wip: refactor(config): fix pointer type

Reviewed-on: #1

.idea/remote-targets.xml

@@ -0,0 +1,55 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="RemoteTargetsManager">
+    <targets>
+      <target name="golang-dev:1.21-bookworm-user" type="docker" uuid="5b79636b-3db9-4e2a-9fd3-03277653ae58">
+        <config>
+          <option name="targetPlatform">
+            <TargetPlatform />
+          </option>
+          <option name="buildImageConfig">
+            <BuildImageConfig>
+              <option name="dockerFile" value="docker/bookworm/Dockerfile" />
+            </BuildImageConfig>
+          </option>
+          <option name="buildNotPull" value="false" />
+          <option name="containerConfig">
+            <ContainerConfig>
+              <option name="runCliOptions" value="-u &quot;1000:1000&quot; --rm" />
+            </ContainerConfig>
+          </option>
+          <option name="pullImageConfig">
+            <PullImageConfig>
+              <option name="tagToPull" value="golang-dev:1.21-bookworm-user" />
+            </PullImageConfig>
+          </option>
+        </config>
+        <ContributedStateBase type="GoLanguageRuntime">
+          <config>
+            <option name="compiledExecutablesVolume">
+              <VolumeState>
+                <option name="targetSpecificBits">
+                  <map>
+                    <entry key="mountAsVolume" value="false" />
+                  </map>
+                </option>
+              </VolumeState>
+            </option>
+            <option name="goPath" value="/go" />
+            <option name="goRoot" value="/usr/local/go/bin/go" />
+            <option name="goVersion" value="go1.21.5 linux/amd64" />
+            <option name="projectSourcesVolume">
+              <VolumeState>
+                <option name="targetSpecificBits">
+                  <map>
+                    <entry key="mountAsVolume" value="false" />
+                  </map>
+                </option>
+              </VolumeState>
+            </option>
+          </config>
+        </ContributedStateBase>
+      </target>
+    </targets>
+  </component>
+</project>

Makefile

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

@@ -1,2 +1,139 @@
 # 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

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

cmd/wingmate/bridge.go

@@ -1,60 +1,53 @@
 package main
 
 import (
-	"time"
-
 	"gitea.suyono.dev/suyono/wingmate/config"
 	wminit "gitea.suyono.dev/suyono/wingmate/init"
+	"gitea.suyono.dev/suyono/wingmate/task"
 )
 
-type wPath struct {
-	path string
-}
-
-func (p wPath) Path() string {
-	return p.path
-}
-
 type wConfig struct {
-	services []wminit.Path
-	cron     []wminit.Cron
+	tasks *task.Tasks
 }
 
-func (c wConfig) Services() []wminit.Path {
-	return c.services
+func (c *wConfig) Tasks() wminit.Tasks {
+	return c.tasks
 }
 
-func (c wConfig) Cron() []wminit.Cron {
-	return c.cron
-}
-
-type wCron struct {
-	iCron *config.Cron
-}
-
-func (c wCron) TimeToRun(now time.Time) bool {
-	return c.iCron.TimeToRun(now)
-}
-
-func (c wCron) Command() wminit.Path {
-	return wPath{
-		path: c.iCron.Command(),
-	}
-}
-
-func convert(cfg *config.Config) wConfig {
-	retval := wConfig{
-		services: make([]wminit.Path, 0, len(cfg.ServicePaths)),
-		cron:     make([]wminit.Cron, 0, len(cfg.Cron)),
+func convert(cfg *config.Config) *wConfig {
+	retval := &wConfig{
+		tasks: task.NewTasks(),
 	}
 
 	for _, s := range cfg.ServicePaths {
-		retval.services = append(retval.services, wPath{path: s})
+		retval.tasks.AddV0Service(s)
+
 	}
 
