volumes: be more tolerant and fix infinite loop

Make Podman more tolerant when parsing image volumes during container
creation and further fix an infinite loop when checking them.

Consider `VOLUME ['/etc/foo', '/etc/bar']` in a Containerfile.  While
it looks correct to the human eye, the single quotes are wrong and yield
the two volumes to be `[/etc/foo,` and `/etc/bar]` in Podman and Docker.

When running the container, it'll create a directory `bar]` in `/etc`
and a directory `[` in `/` with two subdirectories `etc/foo,`.  This
behavior is surprising to me but how Docker behaves.  We may improve on
that in the future.  Note that the correct way to syntax for volumes in
a Containerfile is `VOLUME /A /B /C` or `VOLUME ["/A", "/B", "/C"]`;
single quotes are not supported.

This change restores this behavior without breaking container creation
or ending up in an infinite loop.

BZ: https://bugzilla.redhat.com/show_bug.cgi?id=2014149
Signed-off-by: Valentin Rothberg <[email protected]>

libpod/container_path_resolution.go

@@ -161,7 +161,7 @@ func isPathOnBindMount(c *Container, containerPath string) bool {
 		if cleanedContainerPath == filepath.Clean(m.Destination) {
 			return true
 		}
-		for dest := m.Destination; dest != "/"; dest = filepath.Dir(dest) {
+		for dest := m.Destination; dest != "/" && dest != "."; dest = filepath.Dir(dest) {
 			if cleanedContainerPath == dest {
 				return true
 			}

pkg/specgen/generate/storage.go

@@ -214,9 +214,6 @@ func getImageVolumes(ctx context.Context, img *libimage.Image, s *specgen.SpecGe
 	}
 	for volume := range inspect.Config.Volumes {
 		logrus.Debugf("Image has volume at %q", volume)
-		if err = parse.ValidateVolumeCtrDir(volume); err != nil {
-			return nil, nil, err
-		}
 		cleanDest := filepath.Clean(volume)
 		switch mode {
 		case "", "anonymous":

test/system/070-build.bats

@@ -39,6 +39,7 @@ EOF
     cat >$dockerfile <<EOF
 FROM $IMAGE
 RUN echo $rand_content > /$rand_filename
+VOLUME ['/etc/foo', '/etc/bar']
 EOF
 
     run_podman buildx build --load -t build_test --format=docker $tmpdir
@@ -47,6 +48,14 @@ EOF
     run_podman run --rm build_test cat /$rand_filename
     is "$output"   "$rand_content"   "reading generated file in image"
 
+    # Make sure the volumes are created at surprising yet Docker-compatible
+    # destinations (see bugzilla.redhat.com/show_bug.cgi?id=2014149).
+    run_podman run --rm build_test find /[ /etc/bar\] -print
+    is "$output" "/\[
+/\[/etc
+/\[/etc/foo,
+/etc/bar]" "weird VOLUME gets converted to directories with brackets and comma"
+
     run_podman rmi -f build_test
 }