func pruneNetworkAndVerify(c *check.C, d *daemon.Swarm, kept, pruned []string) {
_, err := d.Cmd("network", "prune", "--force")
c.Assert(err, checker.IsNil)
out, err := d.Cmd("network", "ls", "--format", "{{.Name}}")
c.Assert(err, checker.IsNil)
for _, s := range kept {
c.Assert(out, checker.Contains, s)
}
for _, s := range pruned {
c.Assert(out, checker.Not(checker.Contains), s)
}
}
func (s *DockerSwarmSuite) TestAPISwarmLeaderElection(c *check.C) {
// Create 3 nodes
d1 := s.AddDaemon(c, true, true)
d2 := s.AddDaemon(c, true, true)
d3 := s.AddDaemon(c, true, true)
// assert that the first node we made is the leader, and the other two are followers
c.Assert(d1.GetNode(c, d1.NodeID).ManagerStatus.Leader, checker.True)
c.Assert(d1.GetNode(c, d2.NodeID).ManagerStatus.Leader, checker.False)
c.Assert(d1.GetNode(c, d3.NodeID).ManagerStatus.Leader, checker.False)
d1.Stop(c)
var (
leader *daemon.Swarm // keep track of leader
followers []*daemon.Swarm // keep track of followers
)
checkLeader := func(nodes ...*daemon.Swarm) checkF {
return func(c *check.C) (interface{}, check.CommentInterface) {
// clear these out before each run
leader = nil
followers = nil
for _, d := range nodes {
if d.GetNode(c, d.NodeID).ManagerStatus.Leader {
leader = d
} else {
followers = append(followers, d)
}
}
if leader == nil {
return false, check.Commentf("no leader elected")
}
return true, check.Commentf("elected %v", leader.ID())
}
}
// wait for an election to occur
waitAndAssert(c, defaultReconciliationTimeout, checkLeader(d2, d3), checker.True)
// assert that we have a new leader
c.Assert(leader, checker.NotNil)
// Keep track of the current leader, since we want that to be chosen.
stableleader := leader
// add the d1, the initial leader, back
d1.Start(c)
// TODO(stevvooe): may need to wait for rejoin here
// wait for possible election
waitAndAssert(c, defaultReconciliationTimeout, checkLeader(d1, d2, d3), checker.True)
// pick out the leader and the followers again
// verify that we still only have 1 leader and 2 followers
c.Assert(leader, checker.NotNil)
c.Assert(followers, checker.HasLen, 2)
// and that after we added d1 back, the leader hasn't changed
c.Assert(leader.NodeID, checker.Equals, stableleader.NodeID)
}