Add tracking for container exec sessions to DB

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

Closes: #412
Approved by: baude

libpod/boltdb_state.go

@@ -140,6 +140,9 @@ func (s *BoltState) Refresh() error {
 			state.Mountpoint = ""
 			state.Mounted = false
 			state.State = ContainerStateConfigured
+			state.IPAddress = ""
+			state.SubnetMask = ""
+			state.ExecSessions = make(map[string]int)
 
 			newStateBytes, err := json.Marshal(state)
 			if err != nil {

libpod/container.go

@@ -141,6 +141,9 @@ type containerState struct {
 	IPAddress string `json:"ipAddress"`
 	// Subnet mask of container (if network namespace was created)
 	SubnetMask string `json:"subnetMask"`
+	// ExecSessions contains active exec sessions for container
+	// Exec session ID is mapped to PID of exec process
+	ExecSessions map[string]int `json:"execSessions,omitempty"`
 }
 
 // ContainerConfig contains all information that was used to create the
@@ -574,7 +577,8 @@ func (c *Container) OOMKilled() (bool, error) {
 }
 
 // PID returns the PID of the container
-// An error is returned if the container is not running
+// If the container is not running, a pid of 0 will be returned. No error will
+// occur.
 func (c *Container) PID() (int, error) {
 	if !c.locked {
 		c.lock.Lock()
@@ -588,6 +592,26 @@ func (c *Container) PID() (int, error) {
 	return c.state.PID, nil
 }
 
+// ExecSessions retrieves active exec sessions running in the container
+// The result is a map from session ID to the PID of the exec process
+func (c *Container) ExecSessions() (map[string]int, error) {
+	if !c.locked {
+		c.lock.Lock()
+		defer c.lock.Unlock()
+
+		if err := c.syncContainer(); err != nil {
+			return nil, err
+		}
+	}
+
+	returnMap := make(map[string]int, len(c.state.ExecSessions))
+	for k, v := range c.state.ExecSessions {
+		returnMap[k] = v
+	}
+
+	return returnMap, nil
+}
+
 // Misc Accessors
 // Most will require locking
 

libpod/container_ffjson.go

@@ -2439,7 +2439,7 @@ func (j *containerState) MarshalJSONBuf(buf fflib.EncodingBuffer) error {
 	var obj []byte
 	_ = obj
 	_ = err
-	buf.WriteString(`{"state":`)
+	buf.WriteString(`{ "state":`)
 	fflib.FormatBits2(buf, uint64(j.State), 10, j.State < 0)
 	buf.WriteByte(',')
 	if len(j.ConfigPath) != 0 {
@@ -2515,6 +2515,24 @@ func (j *containerState) MarshalJSONBuf(buf fflib.EncodingBuffer) error {
 	fflib.WriteJsonString(buf, string(j.IPAddress))
 	buf.WriteString(`,"subnetMask":`)
 	fflib.WriteJsonString(buf, string(j.SubnetMask))
+	buf.WriteByte(',')
+	if len(j.ExecSessions) != 0 {
+		if j.ExecSessions == nil {
+			buf.WriteString(`"execSessions":null`)
+		} else {
+			buf.WriteString(`"execSessions":{ `)
+			for key, value := range j.ExecSessions {
+				fflib.WriteJsonString(buf, key)
+				buf.WriteString(`:`)
+				fflib.FormatBits2(buf, uint64(value), 10, value < 0)
+				buf.WriteByte(',')
+			}
+			buf.Rewind(1)
+			buf.WriteByte('}')
+		}
+		buf.WriteByte(',')
+	}
+	buf.Rewind(1)
 	buf.WriteByte('}')
 	return nil
 }
@@ -2546,6 +2564,8 @@ const (
 	ffjtcontainerStateIPAddress
 
 	ffjtcontainerStateSubnetMask
+
+	ffjtcontainerStateExecSessions
 )
 
 var ffjKeycontainerStateState = []byte("state")
@@ -2572,6 +2592,8 @@ var ffjKeycontainerStateIPAddress = []byte("ipAddress")
 
 var ffjKeycontainerStateSubnetMask = []byte("subnetMask")
 
