feat(canary): support use cookie value and pattern (kubernetes#8)

* feat(canary): support use cookie value

* feat: support use cookie pattern

Co-authored-by: Lisheng Zheng <zhenglisheng@caicloud.io>

docs/user-guide/nginx-configuration/annotations.md

@@ -39,6 +39,8 @@ You can add these Kubernetes annotations to specific Ingress objects to customiz
 |[nginx.ingress.kubernetes.io/canary-by-header-value](#canary)|string|
 |[nginx.ingress.kubernetes.io/canary-by-header-pattern](#canary)|string|
 |[nginx.ingress.kubernetes.io/canary-by-cookie](#canary)|string|
+|[nginx.ingress.kubernetes.io/canary-by-cookie-value](#canary)|string|
+|[nginx.ingress.kubernetes.io/canary-by-cookie-pattern](#canary)|string|
 |[nginx.ingress.kubernetes.io/canary-weight](#canary)|number|
 |[nginx.ingress.kubernetes.io/client-body-buffer-size](#client-body-buffer-size)|string|
 |[nginx.ingress.kubernetes.io/configuration-snippet](#configuration-snippet)|string|
@@ -133,6 +135,12 @@ In some cases, you may want to "canary" a new set of changes by sending a small
 
 * `nginx.ingress.kubernetes.io/canary-weight`: The integer based (0 - 100) percent of random requests that should be routed to the service specified in the canary Ingress. A weight of 0 implies that no requests will be sent to the service in the Canary ingress by this canary rule. A weight of 100 means implies all requests will be sent to the alternative service specified in the Ingress.
 
+* `nginx.ingress.kubernetes.io/canary-by-cookie-value`: The cookie value to match for notifying the Ingress to route the request to the service specified in the Canary Ingress. When the request cookie is set to this value, it will be routed to the canary. For any other header value, the header will be ignored and the request compared against the other canary rules by precedence. This annotation has to be used together with . The annotation is an extension of the `nginx.ingress.kubernetes.io/canary-by-cookie` to allow customizing the header value instead of using hardcoded values. It doesn't have any effect if the `nginx.ingress.kubernetes.io/canary-by-cookie` annotation is not defined.
+
+* `nginx.ingress.kubernetes.io/canary-by-cookie-pattern`: This works the same way as `canary-by-cookie-value` except it does PCRE Regex matching. Note that when `canary-by-cookie-value` is set this annotation will be ignored. When the given Regex causes error during request processing, the request will be considered as not matching.
+
+* `nginx.ingress.kubernetes.io/canary-weight`: The integer based (0 - 100) percent of random requests that should be routed to the service specified in the canary Ingress. A weight of 0 implies that no requests will be sent to the service in the Canary ingress by this canary rule. A weight of 100 means implies all requests will be sent to the alternative service specified in the Ingress.   
+
 Canary rules are evaluated in order of precedence. Precedence is as follows:
 `canary-by-header -> canary-by-cookie -> canary-weight`
 

internal/ingress/annotations/canary/main.go

@@ -18,7 +18,6 @@ package canary
 
 import (
 	networking "k8s.io/api/networking/v1beta1"
-
 	"k8s.io/ingress-nginx/internal/ingress/annotations/parser"
 	"k8s.io/ingress-nginx/internal/ingress/errors"
 	"k8s.io/ingress-nginx/internal/ingress/resolver"
@@ -36,6 +35,8 @@ type Config struct {
 	HeaderValue   string
 	HeaderPattern string
 	Cookie        string
+	CookieValue   string
+	CookiePattern string
 }
 
 // NewParser parses the ingress for canary related annotations
@@ -79,8 +80,17 @@ func (c canary) Parse(ing *networking.Ingress) (interface{}, error) {
 		config.Cookie = ""
 	}
 
+	config.CookieValue, err = parser.GetStringAnnotation("canary-by-cookie-value", ing)
+	if err != nil {
+		config.CookieValue = ""
+	}
+
+	config.CookiePattern, err = parser.GetStringAnnotation("canary-by-cookie-pattern", ing)
+	if err != nil {
+		config.CookiePattern = ""
+	}
 	if !config.Enabled && (config.Weight > 0 || len(config.Header) > 0 || len(config.HeaderValue) > 0 || len(config.Cookie) > 0 ||
-		len(config.HeaderPattern) > 0) {
+		len(config.HeaderPattern) > 0 || len(config.CookieValue) > 0 || len(config.CookiePattern) > 0) {
 		return nil, errors.NewInvalidAnnotationConfiguration("canary", "configured but not enabled")
 	}
 

internal/ingress/controller/controller.go

@@ -805,6 +805,8 @@ func (n *NGINXController) createUpstreams(data []*ingress.Ingress, du *ingress.B
 					HeaderValue:   anns.Canary.HeaderValue,
 					HeaderPattern: anns.Canary.HeaderPattern,
 					Cookie:        anns.Canary.Cookie,
+					CookieValue:   anns.Canary.CookieValue,
+					CookiePattern: anns.Canary.CookiePattern,
 				}
 			}
 
@@ -869,6 +871,8 @@ func (n *NGINXController) createUpstreams(data []*ingress.Ingress, du *ingress.B
 						HeaderValue:   anns.Canary.HeaderValue,
 						HeaderPattern: anns.Canary.HeaderPattern,
 						Cookie:        anns.Canary.Cookie,
+						CookieValue:   anns.Canary.CookieValue,
+						CookiePattern: anns.Canary.CookiePattern,
 					}
 				}
 

internal/ingress/types.go

@@ -120,6 +120,10 @@ type TrafficShapingPolicy struct {
 	HeaderPattern string `json:"headerPattern"`
 	// Cookie on which to redirect requests to this backend
 	Cookie string `json:"cookie"`
+	// CookieValue on which to redirect requests to this backend
+	CookieValue string `json:"cookieValue"`
+	// CookiePattern the cookie value match pattern, support exact, regex.
+	CookiePattern string `json:"cookiePattern"`
 }
 
 // HashInclude defines if a field should be used or not to calculate the hash

internal/ingress/types_equals.go

@@ -253,6 +253,12 @@ func (tsp1 TrafficShapingPolicy) Equal(tsp2 TrafficShapingPolicy) bool {
 	if tsp1.Cookie != tsp2.Cookie {
 		return false
 	}
+	if tsp1.CookieValue != tsp2.CookieValue {
+		return false
+	}
+	if tsp1.CookiePattern != tsp2.CookiePattern {
+		return false
+	}
 
 	return true
 }

rootfs/etc/nginx/lua/balancer.lua

@@ -237,7 +237,22 @@ local function route_to_alternative_balancer(balancer)
   local target_cookie = traffic_shaping_policy.cookie
   local cookie = ngx.var["cookie_" .. target_cookie]
   if cookie then
-    if cookie == "always" then
+    if traffic_shaping_policy.cookieValue
+            and #traffic_shaping_policy.cookieValue > 0 then
+      if traffic_shaping_policy.cookieValue == cookie then
+        return true
+      end
+    elseif traffic_shaping_policy.cookiePattern
+            and #traffic_shaping_policy.cookiePattern > 0 then
+      local m, err = ngx.re.match(cookie, traffic_shaping_policy.cookiePattern)
+      if m then
+        return true
+      elseif  err then
+        ngx.log(ngx.ERR, "error when matching canary-by-cookie-pattern: '",
+                traffic_shaping_policy.cookiePattern, "', error: ", err)
+        return false
+      end
+    elseif cookie == "always" then
       return true
     elseif cookie == "never" then
       return false