Revert "client-go: remove no longer used finalURLTemplate"

The functionality provided by the finalURLTemplate is still used by certain external projects to track the request latency for requests performed to kube-apiserver. Using a template of the URL, instead of the URL itself, prevents the explosion of label cardinality in exposed metrics since it aggregates the URLs in a way that common URLs requests are reported as being the same. This reverts commit bebf5a608f68523fc430a44f6db26b16022dc862. Signed-off-by: André Martins <[email protected]> Kubernetes-commit: 11e16c63c87f07e9e68977c74b937989983754c1
kubernetes · Aug 8, 2022 · 1a46dfd · 1a46dfd
1 parent b3e4a40
commit 1a46dfd
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Showing 2 changed files with 280 additions and 2 deletions.
diff --git a/rest/request.go b/rest/request.go
@@ -508,6 +508,84 @@ func (r *Request) URL() *url.URL {
 	return finalURL
 }
 
+// finalURLTemplate is similar to URL(), but will make all specific parameter values equal
+// - instead of name or namespace, "{name}" and "{namespace}" will be used, and all query
+// parameters will be reset. This creates a copy of the url so as not to change the
+// underlying object.
+func (r Request) finalURLTemplate() url.URL {
+	newParams := url.Values{}
+	v := []string{"{value}"}
+	for k := range r.params {
+		newParams[k] = v
+	}
+	r.params = newParams
+	url := r.URL()
+
+	segments := strings.Split(url.Path, "/")
+	groupIndex := 0
+	index := 0
+	trimmedBasePath := ""
+	if url != nil && r.c.base != nil && strings.Contains(url.Path, r.c.base.Path) {
+		p := strings.TrimPrefix(url.Path, r.c.base.Path)
+		if !strings.HasPrefix(p, "/") {
+			p = "/" + p
+		}
+		// store the base path that we have trimmed so we can append it
+		// before returning the URL
+		trimmedBasePath = r.c.base.Path
+		segments = strings.Split(p, "/")
+		groupIndex = 1
+	}
+	if len(segments) <= 2 {
+		return *url
+	}
+
+	const CoreGroupPrefix = "api"
+	const NamedGroupPrefix = "apis"
+	isCoreGroup := segments[groupIndex] == CoreGroupPrefix
+	isNamedGroup := segments[groupIndex] == NamedGroupPrefix
+	if isCoreGroup {
+		// checking the case of core group with /api/v1/... format
+		index = groupIndex + 2
+	} else if isNamedGroup {
+		// checking the case of named group with /apis/apps/v1/... format
+		index = groupIndex + 3
+	} else {
+		// this should not happen that the only two possibilities are /api... and /apis..., just want to put an
+		// outlet here in case more API groups are added in future if ever possible:
+		// https://kubernetes.io/docs/concepts/overview/kubernetes-api/#api-groups
+		// if a wrong API groups name is encountered, return the {prefix} for url.Path
+		url.Path = "/{prefix}"
+		url.RawQuery = ""
+		return *url
+	}
+	//switch segLength := len(segments) - index; segLength {
+	switch {
+	// case len(segments) - index == 1:
+	// resource (with no name) do nothing
+	case len(segments)-index == 2:
+		// /$RESOURCE/$NAME: replace $NAME with {name}
+		segments[index+1] = "{name}"
+	case len(segments)-index == 3:
+		if segments[index+2] == "finalize" || segments[index+2] == "status" {
+			// /$RESOURCE/$NAME/$SUBRESOURCE: replace $NAME with {name}
+			segments[index+1] = "{name}"
+		} else {
+			// /namespace/$NAMESPACE/$RESOURCE: replace $NAMESPACE with {namespace}
+			segments[index+1] = "{namespace}"
+		}
+	case len(segments)-index >= 4:
+		segments[index+1] = "{namespace}"
+		// /namespace/$NAMESPACE/$RESOURCE/$NAME: replace $NAMESPACE with {namespace},  $NAME with {name}
+		if segments[index+3] != "finalize" && segments[index+3] != "status" {
+			// /$RESOURCE/$NAME/$SUBRESOURCE: replace $NAME with {name}
+			segments[index+3] = "{name}"
+		}
+	}
+	url.Path = path.Join(trimmedBasePath, path.Join(segments...))
