Add "ignored paths" for the proxy

README.md

@@ -190,9 +190,12 @@ The following table lists the supported annotations for Kubernetes `Deployments`
 
 #### Pod Annotations
 
+The following table lists the supported annotations for Kubernetes `Pods` and their default values.
+
 | Annotation | Description | Default |
 | ---------- | ----------- | ------- |
 | `osiris.deislabs.io/enabled` | Enable the metrics collecting proxy sidecar container to be injected into this pod. Allowed values: `y`, `yes`, `true`, `on`, `1`. | _no value_ (= disabled) |
+| `osiris.deislabs.io/ignoredPaths` | The list of (url) paths that should be "ignored" by Osiris. Requests to such paths won't be "counted" by the proxy. Format: comma-separated string. | _no value_ |
 
 #### Service Annotations
 

example/hello-osiris.yaml

@@ -57,6 +57,7 @@ spec:
         app: hello-osiris
       annotations:
         osiris.deislabs.io/enabled: "true"
+        osiris.deislabs.io/ignoredPaths: "/first/path,/second-path"
     spec:
       containers:
       - name: hello-osiris

pkg/kubernetes/osiris.go

@@ -7,6 +7,7 @@ import (
 )
 
 const (
+	IgnoredPathsAnnotationName         = "osiris.deislabs.io/ignoredPaths"
 	osirisEnabledAnnotationName        = "osiris.deislabs.io/enabled"
 	metricsCheckIntervalAnnotationName = "osiris.deislabs.io/metricsCheckInterval"
 )

pkg/metrics/proxy/injector/pod_patch.go

@@ -127,6 +127,10 @@ func (i *injector) getPodPatchOperations(
 					Name:  "METRICS_AND_HEALTH_PORT",
 					Value: fmt.Sprintf("%d", metricsAndHealthPort),
 				},
+				{
+					Name:  "IGNORED_PATHS",
+					Value: pod.Annotations[kubernetes.IgnoredPathsAnnotationName],
+				},
 			},
 			Ports: []corev1.ContainerPort{
 				{

pkg/metrics/proxy/proxy/config.go

@@ -18,12 +18,15 @@ var portMappingRegex = regexp.MustCompile(`^(?:\d+\:\d+,)*(?:\d+\:\d+)$`)
 type config struct {
 	PortMappings         string `envconfig:"PORT_MAPPINGS" required:"true"`
 	MetricsAndHealthPort int    `envconfig:"METRICS_AND_HEALTH_PORT" required:"true"` // nolint: lll
+	// comma-separated list of URL paths that won't be counted
+	IgnoredPaths string `envconfig:"IGNORED_PATHS"`
 }
 
 // Config represents configuration options for the Osiris Proxy
 type Config struct {
 	PortMappings         map[int]int
 	MetricsAndHealthPort int
+	IgnoredPaths         map[string]struct{}
 }
 
 // NewConfigWithDefaults returns a Config object with default values already
@@ -59,5 +62,13 @@ func GetConfigFromEnvironment() (Config, error) {
 
 	c.MetricsAndHealthPort = internalC.MetricsAndHealthPort
 
+	ignoredPaths := strings.Split(internalC.IgnoredPaths, ",")
+	if len(ignoredPaths) > 0 {
+		c.IgnoredPaths = make(map[string]struct{}, len(ignoredPaths))
+		for _, ignoredPath := range ignoredPaths {
+			c.IgnoredPaths[ignoredPath] = struct{}{}
+		}
+	}
+
 	return c, nil
 }

pkg/metrics/proxy/proxy/proxy.go

@@ -26,6 +26,7 @@ type proxy struct {
 	connectionsClosed    *uint64
 	dynamicProxies       []tcp.DynamicProxy
 	healthzAndMetricsSvr *http.Server
+	ignoredPaths         map[string]struct{}
 }
 
 func NewProxy(cfg Config) (Proxy, error) {
@@ -40,20 +41,21 @@ func NewProxy(cfg Config) (Proxy, error) {
 			Addr:    fmt.Sprintf(":%d", cfg.MetricsAndHealthPort),
 			Handler: healthzAndMetricsMux,
 		},
+		ignoredPaths: cfg.IgnoredPaths,
 	}
 
 	for listenPort, targetPort := range cfg.PortMappings {
 		tp := targetPort
 		dynamicProxy, err := tcp.NewDynamicProxy(
 			fmt.Sprintf(":%d", listenPort),
 			func(r *http.Request) (string, int, error) {
-				if !isKubeProbe(r) {
+				if !p.isIgnoredRequest(r) {
 					atomic.AddUint64(p.connectionsOpened, 1)
 				}
 				return "localhost", tp, nil
 			},
 			func(r *http.Request) error {
-				if !isKubeProbe(r) {
+				if !p.isIgnoredRequest(r) {
 					atomic.AddUint64(p.connectionsClosed, 1)
 				}
 				return nil
@@ -139,6 +141,18 @@ func (p *proxy) handleMetricsRequest(w http.ResponseWriter, _ *http.Request) {
 	}
 }
 
+func (p *proxy) isIgnoredRequest(r *http.Request) bool {
+	return p.isIgnoredPath(r) || isKubeProbe(r)
+}
+
+func (p *proxy) isIgnoredPath(r *http.Request) bool {
+	if r.URL == nil || len(r.URL.Path) == 0 {
+		return false
+	}
+	_, found := p.ignoredPaths[r.URL.Path]
+	return found
+}
+
 func isKubeProbe(r *http.Request) bool {
 	return strings.Contains(r.Header.Get("User-Agent"), "kube-probe")
 }