podman logs on created container should exit

when running podman logs on a created container (which has no logs),
podman should return gracefully (like docker) with a 0 return code. if
multiple containers are provided and one is only in the created state
(and no follow is used), we still display the logs for the other ids.

fixes issue #2677

Signed-off-by: baude <bbaude@redhat.com>

2 files changed, 16 insertions, 1 deletions

diff --git a/libpod/container_log.go b/libpod/container_log.go
index 7964e4022..e998ad316 100644
--- a/libpod/container_log.go
+++ b/libpod/container_log.go
@@ -3,6 +3,7 @@ package libpod
 import (
 	"fmt"
 	"io/ioutil"
+	"os"
 	"strings"
 	"sync"
 	"time"
@@ -54,6 +55,10 @@ func (r *Runtime) Log(containers []*Container, options *LogOptions, logChannel c
 func (c *Container) ReadLog(options *LogOptions, logChannel chan *LogLine) error {
 	t, tailLog, err := getLogFile(c.LogPath(), options)
 	if err != nil {
+		// If the log file does not exist, this is not fatal.
+		if os.IsNotExist(errors.Cause(err)) {
+			return nil
+		}
 		return errors.Wrapf(err, "unable to read log file %s for %s ", c.ID(), c.LogPath())
 	}
 	options.WaitGroup.Add(1)
@@ -111,7 +116,7 @@ func getLogFile(path string, options *LogOptions) (*tail.Tail, []*LogLine, error
 		Whence: whence,
 	}
 
-	t, err := tail.TailFile(path, tail.Config{Poll: true, Follow: options.Follow, Location: &seek, Logger: tail.DiscardingLogger})
+	t, err := tail.TailFile(path, tail.Config{MustExist: true, Poll: true, Follow: options.Follow, Location: &seek, Logger: tail.DiscardingLogger})
 	return t, logTail, err
 }
 
diff --git a/test/e2e/logs_test.go b/test/e2e/logs_test.go
index d383a83b3..d051e3dba 100644
--- a/test/e2e/logs_test.go
+++ b/test/e2e/logs_test.go
@@ -132,4 +132,14 @@ var _ = Describe("Podman logs", func() {
 		Expect(len(output)).To(Equal(6))
 		Expect(strings.Contains(output[0], cid1[:12]) || strings.Contains(output[0], cid2[:12])).To(BeTrue())
 	})
+
+	It("podman logs on a created container should result in 0 exit code", func() {
+		session := podmanTest.Podman([]string{"create", "-dt", "--name", "log", ALPINE})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(BeZero())
+
+		results := podmanTest.Podman([]string{"logs", "log"})
+		results.WaitWithDefaultTimeout()
+		Expect(results.ExitCode()).To(BeZero())
+	})
 })