diff --git a/testutil/daemon/daemon.go b/testutil/daemon/daemon.go index 9c8d3f9471b29..2106469ae2f5e 100644 --- a/testutil/daemon/daemon.go +++ b/testutil/daemon/daemon.go @@ -19,6 +19,7 @@ import ( "github.com/docker/docker/container" "github.com/docker/docker/pkg/ioutils" "github.com/docker/docker/pkg/stringid" + "github.com/docker/docker/pkg/tailfile" "github.com/docker/docker/testutil/request" "github.com/docker/go-connections/sockets" "github.com/docker/go-connections/tlsconfig" @@ -296,10 +297,41 @@ func (d *Daemon) Cleanup(t testing.TB) { cleanupNetworkNamespace(t, d) } +// TailLogsT attempts to tail N lines from the daemon logs. +// If there is an error the error is only logged, it does not cause an error with the test. +func (d *Daemon) TailLogsT(t LogT, n int) { + lines, err := d.TailLogs(n) + if err != nil { + t.Logf("[%s] %v", d.id, err) + return + } + for _, l := range lines { + t.Logf("[%s] %s", d.id, string(l)) + } +} + +// TailLogs tails N lines from the daemon logs +func (d *Daemon) TailLogs(n int) ([][]byte, error) { + logF, err := os.Open(d.logFile.Name()) + if err != nil { + return nil, errors.Wrap(err, "error opening daemon log file after failed start") + } + + defer logF.Close() + lines, err := tailfile.TailFile(logF, n) + if err != nil { + return nil, errors.Wrap(err, "error tailing log daemon logs") + } + + return lines, nil + +} + // Start starts the daemon and return once it is ready to receive requests. func (d *Daemon) Start(t testing.TB, args ...string) { t.Helper() if err := d.StartWithError(args...); err != nil { + d.TailLogsT(t, 20) d.DumpStackAndQuit() // in case the daemon is stuck t.Fatalf("[%s] failed to start daemon with arguments %v : %v", d.id, d.args, err) }