Makefile

@@ -1,13 +1,6 @@
 DESTDIR = /usr/local/bin
 
-installs = install-dir
+all: wingmate dummy oneshot spawner starter pidproxy exec
-programs = wingmate pidproxy exec
-ifdef TEST_BUILD
-	programs += oneshot spawner starter dummy
-	installs += install-test
-endif
-
-all: ${programs}
 
 wingmate:
 	$(MAKE) -C cmd/wingmate all
@@ -39,16 +32,12 @@ clean:
 	$(MAKE) -C cmd/experiment/spawner clean
 	$(MAKE) -C cmd/experiment/starter clean
 
-install: ${installs}
+install:
+	install -d ${DESTDIR}
 	$(MAKE) -C cmd/wingmate DESTDIR=${DESTDIR} install
 	$(MAKE) -C cmd/pidproxy DESTDIR=${DESTDIR} install
 	$(MAKE) -C cmd/exec DESTDIR=${DESTDIR} install
-
-install-test:
 	$(MAKE) -C cmd/experiment/dummy DESTDIR=${DESTDIR} install
 	$(MAKE) -C cmd/experiment/oneshot DESTDIR=${DESTDIR} install
 	$(MAKE) -C cmd/experiment/spawner DESTDIR=${DESTDIR} install
 	$(MAKE) -C cmd/experiment/starter DESTDIR=${DESTDIR} install
-
-install-dir:
-	install -d ${DESTDIR}

README.md

@@ -1,139 +1,2 @@
 # wingmate
 
-Wingmate is a process manager for services. It works like init. It starts and restarts services.
-It also has cron feature. It is designed to run in a container/docker. 
-The Wingmate binary do not need any external dependency. 
-Just copy the binary, and exec from the entry point script.
-
-# Getting Started
-
-## Binaries
-
-There are three binaries in this project: `wingmate`, `wmpidproxy`, and `wmexec`.
-
-`wingmate` is the core binary. It reads config, starts, restarts services. It also
-runs cron. Read the [configuration](#configuration) section for files needed to run
-`wingmate`.
-
-`wmpidproxy` is a helper binary for monitoring _legacy style_ service (fork, exit
-initial proces, and continue in background). Read [here](#wingmate-pid-proxy-binary)
-for further details about `wmpidproxy`.
-
-`wmexec` is a helper binary for running process in different `user` or `group`.
-It also useful for setting the process as process group leader.
-Read [here](#wingmate-exec-binary) for further details about `wmexec`.
-
-## Building a container image based on wingmate image in Docker Hub
-
-Wingmate has no dependency other than `alpine` base image, so you just need to copy
-the binaries directly. If you have built your application into an `alpine` based image,
-all you need to do is copy whichever binary you need, crontab file (if you use cron)
-and add some shell script to glue them together. Here is a Dockerfile example.
-
-```Dockerfile
-# Dockerfile
-FROM suyono/wingmate:alpine as source
-
-FROM alpine:latest
-ADD --chmod=755 wingmate/ /etc/wingmate/
-ADD --chmod=755 entry.sh /usr/local/bin/entry.sh
-COPY --from=source /usr/local/bin/wingmate /usr/local/bin/wingmate
-COPY --from=source /usr/local/bin/wmpidproxy /usr/local/bin/wmpidproxy
-COPY --from=source /usr/local/bin/wmexec /usr/local/bin/wmexec
-ENTRYPOINT [ "/usr/local/bin/entry.sh" ]
-CMD [ "/usr/local/bin/wingmate" ]
-```
-You can find some examples for shell script in [alpine docker](docker/alpine) and 
-[bookworm docker](docker/bookworm).
-
-## Configuration
-
-When `wingmate` binary starts, it will look for some files. By default, it will
-try to read the content of `/etc/wingmate` directory. You can change the directory
-where it reads by setting `WINGMATE_CONFIG_PATH` environment variable. The structure
-inside the config path should look like this.
-
-```shell
-/etc
- └── wingmate
-     ├── crontab
-     ├── crontab.d
-     │   ├── cron1.sh
-     │   ├── cron2.sh
-     │   └── cron3.sh
-     └── service
-         ├── one.sh
-         └── spawner.sh
-```
-
-First, `wingmate` will try to read the content of `service` directory. The content of
-this directory should be executables (either shell scripts or binaries). The wingmate
-will run every executable in `service` directory without going into any subdirectory.
-
-Next, `wingmate` will read the `crontab` file. `wingmate` expects the `crontab` file using
-common UNIX crontab file format. Something like this
-
-```shell
- ┌───────────── minute (0–59)
- │ ┌───────────── hour (0–23)
- │ │ ┌───────────── day of the month (1–31)
- │ │ │ ┌───────────── month (1–12)
- │ │ │ │ ┌───────────── day of the week (0–6) (Sunday to Saturday)
- │ │ │ │ │ 
- │ │ │ │ │
- │ │ │ │ │
- * * * * * <commad or shell script or binary>
-```
-
-The command part only support simple command and arguments. Shell expression is not supported
-yet. It is recommended to write a shell script and put the path to shell script in
-the command part.
-
-# Appendix
-## Wingmate PID Proxy binary
-
-`wingmate` works by monitoring its direct children process. When it sees one of its children
-exited, it will start the child process again.
-
-Sometimes you find some services work by running in the background. It means it forks a new 
-process, disconnect the new child from terminal, exit the parent process, and continue 
-running in the child process. This kind of service usually write its background process
-PID in a pid file.
-
-To monitor the background services, `wingmate` utilizes `wmpidproxy`. `wmpidproxy` runs
-in foreground in-place of the background service. It also periodically check whether the
-background service is still running, in current implementation it checks every second.
-
-```shell
-wmpidproxy --pid-file <path to pid file> -- <background service binary/start script>
-```
-#### Example
-Running sshd background with `wingmate` and `wmpidproxy`: [here](example/ssh-docker)
-
-#### Note
-
-It is recommended to configure services to run in foreground if they support it. When services
-running in foreground, they are running as direct children process of `wingmate`.
-`wingmate` monitors children process effectively. Whenever a child process exited/terminated,
-`wingmate` will start it again quickly. Running in foreground also removes the overhead of running
-`wmpidproxy` together with the service.
-
-## Wingmate Exec binary
-
-`wingmate` runs all the services as its children using the same `uid`, `gid`, and in the
-same process group. You can use `wmexec` to run service in different `uid`, `gid`, or make
-the service process as its own process group leader.
-
-#### Syntax
-
-```shell
-wmexec [--user <uid>[:<gid>]] [--setsid] -- <target executable>
-```
-| Option   | Parameter | Description                                                                                              |
-|----------|-----------|----------------------------------------------------------------------------------------------------------|
-| --user   | uid[:gid] | Set the real user ID and the real group id. Uid and Gid can be either in numeric form or in name form    |
-| --setsid |           | Set the process become the leader of its own process group, effectively detaching from parent's terminal |
-
-#### Example
-
-You can find example for `wmexec` in [here](docker/alpine/etc/wingmate) and [here](docker/bookworm/etc/wingmate)