+	var schedule task.CronSchedule
 	for _, c := range cfg.Cron {
-		retval.cron = append(retval.cron, wCron{iCron: c})
+		schedule.Minute = convertSchedule(c.Minute)
+		schedule.Hour = convertSchedule(c.Hour)
+		schedule.DoM = convertSchedule(c.DoM)
+		schedule.Month = convertSchedule(c.Month)
+		schedule.DoW = convertSchedule(c.DoW)
+
+		retval.tasks.AddV0Cron(schedule, c.Command)
 	}
 
 	return retval
 }
+
+func convertSchedule(cfg config.CronTimeSpec) task.CronTimeSpec {
+	switch v := cfg.(type) {
+	case *config.SpecAny:
+		return task.NewCronAnySpec()
+	case *config.SpecExact:
+		return task.NewCronExactSpec(v.Value())
+	case *config.SpecMultiOccurrence:
+		return task.NewCronMultiOccurrenceSpec(v.Values()...)
+	}
+
+	panic("invalid conversion")
+	return nil
+}

config/config_test.go

@@ -10,33 +10,35 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func TestRead(t *testing.T) {
-
-	type testEntry struct {
-		name     string
-		testFunc func(t *testing.T)
-	}
+const (
+	serviceDir = "service"
+)
 
 var (
 	configDir string
-		err       error
 )
 
-	const serviceDir = "service"
-
-	setup := func(t *testing.T) {
+func setup(t *testing.T) {
+	var err error
 	if configDir, err = os.MkdirTemp("", "wingmate-*-test"); err != nil {
 		t.Fatal("setup", err)
 	}
 	viper.Set(EnvConfigPath, configDir)
 }
 
-	tear := func(t *testing.T) {
-		if err = os.RemoveAll(configDir); err != nil {
+func tear(t *testing.T) {
+	if err := os.RemoveAll(configDir); err != nil {
 		t.Fatal("tear", err)
 	}
 }
 
+func TestRead(t *testing.T) {
+
+	type testEntry struct {
+		name     string
+		testFunc func(t *testing.T)
+	}
+
 	mkSvcDir := func(t *testing.T) {
 		if err := os.MkdirAll(path.Join(configDir, serviceDir), 0755); err != nil {
 			t.Fatal("create dir", err)

config/crontab.go

@@ -4,46 +4,34 @@ import (
 	"bufio"
 	"errors"
 	"fmt"
+	"gitea.suyono.dev/suyono/wingmate"
 	"os"
 	"regexp"
 	"strconv"
 	"strings"
-	"time"
-
-	"gitea.suyono.dev/suyono/wingmate"
 )
 
-type CronExactSpec interface {
-	CronTimeSpec
-	Value() uint8
-}
-
-type CronMultipleOccurrenceSpec interface {
-	CronTimeSpec
-	Values() []uint8
-}
-
 type CronTimeSpec interface {
-	Type() wingmate.CronTimeType
-	Match(uint8) bool
+	//Type() wingmate.CronTimeType
+	//Match(uint8) bool
 }
 
 type Cron struct {
-	minute  CronTimeSpec
-	hour    CronTimeSpec
-	dom     CronTimeSpec
-	month   CronTimeSpec
-	dow     CronTimeSpec
-	command string
-	lastRun time.Time
-	hasRun  bool
+	Minute  CronTimeSpec
+	Hour    CronTimeSpec
+	DoM     CronTimeSpec
+	Month   CronTimeSpec
+	DoW     CronTimeSpec
+	Command string
 }
 
 type cronField int
 
 const (
-	CrontabEntryRegex  = `^\s*(?P<minute>\S+)\s+(?P<hour>\S+)\s+(?P<dom>\S+)\s+(?P<month>\S+)\s+(?P<dow>\S+)\s+(?P<command>\S.*\S)\s*$`
-	CrontabSubmatchLen = 7
+	CrontabEntryRegexPattern         = `^\s*(?P<minute>\S+)\s+(?P<hour>\S+)\s+(?P<dom>\S+)\s+(?P<month>\S+)\s+(?P<dow>\S+)\s+(?P<command>\S.*\S)\s*$`
+	CrontabCommentLineRegexPattern   = `^\s*#.*$`
+	CrontabCommentSuffixRegexPattern = `^\s*([^#]+)#.*$`
+	CrontabSubMatchLen               = 7
 
 	minute cronField = iota
 	hour
@@ -52,21 +40,22 @@ const (
 	dow
 )
 
