docker-images/otel-lgtm

OTel LGTM (Alpine + supervisord)

A single-container observability backend running on Alpine Linux with supervisord.

Components:

• Grafana — visualization UI
• Mimir — metrics storage
• Loki — log storage
• Tempo — trace storage
• OpenTelemetry Collector (contrib) — OTLP receiver and router

Ports

Port	Service	Description
3000	Grafana	Web UI
4318	OTel Collector	OTLP/HTTP endpoint

Only these two ports are exposed. All other services communicate internally on 127.0.0.1.

Build

docker build -t otel-lgtm .

The Dockerfile uses BuildKit cache mounts for apk. Make sure BuildKit is enabled (default in recent Docker Desktop / docker buildx).

Build args

Build arg	Default	Description
ALPINE_VERSION	3.24	Alpine Linux base image version
OTELCOL_VERSION	0.154.0	OpenTelemetry Collector Contrib version

Grafana, Mimir, Loki, and Tempo versions are determined by the chosen Alpine repository.

Example:

docker build --build-arg OTELCOL_VERSION=0.155.0 -t otel-lgtm .

Multi-architecture

The Dockerfile detects the build architecture at build time, so it works on both amd64 and arm64. To build a true multi-arch image in one command, use Docker BuildKit / docker buildx:

docker buildx build --platform linux/amd64,linux/arm64 -t otel-lgtm .

Run

docker run -p 3000:3000 -p 4318:4318 -v lgtm-data:/data otel-lgtm

Grafana is available at http://localhost:3000 with anonymous admin access enabled.

Send telemetry to the collector at http://localhost:4318 (OTLP/HTTP).

Data persistence

All persistent data is written under /data:

Path	Service
/data/grafana	Grafana data, logs, and plugins
/data/mimir	Mimir metrics storage
/data/loki	Loki log storage
/data/tempo	Tempo trace storage

Mount a volume there to persist data across container restarts.

Architecture

Application ──OTLP/HTTP──> OTel Collector :4318
    │
    ├─ metrics ──OTLP/HTTP──> Mimir :9009
    ├─ logs ─────OTLP/HTTP──> Loki :3100
    └─ traces ───OTLP/HTTP──> Tempo :3200

Grafana :3000 queries Mimir, Loki, and Tempo.

Read-only root filesystem

The image can be run with an immutable root filesystem (--read-only). A few runtime-only directories must be mounted as writable tmpfs:

docker run --read-only \
  -p 3000:3000 -p 4318:4318 \
  -v lgtm-data:/data \
  --tmpfs /tmp:rw,noexec,nosuid,size=100m \
  --tmpfs /run:rw,noexec,nosuid,size=10m \
  --tmpfs /var/log/supervisor:rw,noexec,nosuid,size=50m \
  otel-lgtm

Persistent data continues to live on the /data volume, while temporary/runtime state stays in memory.

Notes

• This image is intended for development, demo, and testing environments.
• Grafana authentication is disabled (anonymous admin).
• Grafana’s default async plugin pre-installation is disabled to avoid relying on internet access at startup.