hermes/api/gosrc/externalbackendlauncher/main.go
greysoh 28d25c9698
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chore: Adds basic commands and protocol.
2024-12-01 19:11:07 -05:00

133 lines
2.6 KiB
Go

package main
import (
"fmt"
"os"
"os/exec"
"strings"
"time"
"git.greysoh.dev/imterah/nextnet/backendlauncher"
"github.com/charmbracelet/log"
)
type WriteLogger struct {
UseError bool
}
func (writer WriteLogger) Write(p []byte) (n int, err error) {
logSplit := strings.Split(string(p), "\n")
for _, line := range logSplit {
if writer.UseError {
log.Errorf("application: %s", line)
} else {
log.Infof("application: %s", line)
}
}
return len(p), err
}
func main() {
tempDir, err := os.MkdirTemp("", "nextnet-sockets-")
logLevel := os.Getenv("NEXTNET_LOG_LEVEL")
if logLevel != "" {
switch logLevel {
case "debug":
log.SetLevel(log.DebugLevel)
case "info":
log.SetLevel(log.InfoLevel)
case "warn":
log.SetLevel(log.WarnLevel)
case "error":
log.SetLevel(log.ErrorLevel)
case "fatal":
log.SetLevel(log.FatalLevel)
}
}
if len(os.Args) != 3 {
log.Fatalf("missing arguments! example: ./externalbackendlauncher <backend executable> <file with backend arguments>")
}
executablePath := os.Args[1]
executableParamsPath := os.Args[2]
_, err = os.ReadFile(executableParamsPath)
if err != nil {
log.Fatalf("could not read backend parameters: %s", err.Error())
}
_, err = os.Stat(executablePath)
if err != nil {
log.Fatalf("failed backend checks: %s", err.Error())
}
log.Debug("running socket acquisition")
sockPath, sockListener, err := backendlauncher.GetUnixSocket(tempDir)
if err != nil {
log.Fatalf("failed to acquire unix socket: %s", err.Error())
}
log.Debugf("acquisition was successful: %s", sockPath)
go func() {
log.Debug("entering execution loop (in auxiliary goroutine)...")
for {
log.Info("waiting for Unix socket connections...")
sock, err := sockListener.Accept()
if err != nil {
log.Warnf("failed to accept socket connection: %s", err.Error())
}
defer sock.Close()
}
}()
log.Debug("entering execution loop (in main goroutine)...")
stdout := WriteLogger{
UseError: false,
}
stderr := WriteLogger{
UseError: true,
}
for {
log.Info("starting process...")
// TODO: can we reuse cmd?
cmd := exec.Command(executablePath)
cmd.Env = append(cmd.Env, fmt.Sprintf("NEXTNET_API_SOCK=%s", sockPath))
cmd.Stdout = stdout
cmd.Stderr = stderr
err := cmd.Run()
if err != nil {
if err, ok := err.(*exec.ExitError); ok {
log.Warnf("backend died with exit code '%d' and with error '%s'", err.ExitCode(), err.Error())
} else {
log.Warnf("backend died with error: %s", err.Error())
}
} else {
log.Info("process exited gracefully.")
}
log.Info("sleeping 5 seconds, and then restarting process")
time.Sleep(5 * time.Millisecond)
}
}