Added Docker host in Docker Backend Config

config/config.go

@@ -12,6 +12,7 @@ import (
 type Metric string
 
 type BackendConfig struct {
+	DockerHost    string `yaml:"DockerHost"`
 	TLSCACert     string `yaml:"TLSCACert"`
 	TLSCert       string `yaml:"TLSCert"`
 	TLSKey        string `yaml:"TLSKey"`
@@ -49,6 +50,7 @@ func NewConfigFromFile(file string) (Config, error) {
 func (c Config) Print() {
 	fmt.Println("Backend: ", c.Backend)
 	fmt.Println("BackendConfig")
+	fmt.Println("\tDocker Host ", c.BackendConfig.DockerHost)
 	fmt.Println("\tTLSCACert ", c.BackendConfig.TLSCACert)
 	fmt.Println("\tTLSCert ", c.BackendConfig.TLSCert)
 	fmt.Println("\tTLSKey ", c.BackendConfig.TLSKey)

container/backend/docker/docker.go

@@ -22,7 +22,6 @@ import (
 )
 
 const (
-	DockerAPI        = "unix:///var/run/docker.sock"
 	DockerAPIVersion = "v1.23"
 )
 
@@ -35,21 +34,29 @@ func NewDockerBackend(c config.BackendConfig) (*Docker, error) {
 	httpHeaders := map[string]string{
 		"User-Agent": fmt.Sprintf("kappa/%s", version.Version),
 	}
+
+	dockerHost := "unix:///var/run/docker.sock"
+
+	if c.DockerHost != "" {
+		dockerHost = c.DockerHost
+	}
+
 	if c.TLSCert != "" && c.TLSKey != "" {
 		tlsOptions := tlsconfig.Options{
 			CAFile:             c.TLSCACert,
 			CertFile:           c.TLSCert,
 			KeyFile:            c.TLSKey,
 			InsecureSkipVerify: c.AllowInsecure,
 		}
+
 		config, err := tlsconfig.Client(tlsOptions)
 		if err != nil {
 			return nil, err
 		}
 		tr := &http.Transport{
 			TLSClientConfig: config,
 		}
-		proto, addr, _, err := client.ParseHost(DockerAPI)
+		proto, addr, _, err := client.ParseHost(dockerHost)
 		if err != nil {
 			return nil, err
 		}
@@ -59,7 +66,7 @@ func NewDockerBackend(c config.BackendConfig) (*Docker, error) {
 		}
 	}
 
-	client, err := client.NewClient(DockerAPI, DockerAPIVersion, httpClient, httpHeaders)
+	client, err := client.NewClient(dockerHost, DockerAPIVersion, httpClient, httpHeaders)
 	if err != nil {
 		return nil, err
 	}

docs/examples/config.yml

@@ -1,10 +1,7 @@
 ---
 backend: docker
 backend_config:
-  TLSCACert: "/etc/docker/ca.crt"
-  TLSCert: "/etc/docker/server.pem"
-  TLSKey: "/etc/docker/server.key"
-  AllowInsecure: false
+  DockerHost: "unix:///var/run/docker.sock"
 metrics:
   queue_length: "/usr/local/bin/queue_length.sh"
   reqsec:  "/usr/local/bin/reqsec.sh"