[FrontendProxy] Add tracing to Envoy (open-telemetry#613)

* Add tracing to Envoy * Changelog * yamllint * lint * Add doc * Add note to doc * Move env var definition
jmichalak9 · Dec 7, 2022 · 057d1c6 · 057d1c6
1 parent 7212399
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diff --git a/.env b/.env
@@ -3,7 +3,9 @@ IMAGE_VERSION=v1.1.0
 IMAGE_NAME=ghcr.io/open-telemetry/demo
 
 # Collector
-OTEL_EXPORTER_OTLP_ENDPOINT=http://otelcol:4317
+OTEL_COLLECTOR_HOST=otelcol
+OTEL_COLLECTOR_PORT=4317
+OTEL_EXPORTER_OTLP_ENDPOINT=http://${OTEL_COLLECTOR_HOST}:${OTEL_COLLECTOR_PORT}
 OTEL_EXPORTER_OTLP_TRACES_ENDPOINT=${OTEL_EXPORTER_OTLP_ENDPOINT}
 OTEL_EXPORTER_OTLP_METRICS_ENDPOINT=${OTEL_EXPORTER_OTLP_ENDPOINT}
 PUBLIC_OTEL_EXPORTER_OTLP_TRACES_ENDPOINT=http://localhost:4318/v1/traces

diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -150,3 +150,5 @@ significant modifications will be credited to OpenTelemetry Authors.
 ([#512](https://github.com/open-telemetry/opentelemetry-demo/pull/457))
 * Added support for non-root containers
 ([#615](https://github.com/open-telemetry/opentelemetry-demo/pull/615))
+* Add tracing to Envoy (frontend-proxy)
+([#613](https://github.com/open-telemetry/opentelemetry-demo/pull/613))
diff --git a/docker-compose.yml b/docker-compose.yml
@@ -326,6 +326,8 @@ services:
       - GRAFANA_SERVICE_HOST
       - JAEGER_SERVICE_PORT
       - JAEGER_SERVICE_HOST
+      - OTEL_COLLECTOR_HOST
+      - OTEL_COLLECTOR_PORT
       - ENVOY_PORT
     depends_on:
       - frontend

diff --git a/docs/services/frontendproxy.md b/docs/services/frontendproxy.md
@@ -0,0 +1,60 @@
+# Frontend Proxy(Envoy)
+
+The frontend proxy is used as a reverse proxy for user-facing web
+interfaces such as the frontend, Jaeger, Grafana, load generator,
+and feature flag service.
+
+## Enabling OpenTelemetry
+
+**NOTE: Only non-synthetic requests will trigger the envoy tracing.**
+
+In order to enable Envoy to produce spans whenever receiving a request,
+the following configuration is required:
+
+```yaml
+static_resources:
+  listeners:
+    - address:
+        socket_address:
+          address: 0.0.0.0
+          port_value: ${ENVOY_PORT}
+      filter_chains:
+        - filters:
+            - name: envoy.filters.network.http_connection_manager
+              typed_config:
+                "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
+                codec_type: AUTO
+                stat_prefix: ingress_http
+                tracing:
+                  provider:
+                    name: envoy.tracers.opentelemetry
+                    typed_config:
+                      "@type": type.googleapis.com/envoy.config.trace.v3.OpenTelemetryConfig
+                      grpc_service:
+                        envoy_grpc:
+                          cluster_name: opentelemetry_collector
+                        timeout: 0.250s
+                      service_name: frontend-proxy
+
+  clusters:
+    - name: opentelemetry_collector
+      type: STRICT_DNS
+      lb_policy: ROUND_ROBIN
+      typed_extension_protocol_options:
+        envoy.extensions.upstreams.http.v3.HttpProtocolOptions:
+          "@type": type.googleapis.com/envoy.extensions.upstreams.http.v3.HttpProtocolOptions
+          explicit_http_config:
+            http2_protocol_options: {}
+      load_assignment:
+        cluster_name: opentelemetry_collector
+        endpoints:
+          - lb_endpoints:
+              - endpoint:
+                  address:
+                    socket_address:
+                      address: ${OTEL_COLLECTOR_HOST}
+                      port_value: ${OTEL_COLLECTOR_PORT}
+```
+
+Where `OTEL_COLLECTOR_HOST` and `OTEL_COLLECTOR_PORT` are passed via
+environment variables.
diff --git a/src/frontendproxy/envoy.tmpl.yaml b/src/frontendproxy/envoy.tmpl.yaml
@@ -11,6 +11,16 @@ static_resources:
                 "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
                 codec_type: AUTO
                 stat_prefix: ingress_http
+                tracing:
+                  provider:
+                    name: envoy.tracers.opentelemetry
+                    typed_config:
+                      "@type": type.googleapis.com/envoy.config.trace.v3.OpenTelemetryConfig
+                      grpc_service:
+                        envoy_grpc:
+                          cluster_name: opentelemetry_collector
+                        timeout: 0.250s
+                      service_name: frontend-proxy
                 route_config:
                   name: local_route
                   virtual_hosts:
@@ -38,6 +48,23 @@ static_resources:
                       "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router
 
   clusters:
+    - name: opentelemetry_collector
+      type: STRICT_DNS
+      lb_policy: ROUND_ROBIN
+      typed_extension_protocol_options:
+        envoy.extensions.upstreams.http.v3.HttpProtocolOptions:
+          "@type": type.googleapis.com/envoy.extensions.upstreams.http.v3.HttpProtocolOptions
+          explicit_http_config:
+            http2_protocol_options: {}
+      load_assignment:
+        cluster_name: opentelemetry_collector
+        endpoints:
+          - lb_endpoints:
+              - endpoint:
+                  address:
+                    socket_address:
+                      address: ${OTEL_COLLECTOR_HOST}
+                      port_value: ${OTEL_COLLECTOR_PORT}
     - name: frontend
       type: STRICT_DNS
       lb_policy: ROUND_ROBIN