allow proxy to route based on request method

Signed-off-by: Jörn Friedrich Dreyer <jfd@butonic.de>

changelog/unreleased/proxy-method-routing.md

@@ -0,0 +1,5 @@
+Enhancement: http method based routing
+
+We added a method property to proxy routes that allows routing requests to a different backend.
+
+https://github.com/owncloud/ocis/pull/3526

proxy/pkg/config/config.go

@@ -45,8 +45,10 @@ type Policy struct {
 
 // Route defines forwarding routes
 type Route struct {
-	Type     RouteType `yaml:"type"`
-	Endpoint string    `yaml:"endpoint"`
+	Type RouteType `yaml:"type"`
+	// Method optionally limits the route to this HTTP method
+	Method   string `yaml:"method"`
+	Endpoint string `yaml:"endpoint"`
 	// Backend is a static URL to forward the request to
 	Backend string `yaml:"backend"`
 	// Service name to look up in the registry

proxy/pkg/config/defaults/defaultconfig.go

@@ -94,6 +94,15 @@ func DefaultPolicies() []config.Policy {
 					Endpoint: "/remote.php/?preview=1",
 					Backend:  "http://localhost:9115",
 				},
+				{
+					// send webdav REPORT requests to search service
+					// TODO the actual REPORT goes to /dav/files/{username}, which is user specific ... how would this work in a spaces world?
+					// TODO what paths are returned? the href contains the full path so it should be possible to return urls from other spaces?
+					// TODO or we allow a REPORT on /dav/spaces to search all spaces and /dav/space/{spaceid} to search a specific space
+					Method:   "REPORT",
+					Endpoint: "/dav/",
+					Backend:  "http://localhost:9115",
+				},
 				{
 					Endpoint: "/remote.php/",
 					Service:  "ocdav",

proxy/pkg/proxy/proxy.go

@@ -29,7 +29,8 @@ import (
 // MultiHostReverseProxy extends "httputil" to support multiple hosts with different policies
 type MultiHostReverseProxy struct {
 	httputil.ReverseProxy
-	Directors      map[string]map[config.RouteType]map[string]func(req *http.Request)
+	// Directors holds policy        route type        method    endpoint         Director
+	Directors      map[string]map[config.RouteType]map[string]map[string]func(req *http.Request)
 	PolicySelector policy.Selector
 	logger         log.Logger
 	config         *config.Config
@@ -40,7 +41,7 @@ func NewMultiHostReverseProxy(opts ...Option) *MultiHostReverseProxy {
 	options := newOptions(opts...)
 
 	rp := &MultiHostReverseProxy{
-		Directors: make(map[string]map[config.RouteType]map[string]func(req *http.Request)),
+		Directors: make(map[string]map[config.RouteType]map[string]map[string]func(req *http.Request)),
 		logger:    options.Logger,
 		config:    options.Config,
 	}
@@ -124,6 +125,7 @@ func (p *MultiHostReverseProxy) directorSelectionDirector(r *http.Request) {
 		return
 	}
 
+	method := ""
 	// find matching director
 	for _, rt := range config.RouteTypes {
 		var handler func(string, url.URL) bool
@@ -137,25 +139,36 @@ func (p *MultiHostReverseProxy) directorSelectionDirector(r *http.Request) {
 		default:
 			handler = p.prefixRouteMatcher
 		}
-		for endpoint := range p.Directors[pol][rt] {
+		if p.Directors[pol][rt][r.Method] != nil {
+			// use specific method
+			method = r.Method
+		}
+		for endpoint := range p.Directors[pol][rt][method] {
 			if handler(endpoint, *r.URL) {
 
 				p.logger.Debug().
 					Str("policy", pol).
+					Str("method", r.Method).
 					Str("prefix", endpoint).
 					Str("path", r.URL.Path).
 					Str("routeType", string(rt)).
 					Msg("director found")
 
-				p.Directors[pol][rt][endpoint](r)
+				p.Directors[pol][rt][method][endpoint](r)
 				return
 			}
 		}
 	}
 
