From 12ecb72329dd001b5adb77d72d927707e976cf2c Mon Sep 17 00:00:00 2001
From: Erik Brakkee <erik@brakkee.org>
Date: Sun, 21 Jul 2024 21:41:53 +0200
Subject: [PATCH] Lots of work on docuemtation. The docs page now shows the
correct installation dependent URLs. For now using ServerALiveInterval to
avoid disconnects.
---
cmd/agent/agent.go | 4 +-
cmd/converge/server.go | 97 +++++++++++++++++++++++++++++++-
cmd/tcptows/tcptows.go | 3 +
cmd/wsproxy/proxy.go | 3 +
pkg/agent/help.txt | 4 +-
pkg/agent/session.go | 9 ++-
pkg/websocketutil/connections.go | 2 +
pkg/websocketutil/services.go | 3 +
static/index.html | 61 ++++++++++++++------
9 files changed, 163 insertions(+), 23 deletions(-)
diff --git a/cmd/agent/agent.go b/cmd/agent/agent.go
index 2d96d69..6cb5c2d 100755
--- a/cmd/agent/agent.go
+++ b/cmd/agent/agent.go
@@ -92,7 +92,7 @@ func sshServer(hostKeyFile string) *ssh.Server {
}
})
- log.Println("starting ssh server")
+ log.Println("starting ssh server, waiting for debug sessions")
server := ssh.Server{
PasswordHandler: passwordAuth,
SubsystemHandlers: map[string]ssh.SubsystemHandler{
@@ -164,6 +164,8 @@ func main() {
log.Println("WebSocket connection error:", err)
return
}
+ conn.SetReadDeadline(time.Time{})
+ conn.SetWriteDeadline(time.Time{})
wsConn := websocketutil.NewWebSocketConn(conn)
defer wsConn.Close()
diff --git a/cmd/converge/server.go b/cmd/converge/server.go
index 4db9826..fc34ae7 100644
--- a/cmd/converge/server.go
+++ b/cmd/converge/server.go
@@ -1,14 +1,18 @@
package main
import (
+ "bytes"
"cidebug/pkg/converge"
"cidebug/pkg/websocketutil"
"fmt"
+ "io"
"log"
"net"
"net/http"
"os"
"regexp"
+ "strings"
+ "sync"
)
func parsePublicId(path string) (publicId string, _ error) {
@@ -25,6 +29,90 @@ func catchAllHandler(w http.ResponseWriter, r *http.Request) {
return
}
+// filters to filter html content.
+var filters map[string]string = make(map[string]string)
+
+type FileHandlerFilter struct {
+ http.Handler
+}
+
+func (handler FileHandlerFilter) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+ mutex := sync.Mutex{}
+ // pedantic
+ mutex.Lock()
+
+ if r.TLS == nil {
+ filters["secure"] = ""
+ } else {
+ filters["secure"] = "s"
+ }
+ for _, header := range []string{"X-Forwarded-Proto", "X-Scheme", "X-Forwarded-Scheme"} {
+ values := r.Header.Values(header)
+ for _, value := range values {
+ if strings.ToLower(value) == "https" {
+ filters["secure"] = "s"
+ }
+ }
+ }
+ filters["host"] = r.Host
+ mutex.Unlock()
+
+ w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
+ w.Header().Set("Pragma", "no-cache")
+ w.Header().Set("Expires", "0")
+
+ handler.Handler.ServeHTTP(w, r)
+}
+
+type FilteredFileSystem struct {
+ fs http.FileSystem
+}
+
+func (ffs FilteredFileSystem) Open(name string) (http.File, error) {
+ log.Println("Name : " + name)
+ f, err := ffs.fs.Open(name)
+ if err != nil {
+ return nil, err
+ }
+ if !strings.HasSuffix(name, ".html") {
+ return f, nil
+ }
+ return NewFilteredFile(f, filters)
+}
+
+type FilteredFile struct {
+ http.File
+
+ // Read bytes 0..(index-1) already
+ index int
+ fullContents *bytes.Buffer
+}
+
+func NewFilteredFile(f http.File, filter map[string]string) (FilteredFile, error) {
+ file := FilteredFile{
+ index: 0,
+ fullContents: bytes.NewBuffer(make([]byte, 0)),
+ }
+ file.File = f
+
+ _, err := io.Copy(file.fullContents, file.File)
+ if err != nil {
+ return FilteredFile{}, err
+ }
+ contents := file.fullContents.String()
+ for key, value := range filter {
+ key = "@" + key + "@"
+ contents = strings.ReplaceAll(contents, key, value)
+ }
+ file.fullContents = bytes.NewBufferString(contents)
+
+ return file, nil
+}
+
+func (ff FilteredFile) Read(p []byte) (n int, err error) {
+ return ff.fullContents.Read(p)
+}
+
func main() {
downloadDir := "downloads"
@@ -65,7 +153,14 @@ func main() {
http.HandleFunc("/agent/", registrationService.Handle)
http.HandleFunc("/client/", clientService.Handle)
