erik/converge
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

refactoring towards being able to send events from Admin to UI (websocket) without exposing connection info but only metadata.

Browse Source
This commit is contained in:
Erik Brakkee 2024-07-30 19:03:21 +02:00
parent 5533b04a5e
commit bf5120aa5b
7 changed files with 118 additions and 120 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
cmd/agent/agent.go
View File

@ -33,9 +33,12 @@ import (
var hostPrivateKey []byte
func SftpHandler(sess ssh.Session) {
uid := sess.LocalAddr().String()
agent.Login(uid, sess)
defer agent.LogOut(uid)
sessionInfo := comms.NewSessionInfo(
sess.LocalAddr().String(),
"sftp",
)
agent.Login(sessionInfo, sess)
defer agent.LogOut(sessionInfo.ClientId)
debugStream := io.Discard
serverOptions := []sftp.ServerOption{
@ -67,10 +70,12 @@ func sshServer(hostKeyFile string, shellCommand string,
if err != nil {
panic(err)
}
uid := s.LocalAddr().String()
agent.Login(uid, s)
sessionInfo := comms.NewSessionInfo(
s.LocalAddr().String(), "ssh",
)
agent.Login(sessionInfo, s)
iowrappers.SynchronizeStreams(process.Pipe(), s)
agent.LogOut(uid)
agent.LogOut(sessionInfo.ClientId)
// will cause addition goroutines to remmain alive when the SSH
// session is killed. For now acceptable since the agent is a short-lived
// process. Using Kill() here will create defunct processes and in normal

46
pkg/agent/session.go
View File

@ -47,7 +47,7 @@ type AgentState struct {
ticker *time.Ticker
// map of unique session id to a session
sessions map[string]*AgentSession
clients map[string]*AgentSession
lastUserLoginTime time.Time
agentUsed bool
@ -90,7 +90,7 @@ func ConfigureAgent(commChannel comms.CommChannel,
lastExpiryTimmeReported: time.Time{},
tickerInterval: tickerInterval,
ticker: time.NewTicker(tickerInterval),
sessions: make(map[string]*AgentSession),
clients: make(map[string]*AgentSession),
lastUserLoginTime: time.Time{},
agentUsed: false,
@ -120,12 +120,12 @@ func ConfigureAgent(commChannel comms.CommChannel,
}
func Login(sessionId string, sshSession ssh.Session) {
events <- async.Async(login, sessionId, sshSession)
func Login(sessionInfo comms.SessionInfo, sshSession ssh.Session) {
events <- async.Async(login, sessionInfo, sshSession)
}
func LogOut(sessionId string) {
events <- async.Async(logOut, sessionId)
func LogOut(clientId string) {
events <- async.Async(logOut, clientId)
}
// Internal interface synchronous
@ -174,19 +174,10 @@ func holdFileMessage() string {
return message
}
func login(sessionId string, sshSession ssh.Session) {
func login(sessionInfo comms.SessionInfo, sshSession ssh.Session) {
log.Println("New login")
hostname, _ := os.Hostname()
sessionType := sshSession.Subsystem()
if sessionType == "" {
sessionType = "ssh"
}
comms.Send(state.commChannel.SideChannel,
comms.ConvergeMessage{
Value: comms.NewSessionInfo(sessionType),
})
holdFileStats, ok := fileExistsWithStats(holdFilename)
if ok {
if holdFileStats.ModTime().After(time.Now()) {
@ -205,9 +196,16 @@ func login(sessionId string, sshSession ssh.Session) {
startTime: time.Now(),
sshSession: sshSession,
}
state.sessions[sessionId] = &agentSession
state.clients[sessionInfo.ClientId] = &agentSession
state.lastUserLoginTime = time.Now()
state.agentUsed = true
err := comms.SendWithTimeout(state.commChannel.SideChannel,
comms.ConvergeMessage{Value: sessionInfo})
if err != nil {
log.Printf("Could not send session info to converge server, information on server may be incomplete %v", err)
}
logStatus()
printMessage(sshSession, fmt.Sprintf("You are now on %s\n", hostname))
@ -236,9 +234,9 @@ func formatHelpMessage() string {
return helpFormatted
}
func logOut(sessionId string) {
func logOut(clientId string) {
log.Println("User logged out")
delete(state.sessions, sessionId)
delete(state.clients, clientId)
logStatus()
check()
}
@ -254,7 +252,7 @@ func logStatus() {
fmt := "%-20s %-20s %-20s"
log.Println()
log.Printf(fmt, "CLIENT", "START_TIME", "TYPE")
for uid, session := range state.sessions {
for uid, session := range state.clients {
sessionType := session.sshSession.Subsystem()
if sessionType == "" {
sessionType = "ssh"
@ -308,7 +306,7 @@ func holdFileChange() {
}
// Behavior to implement
// 1. there is a global timeout for all agent sessions together: state.agentExpirtyTime
// 1. there is a global timeout for all agent clients together: state.agentExpirtyTime
// 2. The expiry time is relative to the modification time of the .hold file in the
// agent directory or, if that file does not exist, the start time of the agent.
// 3. if we are close to the expiry time then we message users with instruction on
@ -331,12 +329,12 @@ func check() {
if expiryTime.Sub(now) < state.advanceWarningTime {
messageUsers(
fmt.Sprintf("Session will expire at %s", expiryTime.Format(time.DateTime)))
for _, session := range state.sessions {
for _, session := range state.clients {
printHelpMessage(session.sshSession)
}
}
if state.agentUsed && !fileExists(holdFilename) && len(state.sessions) == 0 {
if state.agentUsed && !fileExists(holdFilename) && len(state.clients) == 0 {
log.Printf("All clients disconnected and no '%s' file found, exiting", holdFilename)
os.Exit(0)
}
@ -344,7 +342,7 @@ func check() {
func messageUsers(message string) {
log.Printf("=== Notification to users: %s", message)
for _, session := range state.sessions {
for _, session := range state.clients {
printMessage(session.sshSession, message)
}
}