 	// override default director with root. If any
-	if p.Directors[pol][config.PrefixRoute]["/"] != nil {
-		p.Directors[pol][config.PrefixRoute]["/"](r)
+	switch {
+	case p.Directors[pol][config.PrefixRoute][method]["/"] != nil:
+		// try specific method
+		p.Directors[pol][config.PrefixRoute][method]["/"](r)
+		return
+	case p.Directors[pol][config.PrefixRoute][""]["/"] != nil:
+		// fallback to unspecific method
+		p.Directors[pol][config.PrefixRoute][""]["/"](r)
 		return
 	}
 
@@ -182,20 +195,23 @@ func singleJoiningSlash(a, b string) string {
 func (p *MultiHostReverseProxy) AddHost(policy string, target *url.URL, rt config.Route) {
 	targetQuery := target.RawQuery
 	if p.Directors[policy] == nil {
-		p.Directors[policy] = make(map[config.RouteType]map[string]func(req *http.Request))
+		p.Directors[policy] = make(map[config.RouteType]map[string]map[string]func(req *http.Request))
 	}
 	routeType := config.DefaultRouteType
 	if rt.Type != "" {
 		routeType = rt.Type
 	}
 	if p.Directors[policy][routeType] == nil {
-		p.Directors[policy][routeType] = make(map[string]func(req *http.Request))
+		p.Directors[policy][routeType] = make(map[string]map[string]func(req *http.Request))
+	}
+	if p.Directors[policy][routeType][rt.Method] == nil {
+		p.Directors[policy][routeType][rt.Method] = make(map[string]func(req *http.Request))
 	}
 
 	reg := registry.GetRegistry()
 	sel := selector.NewSelector(selector.Registry(reg))
 
-	p.Directors[policy][routeType][rt.Endpoint] = func(req *http.Request) {
+	p.Directors[policy][routeType][rt.Method][rt.Endpoint] = func(req *http.Request) {
 		if rt.Service != "" {
 			// select next node
 			next, err := sel.Select(rt.Service)

proxy/pkg/proxy/proxy_test.go

@@ -1,15 +1,19 @@
 package proxy
 
 import (
+	"fmt"
+	"net/http"
+	"net/http/httptest"
 	"net/url"
 	"testing"
 
+	"github.com/owncloud/ocis/proxy/pkg/config"
 	"github.com/owncloud/ocis/proxy/pkg/config/defaults"
 )
 
 type matchertest struct {
-	endpoint, target string
-	matches          bool
+	method, endpoint, target string
+	matches                  bool
 }
 
 func TestPrefixRouteMatcher(t *testing.T) {
@@ -99,3 +103,35 @@ func TestSingleJoiningSlash(t *testing.T) {
 		}
 	}
 }
+
+func TestDirectorSelectionDirector(t *testing.T) {
+
+	svr := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		fmt.Fprintf(w, "ok")
+	}))
+	defer svr.Close()
+
+	p := NewMultiHostReverseProxy(Config(&config.Config{
+		PolicySelector: &config.PolicySelector{
+			Static: &config.StaticSelectorConf{
+				Policy: "default",
+			},
+		},
+	}))
+	p.AddHost("default", &url.URL{Host: "ocdav"}, config.Route{Type: config.PrefixRoute, Method: "", Endpoint: "/dav", Backend: "ocdav"})
+	p.AddHost("default", &url.URL{Host: "ocis-webdav"}, config.Route{Type: config.PrefixRoute, Method: "REPORT", Endpoint: "/dav", Backend: "ocis-webdav"})
+
+	table := []matchertest{
+		{method: "PROPFIND", endpoint: "/dav/files/demo/", target: "ocdav"},
+		{method: "REPORT", endpoint: "/dav/files/demo/", target: "ocis-webdav"},
+	}
+
+	for _, test := range table {
+		r := httptest.NewRequest(http.MethodGet, "/dav/files/demo/", nil)
+		p.directorSelectionDirector(r)
+		if r.Host != test.target {
+			t.Errorf("TestDirectorSelectionDirector got host %s expected %s", r.Host, test.target)
+
+		}
+	}
+}