Support multiple path prefixes per service

Adds the ability to route multiple paths to a service. As with the
multiple host routing, specify multiple paths either by comma-delimiting
them or by using the flag multiple times:

    kamal-proxy deploy myservice --path-prefix=/app,/api ...

Author: kevinmcconnell

internal/cmd/deploy.go

@@ -3,6 +3,7 @@ package cmd
 import (
 	"fmt"
 	"net/rpc"
+	"slices"
 
 	"github.com/spf13/cobra"
 
@@ -28,7 +29,7 @@ func newDeployCommand() *deployCommand {
 
 	deployCommand.cmd.Flags().StringVar(&deployCommand.args.TargetURL, "target", "", "Target host to deploy")
 	deployCommand.cmd.Flags().StringSliceVar(&deployCommand.args.Hosts, "host", []string{}, "Host(s) to serve this target on (empty for wildcard)")
-	deployCommand.cmd.Flags().StringVar(&deployCommand.args.PathPrefix, "path-prefix", "", "Deploy the service below the specified path")
+	deployCommand.cmd.Flags().StringSliceVar(&deployCommand.args.PathPrefixes, "path-prefix", []string{}, "Deploy the service below the specified path(s)")
 	deployCommand.cmd.Flags().BoolVar(&deployCommand.args.ServiceOptions.StripPrefix, "strip-path-prefix", true, "With --path-prefix, strip prefix from request before forwarding")
 
 	deployCommand.cmd.Flags().BoolVar(&deployCommand.args.ServiceOptions.TLSEnabled, "tls", false, "Configure TLS for this target (requires a non-empty host)")
@@ -81,7 +82,7 @@ func (c *deployCommand) run(cmd *cobra.Command, args []string) error {
 }
 
 func (c *deployCommand) preRun(cmd *cobra.Command, args []string) error {
-	c.args.PathPrefix = server.NormalizePath(c.args.PathPrefix)
+	c.args.PathPrefixes = server.NormalizePathPrefixes(c.args.PathPrefixes)
 
 	if cmd.Flags().Changed("max-request-body") && !cmd.Flags().Changed("buffer-requests") {
 		return fmt.Errorf("max-request-body can only be set when request buffering is enabled")
@@ -100,7 +101,7 @@ func (c *deployCommand) preRun(cmd *cobra.Command, args []string) error {
 			return fmt.Errorf("host must be set when using TLS")
 		}
 
-		if c.args.PathPrefix != "/" {
+		if !slices.Contains(c.args.PathPrefixes, "/") {
 			return fmt.Errorf("TLS settings must be specified on the root path service")
 		}
 	}

internal/server/commands.go

@@ -20,7 +20,7 @@ type DeployArgs struct {
 	Service        string
 	TargetURL      string
 	Hosts          []string
-	PathPrefix     string
+	PathPrefixes   []string
 	DeployTimeout  time.Duration
 	DrainTimeout   time.Duration
 	ServiceOptions ServiceOptions
@@ -115,7 +115,7 @@ func (h *CommandHandler) Close() error {
 }
 
 func (h *CommandHandler) Deploy(args DeployArgs, reply *bool) error {
-	return h.router.SetServiceTarget(args.Service, args.Hosts, args.PathPrefix, args.TargetURL, args.ServiceOptions, args.TargetOptions, args.DeployTimeout, args.DrainTimeout)
+	return h.router.SetServiceTarget(args.Service, args.Hosts, args.PathPrefixes, args.TargetURL, args.ServiceOptions, args.TargetOptions, args.DeployTimeout, args.DrainTimeout)
 }
 
 func (h *CommandHandler) Pause(args PauseArgs, reply *bool) error {

internal/server/router.go

@@ -93,7 +93,6 @@ func (r *Router) RestoreLastSavedState() error {
 
 func (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	service, prefix := r.serviceForRequest(req)
-	slog.Info("Matched", "service", service.name, "prefix", prefix)
 	if service == nil {
 		SetErrorResponse(w, req, http.StatusNotFound, nil)
 		return
@@ -107,20 +106,20 @@ func (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	service.ServeHTTP(w, req)
 }
 
-func (r *Router) SetServiceTarget(name string, hosts []string, pathPrefix string, targetURL string,
+func (r *Router) SetServiceTarget(name string, hosts []string, pathPrefixes []string, targetURL string,
 	options ServiceOptions, targetOptions TargetOptions,
 	deployTimeout time.Duration, drainTimeout time.Duration,
 ) error {
 	defer r.saveStateSnapshot()
 
-	slog.Info("Deploying", "service", name, "hosts", hosts, "path", pathPrefix, "target", targetURL, "tls", options.TLSEnabled, "strip", options.StripPrefix)
+	slog.Info("Deploying", "service", name, "hosts", hosts, "paths", pathPrefixes, "target", targetURL, "tls", options.TLSEnabled, "strip", options.StripPrefix)
 
 	target, err := r.deployNewTargetWithOptions(targetURL, targetOptions, deployTimeout)
 	if err != nil {
 		return err
 	}
 
-	err = r.setActiveTarget(name, hosts, pathPrefix, target, options, drainTimeout)
+	err = r.setActiveTarget(name, hosts, pathPrefixes, target, options, drainTimeout)
 	if err != nil {
 		return err
 	}
@@ -241,14 +240,17 @@ func (r *Router) ListActiveServices() ServiceDescriptionMap {
 
 	r.withReadLock(func() error {
 		for name, service := range r.services.All() {
-			host := strings.Join(service.hosts, ",")
-			if host == "" {
-				host = "*"
-			}
 			if service.active != nil {
+				host := strings.Join(service.hosts, ",")
+				if host == "" {
+					host = "*"
+				}
+
+				path := strings.Join(service.pathPrefixes, ",")
+
 				result[name] = ServiceDescription{
 					Host:   host,
-					Path:   service.pathPrefix,
+					Path:   path,
 					Target: service.active.Target(),
 					TLS:    service.options.TLSEnabled,
 					State:  service.pauseController.GetState().String(),
@@ -337,11 +339,11 @@ func (r *Router) serviceForHost(host string) *Service {
 	return r.services.ServiceForHost(host)
 }
 
-func (r *Router) setActiveTarget(name string, hosts []string, pathPrefix string, target *Target, options ServiceOptions, drainTimeout time.Duration) error {
+func (r *Router) setActiveTarget(name string, hosts []string, pathPrefixes []string, target *Target, options ServiceOptions, drainTimeout time.Duration) error {
 	var replacedTarget *Target
 
 	err := r.withWriteLock(func() error {
-		conflict := r.services.CheckAvailability(name, hosts, pathPrefix)
+		conflict := r.services.CheckAvailability(name, hosts, pathPrefixes)
 		if conflict != nil {
 			slog.Error("Host settings conflict with another service", "service", conflict.name)
 			return ErrorHostInUse
@@ -350,9 +352,9 @@ func (r *Router) setActiveTarget(name string, hosts []string, pathPrefix string,
 		var err error
 		service := r.services.Get(name)
 		if service == nil {
-			service, err = NewService(name, hosts, pathPrefix, options)
+			service, err = NewService(name, hosts, pathPrefixes, options)
 		} else {
-			err = service.UpdateOptions(hosts, pathPrefix, options)
+			err = service.UpdateOptions(hosts, pathPrefixes, options)
 		}
 		if err != nil {
 			return err