+var (
+	crontabEntryRegex         = regexp.MustCompile(CrontabEntryRegexPattern)
+	crontabCommentLineRegex   = regexp.MustCompile(CrontabCommentLineRegexPattern)
+	crontabCommentSuffixRegex = regexp.MustCompile(CrontabCommentSuffixRegexPattern)
+)
+
 func readCrontab(path string) ([]*Cron, error) {
 	var (
 		file    *os.File
 		err     error
 		scanner *bufio.Scanner
 		line    string
-		re      *regexp.Regexp
 		parts   []string
 		retval  []*Cron
 	)
 
-	if re, err = regexp.Compile(CrontabEntryRegex); err != nil {
-		return nil, err
-	}
-
 	if file, err = os.Open(path); err != nil {
 		return nil, err
 	}
@@ -79,41 +68,48 @@ func readCrontab(path string) ([]*Cron, error) {
 	for scanner.Scan() {
 		line = scanner.Text()
 
-		parts = re.FindStringSubmatch(line)
-		if len(parts) != CrontabSubmatchLen {
+		if crontabCommentLineRegex.MatchString(line) {
+			continue
+		}
+
+		parts = crontabCommentSuffixRegex.FindStringSubmatch(line)
+		if len(parts) == 2 {
+			line = parts[1]
+		}
+
+		parts = crontabEntryRegex.FindStringSubmatch(line)
+		if len(parts) != CrontabSubMatchLen {
 			wingmate.Log().Error().Msgf("invalid entry %s", line)
 			continue
 		}
 
-		c := &Cron{
-			hasRun: false,
-		}
+		c := &Cron{}
 		if err = c.setField(minute, parts[1]); err != nil {
-			wingmate.Log().Error().Msgf("error parsing minute field %+v", err)
+			wingmate.Log().Error().Msgf("error parsing Minute field %+v", err)
 			continue
 		}
 
 		if err = c.setField(hour, parts[2]); err != nil {
-			wingmate.Log().Error().Msgf("error parsing hour field %+v", err)
+			wingmate.Log().Error().Msgf("error parsing Hour field %+v", err)
 			continue
 		}
 
 		if err = c.setField(dom, parts[3]); err != nil {
-			wingmate.Log().Error().Msgf("error parsing day of month field %+v", err)
+			wingmate.Log().Error().Msgf("error parsing Day of Month field %+v", err)
 			continue
 		}
 
 		if err = c.setField(month, parts[4]); err != nil {
-			wingmate.Log().Error().Msgf("error parsing month field %+v", err)
+			wingmate.Log().Error().Msgf("error parsing Month field %+v", err)
 			continue
 		}
 
 		if err = c.setField(dow, parts[5]); err != nil {
-			wingmate.Log().Error().Msgf("error parsing day of week field %+v", err)
+			wingmate.Log().Error().Msgf("error parsing Day of Week field %+v", err)
 			continue
 		}
 
-		c.command = parts[6]
+		c.Command = parts[6]
 
 		retval = append(retval, c)
 	}
@@ -121,35 +117,6 @@ func readCrontab(path string) ([]*Cron, error) {
 	return retval, nil
 }
 
-func (c *Cron) Command() string {
-	return c.command
-}
-
-func (c *Cron) TimeToRun(now time.Time) bool {
-	if c.minute.Match(uint8(now.Minute())) &&
-		c.hour.Match(uint8(now.Hour())) &&
-		c.dom.Match(uint8(now.Day())) &&
-		c.month.Match(uint8(now.Month())) &&
-		c.dow.Match(uint8(now.Weekday())) {
-
-		if c.hasRun {
-			if now.Sub(c.lastRun) <= time.Minute && now.Minute() == c.lastRun.Minute() {
-				return false
-			} else {
-				c.lastRun = now
-				return true
-			}
-		} else {
-
-			c.lastRun = now
-			c.hasRun = true
-			return true
-		}
-	}
-
-	return false
-}
-
 type fieldRange struct {
 	min int
 	max int
@@ -182,25 +149,25 @@ func (c *Cron) setField(field cronField, input string) error {
 	switch field {
 	case minute:
 		fr = newRange(0, 59)
-		cField = &c.minute
+		cField = &c.Minute
 	case hour:
 		fr = newRange(0, 23)
-		cField = &c.hour
+		cField = &c.Hour
 	case dom:
 		fr = newRange(1, 31)
-		cField = &c.dom
+		cField = &c.DoM
 	case month:
 		fr = newRange(1, 12)
-		cField = &c.month
+		cField = &c.Month
 	case dow:
 		fr = newRange(0, 6)
-		cField = &c.dow
+		cField = &c.DoW
 	default:
 		return errors.New("invalid cron field descriptor")
 	}
 