35
pkg/comms/agentserver.go
View File

@ -218,41 +218,6 @@ func CheckProtocolVersion(role Role, channel GOBChannel) error {
}
}
func CheckProtocolVersionOld(role Role, conn io.ReadWriter) error {
channel := NewGOBChannel(conn)
sends := make(chan bool, 10)
receives := make(chan ProtocolVersion, 10)
errors := make(chan error, 10)
SendAsync(channel, ProtocolVersion{Version: PROTOCOL_VERSION}, sends, errors)
ReceiveAsync(channel, receives, errors)
select {
case <-time.After(MESSAGE_TIMEOUT):
log.Println("PROTOCOLVERSION: timeout")
return fmt.Errorf("Timeout waiting for protocol version")
case err := <-errors:
log.Printf("PROTOCOLVERSION: %v", err)
return err
case protocolVersion := <-receives:
otherVersion := protocolVersion.Version
if PROTOCOL_VERSION != otherVersion {
switch role {
case Agent:
log.Printf("Protocol version mismatch: agent %d, converge server %d",
PROTOCOL_VERSION, otherVersion)
case ConvergeServer:
log.Printf("Protocol version mismatch: agent %d, converge server %d",
otherVersion, PROTOCOL_VERSION)
}
return fmt.Errorf("Protocol version mismatch")
}
log.Printf("PROTOCOLVERSION: %v", protocolVersion.Version)
return nil
}
}
// Session info metadata exchange. These are sent over the SSH connection. The agent embedded
// ssh serverlisterns for connections, but we provide a custom listener (AgentListener) that
// decorates the yamux Session (which is a listener) and uses this connection to exchange some

9
pkg/comms/events.go
View File

@ -28,6 +28,8 @@ type ClientInfo struct {
}
type SessionInfo struct {
ClientId string
// "ssh", "sftp"
SessionType string
}
@ -73,8 +75,11 @@ func NewAgentInfo() AgentInfo {
}
}
func NewSessionInfo(sessionType string) SessionInfo {
return SessionInfo{SessionType: sessionType}
func NewSessionInfo(clientId, sessionType string) SessionInfo {
return SessionInfo{
ClientId: clientId,
SessionType: sessionType,
}
}
func NewExpiryTimeUpdate(expiryTime time.Time) ExpiryTimeUpdate {

