Add network namespaces to SQL state

Signed-off-by: Matthew Heon <matthew.heon@gmail.com>

Closes: #109
Approved by: mheon

4 files changed, 98 insertions, 21 deletions

diff --git a/libpod/container.go b/libpod/container.go
index 12fd13f51..ada037531 100644
--- a/libpod/container.go
+++ b/libpod/container.go
@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"github.com/containerd/cgroups"
+	"github.com/containernetworking/plugins/pkg/ns"
 	"github.com/containers/storage"
 	"github.com/containers/storage/pkg/archive"
 	"github.com/cri-o/ocicni/pkg/ocicni"
@@ -100,6 +101,10 @@ type containerRuntimeInfo struct {
 	OOMKilled bool `json:"oomKilled,omitempty"`
 	// PID is the PID of a running container
 	PID int `json:"pid,omitempty"`
+	// NetNSPath is the path of the container's network namespace
+	// Will only be set if config.CreateNetNS is true, or the container was
+	// told to join another container's network namespace
+	NetNS ns.NetNS
 	// TODO: Save information about image used in container if one is used
 }
 
diff --git a/libpod/networking.go b/libpod/networking.go
index 893d6863a..f613ad5f8 100644
--- a/libpod/networking.go
+++ b/libpod/networking.go
@@ -3,11 +3,12 @@ package libpod
 import (
 	"github.com/containernetworking/plugins/pkg/ns"
 	"github.com/cri-o/ocicni/pkg/ocicni"
+	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
 
 // Get an OCICNI network config
-func getPodNetwork(id, name, nsPath string, ports []ocicni.PortMappings) ocicni.PodNetwork {
+func getPodNetwork(id, name, nsPath string, ports []ocicni.PortMapping) ocicni.PodNetwork {
 	return ocicni.PodNetwork{
 		Name:         name,
 		Namespace:    name, // TODO is there something else we should put here? We don't know about Kube namespaces
@@ -17,29 +18,31 @@ func getPodNetwork(id, name, nsPath string, ports []ocicni.PortMappings) ocicni.
 	}
 }
 
-// Create and configure a new network namespace
-func (r *Runtime) createNetNS(id, name string, ports []ocicni.PortMapping) (n ns.NetNS, err error) {
+// Create and configure a new network namespace for a container
+func (r *Runtime) createNetNS(ctr *Container) (err error) {
 	ns, err := ns.NewNS()
 	if err != nil {
-		return nil, errors.Wrapf(err, "error creating network namespace %s", id)
+		return errors.Wrapf(err, "error creating network namespace for container %s", ctr.ID())
 	}
 	defer func() {
 		if err != nil {
 			if err2 := ns.Close(); err2 != nil {
-				logrus.Errorf("Error closing partially created network namespace %s: %v", id, err2)
+				logrus.Errorf("Error closing partially created network namespace for container %s: %v", ctr.ID(), err2)
 			}
 		}
 	}()
 
-	podNetwork := getPodNetwork(id, name, ns.Path(), ports)
+	podNetwork := getPodNetwork(ctr.ID(), ctr.Name(), ns.Path(), ctr.config.PortMappings)
 
 	if err := r.netPlugin.SetUpPod(podNetwork); err != nil {
-		return nil, errors.Wrapf(err, "error configuring network namespace %s", id)
+		return errors.Wrapf(err, "error configuring network namespace for container %s", ctr.ID())
 	}
 
 	// TODO hostport mappings for forwarded ports
 
-	return ns, nil
+	ctr.state.NetNS = ns
+
+	return nil
 }
 
 // Join an existing network namespace
@@ -53,13 +56,25 @@ func joinNetNS(path string) (ns.NetNS, error) {
 }
 
 // Tear down a network namespace
-func (r *Runtime) teardownNetNS(id, name string, ports []ocicni.PortMapping, ns ns.NetNS) error {
+func (r *Runtime) teardownNetNS(ctr *Container) error {
+	if ctr.state.NetNS == nil {
+		// The container has no network namespace, we're set
+		return nil
+	}
+
 	// TODO hostport mappings for forwarded ports should be undone
-	podNetwork := getPodNetwork(id, name, ns.Path(), ports)
+	podNetwork := getPodNetwork(ctr.ID(), ctr.Name(), ctr.state.NetNS.Path(), ctr.config.PortMappings)
 