 	if input == "*" {
-		*cField = &specAny{}
+		*cField = &SpecAny{}
 	} else if strings.HasPrefix(input, "*/") {
 		if parsed64, err = strconv.ParseUint(input[2:], 10, 8); err != nil {
 			return fmt.Errorf("error parse field %+v with input %s: %w", field, input, err)
@@ -217,7 +184,7 @@ func (c *Cron) setField(field cronField, input string) error {
 			current += parsed
 		}
 
-		*cField = &specMultiOccurrence{
+		*cField = &SpecMultiOccurrence{
 			values: multi,
 		}
 	} else {
@@ -237,7 +204,7 @@ func (c *Cron) setField(field cronField, input string) error {
 				multi = append(multi, parsed)
 			}
 
-			*cField = &specMultiOccurrence{
+			*cField = &SpecMultiOccurrence{
 				values: multi,
 			}
 		} else {
@@ -250,7 +217,7 @@ func (c *Cron) setField(field cronField, input string) error {
 				return fmt.Errorf("error parse field %+v with input %s: invalid value", field, input)
 			}
 
-			*cField = &specExact{
+			*cField = &SpecExact{
 				value: parsed,
 			}
 		}
@@ -259,51 +226,21 @@ func (c *Cron) setField(field cronField, input string) error {
 	return nil
 }
 
-type specAny struct{}
+type SpecAny struct{}
 
-func (a *specAny) Type() wingmate.CronTimeType {
-	return wingmate.Any
-}
-
-func (a *specAny) Match(u uint8) bool {
-	return true
-}
-
-type specExact struct {
+type SpecExact struct {
 	value uint8
 }
 
-func (e *specExact) Type() wingmate.CronTimeType {
-	return wingmate.Exact
-}
-
-func (e *specExact) Match(u uint8) bool {
-	return u == e.value
-}
-
-func (e *specExact) Value() uint8 {
+func (e *SpecExact) Value() uint8 {
 	return e.value
 }
 
-type specMultiOccurrence struct {
+type SpecMultiOccurrence struct {
 	values []uint8
 }
 
-func (m *specMultiOccurrence) Type() wingmate.CronTimeType {
-	return wingmate.MultipleOccurrence
-}
-
-func (m *specMultiOccurrence) Match(u uint8) bool {
-	for _, v := range m.values {
-		if v == u {
-			return true
-		}
-	}
-
-	return false
-}
-
-func (m *specMultiOccurrence) Values() []uint8 {
+func (m *SpecMultiOccurrence) Values() []uint8 {
 	out := make([]uint8, len(m.values))
 	copy(out, m.values)
 	return out

config/crontab_test.go

@@ -0,0 +1,128 @@
+package config
+
+import (
+	"gitea.suyono.dev/suyono/wingmate"
+	"github.com/stretchr/testify/assert"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+const (
+	crontabFileName = "crontab"
+)
+
+func TestCrontab(t *testing.T) {
+	type testEntry struct {
+		name    string
+		crontab string
+		wantErr bool
+	}
+
+	_ = wingmate.NewLog(os.Stderr)
+	tests := []testEntry{
+		{
+			name:    "positive",
+			crontab: crontabTestCase0,
+			wantErr: false,
+		},
+		{
+			name:    "with comment",
+			crontab: crontabTestCase1,
+			wantErr: false,
+		},
+		{
+			name:    "various values",
+			crontab: crontabTestCase2,
+			wantErr: false,
+		},
+		{
+			name:    "failed to parse",
+			crontab: crontabTestCase3,
+			wantErr: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			setup(t)
+			defer tear(t)
+
+			writeCrontab(t, tt.crontab)
+
+			cfg, err := Read()
+			if tt.wantErr != (err != nil) {
+				t.Fatalf("wantErr is %v but err is %+v", tt.wantErr, err)
+			}
+
+			t.Logf("cfg: %+v", cfg)
+			for _, c := range cfg.Cron {
+				t.Logf("%+v", c)
+			}
+		})
+	}
+}
+
+func writeCrontab(t *testing.T, content string) {
+	var (
+		f   *os.File
+		err error
+	)
+
+	if f, err = os.Create(filepath.Join(configDir, crontabFileName)); err != nil {
+		t.Fatal("create crontab file", err)
+	}
+	defer func() {
+		_ = f.Close()
+	}()
+
+	if _, err = f.Write([]byte(content)); err != nil {
+		t.Fatal("writing crontab file", err)
+	}
+}
+
+const crontabTestCase0 = `* * * * *  /path/to/executable`
+const crontabTestCase1 = `# this is a comment
+  ## comment with space
+* * * * *  /path/to/executable
+* * * * *  /path/to/executable  # comment as a suffix
+`
+
+const crontabTestCase2 = `# first comment
+*/5 13 3,5,7 * *  /path/to/executable`
+
+const crontabTestCase3 = `a 13 3,5,7 * *  /path/to/executable
+*/5 a 3,5,7 * *  /path/to/executable
+*/5 13 a * *  /path/to/executable
+*/5 13 3,5,7 a *  /path/to/executable
+*/5 13 3,5,7 * a  /path/to/executable
+*/x 13 3,5,7 * a  /path/to/executable
+76 13 3,5,7 * a  /path/to/executable
+*/75 13 3,5,7 * a  /path/to/executable
+*/5 13 3,x,7 * a  /path/to/executable
+*/5 13 3,5,67 * a  /path/to/executable
+*/5 13 * *  /path/to/executable
+*/5 13 3,5,7 * *  /path/to/executable`
+
+func TestSpecExact(t *testing.T) {
+	var val uint8 = 45
+	s := SpecExact{
+		value: val,
+	}
+
+	assert.Equal(t, val, s.Value())
+}
+
+func TestSpecMulti(t *testing.T) {
+	val := []uint8{3, 5, 7, 15}
+	s := SpecMultiOccurrence{
+		values: val,
+	}
+
+	assert.ElementsMatch(t, val, s.Values())
+}
+
+func TestInvalidField(t *testing.T) {
+	c := &Cron{}
+	assert.NotNil(t, c.setField(cronField(99), "x"))
+}

docker/alpine/Dockerfile

@@ -2,6 +2,7 @@ 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

@@ -2,6 +2,7 @@ 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

@@ -0,0 +1,14 @@
+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

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

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

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

init/cron.go

@@ -13,7 +13,7 @@ const (
 	cronTag = "cron"
 )
 
-func (i *Init) cron(wg *sync.WaitGroup, cron Cron, exitFlag <-chan any) {
+func (i *Init) cron(wg *sync.WaitGroup, cron CronTask, exitFlag <-chan any) {
 	defer wg.Done()
 
 	var (
@@ -21,35 +21,40 @@ func (i *Init) cron(wg *sync.WaitGroup, cron Cron, exitFlag <-chan any) {
 		err    error
 		stdout io.ReadCloser
 		stderr io.ReadCloser
+		cmd    *exec.Cmd
 	)
 
 	ticker := time.NewTicker(time.Second * 30)
 cron:
 	for {
 		if cron.TimeToRun(time.Now()) {
-			wingmate.Log().Info().Str(cronTag, cron.Command().Path()).Msg("executing")
-			cmd := exec.Command(cron.Command().Path())
+			wingmate.Log().Info().Str(cronTag, cron.Name()).Msg("executing")
+			if len(cron.Command()) == 1 {
+				cmd = exec.Command(cron.Command()[0])
+			} else {
+				cmd = exec.Command(cron.Command()[0], cron.Command()[1:]...)
+			}
 			iwg = &sync.WaitGroup{}
 
