Add feature to allow sticky sessions per location

controllers/nginx/pkg/template/template.go

@@ -135,6 +135,7 @@ var (
 		"buildRateLimitZones":      buildRateLimitZones,
 		"buildRateLimit":           buildRateLimit,
 		"buildResolvers":           buildResolvers,
+		"buildUpstreamName":        buildUpstreamName,
 		"isLocationAllowed":        isLocationAllowed,
 		"buildLogFormatUpstream":   buildLogFormatUpstream,
 		"buildDenyVariable":        buildDenyVariable,
@@ -257,7 +258,7 @@ func buildLogFormatUpstream(input interface{}) string {
 // (specified through the ingress.kubernetes.io/rewrite-to annotation)
 // If the annotation ingress.kubernetes.io/add-base-url:"true" is specified it will
 // add a base tag in the head of the response from the service
-func buildProxyPass(b interface{}, loc interface{}) string {
+func buildProxyPass(host string, b interface{}, loc interface{}) string {
 	backends := b.([]*ingress.Backend)
 	location, ok := loc.(*ingress.Location)
 	if !ok {
@@ -267,17 +268,23 @@ func buildProxyPass(b interface{}, loc interface{}) string {
 	path := location.Path
 	proto := "http"
 
+	upstreamName := location.Backend
 	for _, backend := range backends {
 		if backend.Name == location.Backend {
 			if backend.Secure || backend.SSLPassthrough {
 				proto = "https"
 			}
+
+			if isSticky(host, location, backend.SessionAffinity.CookieSessionAffinity.Locations) {
+				upstreamName = fmt.Sprintf("sticky-%v", upstreamName)
+			}
+
 			break
 		}
 	}
 
 	// defProxyPass returns the default proxy_pass, just the name of the upstream
-	defProxyPass := fmt.Sprintf("proxy_pass %s://%s;", proto, location.Backend)
+	defProxyPass := fmt.Sprintf("proxy_pass %s://%s;", proto, upstreamName)
 	// if the path in the ingress rule is equals to the target: no special rewrite
 	if path == location.Redirect.Target {
 		return defProxyPass
@@ -408,3 +415,38 @@ func buildDenyVariable(a interface{}) string {
 
 	return fmt.Sprintf("$deny_%v", denyPathSlugMap[l])
 }
+
+func buildUpstreamName(host string, b interface{}, loc interface{}) string {
+	backends := b.([]*ingress.Backend)
+	location, ok := loc.(*ingress.Location)
+	if !ok {
+		return ""
+	}
+
+	upstreamName := location.Backend
+
+	for _, backend := range backends {
+		if backend.Name == location.Backend {
+			if backend.SessionAffinity.AffinityType == "cookie" &&
+				isSticky(host, location, backend.SessionAffinity.CookieSessionAffinity.Locations) {
+				upstreamName = fmt.Sprintf("sticky-%v", upstreamName)
+			}
+
+			break
+		}
+	}
+
+	return upstreamName
+}
+
+func isSticky(host string, loc *ingress.Location, stickyLocations map[string][]string) bool {
+	if _, ok := stickyLocations[host]; ok {
+		for _, sl := range stickyLocations[host] {
+			if sl == loc.Path {
+				return true
+			}
+		}
+	}
+
+	return false
+}

controllers/nginx/pkg/template/template_test.go

@@ -129,7 +129,7 @@ func TestBuildProxyPass(t *testing.T) {
 			Backend:  "upstream-name",
 		}
 
-		pp := buildProxyPass([]*ingress.Backend{}, loc)
+		pp := buildProxyPass("", []*ingress.Backend{}, loc)
 		if !strings.EqualFold(tc.ProxyPass, pp) {
 			t.Errorf("%s: expected \n'%v'\nbut returned \n'%v'", k, tc.ProxyPass, pp)
 		}

