Close #3

conf.go

@@ -6,39 +6,63 @@ import (
 	"log"
 	"os"
 	"regexp"
+	"strings"
 	"time"
 
 	"gopkg.in/yaml.v3"
 )
 
 type Conf struct {
-	Streams map[string]Stream
+	Patterns map[string]string
+	Streams  map[string]*Stream
 }
 
 type Stream struct {
+	name string
+
 	Cmd     []string
 	Filters map[string]*Filter
 }
 
 type Filter struct {
+	stream *Stream
+	name   string
+
 	Regex         []string
-	compiledRegex []regexp.Regexp // Computed after YAML parsing
+	compiledRegex []regexp.Regexp
+	patternName   string
+
 	Retry         uint
 	RetryPeriod   string `yaml:"retry-period"`
-	retryDuration time.Duration // Computed after YAML parsing
+	retryDuration time.Duration
+
 	Actions map[string]*Action
 }
 
 type Action struct {
-	name, filterName, streamName string // Computed after YAML parsing
+	filter *Filter
+	name   string
+
 	Cmd []string
+
 	After         string `yaml:",omitempty"`
-	afterDuration                time.Duration // Computed after YAML parsing
+	afterDuration time.Duration
 }
 
 func (c *Conf) setup() {
-	for streamName, stream := range c.Streams {
+	for patternName, pattern := range c.Patterns {
-		for filterName, filter := range stream.Filters {
+		c.Patterns[patternName] = fmt.Sprintf("(?P<%s>%s)", patternName, pattern)
+	}
+	for streamName := range c.Streams {
+
+		stream := c.Streams[streamName]
+		stream.name = streamName
+
+		for filterName := range stream.Filters {
+
+			filter := stream.Filters[filterName]
+			filter.stream = stream
+			filter.name = filterName
 
 			// Parse Duration
 			retryDuration, err := time.ParseDuration(filter.RetryPeriod)
@@ -48,16 +72,35 @@ func (c *Conf) setup() {
 			filter.retryDuration = retryDuration
 
 			// Compute Regexes
+			// Look for Patterns inside Regexes
 			for _, regex := range filter.Regex {
+				for patternName, pattern := range c.Patterns {
+					if strings.Contains(regex, patternName) {
+
+						switch filter.patternName {
+						case "":
+							filter.patternName = patternName
+						case patternName:
+							// no op
+							filter.patternName = patternName
+						default:
+							log.Fatalf(
+								"ERROR Can't mix different patterns (%s, %s) in same filter (%s.%s)\n",
+								filter.patternName, patternName, streamName, filterName,
+							)
+						}
+
+						regex = strings.Replace(regex, fmt.Sprintf("<%s>", patternName), pattern, 1)
+					}
+				}
 				filter.compiledRegex = append(filter.compiledRegex, *regexp.MustCompile(regex))
 			}
 
-			for actionName, action := range filter.Actions {
+			for actionName := range filter.Actions {
 
-				// Give all relevant infos to Actions
+				action := filter.Actions[actionName]
+				action.filter = filter
 				action.name = actionName
-				action.filterName = filterName
-				action.streamName = streamName
 
 				// Parse Duration
 				if action.After != "" {
@@ -87,7 +130,6 @@ func parseConf(filename string) *Conf {
 	}
 
 	conf.setup()
-	fmt.Printf("conf.Streams[0].Filters[0].Actions: %s\n", conf.Streams["tailDown"].Filters["lookForProuts"].Actions)
 
 	return &conf
 }

main.go

@@ -2,11 +2,14 @@ package main
 
 import (
 	"bufio"
+	"fmt"
 	"log"
-	"time"
 	"os/exec"
+	"strings"
+	"time"
 )
 
+// Executes a command and channel-send its stdout
 func cmdStdout(commandline []string) chan string {
 	lines := make(chan string)
 
@@ -31,45 +34,55 @@ func cmdStdout(commandline []string) chan string {
 	return lines
 }
 
