logs: k8s-file: fix race

Fix a race in the k8s-file logs driver.  When "following" the logs,
Podman will print the container's logs until the end.  Previously,
Podman logged until the state transitioned into something non-running
which opened up a race with the container still running, possibly in
the "stopping" state.

To fix the race, log until we've seen the wait event for the specific
container.  In that case, conmon will have finished writing all logs to
the file, and Podman will read it until EOF.

Further tweak the integration tests for testing `logs -f` on a  running
container.  Previously, the test only checked for one of two lines
stating that there was a race.  Indeed the race was in using `run --rm`
where a log file may be removed before we could fully read it.

Fixes: #10596
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

1 files changed, 8 insertions, 6 deletions

diff --git a/test/e2e/logs_test.go b/test/e2e/logs_test.go
index 4d9cbb48b..b576fa072 100644
--- a/test/e2e/logs_test.go
+++ b/test/e2e/logs_test.go
@@ -173,9 +173,9 @@ var _ = Describe("Podman logs", func() {
 		})
 
 		It("streaming output: "+log, func() {
-			containerName := "logs-f-rm"
+			containerName := "logs-f"
 
-			logc := podmanTest.Podman([]string{"run", "--log-driver", log, "--rm", "--name", containerName, "-dt", ALPINE, "sh", "-c", "echo podman; sleep 1; echo podman"})
+			logc := podmanTest.Podman([]string{"run", "--log-driver", log, "--name", containerName, "-dt", ALPINE, "sh", "-c", "echo podman-1; sleep 1; echo podman-2"})
 			logc.WaitWithDefaultTimeout()
 			Expect(logc).To(Exit(0))
 
@@ -183,10 +183,8 @@ var _ = Describe("Podman logs", func() {
 			results.WaitWithDefaultTimeout()
 			Expect(results).To(Exit(0))
 
-			// TODO: we should actually check for two podman lines,
-			// but as of 2020-06-17 there's a race condition in which
-			// 'logs -f' may not catch all output from a container
-			Expect(results.OutputToString()).To(ContainSubstring("podman"))
+			Expect(results.OutputToString()).To(ContainSubstring("podman-1"))
+			Expect(results.OutputToString()).To(ContainSubstring("podman-2"))
 
 			// Container should now be terminatING or terminatED, but we
 			// have no guarantee of which: 'logs -f' does not necessarily
@@ -199,6 +197,10 @@ var _ = Describe("Podman logs", func() {
 			} else {
 				Expect(inspect.ErrorToString()).To(ContainSubstring("no such container"))
 			}
+
+			results = podmanTest.Podman([]string{"rm", "-f", containerName})
+			results.WaitWithDefaultTimeout()
+			Expect(results).To(Exit(0))
 		})
 
 		It("follow output stopped container: "+log, func() {