Provide annotation to control opentracing

By default you might want opentracing off, but on for a particular
ingress.

Similarly, you might want opentracing globally on, but disabled for
a specific endpoint. To achieve this, `opentracing_propagate_context`
cannot be set when combined with `opentracing off`

A new annotation, `enable-opentracing` allows more fine grained control
of opentracing for specific ingresses.

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

@@ -99,6 +99,7 @@ You can add these Kubernetes annotations to specific Ingress objects to customiz
 |[nginx.ingress.kubernetes.io/ssl-ciphers](#ssl-ciphers)|string|
 |[nginx.ingress.kubernetes.io/connection-proxy-header](#connection-proxy-header)|string|
 |[nginx.ingress.kubernetes.io/enable-access-log](#enable-access-log)|"true" or "false"|
+|[nginx.ingress.kubernetes.io/enable-opentracing](#enable-opentracing)|"true" or "false"|
 |[nginx.ingress.kubernetes.io/lua-resty-waf](#lua-resty-waf)|string|
 |[nginx.ingress.kubernetes.io/lua-resty-waf-debug](#lua-resty-waf)|"true" or "false"|
 |[nginx.ingress.kubernetes.io/lua-resty-waf-ignore-rulesets](#lua-resty-waf)|string|
@@ -670,6 +671,15 @@ Note that rewrite logs are sent to the error_log file at the notice level. To en
 nginx.ingress.kubernetes.io/enable-rewrite-log: "true"
 ```
 
+### Enable Opentracing
+
+Opentracing can be enabled or disabled globally through the ConfigMap but this will sometimes need to be overridden
+to enable it or disable it for a specific ingress (e.g. to turn off tracing of external health check endpoints)
+
+```yaml
+nginx.ingress.kubernetes.io/enable-opentracing: "true"
+```
+
 ### X-Forwarded-Prefix Header
 To add the non-standard `X-Forwarded-Prefix` header to the upstream request with a string value, the following annotation can be used:
 

docs/user-guide/third-party-addons/opentracing.md

@@ -13,6 +13,15 @@ data:
   enable-opentracing: "true"
 ```
 
