forked from cortesi/modd
/
proc.go
253 lines (228 loc) · 5.07 KB
/
proc.go
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package modd
import (
"bufio"
"bytes"
"io"
"os"
"os/exec"
"regexp"
"strings"
"sync"
"time"
"github.com/cortesi/modd/conf"
"github.com/cortesi/modd/varcmd"
"github.com/cortesi/modd/watch"
"github.com/cortesi/termlog"
)
const moddVar = "@mods"
// MinRestart is the minimum amount of time between daemon restarts
const MinRestart = 1 * time.Second
const lineLimit = 80
// shortCommand shortens a command to a name we can use in a notification
// header.
func shortCommand(command string) string {
ret := command
parts := strings.Split(command, "\n")
for _, i := range parts {
i = strings.TrimLeft(i, " \t#")
i = strings.TrimRight(i, " \t\\")
if i != "" {
ret = i
break
}
}
return ret
}
// niceHeader tries to produce a nicer process name. We condense whitespace to
// make commands split over multiple lines with indentation more legible, and
// limit the line length to 80 characters.
func niceHeader(preamble string, command string) string {
pre := termlog.DefaultPalette.Timestamp.SprintFunc()(preamble)
command = termlog.DefaultPalette.Header.SprintFunc()(shortCommand(command))
return pre + command
}
func getShell() string {
return "bash"
}
func logOutput(wg *sync.WaitGroup, fp io.ReadCloser, out func(string, ...interface{})) {
defer wg.Done()
r := bufio.NewReader(fp)
for {
line, _, err := r.ReadLine()
if err != nil {
return
}
out(string(line))
}
}
// ProcError is a process error, possibly containing command output
type ProcError struct {
shorttext string
Output string
}
func (p ProcError) Error() string {
return p.shorttext
}
// RunProc runs a process to completion, sending output to log
func RunProc(cmd string, log termlog.Stream) error {
log.Header()
sh := getShell()
c := exec.Command(sh, "-c", cmd)
stdo, err := c.StdoutPipe()
if err != nil {
return err
}
stde, err := c.StderrPipe()
if err != nil {
return err
}
wg := sync.WaitGroup{}
wg.Add(2)
buff := new(bytes.Buffer)
mut := sync.Mutex{}
go logOutput(
&wg, stde,
func(s string, args ...interface{}) {
log.Warn(s)
mut.Lock()
defer mut.Unlock()
buff.WriteString(s + "\n")
},
)
go logOutput(&wg, stdo, log.Say)
err = c.Start()
if err != nil {
return err
}
err = c.Wait()
wg.Wait()
if err != nil {
log.Shout("%s", c.ProcessState.String())
return ProcError{err.Error(), buff.String()}
}
log.Notice(">> done (%s)", c.ProcessState.UserTime())
return nil
}
// RunPreps runs all commands in sequence. Stops if any command returns an error.
func RunPreps(b conf.Block, vars map[string]string, mod *watch.Mod, log termlog.TermLog) error {
vcmd := varcmd.VarCmd{Block: &b, Mod: mod, Vars: vars}
for _, p := range b.Preps {
cmd, err := vcmd.Render(p.Command)
if err != nil {
return err
}
err = RunProc(cmd, log.Stream(niceHeader("prep: ", p.Command)))
if err != nil {
return err
}
}
return nil
}
type daemon struct {
conf conf.Daemon
log termlog.Stream
cmd *exec.Cmd
vars map[string]string
stop bool
}
func (d *daemon) Run() {
var lastStart time.Time
for d.stop != true {
d.log.Notice(">> starting...")
since := time.Now().Sub(lastStart)
if since < MinRestart {
time.Sleep(MinRestart - since)
}
lastStart = time.Now()
sh := getShell()
vcmd := varcmd.VarCmd{Block: nil, Mod: nil, Vars: d.vars}
finalcmd, err := vcmd.Render(d.conf.Command)
if err != nil {
d.log.Shout("%s", err)
continue
}
c := exec.Command(sh, "-c", finalcmd)
stdo, err := c.StdoutPipe()
if err != nil {
d.log.Shout("%s", err)
continue
}
stde, err := c.StderrPipe()
if err != nil {
d.log.Shout("%s", err)
continue
}
wg := sync.WaitGroup{}
wg.Add(2)
go logOutput(&wg, stde, d.log.Warn)
go logOutput(&wg, stdo, d.log.Say)
err = c.Start()
if err != nil {
d.log.Shout("%s", err)
continue
}
d.cmd = c
err = c.Wait()
wg.Wait()
if err != nil {
d.log.Shout("%s", c.ProcessState.String())
continue
}
}
}
func (d *daemon) Restart() {
if d.cmd != nil {
d.log.Notice(">> sending signal %s", d.conf.RestartSignal)
d.cmd.Process.Signal(d.conf.RestartSignal)
}
}
func (d *daemon) Shutdown(sig os.Signal) {
d.stop = true
if d.cmd != nil {
d.cmd.Process.Signal(sig)
d.cmd.Wait()
}
}
// DaemonPen is a group of daemons, managed as a unit.
type DaemonPen struct {
daemons *[]daemon
sync.Mutex
}
var ws = regexp.MustCompile(`\s\s+`)
// Start starts set of daemons, each specified by a command
func (dp *DaemonPen) Start(daemons []conf.Daemon, vars map[string]string, log termlog.TermLog) {
dp.Lock()
defer dp.Unlock()
d := make([]daemon, len(daemons))
for i, dmn := range daemons {
d[i] = daemon{
conf: dmn,
vars: vars,
log: log.Stream(
niceHeader("daemon: ", dmn.Command),
),
}
go d[i].Run()
}
dp.daemons = &d
}
// Restart all daemons in the pen
func (dp *DaemonPen) Restart() {
dp.Lock()
defer dp.Unlock()
if dp.daemons != nil {
for _, d := range *dp.daemons {
d.Restart()
}
}
}
// Shutdown all daemons in the pen
func (dp *DaemonPen) Shutdown(sig os.Signal) {
dp.Lock()
defer dp.Unlock()
if dp.daemons != nil {
for _, d := range *dp.daemons {
d.Shutdown(sig)
}
}
}