feat: add support for routing an app to a specified host:port

This is useful when there is a service not managed by Dokku but should be exposed via the Dokku routing layer. As an example, some binaries (consul, nomad, vault) expose web uis, and are traditionally run on the host directly vs in a container.

Closes #4665

plugins/network/Makefile

@@ -1,5 +1,5 @@
 SUBCOMMANDS = subcommands/create subcommands/destroy subcommands/exists subcommands/info subcommands/list subcommands/rebuild subcommands/rebuildall subcommands/report subcommands/set
-TRIGGERS = triggers/core-post-deploy triggers/docker-args-process-build triggers/docker-args-process-deploy triggers/docker-args-process-run triggers/install triggers/network-build-config triggers/network-compute-ports triggers/network-config-exists triggers/network-get-ipaddr triggers/network-get-listeners triggers/network-get-port triggers/network-get-property triggers/network-write-ipaddr triggers/network-write-port triggers/post-app-clone-setup triggers/post-app-rename-setup triggers/post-container-create triggers/post-create triggers/post-delete triggers/report
+TRIGGERS = triggers/core-post-deploy triggers/docker-args-process-build triggers/docker-args-process-deploy triggers/docker-args-process-run triggers/install triggers/network-build-config triggers/network-compute-ports triggers/network-config-exists triggers/network-get-ipaddr triggers/network-get-listeners triggers/network-get-port triggers/network-get-property triggers/network-get-static-listeners triggers/network-write-ipaddr triggers/network-write-port triggers/post-app-clone-setup triggers/post-app-rename-setup triggers/post-container-create triggers/post-create triggers/post-delete triggers/report
 BUILD = commands subcommands triggers
 PLUGIN_NAME = network
 

plugins/network/network.go

@@ -3,6 +3,7 @@ package network
 import (
 	"fmt"
 	"io/ioutil"
+	"net"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -17,18 +18,19 @@ import (
 var (
 	// DefaultProperties is a map of all valid network properties with corresponding default property values
 	DefaultProperties = map[string]string{
-		"bind-all-interfaces": "",
 		"attach-post-create":  "",
 		"attach-post-deploy":  "",
+		"bind-all-interfaces": "",
 		"initial-network":     "",
+		"static-web-listener": "",
 		"tld":                 "",
 	}
 
 	// GlobalProperties is a map of all valid global network properties
 	GlobalProperties = map[string]bool{
-		"bind-all-interfaces": true,
 		"attach-post-create":  true,
 		"attach-post-deploy":  true,
+		"bind-all-interfaces": true,
 		"initial-network":     true,
 		"tld":                 true,
 	}
@@ -40,6 +42,10 @@ func BuildConfig(appName string) error {
 		return nil
 	}
 
+	if staticWebListener := reportStaticWebListener(appName); staticWebListener != "" {
+		return nil
+	}
+
 	appRoot := common.AppRoot(appName)
 	s, err := common.PlugnTriggerOutput("ps-current-scale", []string{appName}...)
 	if err != nil {
@@ -97,6 +103,22 @@ func BuildConfig(appName string) error {
 
 // GetContainerIpaddress returns the ipaddr for a given app container
 func GetContainerIpaddress(appName, processType, containerID string) (ipAddr string) {
+	if processType == "web" {
+		if staticWebListener := reportStaticWebListener(appName); staticWebListener != "" {
+			ip, _, err := net.SplitHostPort(staticWebListener)
+			if err == nil {
+				return ip
+			}
+
+			ip2 := net.ParseIP(staticWebListener)
+			if ip2 != nil {
+				return ip2.String()
+			}
+
+			return "127.0.0.1"
+		}
+	}
+
 	if b, err := common.DockerInspect(containerID, "{{ .HostConfig.NetworkMode }}"); err == nil {
 		if string(b[:]) == "host" {
 			return "127.0.0.1"
@@ -123,6 +145,17 @@ func GetContainerIpaddress(appName, processType, containerID string) (ipAddr str
 
 // GetContainerPort returns the port for a given app container
 func GetContainerPort(appName, processType string, containerID string, isHerokuishContainer bool) (port string) {
+	if processType == "web" {
+		if staticWebListener := reportStaticWebListener(appName); staticWebListener != "" {
+			_, port, err := net.SplitHostPort(staticWebListener)
+			if err == nil {
+				return port
+			}
+
+			return "80"
+		}
+	}
+
 	dockerfilePorts := make([]string, 0)
 	if !isHerokuishContainer {
 		configValue := config.GetWithDefault(appName, "DOKKU_DOCKERFILE_PORTS", "")
@@ -156,6 +189,12 @@ func GetContainerPort(appName, processType string, containerID string, isHerokui
 
 // GetListeners returns a string array of app listeners
 func GetListeners(appName string, processType string) []string {
+	if processType == "web" {
+		if staticWebListener := reportStaticWebListener(appName); staticWebListener != "" {
+			return []string{staticWebListener}
+		}
+	}
+
 	appRoot := common.AppRoot(appName)
 
 	ipPrefix := fmt.Sprintf("/IP.%s.", processType)

plugins/network/report.go

@@ -27,6 +27,7 @@ func ReportSingleApp(appName string, format string, infoFlag string) error {
 		"--network-global-initial-network":       reportGlobalInitialNetwork,
 		"--network-global-tld":                   reportGlobalTld,
 		"--network-initial-network":              reportInitialNetwork,
+		"--network-static-web-listener":          reportStaticWebListener,
 		"--network-tld":                          reportTld,
 		"--network-web-listeners":                reportWebListeners,
 	}
@@ -123,6 +124,10 @@ func reportInitialNetwork(appName string) string {
 	return common.PropertyGet("network", appName, "initial-network")
 }
 
+func reportStaticWebListener(appName string) string {
+	return common.PropertyGet("network", appName, "static-web-listener")
+}
+
 func reportTld(appName string) string {
 	return common.PropertyGet("network", appName, "tld")
 }

plugins/network/src/triggers/triggers.go

@@ -59,6 +59,10 @@ func main() {
 		appName := flag.Arg(0)
 		property := flag.Arg(1)
 		err = network.TriggerNetworkGetProperty(appName, property)
+	case "network-get-static-listeners":
+		appName := flag.Arg(0)
+		processType := flag.Arg(1)
+		err = network.TriggerNetworkGetStaticListeners(appName, processType)
 	case "network-write-ipaddr":
 		appName := flag.Arg(0)
 		processType := flag.Arg(1)

plugins/network/triggers.go

@@ -140,6 +140,13 @@ func TriggerNetworkGetProperty(appName string, property string) error {
 	return nil
 }
 
+// TriggerNetworkGetStaticListeners fetches the static listener for the specified app/processType combination
+func TriggerNetworkGetStaticListeners(appName string, processType string) error {
+	staticWebListener := reportStaticWebListener(appName)
+	fmt.Println(staticWebListener)
+	return nil
+}
+
 // TriggerNetworkWriteIpaddr writes the ip to disk
 func TriggerNetworkWriteIpaddr(appName string, processType string, containerIndex string, ip string) error {
 	appRoot := common.AppRoot(appName)