+To enable or disable instrumentation for a single Ingress, use
+the `enable-opentracing` annotation:
+```
+kind: Ingress
+metadata:
+  annotations:
+    nginx.ingress.kubernetes.io/enable-opentracing: "true"
+```
+
 We must also set the host to use when uploading traces:
 
 ```

internal/ingress/annotations/annotations.go

@@ -47,6 +47,7 @@ import (
 	"k8s.io/ingress-nginx/internal/ingress/annotations/log"
 	"k8s.io/ingress-nginx/internal/ingress/annotations/luarestywaf"
 	"k8s.io/ingress-nginx/internal/ingress/annotations/mirror"
+	"k8s.io/ingress-nginx/internal/ingress/annotations/opentracing"
 	"k8s.io/ingress-nginx/internal/ingress/annotations/parser"
 	"k8s.io/ingress-nginx/internal/ingress/annotations/portinredirect"
 	"k8s.io/ingress-nginx/internal/ingress/annotations/proxy"
@@ -90,6 +91,7 @@ type Ingress struct {
 	ExternalAuth       authreq.Config
 	EnableGlobalAuth   bool
 	HTTP2PushPreload   bool
+	Opentracing        opentracing.Config
 	Proxy              proxy.Config
 	ProxySSL           proxyssl.Config
 	RateLimit          ratelimit.Config
@@ -138,6 +140,7 @@ func NewAnnotationExtractor(cfg resolver.Resolver) Extractor {
 			"ExternalAuth":         authreq.NewParser(cfg),
 			"EnableGlobalAuth":     authreqglobal.NewParser(cfg),
 			"HTTP2PushPreload":     http2pushpreload.NewParser(cfg),
+			"Opentracing":          opentracing.NewParser(cfg),
 			"Proxy":                proxy.NewParser(cfg),
 			"ProxySSL":             proxyssl.NewParser(cfg),
 			"RateLimit":            ratelimit.NewParser(cfg),

internal/ingress/annotations/opentracing/main.go

@@ -0,0 +1,57 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package opentracing
+
+import (
+	networking "k8s.io/api/networking/v1beta1"
+
+	"k8s.io/ingress-nginx/internal/ingress/annotations/parser"
+	"k8s.io/ingress-nginx/internal/ingress/resolver"
+)
+
+type opentracing struct {
+	r resolver.Resolver
+}
+
+// Config contains the configuration to be used in the Ingress
+type Config struct {
+	Enabled bool `json:"enabled"`
+	Set     bool `json:"set"`
+}
+
+// Equal tests for equality between two Config types
+func (bd1 *Config) Equal(bd2 *Config) bool {
+	if bd1.Set != bd2.Set {
+		return false
+	} else if bd1.Enabled != bd2.Enabled {
+		return false
+	}
+	return true
+}
+
+// NewParser creates a new serviceUpstream annotation parser
+func NewParser(r resolver.Resolver) parser.IngressAnnotation {
+	return opentracing{r}
+}
+
+func (s opentracing) Parse(ing *networking.Ingress) (interface{}, error) {
+	enabled, err := parser.GetBoolAnnotation("enable-opentracing", ing)
+	if err != nil {
+		return &Config{Set: false, Enabled: false}, nil
+	}
+	return &Config{Set: true, Enabled: enabled}, nil
+}

internal/ingress/annotations/opentracing/main_test.go

@@ -0,0 +1,121 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package opentracing
+
+import (
+	"testing"
+
+	api "k8s.io/api/core/v1"
+	networking "k8s.io/api/networking/v1beta1"
+	meta_v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/intstr"
+	"k8s.io/ingress-nginx/internal/ingress/annotations/parser"
+	"k8s.io/ingress-nginx/internal/ingress/resolver"
+)
+
+func buildIngress() *networking.Ingress {
+	defaultBackend := networking.IngressBackend{
+		ServiceName: "default-backend",
+		ServicePort: intstr.FromInt(80),
+	}
+
+	return &networking.Ingress{
+		ObjectMeta: meta_v1.ObjectMeta{
+			Name:      "foo",
+			Namespace: api.NamespaceDefault,
+		},
+		Spec: networking.IngressSpec{
+			Backend: &networking.IngressBackend{
+				ServiceName: "default-backend",
+				ServicePort: intstr.FromInt(80),
+			},
+			Rules: []networking.IngressRule{
+				{
+					Host: "foo.bar.com",
+					IngressRuleValue: networking.IngressRuleValue{
+						HTTP: &networking.HTTPIngressRuleValue{
+							Paths: []networking.HTTPIngressPath{
+								{
+									Path:    "/foo",
+									Backend: defaultBackend,
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+}
+
+func TestIngressAnnotationOpentracingSetTrue(t *testing.T) {
+	ing := buildIngress()
+
+	data := map[string]string{}
+	data[parser.GetAnnotationWithPrefix("enable-opentracing")] = "true"
+	ing.SetAnnotations(data)
+
+	val, _ := NewParser(&resolver.Mock{}).Parse(ing)
+	openTracing, ok := val.(*Config)
+	if !ok {
+		t.Errorf("expected a Config type")
+	}
+	if !openTracing.Set {
+		t.Errorf("expected annotation value to be set")
+	}
+	if !openTracing.Enabled {
+		t.Errorf("expected annotation value to be true, got false")
+	}
+}
+
+func TestIngressAnnotationOpentracingSetFalse(t *testing.T) {
+	ing := buildIngress()
+
+	// Test with explicitly set to false
+	data := map[string]string{}
+	data[parser.GetAnnotationWithPrefix("enable-opentracing")] = "false"
+	ing.SetAnnotations(data)
+
+	val, _ := NewParser(&resolver.Mock{}).Parse(ing)
+	openTracing, ok := val.(*Config)
+	if !ok {
+		t.Errorf("expected a Config type")
+	}
+	if !openTracing.Set {
+		t.Errorf("expected annotation value to be set")
+	}
+	if openTracing.Enabled {
+		t.Errorf("expected annotation value to be false, got true")
+	}
+}
+
+func TestIngressAnnotationOpentracingUnset(t *testing.T) {
+	ing := buildIngress()
+
+	// Test with no annotation specified
+	data := map[string]string{}
+	ing.SetAnnotations(data)
+
+	val, _ := NewParser(&resolver.Mock{}).Parse(ing)
+	openTracing, ok := val.(*Config)
+	if !ok {
+		t.Errorf("expected a Config type")
+	}
+	if openTracing.Set {
+		t.Errorf("expected annotation value to be unset")
+	}
+}

internal/ingress/controller/controller.go

@@ -1169,6 +1169,7 @@ func locationApplyAnnotations(loc *ingress.Location, anns *annotations.Ingress)
 	loc.ExternalAuth = anns.ExternalAuth
 	loc.EnableGlobalAuth = anns.EnableGlobalAuth
 	loc.HTTP2PushPreload = anns.HTTP2PushPreload
+	loc.Opentracing = anns.Opentracing
 	loc.Proxy = anns.Proxy
 	loc.RateLimit = anns.RateLimit
 	loc.Redirect = anns.Redirect

internal/ingress/types.go

@@ -34,6 +34,7 @@ import (
 	"k8s.io/ingress-nginx/internal/ingress/annotations/luarestywaf"
 	"k8s.io/ingress-nginx/internal/ingress/annotations/mirror"
 	"k8s.io/ingress-nginx/internal/ingress/annotations/modsecurity"
+	"k8s.io/ingress-nginx/internal/ingress/annotations/opentracing"
 	"k8s.io/ingress-nginx/internal/ingress/annotations/proxy"
 	"k8s.io/ingress-nginx/internal/ingress/annotations/proxyssl"
 	"k8s.io/ingress-nginx/internal/ingress/annotations/ratelimit"
@@ -333,6 +334,9 @@ type Location struct {
 	// Mirror allows you to mirror traffic to a "test" backend
 	// +optional
 	Mirror mirror.Config `json:"mirror,omitempty"`
+	// Opentracing allows the global opentracing setting to be overridden for a location
+	// +optional
+	Opentracing opentracing.Config `json:"opentracing"`
 }
 
 // SSLPassthroughBackend describes a SSL upstream server configured

rootfs/etc/nginx/template/nginx.tmpl

@@ -962,8 +962,17 @@ stream {
             set $location_path  {{ $location.Path | escapeLiteralDollar | quote }};
 
             {{ if $all.Cfg.EnableOpentracing }}
+            {{ if and $location.Opentracing.Set (not $location.Opentracing.Enabled) }}
+            opentracing off;
+            {{ else }}
             {{ opentracingPropagateContext $location }};
             {{ end }}
+            {{ else }}
+            {{ if and $location.Opentracing.Set $location.Opentracing.Enabled }}
+            opentracing on;
+            {{ opentracingPropagateContext $location }};
+            {{ end }}
+            {{ end }}
 
             {{ if $location.Mirror.URI }}
             mirror {{ $location.Mirror.URI }};