126 lines
2.6 KiB
Go
126 lines
2.6 KiB
Go
package warden
|
|
|
|
import (
|
|
"fmt"
|
|
"github.com/rs/zerolog/log"
|
|
"os/exec"
|
|
"path/filepath"
|
|
"strings"
|
|
"syscall"
|
|
"time"
|
|
|
|
"github.com/samber/lo"
|
|
)
|
|
|
|
var InstancePool []*AppInstance
|
|
|
|
func GetFromPool(id string) *AppInstance {
|
|
val, ok := lo.Find(InstancePool, func(item *AppInstance) bool {
|
|
return item.Manifest.ID == id
|
|
})
|
|
return lo.Ternary(ok, val, nil)
|
|
}
|
|
|
|
func StartPool() []error {
|
|
var errors []error
|
|
for _, instance := range InstancePool {
|
|
if err := instance.Wake(); err != nil {
|
|
errors = append(errors, err)
|
|
}
|
|
}
|
|
return errors
|
|
}
|
|
|
|
type AppStatus = int8
|
|
|
|
const (
|
|
AppCreated = AppStatus(iota)
|
|
AppStarting
|
|
AppStarted
|
|
AppExited
|
|
AppFailure
|
|
)
|
|
|
|
type AppInstance struct {
|
|
Manifest Application `json:"manifest"`
|
|
|
|
Cmd *exec.Cmd `json:"-"`
|
|
Logger strings.Builder `json:"-"`
|
|
|
|
Status AppStatus `json:"status"`
|
|
}
|
|
|
|
func (v *AppInstance) Wake() error {
|
|
if v.Cmd != nil {
|
|
return nil
|
|
}
|
|
if v.Cmd == nil {
|
|
return v.Start()
|
|
}
|
|
if v.Cmd.Process == nil || v.Cmd.ProcessState == nil {
|
|
return v.Start()
|
|
}
|
|
if v.Cmd.ProcessState.Exited() {
|
|
return v.Start()
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (v *AppInstance) Start() error {
|
|
manifest := v.Manifest
|
|
|
|
if len(manifest.Command) <= 0 {
|
|
return fmt.Errorf("you need set the command for %s to enable process manager", manifest.ID)
|
|
}
|
|
|
|
v.Cmd = exec.Command(manifest.Command[0], manifest.Command[1:]...)
|
|
v.Cmd.Dir = filepath.Join(manifest.Workdir)
|
|
v.Cmd.Env = append(v.Cmd.Env, manifest.Environment...)
|
|
v.Cmd.Stdout = &v.Logger
|
|
v.Cmd.Stderr = &v.Logger
|
|
|
|
// Monitor
|
|
go func() {
|
|
for {
|
|
if v.Cmd != nil && v.Cmd.Process == nil {
|
|
v.Status = AppStarting
|
|
} else if v.Cmd != nil && v.Cmd.ProcessState == nil {
|
|
v.Status = AppStarted
|
|
} else {
|
|
v.Status = AppFailure
|
|
v.Cmd = nil
|
|
return
|
|
}
|
|
time.Sleep(1000 * time.Millisecond)
|
|
}
|
|
}()
|
|
|
|
return v.Cmd.Start()
|
|
}
|
|
|
|
func (v *AppInstance) Stop() error {
|
|
if v.Cmd != nil && v.Cmd.Process != nil {
|
|
if err := v.Cmd.Process.Signal(syscall.SIGTERM); err != nil {
|
|
log.Warn().Int("pid", v.Cmd.Process.Pid).Err(err).Msgf("Failed to send SIGTERM to process...")
|
|
if err = v.Cmd.Process.Kill(); err != nil {
|
|
log.Error().Int("pid", v.Cmd.Process.Pid).Err(err).Msgf("Failed to kill process...")
|
|
return err
|
|
}
|
|
}
|
|
}
|
|
|
|
// We need to wait for the process to exit
|
|
// The wait syscall will read the exit status of the process
|
|
// So that we don't produce defunct processes
|
|
// Refer to https://stackoverflow.com/questions/46293435/golang-exec-command-cause-a-lot-of-defunct-processes
|
|
_ = v.Cmd.Wait()
|
|
|
|
v.Cmd = nil
|
|
v.Status = AppExited
|
|
return nil
|
|
}
|
|
|
|
func (v *AppInstance) Logs() string {
|
|
return v.Logger.String()
|
|
}
|