+	// The network may have already been torn down, so don't fail here, just log
 	if err := r.netPlugin.TearDownPod(podNetwork); err != nil {
-		return errors.Wrapf(err, "failed to remove network namespace %s", id)
+		logrus.Errorf("Failed to tear down network namespace for container %s: %v", ctr.ID(), err)
+	}
+
+	if err := ctr.state.NetNS.Close(); err != nil {
+		return errors.Wrapf(err, "error closing network namespace for container %s", ctr.ID())
 	}
 
+	ctr.state.NetNS = nil
+
 	return nil
 }
diff --git a/libpod/sql_state.go b/libpod/sql_state.go
index d0969a783..97df749e9 100644
--- a/libpod/sql_state.go
+++ b/libpod/sql_state.go
@@ -15,7 +15,7 @@ import (
 
 // DBSchema is the current DB schema version
 // Increments every time a change is made to the database's tables
-const DBSchema = 3
+const DBSchema = 4
 
 // SQLState is a state implementation backed by a persistent SQLite3 database
 type SQLState struct {
@@ -151,7 +151,8 @@ func (s *SQLState) Container(id string) (*Container, error) {
                               containerState.FinishedTime,
                               containerState.ExitCode,
                               containerState.OomKilled,
-                              containerState.Pid
+                              containerState.Pid,
+                              containerState.NetNSPath
                        FROM containers
                        INNER JOIN
                            containerState ON containers.Id = containerState.Id
@@ -186,7 +187,8 @@ func (s *SQLState) LookupContainer(idOrName string) (*Container, error) {
                               containerState.FinishedTime,
                               containerState.ExitCode,
                               containerState.OomKilled,
-                              containerState.Pid
+                              containerState.Pid,
+                              containerState.NetNSPath
                        FROM containers
                        INNER JOIN
                            containerState ON containers.Id = containerState.Id
@@ -270,7 +272,7 @@ func (s *SQLState) AddContainer(ctr *Container) (err error) {
                     ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?
                 );`
 		addCtrState = `INSERT INTO containerState VALUES (
-                    ?, ?, ?, ?, ?, ?, ?, ?, ?, ?
+                    ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?
                 );`
 	)
 
@@ -297,6 +299,11 @@ func (s *SQLState) AddContainer(ctr *Container) (err error) {
 		return errors.Wrapf(err, "error marshaling container %s port mappings to JSON", ctr.ID())
 	}
 
+	netNSPath := ""
+	if ctr.state.NetNS != nil {
+		netNSPath = ctr.state.NetNS.Path()
+	}
+
 	tx, err := s.db.Begin()
 	if err != nil {
 		return errors.Wrapf(err, "error beginning database transaction")
@@ -342,7 +349,8 @@ func (s *SQLState) AddContainer(ctr *Container) (err error) {
 		timeToSQL(ctr.state.FinishedTime),
 		ctr.state.ExitCode,
 		boolToSQL(ctr.state.OOMKilled),
-		ctr.state.PID)
+		ctr.state.PID,
+		netNSPath)
 	if err != nil {
 		return errors.Wrapf(err, "error adding container %s state to database", ctr.ID())
 	}
@@ -381,7 +389,8 @@ func (s *SQLState) UpdateContainer(ctr *Container) error {
                               FinishedTime,
                               ExitCode,
                               OomKilled,
-                              Pid
+                              Pid,
+                              NetNSPath
                        FROM containerState WHERE ID=?;`
 
 	var (
@@ -394,6 +403,7 @@ func (s *SQLState) UpdateContainer(ctr *Container) error {
 		exitCode           int32
 		oomKilled          int
 		pid                int
+		netNSPath          string
 	)
 
 	if !s.valid {
@@ -414,7 +424,8 @@ func (s *SQLState) UpdateContainer(ctr *Container) error {
 		&finishedTimeString,
 		&exitCode,
 		&oomKilled,
-		&pid)
+		&pid,
+		&netNSPath)
 	if err != nil {
 		// The container may not exist in the database
 		if err == sql.ErrNoRows {
@@ -453,6 +464,32 @@ func (s *SQLState) UpdateContainer(ctr *Container) error {
 	}
 	newState.FinishedTime = finishedTime
 
