Added option to share kernel namespaces in libpod and podman

A pause container is added to the pod if the user opts in. The default pause image and command can be overridden. Pause containers are ignored in ps unless the -a option is present. Pod inspect and pod ps show shared namespaces and pause container. A pause container can't be removed with podman rm, and a pod can be removed if it only has a pause container.

Signed-off-by: haircommander <pehunt@redhat.com>

Closes: #1187
Approved by: mheon

1 files changed, 22 insertions, 0 deletions

diff --git a/libpod/container.go b/libpod/container.go
index b79258c43..2e2d29899 100644
--- a/libpod/container.go
+++ b/libpod/container.go
@@ -252,6 +252,19 @@ type ContainerConfig struct {
 	UTSNsCtr    string `json:"utsNsCtr,omitempty"`
 	CgroupNsCtr string `json:"cgroupNsCtr,omitempty"`
 
+	// Whether container shares an NS with the pod
+	// NetNsPod conflicts with the CreateNetNS bool
+	// {namespace}NsPod conflicts with {namespace}NsCtr
+	// The pause container will be considered dependencies of the given container
+	// It must be started before the given container is started
+	IPCNsPod    bool `json:"ipcNsPod,omitempty"`
+	MountNsPod  bool `json:"mountNsPod,omitempty"`
+	NetNsPod    bool `json:"netNsPod,omitempty"`
+	PIDNsPod    bool `json:"pidNsPod,omitempty"`
+	UserNsPod   bool `json:"userNsPod,omitempty"`
+	UTSNsPod    bool `json:"utsNsPod,omitempty"`
+	CgroupNsPod bool `json:"cgroupNsPod,omitempty"`
+
 	// IDs of dependency containers.
 	// These containers must be started before this container is started.
 	Dependencies []string
@@ -328,6 +341,10 @@ type ContainerConfig struct {
 	// LocalVolumes are the built-in volumes we get from the --volumes-from flag
 	// It picks up the built-in volumes of the container used by --volumes-from
 	LocalVolumes []string
+
+	// IsPause is a bool indicating whether this container is a pause container used for
+	// sharing kernel namespaces in a pod
+	IsPause bool `json:"pause"`
 }
 
 // ContainerStatus returns a string representation for users
@@ -956,3 +973,8 @@ func (c *Container) RootGID() int {
 	}
 	return 0
 }
+
+// IsPause returns whether the container is a pause container
+func (c *Container) IsPause() bool {
+	return c.config.IsPause
+}