Fix nil reference error when starting Tempo (#2444)

TESTING.md

@@ -42,6 +42,7 @@ This is the entire checklist on what we should do to assert that Tracetest is wo
   - [ ] [Lightstep example](https://github.com/kubeshop/tracetest/tree/main/examples/tracetest-lightstep)
   - [ ] [New Relic example](https://github.com/kubeshop/tracetest/tree/main/examples/tracetest-new-relic)
   - [ ] [SignalFX example](https://github.com/kubeshop/tracetest/tree/main/examples/tracetest-signalfx)
+  - [ ] [Tempo Cloud example](https://github.com/kubeshop/tracetest/tree/main/examples/quick-start-grafana-cloud-tempo-nodejs)
 
 - Test specific features added/changed on this release:
 

local-config/tempo-cloud/collector.config.yaml

@@ -0,0 +1,27 @@
+receivers:
+  otlp:
+    protocols:
+      grpc:
+      http:
+
+processors:
+  batch:
+    timeout: 100ms
+
+exporters:
+  logging:
+    loglevel: debug
+  otlp:
+    endpoint: tempo-us-central1.grafana.net:443
+    headers:
+      authorization: Basic <tempo-cloud-base64-key>
+      # https://grafana.com/blog/2021/04/13/how-to-send-traces-to-grafana-clouds-tempo-service-with-opentelemetry-collector/
+    tls:
+      insecure: false
+
+service:
+  pipelines:
+    traces:
+      receivers: [otlp]
+      processors: [batch]
+      exporters: [otlp]

local-config/tempo-cloud/docker-compose.yaml

@@ -0,0 +1,24 @@
+version: "3"
+services:
+  postgres:
+    image: postgres:14
+    environment:
+      POSTGRES_PASSWORD: postgres
+      POSTGRES_USER: postgres
+    healthcheck:
+      test: pg_isready -U "$$POSTGRES_USER" -d "$$POSTGRES_DB"
+      interval: 1s
+      timeout: 5s
+      retries: 60
+    ports:
+      - 5432:5432
+
+  otel-collector:
+    image: otel/opentelemetry-collector-contrib:0.73.0
+    command:
+      - "--config"
+      - "/otel-local-config.yaml"
+    volumes:
+      - ./collector.config.yaml:/otel-local-config.yaml
+    ports:
+      - 4317:4317

local-config/tempo-cloud/tracetest.config.yaml

@@ -0,0 +1,21 @@
+postgres:
+  host: localhost
+  user: postgres
+  password: postgres
+  port: 5432
+  dbname: postgres
+  params: sslmode=disable
+
+telemetry:
+  exporters:
+    collector:
+      serviceName: tracetest
+      sampling: 100 # 100%
+      exporter:
+        type: collector
+        collector:
+          endpoint: localhost:4317
+
+server:
+  telemetry:
+    exporter: collector

local-config/tempo-cloud/tracetest.provision.yaml

@@ -0,0 +1,12 @@
+---
+type: DataStore
+spec:
+  name: Grafana Tempo Cloud
+  type: tempo
+  tempo:
+    type: http
+    http:
+      url: https://tempo-us-central1.grafana.net/tempo
+      headers:
+        Authorization: Basic <tempo-cloud-base64-key>
+        # https://grafana.com/blog/2021/04/13/how-to-send-traces-to-grafana-clouds-tempo-service-with-opentelemetry-collector/

server/tracedb/datasource/http.go

@@ -28,7 +28,7 @@ func NewHttpClient(name string, config *datastoreresource.HttpClientConfig, call
 	endpoint, _ := url.Parse(config.Url)
 	client := &http.Client{
 		Transport: &http.Transport{
-			TLSClientConfig: getTlsConfig(config.TLS.Settings.CAFile, config.TLS.Insecure),
+			TLSClientConfig: getTlsConfig(config.TLS),
 		},
 	}
 
@@ -118,13 +118,23 @@ func (client *HttpClient) Request(ctx context.Context, path, method, body string
 	return response, nil
 }
 
-func getTlsConfig(caCertFile string, skipVerify bool) *tls.Config {
+func getTlsConfig(dataStoreTls *datastoreresource.TLS) *tls.Config {
 	tlsConfig := tls.Config{}
 
-	if skipVerify {
+	if dataStoreTls == nil {
+		return &tlsConfig
+	}
+
+	if dataStoreTls.Insecure {
 		tlsConfig.InsecureSkipVerify = true
 	}
 
+	if dataStoreTls.Settings == nil {
+		return &tlsConfig
+	}
+
+	caCertFile := dataStoreTls.Settings.CAFile
+
 	if caCertFile != "" {
 		caCertPool := x509.NewCertPool()
 		caCertPool.AppendCertsFromPEM([]byte(caCertFile))