add support of docker route prefix

README.md

@@ -76,7 +76,7 @@ This is a dynamic provider and file change will be applied automatically.
 
 ### Docker
 
-Docker provider supports a fully automatic discovery (with `--docker.auto`) with no extra configuration and by default redirects all requests like `https://server/<container_name>/(.*)` to the internal IP of the given container and the exposed port. Only active (running) containers will be detected.
+Docker provider supports a fully automatic discovery (with `--docker.auto`) with no extra configuration and by default redirects all requests like `http://<container_name>:<container_port>/(.*)` to the internal IP of the given container and the exposed port. Only active (running) containers will be detected.
 
 This default can be changed with labels:
 
@@ -95,6 +95,8 @@ With `--docker.auto`, all containers with exposed port will be considered as rou
 - Allow only a particular docker network with `--docker.network`
 - Set the label `reproxy.enabled=false` or `reproxy.enabled=no` or `reproxy.enabled=0`
 
+If no `reproxy.route` defined, the default is `http://<container_name>:<container_port>/(.*)`. In case if all proxied source have the same pattern, for example `/api/(.*)` user can define the common prefix (in this case `/api`) for all container-based routes. This can be done with `--docker.prefix` parameter.
+
 This is a dynamic provider and any change in container's status will be applied automatically.
 
 ## SSL support
@@ -183,7 +185,7 @@ ssl:
 assets:
   -a, --assets.location=            assets location [$ASSETS_LOCATION]
       --assets.root=                assets web root (default: /) [$ASSETS_ROOT]
-      --assets.cache=               cache duration for assets (default: 0s) [$ASSETS_CACHE]
+      --assets.cache=               cache duration for assets [$ASSETS_CACHE]
 
 logger:
       --logger.stdout               enable stdout logging [$LOGGER_STDOUT]
@@ -198,6 +200,7 @@ docker:
       --docker.network=             docker network [$DOCKER_NETWORK]
       --docker.exclude=             excluded containers [$DOCKER_EXCLUDE]
       --docker.auto                 enable automatic routing (without labels) [$DOCKER_AUTO]
+      --docker.prefix=              prefix for docker source routes [$DOCKER_PREFIX]
 
 file:
       --file.enabled                enable file provider [$FILE_ENABLED]

app/discovery/provider/docker.go

@@ -29,6 +29,7 @@ type Docker struct {
 	DockerClient    DockerClient
 	Excludes        []string
 	AutoAPI         bool
+	APIPrefix       string
 	RefreshInterval time.Duration
 }
 
@@ -70,10 +71,15 @@ func (d *Docker) List() ([]discovery.URLMapper, error) {
 	res := make([]discovery.URLMapper, 0, len(containers))
 	for _, c := range containers {
 		enabled, explicit := false, false
-		srcURL := fmt.Sprintf("^/%s/(.*)", c.Name)
+		srcURL := fmt.Sprintf("^/%s/(.*)", c.Name) // default destination
+		if d.APIPrefix != "" {
+			prefix := strings.TrimLeft(d.APIPrefix, "/")
+			prefix = strings.TrimRight(prefix, "/")
+			srcURL = fmt.Sprintf("^/%s/%s/(.*)", prefix, c.Name) // default destination with api prefix
+		}
+
 		if d.AutoAPI {
 			enabled = true
-			srcURL = fmt.Sprintf("^/api/%s/(.*)", c.Name)
 		}
 
 		port, err := d.matchedPort(c)

app/discovery/provider/docker_test.go

@@ -93,7 +93,7 @@ func TestDocker_ListWithAutoAPI(t *testing.T) {
 		},
 	}
 
-	d := Docker{DockerClient: dclient, AutoAPI: true}
+	d := Docker{DockerClient: dclient, AutoAPI: true, APIPrefix: "/api"}
 	res, err := d.List()
 	require.NoError(t, err)
 	require.Equal(t, 3, len(res))

app/main.go

@@ -54,11 +54,12 @@ var opts struct {
 	} `group:"logger" namespace:"logger" env-namespace:"LOGGER"`
 
 	Docker struct {
-		Enabled  bool     `long:"enabled" env:"ENABLED" description:"enable docker provider"`
-		Host     string   `long:"host" env:"HOST" default:"unix:///var/run/docker.sock" description:"docker host"`
-		Network  string   `long:"network" env:"NETWORK" default:"" description:"docker network"`
-		Excluded []string `long:"exclude" env:"EXCLUDE" description:"excluded containers" env-delim:","`
-		AutoAPI  bool     `long:"auto" env:"AUTO" description:"enable automatic routing (without labels)"`
+		Enabled   bool     `long:"enabled" env:"ENABLED" description:"enable docker provider"`
+		Host      string   `long:"host" env:"HOST" default:"unix:///var/run/docker.sock" description:"docker host"`
+		Network   string   `long:"network" env:"NETWORK" default:"" description:"docker network"`
+		Excluded  []string `long:"exclude" env:"EXCLUDE" description:"excluded containers" env-delim:","`
+		AutoAPI   bool     `long:"auto" env:"AUTO" description:"enable automatic routing (without labels)"`
+		APIPrefix string   `long:"prefix" env:"PREFIX" description:"prefix for docker source routes"`
 	} `group:"docker" namespace:"docker" env-namespace:"DOCKER"`
 
 	File struct {
@@ -251,7 +252,7 @@ func makeProviders() ([]discovery.Provider, error) {
 		const refreshInterval = time.Second * 10 // seems like a reasonable default
 
 		res = append(res, &provider.Docker{DockerClient: client, Excludes: opts.Docker.Excluded,
-			AutoAPI: opts.Docker.AutoAPI, RefreshInterval: refreshInterval})
+			AutoAPI: opts.Docker.AutoAPI, APIPrefix: opts.Docker.APIPrefix, RefreshInterval: refreshInterval})
 	}
 
 	if len(res) == 0 && opts.Assets.Location == "" {