Add configurable client_sampling and random_sampling for tracing

[WUMUXIAN]

Add configurable client_sampling and random_sampling for tracing
Pull Request Description:
This PR implements the feature requested in issue #7271, allowing users to configure clientSampling and randomSampling rates for Contour's tracing configuration in addition to the existing overallSampling.

Summary

• Adds ClientSampling and RandomSampling fields to the TracingConfig API struct
• Updates internal processing to parse and set these values with defaults of 100%
• Modifies Envoy configuration generation to include the new sampling rates
• Includes validation for the new fields
• All tests updated and passing

Changes

• API: apis/projectcontour/v1alpha1/contourconfig.go
• Validation: apis/projectcontour/v1alpha1/contourconfig_helpers.go
• Processing: cmd/contour/serve.go
• Internal config: internal/xdscache/v3/listener.go, internal/envoy/v3/tracing.go
• Tests: internal/envoy/v3/tracing_test.go
• Code generation: Updated deepcopy and other generated files
• Changelog: changelogs/unreleased/7271-luckyxkw-minor.md

Fixes #7271
Release note: release-note/minor (new feature for enhanced tracing control)

Signed-off-by: Muxian Wu wumuxian1988@gmail.com

[codecov]

Codecov Report

❌ Patch coverage is 72.72727% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 81.18%. Comparing base (00812a4) to head (6f666eb).
⚠️ Report is 9 commits behind head on main.

Files with missing lines	Patch %	Lines
cmd/contour/serve.go	50.00%	5 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7373      +/-   ##
==========================================
- Coverage   81.85%   81.18%   -0.67%     
==========================================
  Files         130      130              
  Lines       15747    15803      +56     
==========================================
- Hits        12889    12829      -60     
- Misses       2574     2613      +39     
- Partials      284      361      +77     

Files with missing lines	Coverage Δ
cmd/contour/servecontext.go	83.88% <100.00%> (-2.75%)	⬇️
internal/envoy/v3/tracing.go	87.71% <100.00%> (-6.40%)	⬇️
internal/xdscache/v3/listener.go	77.31% <100.00%> (-14.62%)	⬇️
pkg/config/parameters.go	78.94% <ø> (-8.17%)	⬇️
cmd/contour/serve.go	22.05% <50.00%> (-1.56%)	⬇️

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[WUMUXIAN]

hi @wilsonwu @tsaarni @sunjayBhatia, can I get this reviewed?

[tsaarni]

Thank you @WUMUXIAN for contributing!

It would be great to add more tests. I think you can add the new parameters to this file to help with the test coverage https://github.com/projectcontour/contour/blob/main/internal/featuretests/v3/tracing_test.go.

We should also add the new parameters to the tracing docs here:

contour/site/content/docs/main/config/tracing.md

Lines 12 to 18 in 07a2134

	Contour supports configuring envoy to export data to OpenTelemetry, and allows users to customize some configurations.
	- Custom service name, the default is `contour`.
	- Custom sampling rate, the default is `100`.
	- Custom the maximum length of the request path, the default is `256`.
	- Customize span tags from literal or request headers.
	- Customize whether to include the pod's hostname and namespace.

The changelog check is failing. You need to rename the file to ./changelogs/unreleased/7373-WUMUXIAN-minor.md. Right now it uses a different name.

Also, the DCO check is failing. You can fix this by rewriting your git history to remove the extra opencode plan file from your first commit. Or, you can just add a sign-off to the commit that removes it. We squash the PR at the end anyway, but we need all commits to have a sign-off for the check to pass.

[WUMUXIAN]

@tsaarni thanks for the review! I have addressed your comments

[tsaarni]

Thank you @WUMUXIAN!

We should add parameters for the configuration file, for those who do not use ContourConfiguration CRD. Here is diff you could use, with some test changes as well