+	return *url
+}
+
 func (r *Request) tryThrottleWithInfo(ctx context.Context, retryInfo string) error {
 	if r.rateLimiter == nil {
 		return nil
@@ -537,7 +615,7 @@ func (r *Request) tryThrottleWithInfo(ctx context.Context, retryInfo string) err
 		// but we use a throttled logger to prevent spamming.
 		globalThrottledLogger.Infof("%s", message)
 	}
-	metrics.RateLimiterLatency.Observe(ctx, r.verb, *r.URL(), latency)
+	metrics.RateLimiterLatency.Observe(ctx, r.verb, r.finalURLTemplate(), latency)
 
 	return err
 }
@@ -826,7 +904,7 @@ func (r *Request) request(ctx context.Context, fn func(*http.Request, *http.Resp
 	// Metrics for total request latency
 	start := time.Now()
 	defer func() {
-		metrics.RequestLatency.Observe(ctx, r.verb, *r.URL(), time.Since(start))
+		metrics.RequestLatency.Observe(ctx, r.verb, r.finalURLTemplate(), time.Since(start))
 	}()
 
 	if r.err != nil {

diff --git a/rest/request_test.go b/rest/request_test.go
@@ -338,6 +338,206 @@ func TestResultIntoWithNoBodyReturnsErr(t *testing.T) {
 	}
 }
 
+func TestURLTemplate(t *testing.T) {
+	uri, _ := url.Parse("http://localhost/some/base/url/path")
+	uriSingleSlash, _ := url.Parse("http://localhost/")
+	testCases := []struct {
+		Request          *Request
+		ExpectedFullURL  string
+		ExpectedFinalURL string
+	}{
+		{
+			// non dynamic client
+			Request: NewRequestWithClient(uri, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("POST").
+				Prefix("api", "v1").Resource("r1").Namespace("ns").Name("nm").Param("p0", "v0"),
+			ExpectedFullURL:  "http://localhost/some/base/url/path/api/v1/namespaces/ns/r1/nm?p0=v0",
+			ExpectedFinalURL: "http://localhost/some/base/url/path/api/v1/namespaces/%7Bnamespace%7D/r1/%7Bname%7D?p0=%7Bvalue%7D",
+		},
+		{
+			// non dynamic client with wrong api group
+			Request: NewRequestWithClient(uri, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("POST").
+				Prefix("pre1", "v1").Resource("r1").Namespace("ns").Name("nm").Param("p0", "v0"),
+			ExpectedFullURL:  "http://localhost/some/base/url/path/pre1/v1/namespaces/ns/r1/nm?p0=v0",
+			ExpectedFinalURL: "http://localhost/%7Bprefix%7D",
+		},
+		{
+			// dynamic client with core group + namespace + resourceResource (with name)
+			// /api/$RESOURCEVERSION/namespaces/$NAMESPACE/$RESOURCE/%NAME
+			Request: NewRequestWithClient(uri, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/api/v1/namespaces/ns/r1/name1"),
+			ExpectedFullURL:  "http://localhost/some/base/url/path/api/v1/namespaces/ns/r1/name1",
+			ExpectedFinalURL: "http://localhost/some/base/url/path/api/v1/namespaces/%7Bnamespace%7D/r1/%7Bname%7D",
+		},
+		{
+			// dynamic client with named group + namespace + resourceResource (with name)
+			// /apis/$NAMEDGROUPNAME/$RESOURCEVERSION/namespaces/$NAMESPACE/$RESOURCE/%NAME
+			Request: NewRequestWithClient(uri, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/apis/g1/v1/namespaces/ns/r1/name1"),
+			ExpectedFullURL:  "http://localhost/some/base/url/path/apis/g1/v1/namespaces/ns/r1/name1",
+			ExpectedFinalURL: "http://localhost/some/base/url/path/apis/g1/v1/namespaces/%7Bnamespace%7D/r1/%7Bname%7D",
+		},
+		{
+			// dynamic client with core group + namespace + resourceResource (with NO name)