- http.Handle("/docs/", http.StripPrefix("/docs/", http.FileServer(http.Dir(downloadDir))))
+
+ filesystem := http.Dir(downloadDir)
+ filteredFilesystem := FilteredFileSystem{
+ fs: filesystem,
+ }
+ fileHandler := FileHandlerFilter{http.FileServer(filteredFilesystem)}
+
+ http.Handle("/docs/", http.StripPrefix("/docs/", fileHandler))
http.HandleFunc("/", catchAllHandler)
// Start HTTP server
diff --git a/cmd/tcptows/tcptows.go b/cmd/tcptows/tcptows.go
index c0a72c8..f99a15f 100644
--- a/cmd/tcptows/tcptows.go
+++ b/cmd/tcptows/tcptows.go
@@ -7,6 +7,7 @@ import (
"log"
"net"
"os"
+ "time"
)
func closeConnection(conn net.Conn) {
@@ -25,6 +26,8 @@ func handleConnection(conn net.Conn, wsURL string) {
log.Println("WebSocket connection error:", err)
return
}
+ _wsConn.SetReadDeadline(time.Time{})
+ _wsConn.SetWriteDeadline(time.Time{})
wsConn := websocketutil.NewWebSocketConn(_wsConn)
defer wsConn.Close()
diff --git a/cmd/wsproxy/proxy.go b/cmd/wsproxy/proxy.go
index 1b6d249..9218ea6 100644
--- a/cmd/wsproxy/proxy.go
+++ b/cmd/wsproxy/proxy.go
@@ -7,6 +7,7 @@ import (
"log"
"net"
"os"
+ "time"
)
func closeConnection(conn net.Conn) {
@@ -29,6 +30,8 @@ func main() {
wsURL := os.Args[1]
_wsConn, _, err := websocket.DefaultDialer.Dial(wsURL, nil)
+ _wsConn.SetReadDeadline(time.Time{})
+ _wsConn.SetWriteDeadline(time.Time{})
if err != nil {
log.Println("WebSocket connection error:", err)
panic(err)
diff --git a/pkg/agent/help.txt b/pkg/agent/help.txt
index 44435ef..0fed91e 100644
--- a/pkg/agent/help.txt
+++ b/pkg/agent/help.txt
@@ -1,4 +1,4 @@
-Session is set to expire at %s
+Session is set to expire at %v
The session expires automatically after %d time.
If there are no more sessions after logging out, the agent
@@ -8,6 +8,6 @@ You can extend this time using
touch $agentdir/.hold
-To prevent the agent from exiting after the last sessioni is gone,
+To prevent the agent from exiting after the last session is gone,
also use the above command in any shell.
diff --git a/pkg/agent/session.go b/pkg/agent/session.go
index 3c705c6..2c8016d 100644
--- a/pkg/agent/session.go
+++ b/pkg/agent/session.go
@@ -144,9 +144,9 @@ func fileExists(filename string) bool {
func (state *AgentState) expiryTime(filename string) time.Time {
stats, err := os.Stat(filename)
if err != nil {
- return state.startTime
+ return state.startTime.Add(state.agentExpriryTime)
}
- return stats.ModTime()
+ return stats.ModTime().Add(state.agentExpriryTime)
}
// Behavior to implement
@@ -177,6 +177,11 @@ func check() {
PrintHelpMessage(session.sshSession)
}
}
+
+ if !fileExists(holdFilename) && len(state.sessions) == 0 {
+ log.Printf("All clients disconnected and no '%s' file found, exiting", holdFilename)
+ os.Exit(0)
+ }
}
func messageUsers(message string) {
diff --git a/pkg/websocketutil/connections.go b/pkg/websocketutil/connections.go
index ea87213..7ff838a 100644
--- a/pkg/websocketutil/connections.go
+++ b/pkg/websocketutil/connections.go
@@ -72,6 +72,8 @@ func ConnectWebSocket(conn net.Conn, urlStr string) (net.Conn, error) {
if err != nil {
return nil, err
}
+ wsConn.SetReadDeadline(time.Time{})
+ wsConn.SetWriteDeadline(time.Time{})
return NewWebSocketConn(wsConn), nil
}
diff --git a/pkg/websocketutil/services.go b/pkg/websocketutil/services.go
index 37efbd5..a1fc248 100644
--- a/pkg/websocketutil/services.go
+++ b/pkg/websocketutil/services.go
@@ -5,6 +5,7 @@ import (
"log"
"net"
"net/http"
+ "time"
)
type WebSocketAddr string
@@ -28,6 +29,8 @@ func handleWebSocket(w http.ResponseWriter, r *http.Request,
log.Println("Error upgrading to WebSocket:", err)
return
}
+ conn.SetReadDeadline(time.Time{})
+ conn.SetWriteDeadline(time.Time{})
wsConn := NewWebSocketConn(conn)
defer wsConn.Close()
diff --git a/static/index.html b/static/index.html
index b479d3a..1b178ba 100644
--- a/static/index.html
+++ b/static/index.html
@@ -14,6 +14,39 @@
<div class="container">
+ <h1>About</h1>
+
+ <p>
+ Converge is a utility for troubleshooting builds on continuous integration serves.
