add support to ; for comments in unit files as per systemd documentation

Signed-off-by: Ahmed Moalla <ahmed.moalla@gmail.com>

pkg/systemd/parser/unitfile.go

@@ -204,7 +204,7 @@ func (f *UnitFile) Dup() *UnitFile {
 }
 
 func lineIsComment(line string) bool {
-	return len(line) == 0 || line[0] == '#' || line[0] == ':'
+	return len(line) == 0 || line[0] == '#' || line[0] == ';'
 }
 
 func lineIsGroup(line string) bool {

pkg/systemd/parser/unitfile_test.go

@@ -314,6 +314,33 @@ func TestUnitDropinPaths_Search(t *testing.T) {
 	}
 }
 
+func TestCommentsIgnored(t *testing.T) {
+	unitWithComments := `[Container]
+# comment
+Name=my-container
+; another comment
+`
+	f := NewUnitFile()
+	if e := f.Parse(unitWithComments); e != nil {
+		panic(e)
+	}
+
+	groups := f.ListGroups()
+	assert.Len(t, groups, 1)
+	assert.Equal(t, "Container", groups[0])
+
+	comments := make([]string, 0, 2)
+	for _, line := range f.groups[0].lines {
+		if line.isComment {
+			comments = append(comments, line.value)
+		}
+	}
+
+	assert.Len(t, comments, 2)
+	assert.Equal(t, "# comment", comments[0])
+	assert.Equal(t, "; another comment", comments[1])
+}
+
 func FuzzParser(f *testing.F) {
 	for _, sample := range samples {
 		f.Add([]byte(sample))

test/e2e/quadlet/comment-with-continuation.container

@@ -11,11 +11,14 @@ After=network-online.target
 [Container]
 # Image=localhost/otherimagename:latest
 Image=localhost/imagename:latest
+; Image=localhost/image:latest
 ContainerName=greatName
+; ContainerName=otherName
 # HostName=my-hostname
 Label=io.containers.autoupdate=registry
 Environment=PUID=1000 PGID=100 SEED_RATIO=1.3 TZ=Europe/Prague
 Volume=./.config:/config
 Volume=./downloads:/downloads
 #   -v /path/to/watch/folder:/watch \
+;   -v /other/path/to/watch/folder:/watch \
 PublishPort=9091:9091