podman: assume user namespace if there are mappings

if some mappings are specified, assume there is a private user
namespace.

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

3 files changed, 12 insertions, 3 deletions

diff --git a/cmd/podman/common/specgen.go b/cmd/podman/common/specgen.go
index ce91e0b2e..ed45a6595 100644
--- a/cmd/podman/common/specgen.go
+++ b/cmd/podman/common/specgen.go
@@ -209,10 +209,15 @@ func FillOutSpecGen(s *specgen.SpecGenerator, c *ContainerCLIOpts, args []string
 		}
 	}
 
-	s.IDMappings, err = util.ParseIDMapping(ns.UsernsMode(c.UserNS), c.UIDMap, c.GIDMap, c.SubUIDName, c.SubGIDName)
+	userNS := ns.UsernsMode(c.UserNS)
+	s.IDMappings, err = util.ParseIDMapping(userNS, c.UIDMap, c.GIDMap, c.SubUIDName, c.SubGIDName)
 	if err != nil {
 		return err
 	}
+	// If some mappings are specified, assume a private user namespace
+	if userNS.IsDefaultValue() && (!s.IDMappings.HostUIDMapping || !s.IDMappings.HostGIDMapping) {
+		s.UserNS.NSMode = specgen.Private
+	}
 
 	s.Terminal = c.TTY
 	ep, err := ExposedPorts(c.Expose, c.Net.PublishPorts, c.PublishAll, nil)
diff --git a/pkg/namespaces/namespaces.go b/pkg/namespaces/namespaces.go
index 2cb3c3f20..2ffbde977 100644
--- a/pkg/namespaces/namespaces.go
+++ b/pkg/namespaces/namespaces.go
@@ -31,7 +31,7 @@ func (n CgroupMode) IsHost() bool {
 
 // IsDefaultValue indicates whether the cgroup namespace has the default value.
 func (n CgroupMode) IsDefaultValue() bool {
-	return n == ""
+	return n == "" || n == defaultType
 }
 
 // IsNS indicates a cgroup namespace passed in by path (ns:<path>)
@@ -102,6 +102,11 @@ func (n UsernsMode) IsAuto() bool {
 	return parts[0] == "auto"
 }
 
+// IsDefaultValue indicates whether the user namespace has the default value.
+func (n UsernsMode) IsDefaultValue() bool {
+	return n == "" || n == defaultType
+}
+
 // GetAutoOptions returns a AutoUserNsOptions with the settings to setup automatically
 // a user namespace.
 func (n UsernsMode) GetAutoOptions() (*storage.AutoUserNsOptions, error) {
diff --git a/test/e2e/run_userns_test.go b/test/e2e/run_userns_test.go
index d4b4f9024..25f12ec2e 100644
--- a/test/e2e/run_userns_test.go
+++ b/test/e2e/run_userns_test.go
@@ -218,7 +218,6 @@ var _ = Describe("Podman UserNS support", func() {
 	})
 
 	It("podman --userns=container:CTR", func() {
-		Skip(v2fail)
 		ctrName := "userns-ctr"
 		session := podmanTest.Podman([]string{"run", "-d", "--uidmap=0:0:1", "--uidmap=1:1:4998", "--name", ctrName, "alpine", "top"})
 		session.WaitWithDefaultTimeout()