remove TODOs from http package and prober

pkg/kubelet/prober/prober.go

@@ -49,16 +49,11 @@ const maxProbeRetries = 3
 
 // Prober helps to check the liveness/readiness/startup of a container.
 type prober struct {
-	exec execprobe.Prober
-	// probe types needs different httpprobe instances so they don't
-	// share a connection pool which can cause collisions to the
-	// same host:port and transient failures. See #49740.
-	readinessHTTP httpprobe.Prober
-	livenessHTTP  httpprobe.Prober
-	startupHTTP   httpprobe.Prober
-	tcp           tcpprobe.Prober
-	grpc          grpcprobe.Prober
-	runner        kubecontainer.CommandRunner
+	exec   execprobe.Prober
+	http   httpprobe.Prober
+	tcp    tcpprobe.Prober
+	grpc   grpcprobe.Prober
+	runner kubecontainer.CommandRunner
 
 	recorder record.EventRecorder
 }
@@ -71,14 +66,12 @@ func newProber(
 
 	const followNonLocalRedirects = false
 	return &prober{
-		exec:          execprobe.New(),
-		readinessHTTP: httpprobe.New(followNonLocalRedirects),
-		livenessHTTP:  httpprobe.New(followNonLocalRedirects),
-		startupHTTP:   httpprobe.New(followNonLocalRedirects),
-		tcp:           tcpprobe.New(),
-		grpc:          grpcprobe.New(),
-		runner:        runner,
-		recorder:      recorder,
+		exec:     execprobe.New(),
+		http:     httpprobe.New(followNonLocalRedirects),
+		tcp:      tcpprobe.New(),
+		grpc:     grpcprobe.New(),
+		runner:   runner,
+		recorder: recorder,
 	}
 }
 
@@ -179,14 +172,7 @@ func (pb *prober) runProbe(probeType probeType, p *v1.Probe, pod *v1.Pod, status
 		url := formatURL(scheme, host, port, path)
 		headers := buildHeader(p.HTTPGet.HTTPHeaders)
 		klog.V(4).InfoS("HTTP-Probe Headers", "headers", headers)
-		switch probeType {
-		case liveness:
-			return pb.livenessHTTP.Probe(url, headers, timeout)
-		case startup:
-			return pb.startupHTTP.Probe(url, headers, timeout)
-		default:
-			return pb.readinessHTTP.Probe(url, headers, timeout)
-		}
+		return pb.http.Probe(url, headers, timeout)
 	}
 	if p.TCPSocket != nil {
 		port, err := extractPort(p.TCPSocket.Port, container)

pkg/kubelet/prober/prober_manager.go

@@ -52,7 +52,6 @@ var ProberResults = metrics.NewCounterVec(
 // probe (AddPod). The worker periodically probes its assigned container and caches the results. The
 // manager use the cached probe results to set the appropriate Ready state in the PodStatus when
 // requested (UpdatePodStatus). Updating probe parameters is not currently supported.
-// TODO: Move liveness probing out of the runtime, to here.
 type Manager interface {
 	// AddPod creates new probe workers for every container probe. This should be called for every
 	// pod created.

pkg/kubelet/prober/worker.go

@@ -261,9 +261,7 @@ func (w *worker) doProbe() (keepGoing bool) {
 		}
 	}
 
-	// TODO: in order for exec probes to correctly handle downward API env, we must be able to reconstruct
-	// the full container environment here, OR we must make a call to the CRI in order to get those environment
-	// values from the running container.
+	// Note, exec probe does NOT have access to pod environment variables or downward API
 	result, err := w.probeManager.prober.probe(w.probeType, w.pod, status, w.container, w.containerID)
 	if err != nil {
 		// Prober error, throw away the result.

pkg/probe/http/http.go

@@ -51,9 +51,10 @@ func NewWithTLSConfig(config *tls.Config, followNonLocalRedirects bool) Prober {
 	// We do not want the probe use node's local proxy set.
 	transport := utilnet.SetTransportDefaults(
 		&http.Transport{
-			TLSClientConfig:   config,
-			DisableKeepAlives: true,
-			Proxy:             http.ProxyURL(nil),
+			TLSClientConfig:    config,
+			DisableKeepAlives:  true,
+			Proxy:              http.ProxyURL(nil),
+			DisableCompression: true, // removes Accept-Encoding header
 		})
 	return httpProber{transport, followNonLocalRedirects}
 }
@@ -68,9 +69,8 @@ type httpProber struct {
 	followNonLocalRedirects bool
 }
 
-// Probe returns a ProbeRunner capable of running an HTTP check.
+// Probe returns a probing result. The only case the err will not be nil is when there is a problem reading the response body.
 func (pr httpProber) Probe(url *url.URL, headers http.Header, timeout time.Duration) (probe.Result, string, error) {
-	pr.transport.DisableCompression = true // removes Accept-Encoding header
 	client := &http.Client{
 		Timeout:       timeout,
 		Transport:     pr.transport,