fn: enable failing test back (#826)

* fn: enable failing test back

* fn: fortifying the stderr output

Modified limitWriter to discard excess data instead
of returning error, this is to allow stderr/stdout
pipes flowing to avoid head-of-line blocking or
data corruption in container stdout/stderr output stream.

api/server/runner_test.go

@@ -146,16 +146,17 @@ func TestRouteRunnerPost(t *testing.T) {
 	}
 }
 
-// removing this flappy test pending on resolution of
-func skipTestRouteRunnerIOPipes(t *testing.T) {
+func TestRouteRunnerIOPipes(t *testing.T) {
 	buf := setLogBuffer()
 	isFailure := false
 
 	// let's make freezer immediate, so that we don't deal with
 	// more timing related issues below. Slightly gains us a bit more
 	// determinism.
-	tweaker := envTweaker("FN_FREEZE_IDLE_MSECS", "0")
-	defer tweaker()
+	tweaker1 := envTweaker("FN_FREEZE_IDLE_MSECS", "0")
+	tweaker2 := envTweaker("FN_MAX_LOG_SIZE", "5")
+	defer tweaker1()
+	defer tweaker2()
 
 	// Log once after we are done, flow of events are important (hot/cold containers, idle timeout, etc.)
 	// for figuring out why things failed.
@@ -188,8 +189,6 @@ func skipTestRouteRunnerIOPipes(t *testing.T) {
 	delayedGarbage := `{"isDebug": true, "postOutGarbage": "YOGURT_YOGURT_YOGURT", "postSleepTime": 1000}`
 	ok := `{"isDebug": true}`
 
-	//multiLogExpect := []string{"BeginOfLogs", "EndOfLogs"}
-
 	containerIds := make([]string, 0)
 
 	for i, test := range []struct {
@@ -276,7 +275,6 @@ func skipTestRouteRunnerIOPipes(t *testing.T) {
 		t.Logf("Test %d: dockerId: %v", i, containerIds[i])
 		time.Sleep(test.sleepAmount)
 	}
-
 	jsonIds := containerIds[0:4]
 
 	// now cross check JSON container ids: