Add output you can stream matches into, so we don't spwan a process at each match

app/daemon.go

@@ -2,6 +2,8 @@ package app
 
 import (
 	"bufio"
+	"bytes"
+	"fmt"
 	"os"
 	"os/exec"
 	"os/signal"
@@ -23,6 +25,61 @@ func IsStringArrayEqual(one, two []string) bool {
 	return true
 }
 
+
+// Executes a command and write to its stdin via input channel until command, or reaction, dies
+func cmdStdin(commandline []string, input <-chan string) {
+	cmd := exec.Command(commandline[0], commandline[1:]...)
+	stdin, err := cmd.StdinPipe()
+	if err != nil {
+		logger.Fatalln("couldn't open stdin on command:", err)
+	}
+	stdout, err := cmd.StdoutPipe()
+	if err != nil {
+		logger.Fatalln("couldn't open stdout on command:", err)
+	}
+	if err := cmd.Start(); err != nil {
+		logger.Fatalln("couldn't start command:", err)
+	}
+	defer stdin.Close()
+
+	logger.Printf(logger.INFO, fmt.Sprintf("Output started with %v\n", commandline))
+
+	// stdout displaying thread
+	go func() {
+		for {
+			// FIXME
+			tmp := make([]byte, 1024)
+			_, err := stdout.Read(tmp)
+			if len(bytes.Trim(tmp, "\x00")) > 0 {
+				for _, line := range strings.Split(strings.ReplaceAll(string(bytes.Trim(tmp, "\x00")), "\r\n", "\n"), "\n") {
+					if len(line) > 0 {
+						logger.Printf(logger.INFO, fmt.Sprintf("Output returned %s", line))
+					}
+				}
+			}
+			if err != nil {
+				logger.Printf(logger.ERROR, fmt.Sprintf("Reading output error: %v\n", err))
+				break
+			}
+		}
+	}()
+
+	// Stdin writing thread
+	go func() {
+		for {
+			in := <-input
+			_, err := stdin.Write([]byte(in))
+			if err != nil {
+				logger.Printf(logger.ERROR, fmt.Sprintf("Writing to output error: %v\n", err))
+				break
+			}
+		}
+	}()
+
+	err = cmd.Wait()
+	logger.Fatalln("command %v stopped: %v", cmd, err)
+}
+
 // Executes a command and channel-send its stdout
 func cmdStdout(commandline []string) chan *string {
 	lines := make(chan *string)
@@ -127,6 +184,16 @@ func (f *Filter) sendActions(match []string, at time.Time) {
 func (a *Action) exec(match []string) {
 	defer wgActions.Done()
 
+	if len(a.Cmd) > 0 {
+		a.execCmd(match)
+	}
+
+	if a.Write != nil {
+		a.execWrite(match)
+	}
+}
+
+func (a *Action) execCmd(match []string) {
 	var computedCommand []string
 	var cmdItem string
 
@@ -153,6 +220,29 @@ func (a *Action) exec(match []string) {
 	}
 }
 
+func (a *Action) execWrite(match []string) {
+	var computedWrite string
+	var writeItem string
+
+	if a.filter.pattern != nil {
+		for _, item := range a.Write.Text {
+			writeItem = strings.Clone(item)
+			for i, p := range a.filter.pattern {
+				writeItem = strings.ReplaceAll(writeItem, p.nameWithBraces, match[i])
+			}
+			if len(computedWrite) > 0 {
+				computedWrite = computedWrite + " " + writeItem
+			} else {
+				computedWrite = writeItem
+			}
+		}
+	} else {
+		computedWrite = strings.Join(a.Write.Text, " ")
+	}
+
+	a.Write.Output.Stdin <- fmt.Sprintf("%s\n", computedWrite)
+}
+
 func ActionsManager(concurrency int) {
 	// concurrency init
 	execActionsC := make(chan PA)
@@ -353,6 +443,14 @@ func StreamManager(s *Stream, endedSignal chan *Stream) {
 
 }
 
+func OutputsManager(c *Conf) {
+	for outputName := range c.Outputs {
+		output := c.Outputs[outputName]
+		output.Stdin = make(chan string)
+		cmdStdin(output.Start, output.Stdin)
+	}
+}
+
 var actions ActionsMap
 var matches MatchesMap
 var actionsLock sync.Mutex
@@ -416,6 +514,7 @@ func Daemon(confFilename string) {
 	_ = runCommands(conf.Start, "start")
 
 	go DatabaseManager(conf)
+	go OutputsManager(conf)
 	go MatchesManager()
 	go ActionsManager(conf.Concurrency)
 

app/startup.go

@@ -21,6 +21,15 @@ func (c *Conf) setup() {
 		c.Concurrency = runtime.NumCPU()
 	}
 
+	for outputName := range c.Outputs {
+		output := c.Outputs[outputName]
+		output.name = outputName
+
+		if len(output.Start) == 0 {
+			logger.Fatalf("Bad configuration: output's start %v is empty!", outputName)
+		}
+	}
+
 	for patternName := range c.Patterns {
 		pattern := c.Patterns[patternName]
 		pattern.name = patternName
@@ -136,6 +145,20 @@ func (c *Conf) setup() {
 				if filter.longuestActionDuration == nil || filter.longuestActionDuration.Milliseconds() < action.afterDuration.Milliseconds() {
 					filter.longuestActionDuration = &action.afterDuration
 				}
+
+				if action.Write != nil {
+					found := false
+					for oname := range c.Outputs {
+						if strings.EqualFold(oname, action.Write.OutputName) {
+							action.Write.Output = c.Outputs[oname]
+							found = true
+						}
+					}
+					if !found {
+						logger.Fatalln(fmt.Sprintf("Bad configuration: action %s.%s.%s refers to undeclared output %s",
+									   stream.name, filter.name, action.name, action.Write.OutputName))
+					}
+				}
 			}
 		}
 	}

app/types.go

@@ -9,12 +9,24 @@ import (
 
 type Conf struct {
 	Concurrency int                 `json:"concurrency"`
+	Outputs     map[string]*Output  `json:"outputs"`
 	Patterns    map[string]*Pattern `json:"patterns"`
 	Streams     map[string]*Stream  `json:"streams"`
 	Start       [][]string          `json:"start"`
 	Stop        [][]string          `json:"stop"`
 }
 
+type Output struct {
+	Start   []string `json:"start"`
+	Stop    []string `json:"stop"`
+	// TODO: Restart when lost communication with output
+	//Restart string   `json:"restart"`
+
+	name   string   `json:"-"`
+
+	Stdin  chan string
+}
+
 type Pattern struct {
 	Regex  string   `json:"regex"`
 	Ignore []string `json:"ignore"`
@@ -52,11 +64,19 @@ type Filter struct {
 	longuestActionDuration *time.Duration
 }
 
+type OutputWrite struct {
+	OutputName string   `json:"output"`
+	Text       []string `json:"text"`
+
+	Output *Output
+}
+
 type Action struct {
 	filter *Filter `json:"-"`
 	name   string  `json:"-"`
 
-	Cmd []string `json:"cmd"`
+	Cmd         []string     `json:"cmd"`
+	Write       *OutputWrite `json:"write"`
 
 	After         string        `json:"after"`
 	afterDuration time.Duration `json:"-"`