@@ -3,18 +3,37 @@ package main
33import (
44 "flag"
55 "fmt"
6+ "io"
67 "os"
8+ "os/exec"
9+ "os/signal"
10+ "path/filepath"
11+ "syscall"
12+ "time"
713
14+ "github.com/erikdubbelboer/gspt"
815 "github.com/jetkvm/kvm"
916)
1017
18+ const (
19+ envChildID = "JETKVM_CHILD_ID"
20+ errorDumpDir = "/userdata/jetkvm/"
21+ errorDumpStateFile = ".has_error_dump"
22+ errorDumpTemplate = "jetkvm-%s.log"
23+ )
24+
25+ func program () {
26+ gspt .SetProcTitle (os .Args [0 ] + " [app]" )
27+ kvm .Main ()
28+ }
29+
1130func main () {
1231 versionPtr := flag .Bool ("version" , false , "print version and exit" )
13- versionJsonPtr := flag .Bool ("version-json" , false , "print version as json and exit" )
32+ versionJSONPtr := flag .Bool ("version-json" , false , "print version as json and exit" )
1433 flag .Parse ()
1534
16- if * versionPtr || * versionJsonPtr {
17- versionData , err := kvm .GetVersionData (* versionJsonPtr )
35+ if * versionPtr || * versionJSONPtr {
36+ versionData , err := kvm .GetVersionData (* versionJSONPtr )
1837 if err != nil {
1938 fmt .Printf ("failed to get version data: %v\n " , err )
2039 os .Exit (1 )
@@ -23,5 +42,129 @@ func main() {
2342 return
2443 }
2544
26- kvm .Main ()
45+ childID := os .Getenv (envChildID )
46+ switch childID {
47+ case "" :
48+ doSupervise ()
49+ case kvm .GetBuiltAppVersion ():
50+ program ()
51+ default :
52+ fmt .Printf ("Invalid build version: %s != %s\n " , childID , kvm .GetBuiltAppVersion ())
53+ os .Exit (1 )
54+ }
55+ }
56+
57+ func supervise () error {
58+ // check binary path
59+ binPath , err := os .Executable ()
60+ if err != nil {
61+ return fmt .Errorf ("failed to get executable path: %w" , err )
62+ }
63+
64+ // check if binary is same as current binary
65+ if info , statErr := os .Stat (binPath ); statErr != nil {
66+ return fmt .Errorf ("failed to get executable info: %w" , statErr )
67+ // check if binary is empty
68+ } else if info .Size () == 0 {
69+ return fmt .Errorf ("binary is empty" )
70+ // check if it's executable
71+ } else if info .Mode ().Perm ()& 0111 == 0 {
72+ return fmt .Errorf ("binary is not executable" )
73+ }
74+ // run the child binary
75+ cmd := exec .Command (binPath )
76+
77+ cmd .Env = append (os .Environ (), []string {envChildID + "=" + kvm .GetBuiltAppVersion ()}... )
78+ cmd .Args = os .Args
79+
80+ logFile , err := os .CreateTemp ("" , "jetkvm-stdout.log" )
81+ defer func () {
82+ // we don't care about the errors here
83+ _ = logFile .Close ()
84+ _ = os .Remove (logFile .Name ())
85+ }()
86+ if err != nil {
87+ return fmt .Errorf ("failed to create log file: %w" , err )
88+ }
89+
90+ // Use io.MultiWriter to write to both the original streams and our buffers
91+ cmd .Stdout = io .MultiWriter (os .Stdout , logFile )
92+ cmd .Stderr = io .MultiWriter (os .Stderr , logFile )
93+ if startErr := cmd .Start (); startErr != nil {
94+ return fmt .Errorf ("failed to start command: %w" , startErr )
95+ }
96+
97+ go func () {
98+ sigChan := make (chan os.Signal , 1 )
99+ signal .Notify (sigChan , syscall .SIGTERM )
100+
101+ sig := <- sigChan
102+ _ = cmd .Process .Signal (sig )
103+ }()
104+
105+ gspt .SetProcTitle (os .Args [0 ] + " [sup]" )
106+
107+ cmdErr := cmd .Wait ()
108+ if cmdErr == nil {
109+ return nil
110+ }
111+
112+ if exiterr , ok := cmdErr .(* exec.ExitError ); ok {
113+ createErrorDump (logFile )
114+ os .Exit (exiterr .ExitCode ())
115+ }
116+
117+ return nil
118+ }
119+
120+ func createErrorDump (logFile * os.File ) {
121+ logFile .Close ()
122+
123+ // touch the error dump state file
124+ if err := os .WriteFile (filepath .Join (errorDumpDir , errorDumpStateFile ), []byte {}, 0644 ); err != nil {
125+ return
126+ }
127+
128+ fileName := fmt .Sprintf (errorDumpTemplate , time .Now ().Format ("20060102150405" ))
129+ filePath := filepath .Join (errorDumpDir , fileName )
130+ if err := os .Rename (logFile .Name (), filePath ); err == nil {
131+ fmt .Printf ("error dump created: %s\n " , filePath )
132+ return
133+ }
134+
135+ fnSrc , err := os .Open (logFile .Name ())
136+ if err != nil {
137+ return
138+ }
139+ defer fnSrc .Close ()
140+
141+ fnDst , err := os .Create (filePath )
142+ if err != nil {
143+ return
144+ }
145+ defer fnDst .Close ()
146+
147+ buf := make ([]byte , 1024 * 1024 )
148+ for {
149+ n , err := fnSrc .Read (buf )
150+ if err != nil && err != io .EOF {
151+ return
152+ }
153+ if n == 0 {
154+ break
155+ }
156+
157+ if _ , err := fnDst .Write (buf [:n ]); err != nil {
158+ return
159+ }
160+ }
161+
162+ fmt .Printf ("error dump created: %s\n " , filePath )
163+ }
164+
165+ func doSupervise () {
166+ err := supervise ()
167+ if err == nil {
168+ return
169+ }
27170}
0 commit comments