+var ffjKeycontainerStateExecSessions = []byte("execSessions")
+
 // UnmarshalJSON umarshall json - template of ffjson
 func (j *containerState) UnmarshalJSON(input []byte) error {
 	fs := fflib.NewFFLexer(input)
@@ -2647,6 +2669,11 @@ mainparse:
 						currentKey = ffjtcontainerStateExitCode
 						state = fflib.FFParse_want_colon
 						goto mainparse
+
+					} else if bytes.Equal(ffjKeycontainerStateExecSessions, kn) {
+						currentKey = ffjtcontainerStateExecSessions
+						state = fflib.FFParse_want_colon
+						goto mainparse
 					}
 
 				case 'f':
@@ -2722,6 +2749,12 @@ mainparse:
 
 				}
 
+				if fflib.EqualFoldRight(ffjKeycontainerStateExecSessions, kn) {
+					currentKey = ffjtcontainerStateExecSessions
+					state = fflib.FFParse_want_colon
+					goto mainparse
+				}
+
 				if fflib.EqualFoldRight(ffjKeycontainerStateSubnetMask, kn) {
 					currentKey = ffjtcontainerStateSubnetMask
 					state = fflib.FFParse_want_colon
@@ -2847,6 +2880,9 @@ mainparse:
 				case ffjtcontainerStateSubnetMask:
 					goto handle_SubnetMask
 
+				case ffjtcontainerStateExecSessions:
+					goto handle_ExecSessions
+
 				case ffjtcontainerStatenosuchkey:
 					err = fs.SkipField(tok)
 					if err != nil {
@@ -3201,6 +3237,115 @@ handle_SubnetMask:
 	state = fflib.FFParse_after_value
 	goto mainparse
 
+handle_ExecSessions:
+
+	/* handler: j.ExecSessions type=map[string]int kind=map quoted=false*/
+
+	{
+
+		{
+			if tok != fflib.FFTok_left_bracket && tok != fflib.FFTok_null {
+				return fs.WrapErr(fmt.Errorf("cannot unmarshal %s into Go value for ", tok))
+			}
+		}
+
+		if tok == fflib.FFTok_null {
+			j.ExecSessions = nil
+		} else {
+
+			j.ExecSessions = make(map[string]int, 0)
+
+			wantVal := true
+
+			for {
+
+				var k string
+
+				var tmpJExecSessions int
+
+				tok = fs.Scan()
+				if tok == fflib.FFTok_error {
+					goto tokerror
+				}
+				if tok == fflib.FFTok_right_bracket {
+					break
+				}
+
+				if tok == fflib.FFTok_comma {
+					if wantVal == true {
+						// TODO(pquerna): this isn't an ideal error message, this handles
+						// things like [,,,] as an array value.
+						return fs.WrapErr(fmt.Errorf("wanted value token, but got token: %v", tok))
+					}
+					continue
+				} else {
+					wantVal = true
+				}
+
+				/* handler: k type=string kind=string quoted=false*/
+
+				{
+
+					{
+						if tok != fflib.FFTok_string && tok != fflib.FFTok_null {
+							return fs.WrapErr(fmt.Errorf("cannot unmarshal %s into Go value for string", tok))
+						}
+					}
+
+					if tok == fflib.FFTok_null {
+
+					} else {
+
+						outBuf := fs.Output.Bytes()
+
+						k = string(string(outBuf))
+
+					}
+				}
+
+				// Expect ':' after key
+				tok = fs.Scan()
+				if tok != fflib.FFTok_colon {
+					return fs.WrapErr(fmt.Errorf("wanted colon token, but got token: %v", tok))
+				}
+
+				tok = fs.Scan()
+				/* handler: tmpJExecSessions type=int kind=int quoted=false*/
+
+				{
+					if tok != fflib.FFTok_integer && tok != fflib.FFTok_null {
+						return fs.WrapErr(fmt.Errorf("cannot unmarshal %s into Go value for int", tok))
+					}
+				}
+
+				{
+
+					if tok == fflib.FFTok_null {
+
+					} else {
+
+						tval, err := fflib.ParseInt(fs.Output.Bytes(), 10, 64)
+
+						if err != nil {
+							return fs.WrapErr(err)
+						}
+
+						tmpJExecSessions = int(tval)
+
+					}
+				}
+
+				j.ExecSessions[k] = tmpJExecSessions
+
+				wantVal = false
+			}
+
+		}
+	}
+
+	state = fflib.FFParse_after_value
+	goto mainparse
+
 wantedvalue:
 	return fs.WrapErr(fmt.Errorf("wanted value token, but got token: %v", tok))
 wrongtokenerror:

libpod/sql_state.go

@@ -14,7 +14,7 @@ import (
 
 // DBSchema is the current DB schema version
 // Increments every time a change is made to the database's tables
-const DBSchema = 11
+const DBSchema = 12
 
 // SQLState is a state implementation backed by a persistent SQLite3 database
 type SQLState struct {
@@ -102,7 +102,8 @@ func (s *SQLState) Refresh() (err error) {
                              Pid=?,
                              NetNSPath=?,
                              IPAddress=?,
-                             SubnetMask=?;`
+                             SubnetMask=?,
+                             ExecSessions=?;`
 
 	if !s.valid {
 		return ErrDBClosed
@@ -132,7 +133,8 @@ func (s *SQLState) Refresh() (err error) {
 		0,
 		"",
 		"",
-		"")
+		"",
+		"{}")
 	if err != nil {
 		return errors.Wrapf(err, "error refreshing database state")
 	}
@@ -269,7 +271,8 @@ func (s *SQLState) UpdateContainer(ctr *Container) error {
                               Pid,
                               NetNSPath,
                               IPAddress,
-                              SubnetMask
+                              SubnetMask,
+                              ExecSessions
                        FROM containerState WHERE ID=?;`
 
 	var (
@@ -285,6 +288,7 @@ func (s *SQLState) UpdateContainer(ctr *Container) error {
 		netNSPath          string
 		ipAddress          string
 		subnetMask         string
+		execSessions       string
 	)
 
 	if !s.valid {
@@ -308,7 +312,8 @@ func (s *SQLState) UpdateContainer(ctr *Container) error {
 		&pid,
 		&netNSPath,
 		&ipAddress,
-		&subnetMask)
+		&subnetMask,
+	        &execSessions)
 	if err != nil {
 		// The container may not exist in the database
 		if err == sql.ErrNoRows {
@@ -333,6 +338,11 @@ func (s *SQLState) UpdateContainer(ctr *Container) error {
 	newState.IPAddress = ipAddress
 	newState.SubnetMask = subnetMask
 
+	newState.ExecSessions = make(map[string]int)
+	if err := json.Unmarshal([]byte(execSessions), &newState.ExecSessions); err != nil {
+		return errors.Wrapf(err, "error parsing container %s exec sessions", ctr.ID())
+	}
+
 	if newState.Mountpoint != "" {
 		newState.Mounted = true
 	}
@@ -395,13 +405,19 @@ func (s *SQLState) SaveContainer(ctr *Container) (err error) {
                           Pid=?,
                           NetNSPath=?,
                           IPAddress=?,
-                          SubnetMask=?
+                          SubnetMask=?,
+                          ExecSessions=?
                        WHERE Id=?;`
 
 	if !ctr.valid {
 		return ErrCtrRemoved
 	}
 
+	execSessionsJSON, err := json.Marshal(ctr.state.ExecSessions)
+	if err != nil {
+		return errors.Wrapf(err, "error marshalling container %s exec sessions", ctr.ID())
+	}
+
 	netNSPath := ""
 	if ctr.state.NetNS != nil {
 		netNSPath = ctr.state.NetNS.Path()
@@ -439,6 +455,7 @@ func (s *SQLState) SaveContainer(ctr *Container) (err error) {
 		netNSPath,
 		ctr.state.IPAddress,
 		ctr.state.SubnetMask,
+		execSessionsJSON,
 		ctr.ID())
 	if err != nil {
 		return errors.Wrapf(err, "error updating container %s state in database", ctr.ID())