+	// Do we need to replace the container's netns?
+	if netNSPath != "" {
+		// Check if the container's old state has a good netns
+		if ctr.state.NetNS != nil && netNSPath == ctr.state.NetNS.Path() {
+			newState.NetNS = ctr.state.NetNS
+		} else {
+			// Tear down the existing namespace
+			if err := s.runtime.teardownNetNS(ctr); err != nil {
+				return err
+			}
+
+			// Open the new network namespace
+			ns, err := joinNetNS(netNSPath)
+			if err != nil {
+				return errors.Wrapf(err, "error joining network namespace for container %s", ctr.ID())
+			}
+			newState.NetNS = ns
+		}
+	} else  {
+		// The container no longer has a network namespace
+		// Tear down the old one
+		if err := s.runtime.teardownNetNS(ctr); err != nil {
+			return err
+		}
+	}
+
 	// New state compiled successfully, swap it into the current state
 	ctr.state = newState
 
@@ -470,9 +507,15 @@ func (s *SQLState) SaveContainer(ctr *Container) error {
                           FinishedTime=?,
                           ExitCode=?,
                           OomKilled=?,
-                          Pid=?
+                          Pid=?,
+                          NetNSPath=?
                        WHERE Id=?;`
 
+	netNSPath := ""
+	if ctr.state.NetNS != nil {
+		netNSPath = ctr.state.NetNS.Path()
+	}
+
 	if !s.valid {
 		return ErrDBClosed
 	}
@@ -504,6 +547,7 @@ func (s *SQLState) SaveContainer(ctr *Container) error {
 		ctr.state.ExitCode,
 		boolToSQL(ctr.state.OOMKilled),
 		ctr.state.PID,
+		netNSPath,
 		ctr.ID())
 	if err != nil {
 		return errors.Wrapf(err, "error updating container %s state in database", ctr.ID())
@@ -593,7 +637,8 @@ func (s *SQLState) AllContainers() ([]*Container, error) {
                               containerState.FinishedTime,
                               containerState.ExitCode,
                               containerState.OomKilled,
-                              containerState.Pid
+                              containerState.Pid,
+                              containerState.NetNSPath
                       FROM containers
                       INNER JOIN
                           containerState ON containers.Id = containerState.Id
diff --git a/libpod/sql_state_internal.go b/libpod/sql_state_internal.go
index 1d1878b9d..e1ecc8ea6 100644
--- a/libpod/sql_state_internal.go
+++ b/libpod/sql_state_internal.go
@@ -200,6 +200,7 @@ func prepareDB(db *sql.DB) (err error) {
             ExitCode INTEGER NOT NULL,
             OomKilled INTEGER NOT NULL,
             Pid INTEGER NOT NULL,
+            NetNSPath TEXT NOT NULL,
             CHECK (State>0),
             CHECK (OomKilled IN (0, 1)),
             FOREIGN KEY (Id) REFERENCES containers(Id) DEFERRABLE INITIALLY DEFERRED
@@ -296,6 +297,7 @@ func ctrFromScannable(row scannable, runtime *Runtime, specsDir string, lockDir
 		exitCode           int32
 		oomKilled          int
 		pid                int
+		netNSPath          string
 	)
 
 	err := row.Scan(
@@ -323,7 +325,8 @@ func ctrFromScannable(row scannable, runtime *Runtime, specsDir string, lockDir
 		&finishedTimeString,
 		&exitCode,
 		&oomKilled,
-		&pid)
+		&pid,
+		&netNSPath)
 	if err != nil {
 		if err == sql.ErrNoRows {
 			return nil, ErrNoSuchCtr
@@ -394,6 +397,15 @@ func ctrFromScannable(row scannable, runtime *Runtime, specsDir string, lockDir
 	}
 	ctr.state.FinishedTime = finishedTime
 
+	// Join the network namespace, if there is one
+	if netNSPath != "" {
+		netNS, err := joinNetNS(netNSPath)
+		if err != nil {
+			return nil, errors.Wrapf(err, "error joining network namespace for container %s", id)
+		}
+		ctr.state.NetNS = netNS
+	}
+
 	ctr.valid = true
 	ctr.runtime = runtime