From 12577e385103d10c481f58d3ced1b9c3942e9629 Mon Sep 17 00:00:00 2001 From: Owen Williams Date: Thu, 14 Nov 2024 10:51:59 -0500 Subject: [PATCH] Add support for values unescaping on `/v1/label/:name/values` endpoint Signed-off-by: Owen Williams --- docs/querying/api.md | 32 +++++++++++++++++++++++++++----- web/api/v1/api.go | 4 ++++ web/api/v1/api_test.go | 30 +++++++++++++++++++++--------- 3 files changed, 52 insertions(+), 14 deletions(-) diff --git a/docs/querying/api.md b/docs/querying/api.md index 0352496f1..87de46328 100644 --- a/docs/querying/api.md +++ b/docs/querying/api.md @@ -433,18 +433,40 @@ URL query parameters: series from which to read the label values. Optional. - `limit=`: Maximum number of returned series. Optional. 0 means disabled. - The `data` section of the JSON response is a list of string label values. -This example queries for all label values for the `job` label: +This example queries for all label values for the `http_status_code` label: ```json -$ curl http://localhost:9090/api/v1/label/job/values +$ curl http://localhost:9090/api/v1/label/http_status_code/values { "status" : "success", "data" : [ - "node", - "prometheus" + "200", + "504" + ] +} +``` + +Label names can optionally be encoded using the Values Escaping method, and is necessary if a name includes the `/` character. To encode a name in this way: + +* Prepend the label with `U__`. +* Letters, numbers, and colons appear as-is. +* Convert single underscores to double underscores. +* For all other characters, use the UTF-8 codepoint as a hex integer, surrounded + by underscores. So ` ` becomes `_20_` and a `.` becomes `_2e_`. + + More information about text escaping can be found in the original UTF-8 [Proposal document](https://github.com/prometheus/proposals/blob/main/proposals/2023-08-21-utf8.md#text-escaping). + +This example queries for all label values for the `http.status_code` label: + +```json +$ curl http://localhost:9090/api/v1/label/U__http_2e_status_code/values +{ + "status" : "success", + "data" : [ + "200", + "404" ] } ``` diff --git a/web/api/v1/api.go b/web/api/v1/api.go index c61e7984f..633ca8393 100644 --- a/web/api/v1/api.go +++ b/web/api/v1/api.go @@ -744,6 +744,10 @@ func (api *API) labelValues(r *http.Request) (result apiFuncResult) { ctx := r.Context() name := route.Param(ctx, "name") + if strings.HasPrefix(name, "U__") { + name = model.UnescapeName(name, model.ValueEncodingEscaping) + } + label := model.LabelName(name) if !label.IsValid() { return apiFuncResult{nil, &apiError{errorBadData, fmt.Errorf("invalid label name: %q", name)}, nil, nil} diff --git a/web/api/v1/api_test.go b/web/api/v1/api_test.go index 4cf5ec36e..e89e284e4 100644 --- a/web/api/v1/api_test.go +++ b/web/api/v1/api_test.go @@ -388,6 +388,7 @@ func TestEndpoints(t *testing.T) { test_metric4{foo="boo", dup="1"} 1+0x100 test_metric4{foo="boo"} 1+0x100 test_metric5{"host.name"="localhost"} 1+0x100 + test_metric5{"junk\n{},=: chars"="bar"} 1+0x100 `) t.Cleanup(func() { storage.Close() }) @@ -3031,6 +3032,17 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E "localhost", }, }, + // Valid escaped utf8 name parameter for utf8 validation. + { + endpoint: api.labelValues, + params: map[string]string{ + "name": "U__junk_0a__7b__7d__2c__3d_:_20__20_chars", + }, + nameValidationScheme: model.UTF8Validation, + response: []string{ + "bar", + }, + }, // Start and end before LabelValues starts. { endpoint: api.labelValues, @@ -3273,7 +3285,7 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E // Label names. { endpoint: api.labelNames, - response: []string{"__name__", "dup", "foo", "host.name"}, + response: []string{"__name__", "dup", "foo", "host.name", "junk\n{},=: chars"}, }, // Start and end before Label names starts. { @@ -3291,7 +3303,7 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E "start": []string{"1"}, "end": []string{"100"}, }, - response: []string{"__name__", "dup", "foo", "host.name"}, + response: []string{"__name__", "dup", "foo", "host.name", "junk\n{},=: chars"}, }, // Start before Label names, end within Label names. { @@ -3300,7 +3312,7 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E "start": []string{"-1"}, "end": []string{"10"}, }, - response: []string{"__name__", "dup", "foo", "host.name"}, + response: []string{"__name__", "dup", "foo", "host.name", "junk\n{},=: chars"}, }, // Start before Label names starts, end after Label names ends. @@ -3310,7 +3322,7 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E "start": []string{"-1"}, "end": []string{"100000"}, }, - response: []string{"__name__", "dup", "foo", "host.name"}, + response: []string{"__name__", "dup", "foo", "host.name", "junk\n{},=: chars"}, }, // Start with bad data for Label names, end within Label names. { @@ -3328,7 +3340,7 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E "start": []string{"1"}, "end": []string{"1000000006"}, }, - response: []string{"__name__", "dup", "foo", "host.name"}, + response: []string{"__name__", "dup", "foo", "host.name", "junk\n{},=: chars"}, }, // Start and end after Label names ends. { @@ -3345,7 +3357,7 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E query: url.Values{ "start": []string{"4"}, }, - response: []string{"__name__", "dup", "foo", "host.name"}, + response: []string{"__name__", "dup", "foo", "host.name", "junk\n{},=: chars"}, }, // Only provide End within Label names, don't provide a start time. { @@ -3353,7 +3365,7 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E query: url.Values{ "end": []string{"20"}, }, - response: []string{"__name__", "dup", "foo", "host.name"}, + response: []string{"__name__", "dup", "foo", "host.name", "junk\n{},=: chars"}, }, // Label names with bad matchers. { @@ -3421,9 +3433,9 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E { endpoint: api.labelNames, query: url.Values{ - "limit": []string{"4"}, + "limit": []string{"5"}, }, - responseLen: 4, // API does not specify which particular values will come back. + responseLen: 5, // API does not specify which particular values will come back. warningsCount: 0, // No warnings if limit isn't exceeded. }, }...)