  22. README.md
  23. SETUP.md
  24. shell.nix
  25. WORKSPACE
README.md

Monogon Monorepo

This is the main repository containing the source code for the Monogon Platform.

This is pre-release software - take a look, and check back later!

Environment

Our build environment is self-contained and requires only minimal host dependencies:

  • A Linux machine or VM.
  • Bazelisk >= v1.15.0 (or a working Nix environment).
  • A reasonably recent kernel with user namespaces enabled.
  • Working KVM with access to /dev/kvm (if you want to run tests).

Our docs assume that Bazelisk is available as bazel on your PATH.

Refer to SETUP.md for detailed instructions.

Monogon OS

Run a single node demo cluster

Build CLI and node image:

bazel build //metropolis/cli/dbg //:launch -c dbg

Launch an ephemeral test node:

bazel test //:launch -c dbg --test_output=streamed

Run a kubectl command while the test is running:

bazel-bin/metropolis/cli/dbg/dbg_/dbg kubectl describe node

Test suite

Run full test suite:

bazel test -c dbg //...