+			// /api/$RESOURCEVERSION/namespaces/$NAMESPACE/$RESOURCE
+			Request: NewRequestWithClient(uri, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/api/v1/namespaces/ns/r1"),
+			ExpectedFullURL:  "http://localhost/some/base/url/path/api/v1/namespaces/ns/r1",
+			ExpectedFinalURL: "http://localhost/some/base/url/path/api/v1/namespaces/%7Bnamespace%7D/r1",
+		},
+		{
+			// dynamic client with named group + namespace + resourceResource (with NO name)
+			// /apis/$NAMEDGROUPNAME/$RESOURCEVERSION/namespaces/$NAMESPACE/$RESOURCE
+			Request: NewRequestWithClient(uri, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/apis/g1/v1/namespaces/ns/r1"),
+			ExpectedFullURL:  "http://localhost/some/base/url/path/apis/g1/v1/namespaces/ns/r1",
+			ExpectedFinalURL: "http://localhost/some/base/url/path/apis/g1/v1/namespaces/%7Bnamespace%7D/r1",
+		},
+		{
+			// dynamic client with core group + resourceResource (with name)
+			// /api/$RESOURCEVERSION/$RESOURCE/%NAME
+			Request: NewRequestWithClient(uri, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/api/v1/r1/name1"),
+			ExpectedFullURL:  "http://localhost/some/base/url/path/api/v1/r1/name1",
+			ExpectedFinalURL: "http://localhost/some/base/url/path/api/v1/r1/%7Bname%7D",
+		},
+		{
+			// dynamic client with named group + resourceResource (with name)
+			// /apis/$NAMEDGROUPNAME/$RESOURCEVERSION/$RESOURCE/%NAME
+			Request: NewRequestWithClient(uri, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/apis/g1/v1/r1/name1"),
+			ExpectedFullURL:  "http://localhost/some/base/url/path/apis/g1/v1/r1/name1",
+			ExpectedFinalURL: "http://localhost/some/base/url/path/apis/g1/v1/r1/%7Bname%7D",
+		},
+		{
+			// dynamic client with named group + namespace + resourceResource (with name) + subresource
+			// /apis/$NAMEDGROUPNAME/$RESOURCEVERSION/namespaces/$NAMESPACE/$RESOURCE/%NAME/$SUBRESOURCE
+			Request: NewRequestWithClient(uri, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/apis/namespaces/namespaces/namespaces/namespaces/namespaces/namespaces/finalize"),
+			ExpectedFullURL:  "http://localhost/some/base/url/path/apis/namespaces/namespaces/namespaces/namespaces/namespaces/namespaces/finalize",
+			ExpectedFinalURL: "http://localhost/some/base/url/path/apis/namespaces/namespaces/namespaces/%7Bnamespace%7D/namespaces/%7Bname%7D/finalize",
+		},
+		{
+			// dynamic client with named group + namespace + resourceResource (with name)
+			// /apis/$NAMEDGROUPNAME/$RESOURCEVERSION/namespaces/$NAMESPACE/$RESOURCE/%NAME
+			Request: NewRequestWithClient(uri, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/apis/namespaces/namespaces/namespaces/namespaces/namespaces/namespaces"),
+			ExpectedFullURL:  "http://localhost/some/base/url/path/apis/namespaces/namespaces/namespaces/namespaces/namespaces/namespaces",
+			ExpectedFinalURL: "http://localhost/some/base/url/path/apis/namespaces/namespaces/namespaces/%7Bnamespace%7D/namespaces/%7Bname%7D",
+		},
+		{
+			// dynamic client with named group + namespace + resourceResource (with NO name) + subresource
+			// /apis/$NAMEDGROUPNAME/$RESOURCEVERSION/namespaces/$NAMESPACE/$RESOURCE/%SUBRESOURCE
+			Request: NewRequestWithClient(uri, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/apis/namespaces/namespaces/namespaces/namespaces/namespaces/finalize"),