 			if stdout, err = cmd.StdoutPipe(); err != nil {
-				wingmate.Log().Error().Str(cronTag, cron.Command().Path()).Msgf("stdout pipe: %+v", err)
+				wingmate.Log().Error().Str(cronTag, cron.Name()).Msgf("stdout pipe: %+v", err)
 				goto fail
 			}
 
 			if stderr, err = cmd.StderrPipe(); err != nil {
-				wingmate.Log().Error().Str(cronTag, cron.Command().Path()).Msgf("stderr pipe: %+v", err)
+				wingmate.Log().Error().Str(cronTag, cron.Name()).Msgf("stderr pipe: %+v", err)
 				_ = stdout.Close()
 				goto fail
 			}
 
 			iwg.Add(1)
-			go i.pipeReader(iwg, stdout, cronTag, cron.Command().Path())
+			go i.pipeReader(iwg, stdout, cronTag, cron.Name())
 
 			iwg.Add(1)
-			go i.pipeReader(iwg, stderr, cronTag, cron.Command().Path())
+			go i.pipeReader(iwg, stderr, cronTag, cron.Name())
 
 			if err := cmd.Start(); err != nil {
-				wingmate.Log().Error().Msgf("starting cron %s error %+v", cron.Command().Path(), err)
+				wingmate.Log().Error().Msgf("starting cron %s error %+v", cron.Name(), err)
 				_ = stdout.Close()
 				_ = stderr.Close()
 				iwg.Wait()
@@ -59,7 +64,7 @@ cron:
 			iwg.Wait()
 
 			if err = cmd.Wait(); err != nil {
-				wingmate.Log().Error().Str(cronTag, cron.Command().Path()).Msgf("got error when waiting: %+v", err)
+				wingmate.Log().Error().Str(cronTag, cron.Name()).Msgf("got error when waiting: %+v", err)
 			}
 		}
 

init/init.go

@@ -6,18 +6,37 @@ import (
 	"time"
 )
 
-type Path interface {
-	Path() string
+type Tasks interface {
+	List() []Task
+	Services() []Task
+	Crones() []CronTask
+	Get(string) (Task, error)
 }
 
-type Cron interface {
-	Command() Path
+type UserGroup interface {
+}
+
+type TaskStatus interface {
+}
+
+type Task interface {
+	Name() string
+	Command() []string
+	Environ() []string
+	Setsid() bool
+	UserGroup() UserGroup
+	Background() bool
+	WorkingDir() string
+	Status() TaskStatus
+}
+
+type CronTask interface {
+	Task
 	TimeToRun(time.Time) bool
 }
 
 type Config interface {
-	Services() []Path
-	Cron() []Cron
+	Tasks() Tasks
 }
 
 type Init struct {
@@ -49,12 +68,12 @@ func (i *Init) Start() {
 	wg.Add(1)
 	go i.sighandler(wg, signalTrigger, sighandlerExit, sigchld)
 
-	for _, s := range i.config.Services() {
+	for _, s := range i.config.Tasks().Services() {
 		wg.Add(1)
 		go i.service(wg, s, signalTrigger)
 	}
 
-	for _, c := range i.config.Cron() {
+	for _, c := range i.config.Tasks().Crones() {
 		wg.Add(1)
 		go i.cron(wg, c, signalTrigger)
 	}

init/service.go

@@ -14,7 +14,7 @@ const (
 	serviceTag = "service"
 )
 