-func (f *Filter) match(line string) bool {
+// Whether one of the filter's regexes is matched on a line
-	log.Printf("trying to match line {%s}...\n", line)
+func (f *Filter) match(line string) string {
 	for _, regex := range f.compiledRegex {
-		log.Printf("...on %s\n", regex.String())
+
-		if match := regex.FindString(line); match != "" {
+		if matches := regex.FindStringSubmatch(line); matches != nil {
-			log.Printf("match `%v` in line: `%v`\n", regex.String(), line)
+
-			return true
+			match := matches[regex.SubexpIndex(f.patternName)]
+
+			log.Printf("INFO %s.%s: match `%v`\n", f.stream.name, f.name, match)
+			return match
 		}
 	}
-	return false
+	return ""
 }
 
-func (f *Filter) launch(line *string) {
+func (f *Filter) execActions(match string) {
+	pattern := fmt.Sprintf("<%s>", f.patternName)
 	for _, a := range f.Actions {
-		go a.launch(line)
+		go a.exec(match, pattern)
 	}
 }
 
-func (a *Action) launch(line *string) {
+func (a *Action) exec(match, pattern string) {
 	if a.afterDuration != 0 {
 		time.Sleep(a.afterDuration)
 	}
-	log.Printf("INFO %s.%s.%s: line {%s} → run %s\n", a.streamName, a.filterName, a.name, *line, a.Cmd)
 
-	cmd := exec.Command(a.Cmd[0], a.Cmd[1:]...)
+	computedCommand := make([]string, 0, len(a.Cmd))
+	for _, item := range a.Cmd {
+		computedCommand = append(computedCommand, strings.ReplaceAll(item, pattern, match))
+	}
+
+	log.Printf("INFO %s.%s.%s: run %s\n", a.filter.stream.name, a.filter.name, a.name, computedCommand)
+
+	cmd := exec.Command(computedCommand[0], computedCommand[1:]...)
 	if ret := cmd.Run(); ret != nil {
-		log.Printf("ERR  %s.%s.%s: line {%s} → run %s, code {%s}\n", a.streamName, a.filterName, a.name, *line, a.Cmd, ret)
+		log.Printf("ERR  %s.%s.%s: run %s, code %s\n", a.filter.stream.name, a.filter.name, a.name, computedCommand, ret)
 	}
 }
 
 func (s *Stream) handle() {
-	log.Printf("streamHandle{%v}: start\n", s.Cmd)
+	log.Printf("INFO %s: start %s\n", s.name, s.Cmd)
 
 	lines := cmdStdout(s.Cmd)
 
 	for line := range lines {
 		for _, filter := range s.Filters {
-			if filter.match(line) {
+			if match := filter.match(line); match != "" {
-				filter.launch(&line)
+				filter.execActions(match)
 			}
 		}
 	}

reaction.yml

@@ -3,21 +3,21 @@ definitions:
   - &iptablesban iptables -I reaction 1 -s <ip> -j block
   - &iptablesunban iptables -D reaction 1 -s <ip> -j block
 
-# regexes:
+patterns:
-#   ip: '(([0-9]{1,3}\.){3}[0-9]{1,3})|([0-9a-fA-F:]{2,90})'
+  ip: '(([0-9]{1,3}\.){3}[0-9]{1,3})|([0-9a-fA-F:]{2,90})'
 
 streams:
   tailDown:
     cmd: [ "tail", "-f", "/home/ao/DOWN" ]
     filters:
-      lookForProuts:
+      findIP:
         regex:
-          - prout
+          - found <ip>
-        retry: 1
+        # retry: 1
         retry-period: 1s
         actions:
           damn:
-            cmd: [ "echo", "DAMN" ]
+            cmd: [ "echo", "<ip>" ]
           sleepdamn:
-            cmd: [ "echo", "sleepDAMN" ]
+            cmd: [ "echo", "sleep", "<ip>" ]
-            after: 2s
+            after: 1s