105
pkg/converge/admin.go
View File

@ -4,6 +4,7 @@ import (
"converge/pkg/comms"
"converge/pkg/concurrency"
"converge/pkg/iowrappers"
"converge/pkg/models"
"fmt"
"io"
"log"
@ -13,59 +14,56 @@ import (
"time"
)
type Agent struct {
type AgentConnection struct {
models.Agent
// server session
commChannel comms.CommChannel
publicId string
startTime time.Time
agentInfo comms.AgentInfo
expiryTime time.Time
}
var clientIdGenerator = concurrency.NewAtomicCounter()
type Client struct {
publicId string
clientId int
agent net.Conn
client iowrappers.ReadWriteAddrCloser
startTime time.Time
sessionType string
type ClientConnection struct {
models.Client
agent net.Conn
client iowrappers.ReadWriteAddrCloser
}
func NewAgent(commChannel comms.CommChannel, publicId string, agentInfo comms.AgentInfo) *Agent {
return &Agent{
func NewAgent(commChannel comms.CommChannel, publicId string, agentInfo comms.AgentInfo) *AgentConnection {
return &AgentConnection{
Agent: models.Agent{
PublicId: publicId,
StartTime: time.Now(),
AgentInfo: agentInfo,
},
commChannel: commChannel,
publicId: publicId,
startTime: time.Now(),
agentInfo: agentInfo,
}
}
func NewClient(publicId string, clientConn iowrappers.ReadWriteAddrCloser,
agentConn net.Conn) *Client {
return &Client{
publicId: publicId,
clientId: clientIdGenerator.IncrementAndGet(),
agent: agentConn,
client: clientConn,
startTime: time.Now(),
agentConn net.Conn) *ClientConnection {
return &ClientConnection{
Client: models.Client{
PublicId: publicId,
ClientId: clientIdGenerator.IncrementAndGet(),
StartTime: time.Now(),
},
agent: agentConn,
client: clientConn,
}
}
type Admin struct {
// map of public id to agent
mutex sync.Mutex
agents map[string]*Agent
clients []*Client
agents map[string]*AgentConnection
clients []*ClientConnection
}
func NewAdmin() *Admin {
admin := Admin{
mutex: sync.Mutex{},
agents: make(map[string]*Agent),
clients: make([]*Client, 0), // not strictly needed
agents: make(map[string]*AgentConnection),
clients: make([]*ClientConnection, 0), // not strictly needed
}
return &admin
}
@ -76,34 +74,34 @@ func (admin *Admin) logStatus() {
"USER", "HOST", "OS")
for _, agent := range admin.agents {
agent.commChannel.Session.RemoteAddr()
log.Printf(fmt, agent.publicId,
agent.startTime.Format(time.DateTime),
agent.expiryTime.Format(time.DateTime),
agent.agentInfo.Username,
agent.agentInfo.Hostname,
agent.agentInfo.OS)
log.Printf(fmt, agent.PublicId,
agent.StartTime.Format(time.DateTime),
agent.ExpiryTime.Format(time.DateTime),
agent.AgentInfo.Username,
agent.AgentInfo.Hostname,
agent.AgentInfo.OS)
}
log.Println("")
fmt = "%-10s %-20s %-20s %-20s %-20s\n"
log.Printf(fmt, "CLIENT", "AGENT", "ACTIVE_SINCE", "REMOTE_ADDRESS", "SESSION_TYPE")
for _, client := range admin.clients {
log.Printf(fmt,
strconv.Itoa(client.clientId),
client.publicId,
client.startTime.Format(time.DateTime),
strconv.Itoa(client.ClientId),
client.PublicId,
client.StartTime.Format(time.DateTime),
client.client.RemoteAddr(),
client.sessionType)
client.SessionType)
}
log.Printf("\n")
}
func (admin *Admin) addAgent(publicId string, agentInfo comms.AgentInfo, conn io.ReadWriteCloser) (*Agent, error) {
func (admin *Admin) addAgent(publicId string, agentInfo comms.AgentInfo, conn io.ReadWriteCloser) (*AgentConnection, error) {
admin.mutex.Lock()
defer admin.mutex.Unlock()
agent := admin.agents[publicId]
if agent != nil {
return nil, fmt.Errorf("A different agent with same publicId '%s' already registered", publicId)