cmd/pidproxy/pidproxy.go

@@ -1,8 +1,6 @@
 package main
 
 import (
-	"bufio"
-	"errors"
 	"log"
 	"os"
 	"os/exec"
@@ -94,13 +92,13 @@ func pidProxy(cmd *cobra.Command, args []string) error {
 		err error
 		pid int
 		sc  chan os.Signal
-		t   *time.Ticker
+		t   *time.Timer
 	)
 
 	sc = make(chan os.Signal, 1)
 	signal.Notify(sc, unix.SIGTERM)
 
-	t = time.NewTicker(time.Second)
+	t = time.NewTimer(time.Second)
 
 check:
 	for {
@@ -132,6 +130,8 @@ func readPid(pidFile string) (int, error) {
 	var (
 		file  *os.File
 		err   error
+		buf   []byte
+		n     int
 		pid64 int64
 	)
 
@@ -142,15 +142,18 @@ func readPid(pidFile string) (int, error) {
 		_ = file.Close()
 	}()
 
-	scanner := bufio.NewScanner(file)
+	buf = make([]byte, 1024)
-	if scanner.Scan() {
+	n, err = file.Read(buf)
-		if pid64, err = strconv.ParseInt(scanner.Text(), 10, 64); err != nil {
+	if err != nil {
-			return 0, err
+		return 0, err
-		}
-		return int(pid64), nil
-	} else {
-		return 0, errors.New("invalid scanner")
 	}
+
+	pid64, err = strconv.ParseInt(string(buf[:n]), 10, 64)
+	if err != nil {
+		return 0, err
+	}
+
+	return int(pid64), nil
 }
 
 func startProcess(arg0 string, args ...string) {

docker/alpine/Dockerfile

@@ -2,7 +2,6 @@ FROM golang:1.21-alpine as builder
 
 ADD . /root/wingmate
 WORKDIR /root/wingmate/
-ARG TEST_BUILD
 RUN apk add make build-base && CGO_ENABLED=1 make all && make DESTDIR=/usr/local/bin/wingmate install
 
 

docker/bookworm/Dockerfile

@@ -2,7 +2,6 @@ FROM golang:1.21-bookworm as builder
 
 ADD . /root/wingmate
 WORKDIR /root/wingmate/
-ARG TEST_BUILD
 RUN make all && make DESTDIR=/usr/local/bin/wingmate install
 
 

example/ssh-docker/Dockerfile

@@ -1,14 +0,0 @@
-FROM suyono/wingmate:alpine as source
-
-FROM alpine:3.19
-
-RUN apk update && apk add tzdata openssh-server && \
-    ln -s /usr/share/zoneinfo/Australia/Sydney /etc/localtime && ssh-keygen -A
-
-COPY --from=source /usr/local/bin/wingmate /usr/local/bin/
-COPY --from=source /usr/local/bin/wmpidproxy /usr/local/bin/
-ADD --chmod=755 example/ssh-docker/entry.sh /usr/local/bin/entry.sh
-ADD --chmod=755 example/ssh-docker/etc /etc
-
-ENTRYPOINT [ "/usr/local/bin/entry.sh" ]
-CMD [ "/usr/local/bin/wingmate" ]

example/ssh-docker/entry.sh

@@ -1,7 +0,0 @@
-#!/bin/sh
-
-if [ $# -gt 0 ]; then
-    exec "$@"
-else
-    exec /usr/local/bin/wingmate
-fi

example/ssh-docker/etc/wingmate/service/sshd.sh

@@ -1,3 +0,0 @@
-#!/bin/sh
-
-exec /usr/local/bin/wmpidproxy --pid-file /var/run/sshd.pid -- /usr/sbin/sshd