-func (i *Init) service(wg *sync.WaitGroup, path Path, exitFlag <-chan any) {
+func (i *Init) service(wg *sync.WaitGroup, task Task, exitFlag <-chan any) {
 	defer wg.Done()
 
 	var (
@@ -23,37 +23,42 @@ func (i *Init) service(wg *sync.WaitGroup, path Path, exitFlag <-chan any) {
 		stderr     io.ReadCloser
 		stdout     io.ReadCloser
 		failStatus bool
+		cmd        *exec.Cmd
 	)
 
 	defer func() {
-		wingmate.Log().Info().Str(serviceTag, path.Path()).Msg("stopped")
+		wingmate.Log().Info().Str(serviceTag, task.Name()).Msg("stopped")
 	}()
 
 service:
 	for {
 		failStatus = false
-		cmd := exec.Command(path.Path())
+		if len(task.Command()) == 1 {
+			cmd = exec.Command(task.Command()[0])
+		} else {
+			cmd = exec.Command(task.Command()[0], task.Command()[1:]...)
+		}
 		iwg = &sync.WaitGroup{}
 
 		if stdout, err = cmd.StdoutPipe(); err != nil {
-			wingmate.Log().Error().Str(serviceTag, path.Path()).Msgf("stdout pipe: %#v", err)
+			wingmate.Log().Error().Str(serviceTag, task.Name()).Msgf("stdout pipe: %#v", err)
 			failStatus = true
 			goto fail
 		}
 		iwg.Add(1)
-		go i.pipeReader(iwg, stdout, serviceTag, path.Path())
+		go i.pipeReader(iwg, stdout, serviceTag, task.Name())
 
 		if stderr, err = cmd.StderrPipe(); err != nil {
-			wingmate.Log().Error().Str(serviceTag, path.Path()).Msgf("stderr pipe: %#v", err)
+			wingmate.Log().Error().Str(serviceTag, task.Name()).Msgf("stderr pipe: %#v", err)
 			_ = stdout.Close()
 			failStatus = true
 			goto fail
 		}
 		iwg.Add(1)
-		go i.pipeReader(iwg, stderr, serviceTag, path.Path())
+		go i.pipeReader(iwg, stderr, serviceTag, task.Name())
 
 		if err = cmd.Start(); err != nil {
-			wingmate.Log().Error().Msgf("starting service %s error %#v", path.Path(), err)
+			wingmate.Log().Error().Msgf("starting service %s error %#v", task.Name(), err)
 			failStatus = true
 			_ = stdout.Close()
 			_ = stderr.Close()
@@ -64,7 +69,7 @@ service:
 		iwg.Wait()
 
 		if err = cmd.Wait(); err != nil {
-			wingmate.Log().Error().Str(serviceTag, path.Path()).Msgf("got error when waiting: %+v", err)
+			wingmate.Log().Error().Str(serviceTag, task.Name()).Msgf("got error when waiting: %+v", err)
 		}
 	fail:
 		if failStatus {