return nil, fmt.Errorf("A different agent with same PublicId '%s' already registered", publicId)
}
commChannel, err := comms.NewCommChannel(comms.ConvergeServer, conn)
@ -117,14 +115,14 @@ func (admin *Admin) addAgent(publicId string, agentInfo comms.AgentInfo, conn io
return agent, nil
}
func (admin *Admin) addClient(publicId string, clientConn iowrappers.ReadWriteAddrCloser) (*Client, error) {
func (admin *Admin) addClient(publicId string, clientConn iowrappers.ReadWriteAddrCloser) (*ClientConnection, error) {
admin.mutex.Lock()
defer admin.mutex.Unlock()
agent := admin.agents[publicId]
if agent == nil {
// we should setup on-demend connections ot agents later.
return nil, fmt.Errorf("No agent found for publicId '%s'", publicId)
return nil, fmt.Errorf("No agent found for PublicId '%s'", publicId)
}
agentConn, err := agent.commChannel.Session.Open()
@ -139,7 +137,7 @@ func (admin *Admin) addClient(publicId string, clientConn iowrappers.ReadWriteAd
// Before using this connection for SSH we use it to send client metadata to the
// agent
err = comms.SendClientInfo(agentConn, comms.ClientInfo{
ClientId: client.clientId,
ClientId: client.ClientId,
})
if err != nil {
return nil, err
@ -168,18 +166,18 @@ func (admin *Admin) RemoveAgent(publicId string) error {
return nil
}
func (admin *Admin) RemoveClient(client *Client) error {
func (admin *Admin) RemoveClient(client *ClientConnection) error {
admin.mutex.Lock()
defer admin.mutex.Unlock()
log.Printf("Removing client: '%s' created at %s\n", client.publicId,
client.startTime.Format("2006-01-02 15:04:05"))
log.Printf("Removing client: '%d' created at %s\n", client.ClientId,
client.StartTime.Format(time.DateTime))
// try to explicitly close connection to the agent.
_ = client.agent.Close()
_ = client.client.Close()
for i, _client := range admin.clients {
if _client == _client {
if _client.ClientId == client.ClientId {
admin.clients = append(admin.clients[:i], admin.clients[i+1:]...)
break
}
@ -212,26 +210,27 @@ func (admin *Admin) Register(publicId string, conn io.ReadWriteCloser,
go func() {
comms.ListenForAgentEvents(agent.commChannel.SideChannel,
func(info comms.AgentInfo) {
agent.agentInfo = info
agent.AgentInfo = info
admin.logStatus()
},
func(session comms.SessionInfo) {
log.Println("Recceived sessioninfo ", session)
for _, client := range admin.clients {
// a bit hacky. There should be at most one client that has an unset session
// Very unlikely for multiple sessions to start at the same point in time.
if client.publicId == agent.publicId && client.sessionType != session.SessionType {
client.sessionType = session.SessionType
if strconv.Itoa(client.ClientId) == session.ClientId {
client.SessionType = session.SessionType
break
}
}
},
func(expiry comms.ExpiryTimeUpdate) {
agent.expiryTime = expiry.ExpiryTime
agent.ExpiryTime = expiry.ExpiryTime
admin.logStatus()
})
}()
go log.Printf("Agent registered: '%s'\n", publicId)
go log.Printf("AgentConnection registered: '%s'\n", publicId)
for !agent.commChannel.Session.IsClosed() {
time.Sleep(250 * time.Millisecond)
}

14
pkg/models/agent.go Normal file
View File

@ -0,0 +1,14 @@
package models
import (
"converge/pkg/comms"
"time"
)
type Agent struct {
PublicId string
StartTime time.Time
AgentInfo comms.AgentInfo
ExpiryTime time.Time
}

12
pkg/models/client.go Normal file
View File

@ -0,0 +1,12 @@
package models
import (
"time"
)
type Client struct {
PublicId string
ClientId int
StartTime time.Time
SessionType string
}