libpod/sql_state_internal.go

@@ -33,7 +33,8 @@ const (
                                  containerState.Pid,
                                  containerState.NetNSPath,
                                  containerState.IPAddress,
-                                 containerState.SubnetMask
+                                 containerState.SubnetMask,
+                                 containerState.ExecSessions
                           FROM containers
                           INNER JOIN
                               containerState ON containers.Id = containerState.Id `
@@ -274,6 +275,7 @@ func prepareDB(db *sql.DB) (err error) {
             NetNSPath    TEXT    NOT NULL,
             IPAddress    TEXT    NOT NULL,
             SubnetMask   TEXT    NOT NULL,
+            ExecSessions TEXT    NOT NULL,
 
             CHECK (State>0),
             CHECK (OomKilled IN (0, 1)),
@@ -483,6 +485,7 @@ func (s *SQLState) ctrFromScannable(row scannable) (*Container, error) {
 		netNSPath          string
 		ipAddress          string
 		subnetMask         string
+		execSessions       string
 	)
 
 	err := row.Scan(
@@ -536,7 +539,8 @@ func (s *SQLState) ctrFromScannable(row scannable) (*Container, error) {
 		&pid,
 		&netNSPath,
 		&ipAddress,
-		&subnetMask)
+		&subnetMask,
+		&execSessions)
 	if err != nil {
 		if err == sql.ErrNoRows {
 			return nil, ErrNoSuchCtr
@@ -616,6 +620,11 @@ func (s *SQLState) ctrFromScannable(row scannable) (*Container, error) {
 		return nil, errors.Wrapf(err, "error parsing container %s DNS server JSON", id)
 	}
 
+	ctr.state.ExecSessions = make(map[string]int)
+	if err := json.Unmarshal([]byte(execSessions), &ctr.state.ExecSessions); err != nil {
+		return nil, errors.Wrapf(err, "error parsing container %s exec sessions JSON", id)
+	}
+
 	labels := make(map[string]string)
 	if err := json.Unmarshal([]byte(labelsJSON), &labels); err != nil {
 		return nil, errors.Wrapf(err, "error parsing container %s labels JSON", id)
@@ -753,7 +762,7 @@ func (s *SQLState) addContainer(ctr *Container, pod *Pod) (err error) {
 		addCtrState = `INSERT INTO containerState VALUES (
                     ?, ?, ?, ?, ?,
                     ?, ?, ?, ?, ?,
-                    ?, ?, ?
+                    ?, ?, ?, ?
                 );`
 		addRegistry   = "INSERT INTO registry VALUES (?, ?);"
 		checkCtrInPod = "SELECT 1 FROM containers WHERE Id=? AND Pod=?;"
@@ -795,6 +804,11 @@ func (s *SQLState) addContainer(ctr *Container, pod *Pod) (err error) {
 		return errors.Wrapf(err, "error marshaling container %s labels to JSON", ctr.ID())
 	}
 
+	execSessionsJSON, err := json.Marshal(ctr.state.ExecSessions)
+	if err != nil {
+		return errors.Wrapf(err, "error marshalling container %s exec sessions to JSON", ctr.ID())
+	}
+
 	netNSPath := ""
 	if ctr.state.NetNS != nil {
 		netNSPath = ctr.state.NetNS.Path()
@@ -918,7 +932,8 @@ func (s *SQLState) addContainer(ctr *Container, pod *Pod) (err error) {
 		ctr.state.PID,
 		netNSPath,
 		ctr.state.IPAddress,
-		ctr.state.SubnetMask)
+		ctr.state.SubnetMask,
+		execSessionsJSON)
 	if err != nil {
 		return errors.Wrapf(err, "error adding container %s state to database", ctr.ID())
 	}

libpod/test_common.go

@@ -55,6 +55,7 @@ func getTestContainer(id, name, locksDir string) (*Container, error) {
 			Mounted:    true,
 			Mountpoint: "/does/not/exist/tmp/" + id,
 			PID:        1234,
+			ExecSessions: map[string]int{"abcd": 101, "ef01": 202},
 		},
 		valid: true,
 	}