Expose Run from pmuxlib (renamed from pmuxproc)

README.md

@@ -62,7 +62,6 @@ stubborn-pinger › rtt min/avg/max/mdev = 11.161/11.161/11.161/0.000 ms
 
 ... Ctrl-C ...
 
-pmux            ~ interrupt signal received, killing all sub-processes
 stubborn-pinger » i will never stop, you will have to SIGKILL me!
 pinger          ~ exit code -1, process exited: signal: interrupt
 pinger          ~ stopped process handler
@@ -75,5 +74,4 @@ stubborn-pinger › rtt min/avg/max/mdev = 14.793/14.793/14.793/0.000 ms
 stubborn-pinger ~ forcefully killing process
 stubborn-pinger ~ exit code -1, process exited: signal: killed
 stubborn-pinger ~ stopped process handler
-pmux            ~ exited gracefully, ciao!
 ```

main.go

@@ -1,164 +1,19 @@
 package main
 
 import (
-	"bufio"
 	"context"
-	"errors"
 	"flag"
 	"fmt"
-	"io"
 	"io/ioutil"
 	"os"
 	"os/signal"
-	"strings"
-	"sync"
 	"syscall"
-	"time"
 
-	"github.com/cryptic-io/pmux/pmuxproc"
+	"github.com/cryptic-io/pmux/pmuxlib"
 
 	"gopkg.in/yaml.v2"
 )
 
-// pname used by pmux itself for logging.
-const pmuxPName = "pmux"
-
-// characters used to denote different kinds of logs
-const (
-	logSepStdout = '›'
-	logSepStderr = '»'
-	logSepSys    = '~'
-)
-
-type logger struct {
-	timeFmt string
-
-	l      *sync.Mutex
-	out    io.Writer
-	outBuf *bufio.Writer
-
-	// maxPNameLen is a pointer because it changes when WithPrefix is called.
-	maxPNameLen *uint64
-
-	pname string
-	sep   rune
-}
-
-func newLogger(
-	out io.Writer,
-	sep rune,
-	timeFmt string,
-) *logger {
-
-	pname := pmuxPName
-	maxPNameLen := uint64(len(pname))
-
-	l := &logger{
-		timeFmt:     timeFmt,
-		maxPNameLen: &maxPNameLen,
-		l:           new(sync.Mutex),
-		out:         out,
-		outBuf:      bufio.NewWriter(out),
-		pname:       pname,
-		sep:         sep,
-	}
-
-	return l
-}
-
-func (l *logger) withSep(sep rune) *logger {
-	l2 := *l
-	l2.sep = sep
-	return &l2
-}
-
-func (l *logger) withPName(pname string) *logger {
-	l2 := *l
-	l2.pname = pname
-
-	l2.l.Lock()
-	defer l2.l.Unlock()
-
-	if pnameLen := uint64(len(pname)); pnameLen > *l2.maxPNameLen {
-		*l2.maxPNameLen = pnameLen
-	}
-
-	return &l2
-}
-
-func (l *logger) Close() {
-
-	l.l.Lock()
-	defer l.l.Unlock()
-
-	l.outBuf.Flush()
-
-	if syncer, ok := l.out.(interface{ Sync() error }); ok {
-		_ = syncer.Sync()
-	} else if flusher, ok := l.out.(interface{ Flush() error }); ok {
-		_ = flusher.Flush()
-	}
-
-	// this generally shouldn't be necessary, but we could run into cases (e.g.
-	// during a force-kill) where further Prints are called after a Close. These
-	// should just do nothing.
-	l.out = ioutil.Discard
-	l.outBuf = bufio.NewWriter(l.out)
-}
-
-func (l *logger) println(line string) {
-
-	l.l.Lock()
-	defer l.l.Unlock()
-
-	if l.timeFmt != "" {
-		fmt.Fprintf(
-			l.outBuf,
-			"%s %c ",
-			time.Now().Format(l.timeFmt),
-			l.sep,
-		)
-	}
-
-	fmt.Fprintf(
-		l.outBuf,
-		"%s%s%c %s\n",
-		l.pname,
-		strings.Repeat(" ", int(*l.maxPNameLen+1)-len(l.pname)),
-		l.sep,
-		line,
-	)
-
-	l.outBuf.Flush()
-}
-
-func (l *logger) Println(line string) {
-	l.println(line)
-}
-
-func (l *logger) Printf(msg string, args ...interface{}) {
-	l.Println(fmt.Sprintf(msg, args...))
-}
-
-type processConfig struct {
-	pmuxproc.Config `yaml:",inline"`
-	Name            string `yaml:"name"`
-}
-
-type config struct {
-	TimeFormat string          `yaml:"timeFormat"`
-	Processes  []processConfig `yaml:"processes"`
-}
-
-func (cfg config) init() (config, error) {
-
-	if len(cfg.Processes) == 0 {
-		return config{}, errors.New("no processes defined")
-	}
-
-	return cfg, nil
-}
-
 func main() {
 
 	cfgPath := flag.String("c", "./pmux.yml", "Path to config yaml file")
@@ -169,58 +24,24 @@ func main() {
 		panic(fmt.Sprintf("couldn't read cfg file at %q: %v", *cfgPath, err))
 	}
 
-	var cfg config
+	var cfg pmuxlib.Config
 	if err := yaml.Unmarshal(cfgB, &cfg); err != nil {
 		panic(fmt.Sprintf("couldn't parse cfg file: %v", err))
-
-	} else if cfg, err = cfg.init(); err != nil {
-		panic(fmt.Sprintf("initializing config: %v", err))
 	}
 
-	stdoutLogger := newLogger(os.Stdout, logSepStdout, cfg.TimeFormat)
-	defer stdoutLogger.Close()
-
-	stderrLogger := newLogger(os.Stderr, logSepStderr, cfg.TimeFormat)
-	defer stderrLogger.Close()
-
-	sysLogger := stderrLogger.withSep(logSepSys)
-
-	defer sysLogger.Println("exited gracefully, ciao!")
-
 	ctx, cancel := context.WithCancel(context.Background())
 	go func() {
 		sigCh := make(chan os.Signal, 2)
 		signal.Notify(sigCh, os.Interrupt, syscall.SIGTERM)
 
-		sig := <-sigCh
+		<-sigCh
-		sysLogger.Printf("%v signal received, waiting for child processes to exit", sig)
 		cancel()
 
 		<-sigCh
-		sysLogger.Printf("forcefully exiting pmux process, there may be zombie child processes being left behind, good luck!")
+		fmt.Fprintln(os.Stderr, "forcefully exiting pmux process, there may be zombie child processes being left behind, good luck!")
-		sysLogger.Close()
+		os.Stderr.Sync()
 		os.Exit(1)
 	}()
 
-	var wg sync.WaitGroup
+	pmuxlib.Run(ctx, cfg)
-	defer wg.Wait()
-
-	for _, cfgProc := range cfg.Processes {
-		wg.Add(1)
-		go func(procCfg processConfig) {
-			defer wg.Done()
-
-			stdoutLogger := stdoutLogger.withPName(procCfg.Name)
-			stderrLogger := stderrLogger.withPName(procCfg.Name)
-			sysLogger := sysLogger.withPName(procCfg.Name)
-
-			defer sysLogger.Printf("stopped process handler")
-
-			sysLogger.Println("starting process")
-
-			pmuxproc.RunProcess(
-				ctx, stdoutLogger, stderrLogger, sysLogger, procCfg.Config,
-			)
-		}(cfgProc)
-	}
 }

pmuxlib/logger.go

@@ -0,0 +1,158 @@
+package pmuxlib
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"strings"
+	"sync"
+	"time"
+)
+
+// pname used by pmux itself for logging.
+const pmuxPName = "pmux"
+
+// characters used to denote different kinds of logs
+const (
+	logSepStdout = '›'
+	logSepStderr = '»'
+	logSepSys    = '~'
+)
+
+// Logger is used by RunProcess to log process details in realtime. You can use
+// a new(NullLogger) if you don't care.
+type Logger interface {
+	Println(string)
+	Printf(string, ...interface{})
+}
+
+// NullLogger is an implementation of Logger which doesn't do anything.
+type NullLogger struct{}
+
+func (*NullLogger) Println(string)                {}
+func (*NullLogger) Printf(string, ...interface{}) {}
+
+// PlainLogger implements Logger by writing each line directly to the given
+// io.Writer as-is.
+type PlainLogger struct {
+	io.Writer
+}
+
+func (l PlainLogger) Println(line string) {
+	fmt.Fprintln(l, line)
+}
+
+func (l PlainLogger) Printf(str string, args ...interface{}) {
+	fmt.Fprintf(l, str, args...)
+}
+
+type logger struct {
+	timeFmt string
+
+	l      *sync.Mutex
+	out    io.Writer
+	outBuf *bufio.Writer
+
+	// maxPNameLen is a pointer because it changes when WithPrefix is called.
+	maxPNameLen *uint64
+
+	pname string
+	sep   rune
+}
+
+func newLogger(
+	out io.Writer,
+	sep rune,
+	timeFmt string,
+) *logger {
+
+	pname := pmuxPName
+	maxPNameLen := uint64(len(pname))
+
+	l := &logger{
+		timeFmt:     timeFmt,
+		maxPNameLen: &maxPNameLen,
+		l:           new(sync.Mutex),
+		out:         out,
+		outBuf:      bufio.NewWriter(out),
+		pname:       pname,
+		sep:         sep,
+	}
+
+	return l
+}
+
+func (l *logger) withSep(sep rune) *logger {
+	l2 := *l
+	l2.sep = sep
+	return &l2
+}
+
+func (l *logger) withPName(pname string) *logger {
+	l2 := *l
+	l2.pname = pname
+
+	l2.l.Lock()
+	defer l2.l.Unlock()
+
+	if pnameLen := uint64(len(pname)); pnameLen > *l2.maxPNameLen {
+		*l2.maxPNameLen = pnameLen
+	}
+
+	return &l2
+}
+
+func (l *logger) Close() {
+
+	l.l.Lock()
+	defer l.l.Unlock()
+
+	l.outBuf.Flush()
+
+	if syncer, ok := l.out.(interface{ Sync() error }); ok {
+		_ = syncer.Sync()
+	} else if flusher, ok := l.out.(interface{ Flush() error }); ok {
+		_ = flusher.Flush()
+	}
+
+	// this generally shouldn't be necessary, but we could run into cases (e.g.
+	// during a force-kill) where further Prints are called after a Close. These
+	// should just do nothing.
+	l.out = ioutil.Discard
+	l.outBuf = bufio.NewWriter(l.out)
+}
+
+func (l *logger) println(line string) {
+
+	l.l.Lock()
+	defer l.l.Unlock()
+
+	if l.timeFmt != "" {
+		fmt.Fprintf(
+			l.outBuf,
+			"%s %c ",
+			time.Now().Format(l.timeFmt),
+			l.sep,
+		)
+	}
+
+	fmt.Fprintf(
+		l.outBuf,
+		"%s%s%c %s\n",
+		l.pname,
+		strings.Repeat(" ", int(*l.maxPNameLen+1)-len(l.pname)),
+		l.sep,
+		line,
+	)
+
+	l.outBuf.Flush()
+}
+
+func (l *logger) Println(line string) {
+	l.println(line)
+}
+
+func (l *logger) Printf(msg string, args ...interface{}) {
+	l.Println(fmt.Sprintf(msg, args...))
+}

pmuxlib/pmuxlib.go

@@ -0,0 +1,49 @@
+// Package pmuxlib implements the process management aspects of the pmux
+// process.
+package pmuxlib
+
+import (
+	"context"
+	"os"
+	"sync"
+)
+
+type Config struct {
+	TimeFormat string          `yaml:"timeFormat"`
+	Processes  []ProcessConfig `yaml:"processes"`
+}
+
+// Run runs the given configuration as if this was a real pmux process.
+func Run(ctx context.Context, cfg Config) {
+
+	stdoutLogger := newLogger(os.Stdout, logSepStdout, cfg.TimeFormat)
+	defer stdoutLogger.Close()
+
+	stderrLogger := newLogger(os.Stderr, logSepStderr, cfg.TimeFormat)
+	defer stderrLogger.Close()
+
+	sysLogger := stderrLogger.withSep(logSepSys)
+	defer sysLogger.Println("exited gracefully, ciao!")
+
+	var wg sync.WaitGroup
+	defer wg.Wait()
+
+	for _, cfgProc := range cfg.Processes {
+		wg.Add(1)
+		go func(procCfg ProcessConfig) {
+			defer wg.Done()
+
+			stdoutLogger := stdoutLogger.withPName(procCfg.Name)
+			stderrLogger := stderrLogger.withPName(procCfg.Name)
+			sysLogger := sysLogger.withPName(procCfg.Name)
+
+			sysLogger.Println("starting process")
+			defer sysLogger.Println("stopped process handler")
+
+			RunProcess(
+				ctx, stdoutLogger, stderrLogger, sysLogger, procCfg,
+			)
+
+		}(cfgProc)
+	}
+}

pmuxlib/proc.go

@@ -1,6 +1,4 @@
-// Package pmuxproc implements the process management aspects of the pmux
+package pmuxlib
-// process.
-package pmuxproc
 
 import (
 	"bufio"
@@ -15,8 +13,11 @@ import (
 	"time"
 )
 
-// Config is used to configure a process via RunProcess.
+// ProcessConfig is used to configure a process via RunProcess.
-type Config struct {
+type ProcessConfig struct {
+
+	// Name of the process to be run. This only gets used by RunPmux.
+	Name string
 
 	// Cmd and Args describe the actual process to run.
 	Cmd  string   `yaml:"cmd"`
@@ -48,7 +49,7 @@ type Config struct {
 	NoRestartOn []int `yaml:"noRestartOn"`
 }
 
-func (cfg Config) withDefaults() Config {
+func (cfg ProcessConfig) withDefaults() ProcessConfig {
 
 	if cfg.MinWait == 0 {
 		cfg.MinWait = 1 * time.Second
@@ -65,10 +66,10 @@ func (cfg Config) withDefaults() Config {
 	return cfg
 }
 
-// RunProcessOnce runs the process described by the Config (though it doesn't
+// RunProcessOnce runs the process described by the ProcessConfig (though it
-// use all fields from the Config). The process is killed if the context is
+// doesn't use all fields from the ProcessConfig). The process is killed if the
-// canceled. The exit status of the process is returned, or -1 if the process
+// context is canceled. The exit status of the process is returned, or -1 if the
-// was never started.
+// process was never started.
 //
 // It returns nil if the process exits normally with a zero status. It returns
 // an error otherwise.
@@ -78,7 +79,7 @@ func (cfg Config) withDefaults() Config {
 func RunProcessOnce(
 	ctx context.Context,
 	stdoutLogger, stderrLogger, sysLogger Logger,
-	cfg Config,
+	cfg ProcessConfig,
 ) (
 	int, error,
 ) {
@@ -165,8 +166,8 @@ func RunProcessOnce(
 	return exitCode, nil
 }
 
-// RunProcess is a process (configured by Config) until the context is canceled,
+// RunProcess is a process (configured by ProcessConfig) until the context is
-// at which point the process is killed and RunProcess returns.
+// canceled, at which point the process is killed and RunProcess returns.
 //
 // The process will be restarted if it exits of its own accord. There will be a
 // brief wait time between each restart, with an exponential backup mechanism so
@@ -177,7 +178,7 @@ func RunProcessOnce(
 func RunProcess(
 	ctx context.Context,
 	stdoutLogger, stderrLogger, sysLogger Logger,
-	cfg Config,
+	cfg ProcessConfig,
 ) {
 
 	cfg = cfg.withDefaults()

pmuxproc/logger.go

@@ -1,33 +0,0 @@
-package pmuxproc
-
-import (
-	"fmt"
-	"io"
-)
-
-// Logger is used by RunProcess to log process details in realtime. You can use
-// a new(NullLogger) if you don't care.
-type Logger interface {
-	Println(string)
-	Printf(string, ...interface{})
-}
-
-// NullLogger is an implementation of Logger which doesn't do anything.
-type NullLogger struct{}
-
-func (*NullLogger) Println(string)                {}
-func (*NullLogger) Printf(string, ...interface{}) {}
-
-// PlainLogger implements Logger by writing each line directly to the given
-// io.Writer as-is.
-type PlainLogger struct {
-	io.Writer
-}
-
-func (l PlainLogger) Println(line string) {
-	fmt.Fprintln(l, line)
-}
-
-func (l PlainLogger) Printf(str string, args ...interface{}) {
-	fmt.Fprintf(l, str, args...)
-}