registry/internal/api/handlers/v0/health_test.go
pree-dew d237fc90f8
Add OpenTelemetry metrics instrumentation (#290)
## Motivation and Context
- It is important to have basic observability in place so that
availability issues can be figured out easily

## How Has This Been Tested?
- Registration of metrics is tested
- Prometheus endpoint `/metrics` is included in test cases to test the
metrics exposed
- Test locally to understand any regression.

## Breaking Changes
- No

## Types of changes
<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [ ] Bug fix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update

## Checklist
<!-- Go over all the following points, and put an `x` in all the boxes
that apply. -->
- [x] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [x] My code follows the repository's style guidelines
- [x] New and existing tests pass locally
- [x] I have added appropriate error handling
- [ ] I have added or updated documentation as needed

## Additional context
- Telemetry implementation is currently done by keeping metrics in mind
as of now, other types of telemetry can be added on top of it later.
- Instrumentation takes care of these problems already:
- Cardinality control by limiting latency buckets and not including
labels that grows with throughput.
  - Latency buckets are added as per SLA guidelines
  - Each metric prefixed with `mcp` to easily identify.
- Pulling mechanism is used since the idea is to scrape metrics via an
agent like vmagent, prometheus agent or otel-collector.
- Metrics follow standard approach of defining counters, histogram and
gauges as per opentelemetry guidelines.
2025-08-21 14:23:37 +01:00

86 lines
2.1 KiB
Go

package v0_test
import (
"context"
"net/http"
"net/http/httptest"
"testing"
"github.com/danielgtaylor/huma/v2"
"github.com/danielgtaylor/huma/v2/adapters/humago"
"github.com/stretchr/testify/assert"
v0 "github.com/modelcontextprotocol/registry/internal/api/handlers/v0"
"github.com/modelcontextprotocol/registry/internal/config"
"github.com/modelcontextprotocol/registry/internal/telemetry"
)
func TestHealthEndpoint(t *testing.T) {
// Test cases
testCases := []struct {
name string
config *config.Config
expectedStatus int
expectedBody v0.HealthBody
}{
{
name: "returns health status with github client id",
config: &config.Config{
GithubClientID: "test-github-client-id",
},
expectedStatus: http.StatusOK,
expectedBody: v0.HealthBody{
Status: "ok",
GitHubClientID: "test-github-client-id",
},
},
{
name: "returns health status without github client id",
config: &config.Config{
GithubClientID: "",
},
expectedStatus: http.StatusOK,
expectedBody: v0.HealthBody{
Status: "ok",
GitHubClientID: "",
},
},
}
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
// Create a new test API
mux := http.NewServeMux()
api := humago.New(mux, huma.DefaultConfig("Test API", "1.0.0"))
shutdownTelemetry, metrics, _ := telemetry.InitMetrics("test")
// Register the health endpoint
v0.RegisterHealthEndpoint(api, tc.config, metrics)
// Create a test request
req := httptest.NewRequest(http.MethodGet, "/v0/health", nil)
w := httptest.NewRecorder()
// Serve the request
mux.ServeHTTP(w, req)
// shut down the metric provider
_ = shutdownTelemetry(context.Background())
// Check the status code
assert.Equal(t, tc.expectedStatus, w.Code)
// Check the response body
// Since Huma adds a $schema field, we'll check individual fields
body := w.Body.String()
assert.Contains(t, body, `"status":"ok"`)
if tc.config.GithubClientID != "" {
assert.Contains(t, body, `"github_client_id":"test-github-client-id"`)
} else {
assert.NotContains(t, body, `"github_client_id"`)
}
})
}
}