Configure OpenTelemetry in nginx

Author: Taucher2003

container/config-generator/templates/nginx.default.conf.erb

@@ -42,6 +42,12 @@ server {
   server_name <%= env!('HOSTNAME') %>;
 <% end %>
 
+<% if env?('OPENTELEMETRY_ENABLED') -%>
+  otel_trace on;
+  otel_trace_context propagate;
+  otel_span_name "$request_method $request_uri";
+<% end -%>
+
   location = /graphql {
     proxy_pass http://sagittarius_rails_web;
     proxy_set_header Host $host;

container/config-generator/templates/nginx.otel.conf.erb

@@ -0,0 +1,10 @@
+<% if env?('OPENTELEMETRY_ENABLED') -%>
+otel_exporter {
+    endpoint <%= env!('OPENTELEMETRY_GRPC_HOST') %>;
+    interval 5s;
+    batch_size 512;
+    batch_count 4;
+}
+
+otel_service_name <%= env('OPENTELEMETRY_SERVICE_NAME_NGINX', 'nginx') %>;
+<% end -%>

docker-compose/.env

@@ -72,6 +72,7 @@ VELORUM_JWT_SECRET=088cfc7a7fc2b07696d8ee5e1ea9d642
 
 # OpenTelemetry
 OPENTELEMETRY_ENABLED=false
+OPENTELEMETRY_GRPC_HOST=http://localhost:4317
 OPENTELEMETRY_LOGS_HTTP_ENDPOINT=http://localhost:4318/v1/logs
 OPENTELEMETRY_METRICS_HTTP_ENDPOINT=http://localhost:4318/v1/metrics
 OPENTELEMETRY_TRACES_HTTP_ENDPOINT=http://localhost:4318/v1/traces

docker-compose/docker-compose.yml

@@ -128,7 +128,7 @@ services:
       - ide_velorum
 
   nginx:
-    image: nginx:1.31.1-alpine-slim
+    image: nginx:1.31.1-alpine-otel
     depends_on:
       config-generator:
         condition: service_completed_successfully
@@ -146,6 +146,10 @@ services:
     entrypoint: |
       sh -c "
         cp /tmp/generated-configs/nginx.default.conf /etc/nginx/conf.d/default.conf
+        if [ -s /tmp/generated-configs/nginx.otel.conf ]; then
+          sed -i '1i load_module modules/ngx_otel_module.so;' /etc/nginx/nginx.conf
+          cp /tmp/generated-configs/nginx.otel.conf /etc/nginx/conf.d/otel.conf
+        fi
         nginx -t
         exec nginx -g 'daemon off;'
       "