+			ExpectedFullURL:  "http://localhost/some/base/url/path/apis/namespaces/namespaces/namespaces/namespaces/namespaces/finalize",
+			ExpectedFinalURL: "http://localhost/some/base/url/path/apis/namespaces/namespaces/namespaces/%7Bnamespace%7D/namespaces/finalize",
+		},
+		{
+			// dynamic client with named group + namespace + resourceResource (with NO name) + subresource
+			// /apis/$NAMEDGROUPNAME/$RESOURCEVERSION/namespaces/$NAMESPACE/$RESOURCE/%SUBRESOURCE
+			Request: NewRequestWithClient(uri, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/apis/namespaces/namespaces/namespaces/namespaces/namespaces/status"),
+			ExpectedFullURL:  "http://localhost/some/base/url/path/apis/namespaces/namespaces/namespaces/namespaces/namespaces/status",
+			ExpectedFinalURL: "http://localhost/some/base/url/path/apis/namespaces/namespaces/namespaces/%7Bnamespace%7D/namespaces/status",
+		},
+		{
+			// dynamic client with named group + namespace + resourceResource (with no name)
+			// /apis/$NAMEDGROUPNAME/$RESOURCEVERSION/namespaces/$NAMESPACE/$RESOURCE/%NAME
+			Request: NewRequestWithClient(uri, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/apis/namespaces/namespaces/namespaces/namespaces/namespaces"),
+			ExpectedFullURL:  "http://localhost/some/base/url/path/apis/namespaces/namespaces/namespaces/namespaces/namespaces",
+			ExpectedFinalURL: "http://localhost/some/base/url/path/apis/namespaces/namespaces/namespaces/%7Bnamespace%7D/namespaces",
+		},
+		{
+			// dynamic client with named group + resourceResource (with name) + subresource
+			// /apis/$NAMEDGROUPNAME/$RESOURCEVERSION/namespaces/$NAMESPACE/$RESOURCE/%NAME
+			Request: NewRequestWithClient(uri, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/apis/namespaces/namespaces/namespaces/namespaces/finalize"),
+			ExpectedFullURL:  "http://localhost/some/base/url/path/apis/namespaces/namespaces/namespaces/namespaces/finalize",
+			ExpectedFinalURL: "http://localhost/some/base/url/path/apis/namespaces/namespaces/namespaces/%7Bname%7D/finalize",
+		},
+		{
+			// dynamic client with named group + resourceResource (with name) + subresource
+			// /apis/$NAMEDGROUPNAME/$RESOURCEVERSION/namespaces/$NAMESPACE/$RESOURCE/%NAME
+			Request: NewRequestWithClient(uri, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/apis/namespaces/namespaces/namespaces/namespaces/status"),
+			ExpectedFullURL:  "http://localhost/some/base/url/path/apis/namespaces/namespaces/namespaces/namespaces/status",
+			ExpectedFinalURL: "http://localhost/some/base/url/path/apis/namespaces/namespaces/namespaces/%7Bname%7D/status",
+		},
+		{
+			// dynamic client with named group + resourceResource (with name)
+			// /apis/$NAMEDGROUPNAME/$RESOURCEVERSION/$RESOURCE/%NAME
+			Request: NewRequestWithClient(uri, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/apis/namespaces/namespaces/namespaces/namespaces"),
+			ExpectedFullURL:  "http://localhost/some/base/url/path/apis/namespaces/namespaces/namespaces/namespaces",
+			ExpectedFinalURL: "http://localhost/some/base/url/path/apis/namespaces/namespaces/namespaces/%7Bname%7D",
+		},
+		{
+			// dynamic client with named group + resourceResource (with no name)
+			// /apis/$NAMEDGROUPNAME/$RESOURCEVERSION/$RESOURCE/%NAME
