Allow --ro=[true|false] with mount flag

The 'podman run --mount' flag previously allowed the 'ro' option
to be specified, but was missing the ability to set it to a bool
(as is allowed by docker). Add that. While we're at it, allow
setting 'rw' explicitly as well.

Fixes containers#2980

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

pkg/spec/storage.go

@@ -410,13 +410,42 @@ func getBindMount(args []string) (spec.Mount, error) {
 
 	setSource := false
 	setDest := false
+	setRORW := false
 
 	for _, val := range args {
 		kv := strings.Split(val, "=")
 		switch kv[0] {
 		case "bind-nonrecursive":
 			newMount.Options = append(newMount.Options, "bind")
-		case "ro", "nosuid", "nodev", "noexec":
+		case "ro", "rw":
+			if setRORW {
+				return newMount, errors.Wrapf(optionArgError, "cannot pass 'ro' or 'rw' options more than once")
+			}
+			setRORW = true
+			// Can be formatted as one of:
+			// ro
+			// ro=[true|false]
+			// rw
+			// rw=[true|false]
+			if len(kv) == 1 {
+				newMount.Options = append(newMount.Options, kv[0])
+			} else if len(kv) == 2 {
+				switch strings.ToLower(kv[1]) {
+				case "true":
+					newMount.Options = append(newMount.Options, kv[0])
+				case "false":
+					// Set the opposite only for rw
+					// ro's opposite is the default
+					if kv[0] == "rw" {
+						newMount.Options = append(newMount.Options, "ro")
+					}
+				default:
+					return newMount, errors.Wrapf(optionArgError, "%s must be set to true or false, instead received %q", kv[0], kv[1])
+				}
+			} else {
+				return newMount, errors.Wrapf(optionArgError, "badly formatted option %q", val)
+			}
+		case "nosuid", "nodev", "noexec":
 			// TODO: detect duplication of these options.
 			// (Is this necessary?)
 			newMount.Options = append(newMount.Options, kv[0])

test/e2e/run_volume_test.go

@@ -136,4 +136,22 @@ var _ = Describe("Podman run with volumes", func() {
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 	})
+
+	It("podman run with mount flag and boolean options", func() {
+		mountPath := filepath.Join(podmanTest.TempDir, "secrets")
+		os.Mkdir(mountPath, 0755)
+		session := podmanTest.Podman([]string{"run", "--rm", "--mount", fmt.Sprintf("type=bind,src=%s,target=/run/test,ro=false", mountPath), ALPINE, "grep", "/run/test", "/proc/self/mountinfo"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		Expect(session.OutputToString()).To(ContainSubstring("/run/test rw"))
+
+		session = podmanTest.Podman([]string{"run", "--rm", "--mount", fmt.Sprintf("type=bind,src=%s,target=/run/test,ro=true", mountPath), ALPINE, "grep", "/run/test", "/proc/self/mountinfo"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+		Expect(session.OutputToString()).To(ContainSubstring("/run/test ro"))
+
+		session = podmanTest.Podman([]string{"run", "--rm", "--mount", fmt.Sprintf("type=bind,src=%s,target=/run/test,ro=true,rw=false", mountPath), ALPINE, "grep", "/run/test", "/proc/self/mountinfo"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Not(Equal(0)))
+	})
 })