OTLP connection refused

[heeelga]

OTLP_ENABLED is set to true, the traefik container is able to rearch the backend, however the traefik log shows connection refused messages. Inside of the backend container, the ports does not seem to be routed.

{"time":"2025-08-08T07:51:58Z","caller":"log/log.go:245","level":"debug","message":"2025/08/08 07:51:58 handler.go:30: traces export: Post "http://backend:4318/v1/traces\": dial tcp 172.25.0.3:4318: connect: connection refused"}

Inside the backend container:
~ # nc -vz 127.0.0.1 4318 || true
~ # nc -vz 127.0.0.1 4317 || true
~ # nc -vz 127.0.0.1 3001 || true
127.0.0.1 (127.0.0.1:3001) open

curl http://localhost:3001/api/otlp/status results in: 404 page not found

[hhftechnology]

share your compose file

[heeelga]

Sure, its just the basic one you provided with your project:

networks:
proxy:
driver: bridge
dashboard-network:
driver: bridge

volumes:
traefik-logs:
traefik-certs:
maxmind-data:

services:

Enhanced Dashboard Backend with OTLP support

backend:
build: ./backend
container_name: ${BACKEND_CONTAINER_NAME:-traefik-dashboard-backend-otlp}
restart: unless-stopped
networks:
- dashboard-network
ports:
- "3001:3001" # API port
- "4317:4317" # OTLP GRPC port
- "4318:4318" # OTLP HTTP port
volumes:
- ${TRAEFIK_LOG_PATH:-./logs}:/logs:ro
- maxmind-data:/maxmind:ro
environment:
# Basic configuration
- PORT=3001
- TRAEFIK_LOG_FILE=/logs/access.log

  # MaxMind GeoIP configuration
  - USE_MAXMIND=${USE_MAXMIND:-true}
  - MAXMIND_DB_PATH=/maxmind/GeoLite2-City.mmdb
  - MAXMIND_FALLBACK_ONLINE=${MAXMIND_FALLBACK_ONLINE:-true}

  # OTLP Configuration
  - OTLP_ENABLED=${OTLP_ENABLED:-true}
  - OTLP_GRPC_PORT=${OTLP_GRPC_PORT:-4317}
  - OTLP_HTTP_PORT=${OTLP_HTTP_PORT:-4318}

  # Performance tuning
  - GOGC=${GOGC:-50}
  - GOMEMLIMIT=${GOMEMLIMIT:-500MiB}
healthcheck:
  test: ["CMD", "wget", "--quiet", "--tries=1", "--spider", "http://localhost:3001/health"]
  interval: 30s
  timeout: 10s
  retries: 3
deploy:
  resources:
    limits:
      cpus: '1.0'
      memory: 512M
    reservations:
      cpus: '0.2'
      memory: 128M

Dashboard Frontend

frontend:
build: ./frontend
container_name: ${FRONTEND_CONTAINER_NAME:-traefik-dashboard-frontend-otlp}
restart: unless-stopped
networks:
- dashboard-network
- proxy
ports:
- "${FRONTEND_PORT:-3000}:80"
environment:
- BACKEND_SERVICE=${BACKEND_SERVICE_NAME:-backend}
- BACKEND_PORT=${PORT:-3001}
depends_on:
- backend
labels:
# Traefik labels for routing (optional)
- "traefik.enable=true"
- "traefik.docker.network=traefik-network"
- "traefik.http.routers.dashboard-frontend.rule=Host(dashboard.localhost) || Host(dashboard.example.com)"
- "traefik.http.routers.dashboard-frontend.entrypoints=websecure"
- "traefik.http.services.dashboard-frontend.loadbalancer.server.port=80"
healthcheck:
test: ["CMD", "wget", "--quiet", "--tries=1", "--spider", "http://localhost/"]
interval: 30s
timeout: 10s
retries: 3
deploy:
resources:
limits:
cpus: '0.5'
memory: 256M
reservations:
cpus: '0.1'
memory: 64M

MaxMind GeoLite2 database updater

maxmind-updater:
image: alpine:latest
container_name: maxmind-db-updater
restart: "no"
volumes:
- maxmind-data:/data
environment:
- MAXMIND_LICENSE_KEY=${MAXMIND_LICENSE_KEY:-your-license-key-here}
command: >
sh -c "
apk add --no-cache wget tar &&
cd /data &&
if [ ! -f GeoLite2-City.mmdb ] || [ $$(find . -name 'GeoLite2-City.mmdb' -mtime +7) ]; then
echo 'Downloading/updating MaxMind GeoLite2-City database...' &&
wget -O GeoLite2-City.tar.gz 'https://download.maxmind.com/app/geoip_download?edition_id=GeoLite2-City&license_key=$$MAXMIND_LICENSE_KEY&suffix=tar.gz' &&
tar -xzf GeoLite2-City.tar.gz --strip-components=1 '*/GeoLite2-City.mmdb' &&
rm -f GeoLite2-City.tar.gz &&
echo 'MaxMind database updated successfully'
else
echo 'MaxMind database is up to date'
fi
"

[hhftechnology]

https://forum.hhf.technology/t/visualizing-your-traefik-logs-deploying-the-traefik-log-dashboard-with-the-pangolin-stack/3263/16?u=hhf.technoloy