Added ability to skip containers (#416)

* Added ability to skip containers on custom label key:value pairs and not just the default label=true

* refactored logic for ignoring containers with custom labels

* fixes to simplify logic

* fixes to simplify logic

* Updated README and CHANGELOG markdowns

* pump.go needs to reassign label var if label is of the form key:value

* fixing up a few things based on feedback

CHANGELOG.md

@@ -10,6 +10,7 @@ All notable changes to this project will be documented in this file.
 - @gbolo added ability to control the TLS client trust store
 - @gbolo added option to harden the TLS client
 - @chopmann added option to bind the http server to an address
+- @ibrokethecloud added ability to add custom key:value pairs as EXCLUDE_LABEL.
 
 ### Removed
 

README.md

@@ -167,7 +167,7 @@ If you use multiline logging with raw, it's recommended to json encode the Data
 * `BACKLOG` - suppress container tail backlog
 * `TAIL` - specify the number of lines in the log tail to capture when logspout starts (default `all`)
 * `DEBUG` - emit debug logs
-* `EXCLUDE_LABEL` - exclude logs with a given label
+* `EXCLUDE_LABEL` - exclude containers with a given label. The label can have a value of true or a custom value matched with : after the label name like label_name:label_value.
 * `INACTIVITY_TIMEOUT` - detect hang in Docker API (default 0)
 * `HTTP_BIND_ADDRESS` - configure which interface address to listen on (default 0.0.0.0)
 * `PORT` or `HTTP_PORT` - configure which port to listen on (default 80)

router/pump.go

@@ -86,9 +86,18 @@ func ignoreContainer(container *docker.Container) bool {
 			return true
 		}
 	}
+
 	excludeLabel := getopt("EXCLUDE_LABEL", "")
+	excludeValue := "true"
+	// support EXCLUDE_LABEL having a custom label value
+	excludeLabelArr := strings.Split(excludeLabel, ":")
+	if len(excludeLabelArr) == 2 {
+		excludeValue = excludeLabelArr[1]
+		excludeLabel = excludeLabelArr[0]
+	}
+
 	if value, ok := container.Config.Labels[excludeLabel]; ok {
-		return len(excludeLabel) > 0 && strings.ToLower(value) == "true"
+		return len(excludeLabel) > 0 && strings.ToLower(value) == strings.ToLower(excludeValue)
 	}
 	return false
 }
@@ -212,7 +221,7 @@ func (p *LogsPump) pumpLogs(event *docker.APIEvents, backlog bool, inactivityTim
 
 	// RawTerminal with container Tty=false injects binary headers into
 	// the log stream that show up as garbage unicode characters
-	rawTerminal := false 
+	rawTerminal := false
 	if allowTTY && container.Config.Tty {
 		rawTerminal = true
 	}

router/pump_test.go

@@ -74,6 +74,24 @@ func TestPumpIgnoreContainer(t *testing.T) {
 	}
 }
 
+func TestPumpIgnoreContainerCustomLabels(t *testing.T) {
+	os.Setenv("EXCLUDE_LABEL", "k8s-app:canal")
+	defer os.Unsetenv("EXCLUDE_LABEL")
+	containers := []struct {
+		in  *docker.Config
+		out bool
+	}{
+		{&docker.Config{Labels: map[string]string{"k8s-app": "canal"}}, true},
+		{&docker.Config{Labels: map[string]string{"app": "demo-app"}}, false},
+	}
+
+	for _, conf := range containers {
+		if actual := ignoreContainer(&docker.Container{Config: conf.in}); actual != conf.out {
+			t.Errorf("expected %v got %v", conf.out, actual)
+		}
+	}
+}
+
 func TestPumpIgnoreContainerAllowTTYDefault(t *testing.T) {
 	containers := []struct {
 		in  *docker.Config