controllers/nginx/rootfs/etc/nginx/template/nginx.tmpl

@@ -225,16 +225,25 @@ http {
     proxy_pass_header Server;
     {{ end }}
 
-    {{range $name, $upstream := $backends}}
-    upstream {{$upstream.Name}} {
-        {{ if eq $upstream.SessionAffinity.AffinityType "cookie" }}
-        sticky hash={{$upstream.SessionAffinity.CookieSessionAffinity.Hash}} name={{$upstream.SessionAffinity.CookieSessionAffinity.Name}}  httponly;
-        {{ else }}
+    {{ range $name, $upstream := $backends }}
+    {{ if eq $upstream.SessionAffinity.AffinityType "cookie" }}
+    upstream sticky-{{ $upstream.Name }} {
+        sticky hash={{ $upstream.SessionAffinity.CookieSessionAffinity.Hash }} name={{ $upstream.SessionAffinity.CookieSessionAffinity.Name }}  httponly;
+
+        {{ if (gt $cfg.UpstreamKeepaliveConnections 0) }}
+        keepalive {{ $cfg.UpstreamKeepaliveConnections }};
+        {{ end }}
+
+        {{ range $server := $upstream.Endpoints }}server {{ $server.Address | formatIP }}:{{ $server.Port }} max_fails={{ $server.MaxFails }} fail_timeout={{ $server.FailTimeout }};
+        {{ end }}
+    }
+    {{ end }}
+
+    upstream {{ $upstream.Name }} {
         # Load balance algorithm; empty for round robin, which is the default
         {{ if ne $cfg.LoadBalanceAlgorithm "round_robin" }}
         {{ $cfg.LoadBalanceAlgorithm }};
         {{ end }}
-        {{ end }}
 
         {{ if (gt $cfg.UpstreamKeepaliveConnections 0) }}
         keepalive {{ $cfg.UpstreamKeepaliveConnections }};
@@ -343,8 +352,7 @@ http {
         {{ end }}
 
         location {{ $path }} {
-            set $proxy_upstream_name "{{ $location.Backend }}";
-
+            set $proxy_upstream_name "{{ buildUpstreamName $server.Hostname $backends $location }}";
             {{ if isLocationAllowed $location }}
             {{ if gt (len $location.Whitelist.CIDR) 0 }}
             if ({{ buildDenyVariable (print $server.Hostname "_"  $path) }}) {
@@ -439,7 +447,7 @@ http {
             {{/* Add any additional configuration defined */}}
             {{ $location.ConfigurationSnippet }}
 
-            {{ buildProxyPass $backends $location }}
+            {{ buildProxyPass $server.Hostname $backends $location }}
             {{ else }}
             #{{ $location.Denied }}
             return 503;

core/pkg/ingress/controller/controller.go

@@ -791,14 +791,21 @@ func (ic *GenericController) createUpstreams(data []interface{}) map[string]*ing
 				if !upstreams[name].Secure {
 					upstreams[name].Secure = secUpstream.Secure
 				}
+
 				if upstreams[name].SecureCACert.Secret == "" {
 					upstreams[name].SecureCACert = secUpstream.CACert
 				}
+
 				if upstreams[name].SessionAffinity.AffinityType == "" {
 					upstreams[name].SessionAffinity.AffinityType = affinity.AffinityType
 					if affinity.AffinityType == "cookie" {
 						upstreams[name].SessionAffinity.CookieSessionAffinity.Name = affinity.CookieConfig.Name
 						upstreams[name].SessionAffinity.CookieSessionAffinity.Hash = affinity.CookieConfig.Hash
+
+						if _, ok := upstreams[name].SessionAffinity.CookieSessionAffinity.Locations[rule.Host]; !ok {
+							upstreams[name].SessionAffinity.CookieSessionAffinity.Locations[rule.Host] = []string{}
+						}
+						upstreams[name].SessionAffinity.CookieSessionAffinity.Locations[rule.Host] = append(upstreams[name].SessionAffinity.CookieSessionAffinity.Locations[rule.Host], path.Path)
 					}
 				}
 

core/pkg/ingress/controller/util.go

@@ -39,6 +39,11 @@ func newUpstream(name string) *ingress.Backend {
 	return &ingress.Backend{
 		Name:      name,
 		Endpoints: []ingress.Endpoint{},
+		SessionAffinity: ingress.SessionAffinityConfig{
+			CookieSessionAffinity: ingress.CookieSessionAffinity{
+				Locations: make(map[string][]string),
+			},
+		},
 	}
 }
 

core/pkg/ingress/types.go

@@ -174,8 +174,9 @@ type SessionAffinityConfig struct {
 
 // CookieSessionAffinity defines the structure used in Affinity configured by Cookies.
 type CookieSessionAffinity struct {
-	Name string `json:"name"`
-	Hash string `json:"hash"`
+	Name      string              `json:"name"`
+	Hash      string              `json:"hash"`
+	Locations map[string][]string `json:"locations,omitempty"`
 }
 
 // Endpoint describes a kubernetes endpoint in a backend