task/cron.go

@@ -0,0 +1,139 @@
+package task
+
+import (
+	wminit "gitea.suyono.dev/suyono/wingmate/init"
+	"time"
+)
+
+type CronSchedule struct {
+	Minute CronTimeSpec
+	Hour   CronTimeSpec
+	DoM    CronTimeSpec
+	Month  CronTimeSpec
+	DoW    CronTimeSpec
+}
+
+type CronTimeSpec interface {
+	Match(uint8) bool
+}
+
+type CronAnySpec struct {
+}
+
+func NewCronAnySpec() *CronAnySpec {
+	return &CronAnySpec{}
+}
+
+func (cas *CronAnySpec) Match(u uint8) bool {
+	return true
+}
+
+type CronExactSpec struct {
+	value uint8
+}
+
+func NewCronExactSpec(v uint8) *CronExactSpec {
+	return &CronExactSpec{
+		value: v,
+	}
+}
+
+func (ces *CronExactSpec) Match(u uint8) bool {
+	return u == ces.value
+}
+
+type CronMultiOccurrenceSpec struct {
+	values []uint8
+}
+
+func NewCronMultiOccurrenceSpec(v ...uint8) *CronMultiOccurrenceSpec {
+	retval := &CronMultiOccurrenceSpec{}
+	if len(v) > 0 {
+		retval.values = make([]uint8, len(v))
+		copy(retval.values, v)
+	}
+
+	return retval
+}
+
+func (cms *CronMultiOccurrenceSpec) Match(u uint8) bool {
+	for _, v := range cms.values {
+		if v == u {
+			return true
+		}
+	}
+
+	return false
+}
+
+type Cron struct {
+	CronSchedule
+	name    string
+	command []string
+	lastRun time.Time
+	hasRun  bool //NOTE: make sure initialised as false
+}
+
+func (c *Cron) Name() string {
+	return c.name
+}
+
+func (c *Cron) Command() []string {
+	retval := make([]string, len(c.command))
+	copy(retval, c.command)
+	return retval
+}
+
+func (c *Cron) Environ() []string {
+	panic("not implemented")
+	return nil
+}
+
+func (c *Cron) Setsid() bool {
+	panic("not implemented")
+	return false
+}
+
+func (c *Cron) UserGroup() wminit.UserGroup {
+	panic("not implemented")
+	return nil
+}
+
+func (c *Cron) Background() bool {
+	panic("not implemented")
+	return false
+}
+
+func (c *Cron) WorkingDir() string {
+	panic("not implemented")
+	return ""
+}
+
+func (c *Cron) Status() wminit.TaskStatus {
+	panic("not implemented")
+	return nil
+}
+
+func (c *Cron) TimeToRun(now time.Time) bool {
+	if c.Minute.Match(uint8(now.Minute())) &&
+		c.Hour.Match(uint8(now.Hour())) &&
+		c.DoM.Match(uint8(now.Day())) &&
+		c.Month.Match(uint8(now.Month())) &&
+		c.DoW.Match(uint8(now.Weekday())) {
+
+		if c.hasRun {
+			if now.Sub(c.lastRun) <= time.Minute && now.Minute() == c.lastRun.Minute() {
+				return false
+			} else {
+				c.lastRun = now
+				return true
+			}
+		} else {
+			c.lastRun = now
+			c.hasRun = true
+			return true
+		}
+	}
+
+	return false
+}

task/task.go

@@ -0,0 +1,95 @@
+package task
+
+import (
+	wminit "gitea.suyono.dev/suyono/wingmate/init"
+)
+
+type Tasks struct {
+	services []wminit.Task
+	crones   []wminit.CronTask
+}
+
+func NewTasks() *Tasks {
+	return &Tasks{
+		services: make([]wminit.Task, 0),
+		crones:   make([]wminit.CronTask, 0),
+	}
+}
+
+func (ts *Tasks) AddV0Service(path string) {
+	ts.services = append(ts.services, &Task{
+		name:    path,
+		command: []string{path},
+	})
+}
+
+func (ts *Tasks) AddV0Cron(schedule CronSchedule, path string) {
+	ts.crones = append(ts.crones, &Cron{
+		CronSchedule: schedule,
+		name:         path,
+		command:      []string{path},
+	})
+}
+
+func (ts *Tasks) List() []wminit.Task {
+	panic("not implemented")
+	return nil
+}
+
+func (ts *Tasks) Services() []wminit.Task {
+	return ts.services
+}
+
+func (ts *Tasks) Crones() []wminit.CronTask {
+	return ts.crones
+}
+
+func (ts *Tasks) Get(name string) (wminit.Task, error) {
+	panic("not implemented")
+	return nil, nil
+}
+
+type Task struct {
+	name    string
+	command []string
+}
+
+func (t *Task) Name() string {
+	return t.name
+}
+
+func (t *Task) Command() []string {
+	retval := make([]string, len(t.command))
+	copy(retval, t.command)
+	return retval
+}
+
+func (t *Task) Environ() []string {
+	panic("not implemented")
+	return nil
+}
+
+func (t *Task) Setsid() bool {
+	panic("not implemented")
+	return false
+}
+
+func (t *Task) UserGroup() wminit.UserGroup {
+	panic("not implemented")
+	return nil
+}
+
+func (t *Task) Background() bool {
+	panic("not implemented")
+	return false
+}
+
+func (t *Task) WorkingDir() string {
+	panic("not implemented")
+	return ""
+}
+
+func (t *Task) Status() wminit.TaskStatus {
+	panic("not implemented")
+	return nil
+}