diff --git a/cmd/contour/servecontext.go b/cmd/contour/servecontext.go
index 8c4ee27d..e7f4a77e 100644
--- a/cmd/contour/servecontext.go
+++ b/cmd/contour/servecontext.go
@@ -413,6 +413,8 @@ func (ctx *serveContext) convertToContourConfigurationSpec() contour_v1alpha1.Co
                        IncludePodDetail: ctx.Config.Tracing.IncludePodDetail,
                        ServiceName:      ctx.Config.Tracing.ServiceName,
                        OverallSampling:  ctx.Config.Tracing.OverallSampling,
+                       ClientSampling:   ctx.Config.Tracing.ClientSampling,
+                       RandomSampling:   ctx.Config.Tracing.RandomSampling,
                        MaxPathTagLength: ctx.Config.Tracing.MaxPathTagLength,
                        CustomTags:       customTags,
                        ExtensionService: &contour_v1alpha1.NamespacedName{
diff --git a/cmd/contour/servecontext_test.go b/cmd/contour/servecontext_test.go
index b3dfee1f..a0678f8f 100644
--- a/cmd/contour/servecontext_test.go
+++ b/cmd/contour/servecontext_test.go
@@ -833,6 +833,8 @@ func TestConvertServeContext(t *testing.T) {
                                        IncludePodDetail: ptr.To(false),
                                        ServiceName:      ptr.To("contour"),
                                        OverallSampling:  ptr.To("100"),
+                                       ClientSampling:   ptr.To("75"),
+                                       RandomSampling:   ptr.To("50"),
                                        MaxPathTagLength: ptr.To(uint32(256)),
                                        CustomTags: []config.CustomTag{
                                                {
@@ -853,6 +855,8 @@ func TestConvertServeContext(t *testing.T) {
                                        IncludePodDetail: ptr.To(false),
                                        ServiceName:      ptr.To("contour"),
                                        OverallSampling:  ptr.To("100"),
+                                       ClientSampling:   ptr.To("75"),
+                                       RandomSampling:   ptr.To("50"),
                                        MaxPathTagLength: ptr.To(uint32(256)),
                                        CustomTags: []*contour_v1alpha1.CustomTag{
                                                {
diff --git a/pkg/config/parameters.go b/pkg/config/parameters.go
index 1e4c397d..afb0e09b 100644
--- a/pkg/config/parameters.go
+++ b/pkg/config/parameters.go
@@ -727,6 +727,14 @@ type Tracing struct {
        // the default value is 100.
        OverallSampling *string `yaml:"overallSampling,omitempty"`
 
+       // ClientSampling defines the sampling rate when x-client-trace-id header is set.
+       // the default value is 100.
+       ClientSampling *string `yaml:"clientSampling,omitempty"`
+
+       // RandomSampling defines the random sampling rate for all requests.
+       // the default value is 100.
+       RandomSampling *string `yaml:"randomSampling,omitempty"`
+
        // MaxPathTagLength defines maximum length of the request path
        // to extract and include in the HttpUrl tag.
        // the default value is 256.
diff --git a/pkg/config/parameters_test.go b/pkg/config/parameters_test.go
index 6d689619..0fd66f82 100644
--- a/pkg/config/parameters_test.go
+++ b/pkg/config/parameters_test.go
@@ -682,6 +682,8 @@ func TestTracingConfigValidation(t *testing.T) {
                IncludePodDetail: ptr.To(false),
                ServiceName:      ptr.To("contour"),
                OverallSampling:  ptr.To("100"),
+               ClientSampling:   ptr.To("50"),
+               RandomSampling:   ptr.To("75"),
                MaxPathTagLength: ptr.To(uint32(256)),
                CustomTags:       nil,
                ExtensionService: "projectcontour/otel-collector",
@@ -700,6 +702,8 @@ func TestTracingConfigValidation(t *testing.T) {
        trace = &Tracing{
                IncludePodDetail: ptr.To(false),
                OverallSampling:  ptr.To("100"),
+               ClientSampling:   ptr.To("75"),
+               RandomSampling:   ptr.To("50"),
                MaxPathTagLength: ptr.To(uint32(256)),
                CustomTags:       nil,
                ExtensionService: "projectcontour/otel-collector",

[WUMUXIAN]

@tsaarni addressed the comments again! thank you

[WUMUXIAN]

@tsaarni I also squashed everything into 1 commit as the number has grown quite a bit..

[tsaarni]

@WUMUXIAN Sorry it took me a while to get back to this. I've added a few more comments.

You can find a diff here that you can use if you want: https://gist.githubusercontent.com/tsaarni/ad3bea53a9ce621444e2caff368d146d/raw/a129a2e3eb44d30381173b5ff75e0a871ce4360b/gistfile0.txt

[WUMUXIAN]

@tsaarni addressed comments

[tsaarni]

@WUMUXIAN Thank You for contributing!

[WUMUXIAN]

@tsaarni happy to do so! can you please take a look at #7372 too? I want to be able to se ja3/ja4, thank you!