@@ -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 +42,128 @@ 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+ func supervise () error {
57+ // check binary path
58+ binPath , err := os .Executable ()
59+ if err != nil {
60+ return fmt .Errorf ("failed to get executable path: %w" , err )
61+ }
62+
63+ // check if binary is same as current binary
64+ if info , statErr := os .Stat (binPath ); statErr != nil {
65+ return fmt .Errorf ("failed to get executable info: %w" , statErr )
66+ // check if binary is empty
67+ } else if info .Size () == 0 {
68+ return fmt .Errorf ("binary is empty" )
69+ // check if it's executable
70+ } else if info .Mode ().Perm ()& 0111 == 0 {
71+ return fmt .Errorf ("binary is not executable" )
72+ }
73+ // run the child binary
74+ cmd := exec .Command (binPath )
75+
76+ cmd .Env = append (os .Environ (), []string {envChildID + "=" + kvm .GetBuiltAppVersion ()}... )
77+ cmd .Args = os .Args
78+
79+ logFile , err := os .CreateTemp ("" , "jetkvm-stdout.log" )
80+ defer func () {
81+ // we don't care about the errors here
82+ _ = logFile .Close ()
83+ _ = os .Remove (logFile .Name ())
84+ }()
85+ if err != nil {
86+ return fmt .Errorf ("failed to create log file: %w" , err )
87+ }
88+
89+ // Use io.MultiWriter to write to both the original streams and our buffers
90+ cmd .Stdout = io .MultiWriter (os .Stdout , logFile )
91+ cmd .Stderr = io .MultiWriter (os .Stderr , logFile )
92+ if startErr := cmd .Start (); startErr != nil {
93+ return fmt .Errorf ("failed to start command: %w" , startErr )
94+ }
95+
96+ go func () {
97+ sigChan := make (chan os.Signal , 1 )
98+ signal .Notify (sigChan , syscall .SIGTERM )
99+
100+ sig := <- sigChan
101+ cmd .Process .Signal (sig )
102+ }()
103+
104+ gspt .SetProcTitle (os .Args [0 ] + " [sup]" )
105+
106+ cmdErr := cmd .Wait ()
107+ if cmdErr == nil {
108+ return nil
109+ }
110+
111+ if exiterr , ok := cmdErr .(* exec.ExitError ); ok {
112+ createErrorDump (logFile )
113+ os .Exit (exiterr .ExitCode ())
114+ }
115+
116+ return nil
117+ }
118+
119+ func createErrorDump (logFile * os.File ) {
120+ logFile .Close ()
121+
122+ // touch the error dump state file
123+ if err := os .WriteFile (filepath .Join (errorDumpDir , errorDumpStateFile ), []byte {}, 0644 ); err != nil {
124+ return
125+ }
126+
127+ fileName := fmt .Sprintf (errorDumpTemplate , time .Now ().Format ("20060102150405" ))
128+ filePath := filepath .Join (errorDumpDir , fileName )
129+ if err := os .Rename (logFile .Name (), filePath ); err == nil {
130+ fmt .Printf ("error dump created: %s\n " , filePath )
131+ return
132+ }
133+
134+ fnSrc , err := os .Open (logFile .Name ())
135+ if err != nil {
136+ return
137+ }
138+ defer fnSrc .Close ()
139+
140+ fnDst , err := os .Create (filePath )
141+ if err != nil {
142+ return
143+ }
144+ defer fnDst .Close ()
145+
146+ buf := make ([]byte , 1024 * 1024 )
147+ for {
148+ n , err := fnSrc .Read (buf )
149+ if err != nil && err != io .EOF {
150+ return
151+ }
152+ if n == 0 {
153+ break
154+ }
155+
156+ if _ , err := fnDst .Write (buf [:n ]); err != nil {
157+ return
158+ }
159+ }
160+
161+ fmt .Printf ("error dump created: %s\n " , filePath )
162+ }
163+
164+ func doSupervise () {
165+ err := supervise ()
166+ if err == nil {
167+ return
168+ }
27169}
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