Filter by label (#236)

* Filter by label

* Filter by label - fix with return statement

* Prefer strings.SplitN

* Ignore label filters if missing semicolon would cause panic

README.md

@@ -69,8 +69,14 @@ You can tell logspout to only include certain containers by setting filter param
 		--volume=/var/run/docker.sock:/var/run/docker.sock \
 		gliderlabs/logspout \
 		raw://192.168.10.10:5000?filter.sources=stdout%2Cstderr
+
+	# Forward logs from containers with both label 'a' starting with 'x', and label 'b' ending in 'y'.
+	$ docker run \
+		--volume=/var/run/docker.sock:/var/run/docker.sock \
+		gliderlabs/logspout \
+		raw://192.168.10.10:5000?filter.labels=a:x*%2Cb:*y
 
-Note that you must URL-encode parameter values such as the comma in `filter.sources`.
+Note that you must URL-encode parameter values such as the comma in `filter.sources` and `filter.labels`.
 
 #### Multiple logging destinations
 

logspout.go

@@ -57,7 +57,7 @@ func main() {
 			fmt.Fprintf(w, "#   %s\t%s\t%s\t%s\t%s\n",
 				route.Adapter,
 				route.Address,
-				route.FilterID+route.FilterName,
+				route.FilterID+route.FilterName+strings.Join(route.FilterLabels, ","),
 				strings.Join(route.FilterSources, ","),
 				route.Options)
 		}

router/pump.go

@@ -259,7 +259,8 @@ func (p *LogsPump) Route(route *Route, logstream chan *Message) {
 	for _, pump := range p.pumps {
 		if route.MatchContainer(
 			normalID(pump.container.ID),
-			normalName(pump.container.Name)) {
+			normalName(pump.container.Name),
+			pump.container.Config.Labels) {
 
 			pump.add(logstream, route)
 			defer pump.remove(logstream)
@@ -280,7 +281,8 @@ func (p *LogsPump) Route(route *Route, logstream chan *Message) {
 			case "start", "restart":
 				if route.MatchContainer(
 					normalID(event.pump.container.ID),
-					normalName(event.pump.container.Name)) {
+					normalName(event.pump.container.Name),
+					event.pump.container.Config.Labels) {
 
 					event.pump.add(logstream, route)
 					defer event.pump.remove(logstream)

router/routes.go

@@ -98,6 +98,8 @@ func (rm *RouteManager) AddFromUri(uri string) error {
 				r.FilterID = value
 			case "filter.name":
 				r.FilterName = value
+			case "filter.labels":
+				r.FilterLabels = strings.Split(value, ",")
 			case "filter.sources":
 				r.FilterSources = strings.Split(value, ",")
 			default:

router/types.go

@@ -61,6 +61,7 @@ type Route struct {
 	FilterID      string            `json:"filter_id,omitempty"`
 	FilterName    string            `json:"filter_name,omitempty"`
 	FilterSources []string          `json:"filter_sources,omitempty"`
+	FilterLabels  []string          `json:"filter_labels,omitempty"`
 	Adapter       string            `json:"adapter"`
 	Address       string            `json:"address"`
 	Options       map[string]string `json:"options,omitempty"`
@@ -97,7 +98,7 @@ func (r *Route) Close() {
 }
 
 func (r *Route) matchAll() bool {
-	if r.FilterID == "" && r.FilterName == "" && len(r.FilterSources) == 0 {
+	if r.FilterID == "" && r.FilterName == "" && len(r.FilterSources) == 0 && len(r.FilterLabels) == 0 {
 		return true
 	}
 	return false
@@ -107,7 +108,7 @@ func (r *Route) MultiContainer() bool {
 	return r.matchAll() || strings.Contains(r.FilterName, "*")
 }
 
-func (r *Route) MatchContainer(id, name string) bool {
+func (r *Route) MatchContainer(id, name string, labels map[string]string) bool {
 	if r.matchAll() {
 		return true
 	}
@@ -118,6 +119,18 @@ func (r *Route) MatchContainer(id, name string) bool {
 	if err != nil || (r.FilterName != "" && !match) {
 		return false
 	}
+	for _,label := range r.FilterLabels {
+		labelParts := strings.SplitN(label, ":", 2)
+		if len(labelParts) > 1 {
+			labelKey := labelParts[0]
+			labelValue := labelParts[1]
+			labelMatch, labelErr := path.Match(labelValue, labels[labelKey])
+			if labelErr != nil || (labelValue != "" && !labelMatch) {
+				return false
+			}
+		}
+	}
+
 	return true
 }
 

routesapi/README.md

@@ -15,12 +15,13 @@ Takes a JSON object like this:
 		"address": "logaggregator.service.consul",
 		"filter_name": "*_db",
 		"filter_sources": ["stdout"],
+		"filter_labels": ["com.example.foo:bar*"],
 		"options": {
 			"append_tag": ".db"
 		}
 	}
 
-The main fields are `adapter` and `address`. The field `options` is passed to the adapter. There are three filter fields: `filter_name`, `filter_sources`, and `filter_id`. These let you limit which containers or types of logs to route. Use `filter_id` to limit to a particular container by ID. Use `filter_name` to match against container names. These can include wildcards. Use `filter_sources` to limit to `stdout` or `stderr`, or soon `syslog`.
+The main fields are `adapter` and `address`. The field `options` is passed to the adapter. There are four filter fields: `filter_name`, `filter_sources`, `filter_id`, and `filter_labels`. These let you limit which containers or types of logs to route. Use `filter_id` to limit to a particular container by ID. Use `filter_name` to match against container names. These can include wildcards. Use `filter_sources` to limit to `stdout` or `stderr`, or soon `syslog`. Use `filter_labels` to limit containers to require specific labels. These can include wildcards.
 
 To route all logs of all types on all containers, don't specify any filter values.