xray client: return an error if the HTTP request failed

CHANGELOG.md

@@ -16,6 +16,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 - The superfluous `response.WriteHeader` call in `go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp` when the response writer is flushed. (#5634)
 - Custom attributes targeting metrics recorded by the `go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp` are not ignored anymore. (#5129)
+- Erroneous response code of `getSamplingRules` in `go.opentelemetry.io/contrib/samplers/aws/xray/internal/client.go` will result in an error despite an empty sampling manifest. (#)
 
 ### Deprecated
 

samplers/aws/xray/internal/client.go

@@ -139,6 +139,10 @@ func (c *xrayClient) getSamplingRules(ctx context.Context) (*getSamplingRulesOut
 	}
 	defer output.Body.Close()
 
+	if output.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("xray client: unable to retrieve sampling settings, expected response status code 200, got: %d", output.StatusCode)
+	}
+
 	var samplingRulesOutput *getSamplingRulesOutput
 	if err := json.NewDecoder(output.Body).Decode(&samplingRulesOutput); err != nil {
 		return nil, fmt.Errorf("xray client: unable to unmarshal the response body: %w", err)

samplers/aws/xray/internal/client_test.go

@@ -261,3 +261,22 @@ func TestEndpointIsNotReachable(t *testing.T) {
 	_, err = client.getSamplingRules(context.Background())
 	assert.Error(t, err)
 }
+
+func TestRespondsWithErrorStatusCode(t *testing.T) {
+	testServer := httptest.NewServer(http.HandlerFunc(func(res http.ResponseWriter, _ *http.Request) {
+		res.WriteHeader(http.StatusForbidden)
+		_, err := res.Write([]byte(`{}`))
+		require.NoError(t, err)
+	}))
+	t.Cleanup(testServer.Close)
+
+	u, err := url.Parse(testServer.URL)
+	require.NoError(t, err)
+
+	client, err := newClient(*u)
+	require.NoError(t, err)
+
+	samplingRules, err := client.getSamplingRules(context.Background())
+	require.Error(t, err)
+	require.Nil(t, samplingRules)
+}