+			Request: NewRequestWithClient(uri, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/apis/namespaces/namespaces/namespaces"),
+			ExpectedFullURL:  "http://localhost/some/base/url/path/apis/namespaces/namespaces/namespaces",
+			ExpectedFinalURL: "http://localhost/some/base/url/path/apis/namespaces/namespaces/namespaces",
+		},
+		{
+			// dynamic client with wrong api group + namespace + resourceResource (with name) + subresource
+			// /apis/$NAMEDGROUPNAME/$RESOURCEVERSION/namespaces/$NAMESPACE/$RESOURCE/%NAME/$SUBRESOURCE
+			Request: NewRequestWithClient(uri, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/pre1/namespaces/namespaces/namespaces/namespaces/namespaces/namespaces/finalize"),
+			ExpectedFullURL:  "http://localhost/some/base/url/path/pre1/namespaces/namespaces/namespaces/namespaces/namespaces/namespaces/finalize",
+			ExpectedFinalURL: "http://localhost/%7Bprefix%7D",
+		},
+		{
+			// dynamic client with core group + namespace + resourceResource (with name) where baseURL is a single /
+			// /api/$RESOURCEVERSION/namespaces/$NAMESPACE/$RESOURCE/%NAME
+			Request: NewRequestWithClient(uriSingleSlash, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/api/v1/namespaces/ns/r2/name1"),
+			ExpectedFullURL:  "http://localhost/api/v1/namespaces/ns/r2/name1",
+			ExpectedFinalURL: "http://localhost/api/v1/namespaces/%7Bnamespace%7D/r2/%7Bname%7D",
+		},
+		{
+			// dynamic client with core group + namespace + resourceResource (with name) where baseURL is 'some/base/url/path'
+			// /api/$RESOURCEVERSION/namespaces/$NAMESPACE/$RESOURCE/%NAME
+			Request: NewRequestWithClient(uri, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/api/v1/namespaces/ns/r3/name1"),
+			ExpectedFullURL:  "http://localhost/some/base/url/path/api/v1/namespaces/ns/r3/name1",
+			ExpectedFinalURL: "http://localhost/some/base/url/path/api/v1/namespaces/%7Bnamespace%7D/r3/%7Bname%7D",
+		},
+		{
+			// dynamic client where baseURL is a single /
+			// /
+			Request: NewRequestWithClient(uriSingleSlash, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/"),
+			ExpectedFullURL:  "http://localhost/",
+			ExpectedFinalURL: "http://localhost/",
+		},
+		{
+			// dynamic client where baseURL is a single /
+			// /version
+			Request: NewRequestWithClient(uriSingleSlash, "", ClientContentConfig{GroupVersion: schema.GroupVersion{Group: "test"}}, nil).Verb("DELETE").
+				Prefix("/version"),
+			ExpectedFullURL:  "http://localhost/version",
+			ExpectedFinalURL: "http://localhost/version",
+		},
+	}
+	for i, testCase := range testCases {
+		r := testCase.Request
+		full := r.URL()
+		if full.String() != testCase.ExpectedFullURL {
+			t.Errorf("%d: unexpected initial URL: %s %s", i, full, testCase.ExpectedFullURL)
+		}
+		actualURL := r.finalURLTemplate()
+		actual := actualURL.String()
+		if actual != testCase.ExpectedFinalURL {
+			t.Errorf("%d: unexpected URL template: %s %s", i, actual, testCase.ExpectedFinalURL)
+		}
+		if r.URL().String() != full.String() {
+			t.Errorf("%d, creating URL template changed request: %s -> %s", i, full.String(), r.URL().String())
+		}
+	}
+}
+
 func TestTransformResponse(t *testing.T) {
 	invalid := []byte("aaaaa")
 	uri, _ := url.Parse("http://localhost")