+ It solves a common problem where the cause of job failure is difficult to determine.
+ This is complicated furhter by the fact that build jobs are usually run on a build
+ farm where there is no access to the build agents or in more modern envrionments when
+ jobs are run in ephemeral containers.
+ </p>
+
+ <p>
+ With Converge it is possible to get remote shell access to such jobs. This works
+ by configuring the build job to connect to a Converge server using an agent program.
+ The agent program can be downloaded from within the CI job using curl or wget.
+ Next, an end-use can connect to the Converge server, a rendez-vous server, that connects
+ the client and server together.
+ </p>
+
+ <p>
+ The setup is such that the connection from client (end-user) to server (agent on CI job)
+ is end-to-end encrypted. The Converge server itself is no more than a bitpipe which pumps
+ data between client and agent.
+ </p>
+
+ <p>
+ Both ssh and sftp are supported. Multiple shells are also allowed.
+ </p>
+
+ <p>
+ There is a timeout mechanism in the agent such that jobs do not hang indefinetely waiting
+ for a connection.
+ </p>
+
<h1>Usage</h1>
<h2>Continous integration jobs</h2>
@@ -22,12 +55,12 @@
In a continous integration job, download the agent, chmod it and run it.
</p>
<pre>
- curl https://HOSTPORT/docs/agent > agent
- ./agent wss://HOST:PORT/agent/ID
- chmod 755 agent
+ curl http@secure@://@host@/docs/agent > agent
+ chmod 755 agent
+ ./agent ws@secure@://@host@/agent/ID
</pre>
<p>
- Above, HOST:PORT is the hostname:port of the converge server and ID is a unique id
+ Above, ID is a unique id
for the job. This should not conflict with other ids.
This connects the agent to the converge server. Clients can now connect to converge
@@ -37,7 +70,7 @@
<h2>Local clients: using ssh proxy command </h2>
<pre>
- curl https://HOST:PORT/docs/wsproxy > wsproxy
+ curl http@secure@://@host@/docs/wsproxy > wsproxy
chmod 755 wsproxy
</pre>
@@ -49,8 +82,8 @@
</p>
<pre>
- ssh -oProxyCommand="wsproxy https://HOST:PORT/client/ID" -p 10000 abc@localhost
- sftp -oProxyCommand="wsproxy https://HOST:PORT/client/ID" -oPort 10000 abc@localhost
+ ssh -oServerAliveInterval=10 -oProxyCommand="wsproxy ws@secure@://@host@/client/ID" abc@localhost
+ sftp -oServerAliveInterval=10 -oProxyCommand="wsproxy ws@secure@://@host@/client/ID" abc@localhost
</pre>
<p>
@@ -70,15 +103,9 @@
</p>
<pre>
- # for HTTP hosted server
- curl http://HOST:PORT/docs/tcptows > tcptows
+ curl http@secure@://@host@/docs/tcptows > tcptows
chmod 755 tcptows
- ./tcptows 10000 ws://HOST:PORT/client/ID
-
- # for HTTPS hosted server
- curl https://HOST:PORT/docs/tcptows > tcptows
- chmod 755 tcptows
- ./tcptows 10000 wss://HOST:PORT/client/ID
+ ./tcptows 10000 ws@secure@://@host@/client/ID
</pre>
<p>
@@ -90,8 +117,8 @@
</p>
<pre>
- ssh -p 10000 abc@localhost
- sftp -oPort 10000 abc@localhost
+ ssh -oServerAliveInterval=10 -p 10000 abc@localhost
+ sftp -oServerAliveInterval=10 -oPort 10000 abc@localhost
</pre>
<p>