fix(logs): improve timestamp precision in container logs

pkg/api/handlers/compat/containers_logs.go

@@ -155,7 +155,7 @@ func LogsFromContainer(w http.ResponseWriter, r *http.Request) {
 		}
 
 		if query.Timestamps {
-			frame.WriteString(line.Time.Format(time.RFC3339))
+			frame.WriteString(line.Time.Format(logs.LogTimeFormat))
 			frame.WriteString(" ")
 		}
 

test/apiv2/20-containers.at

@@ -159,6 +159,18 @@ like "$(<$WORKDIR/curl.headers.out)" ".*HTTP.* 200 OK.*" \
 
 podman rm -f -t0 $CTRNAME
 
+# verify API logs return timestamps with nanosecond precision
+CTRNAME=timestamp-test
+podman run --name $CTRNAME -d $IMAGE sh -c "echo test message"
+podman wait $CTRNAME
+t GET "containers/${CTRNAME}/logs?timestamps=true&stdout=true" 200
+# /logs returns application/octet-stream with binary headers. Strip null bytes.
+# Verify timestamp format includes nanoseconds (LogTimeFormat with 9 zero-padded digits)
+# Timezone can be 'Z' (UTC) or '+/-HH:MM'
+like "$(tr -d \\0 <$WORKDIR/curl.result.out)" ".*[0-9]\\{4\\}-[0-9]\\{2\\}-[0-9]\\{2\\}T[0-9]\\{2\\}:[0-9]\\{2\\}:[0-9]\\{2\\}\\.[0-9]\\{9\\}\\(Z\\|[+-][0-9]\\{2\\}:[0-9]\\{2\\}\\).*test message.*" \
+     "logs timestamps should include nanosecond precision"
+podman rm -f $CTRNAME
+
 CTRNAME=test123
 podman run --name $CTRNAME -d $IMAGE top
 t GET libpod/containers/$CTRNAME/top?ps_args=--invalid 500 \

test/e2e/logs_test.go

@@ -182,6 +182,29 @@ var _ = Describe("Podman logs", func() {
 			}).WithTimeout(logTimeout).Should(Succeed())
 		})
 
+		It("timestamps with nanosecond precision: "+log, func() {
+			skipIfJournaldInContainer()
+
+			logc := podmanTest.Podman([]string{"run", "--log-driver", log, "-dt", ALPINE, "echo", "test message"})
+			logc.WaitWithDefaultTimeout()
+			Expect(logc).To(ExitCleanly())
+			cid := logc.OutputToString()
+
+			wait := podmanTest.Podman([]string{"wait", cid})
+			wait.WaitWithDefaultTimeout()
+			Expect(wait).To(ExitCleanly())
+
+			Eventually(func(g Gomega) {
+				results := podmanTest.Podman([]string{"logs", "-t", cid})
+				results.WaitWithDefaultTimeout()
+				g.Expect(results).To(ExitCleanly())
+				// LogTimeFormat: 2006-01-02T15:04:05.000000000Z07:00
+				// Verify timestamp contains nanoseconds (exactly 9 digits, zero-padded)
+				// Timezone can be 'Z' (UTC) or '+/-HH:MM'
+				g.Expect(results.OutputToString()).To(MatchRegexp(`\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{9}(Z|[+-]\d{2}:\d{2})\s+test message`))
+			}).WithTimeout(logTimeout).Should(Succeed())
+		})
+
 		It("since time 2017-08-07: "+log, func() {
 			skipIfJournaldInContainer()