example: add Docker Compose example

This commit adds a new Docker Compose example for users to quickly test
running Alloy either in a Docker container or locally, sending data to
databases in a Docker container.

By default, the following are deployed:

* Visualization
  * Grafana 10.1.9
  * A one-shot container to deploy the Alloy mixin to Grafana
  * A container which watches the Alloy mixin folder and deploys changes
    automatically

* Databases
  * Mimir 2.12.0
  * Loki 3.0.0
  * Tempo 2.4.1
  * Pyroscope 1.5.0

Grafana Alloy can also be deployed by passing the `--profile=alloy`
command to Docker Compose when starting and stopping:

```
docker compose --profile=alloy up -d
```

```
docker compose --profile=alloy down
```

Alternatively, Alloy can be run locally using the config file in
example/config/alloy/config.alloy.

The default Alloy configuration used in the Docker Compose environment
configures Alloy to self-collect metrics, logs, traces, and profiles,
and send them to the backend databases.

example/README.md

@@ -0,0 +1,52 @@
+# Docker Compose example
+
+This directory contains a Docker Compose environment that can be used to test
+Grafana Alloy.
+
+By default, only Grafana and databases are exposed:
+
+* Grafana, for visualizing telemetry (`localhost:3000`)
+* Grafana Mimir, for storing metrics (`localhost:9009`)
+* Grafana Loki, for storing logs (`localhost:3000`)
+* Grafana Tempo, for storing traces (`localhost:3200`)
+* Grafana Pyroscope, for storing profiles (`localhost:4040`)
+
+Grafana is automatically provisioned with the appropriate datasources and
+dashboards for monitoring Grafana Alloy.
+
+To start the environment, run:
+
+```bash
+docker compose up -d
+```
+
+To stop the environment, run:
+
+```bash
+docker compose down
+```
+
+## Running Alloy
+
+Alloy can either be run locally or within Docker Compose. The [example
+configuration](./config/alloy/config.alloy) can be used to send self-monitoring
+data from a local Alloy to the various databases running in Docker Compose.
+
+To run Alloy within Docker Compose, pass `--profile=alloy` to `docker compose`
+when starting and stopping the environment:
+
+```bash
+docker compose --profile=alloy up -d
+```
+
+```bash
+docker compose --profile=alloy down
+```
+
+## Visualizing
+
+To visualize Alloy data in Grafana, open <http://localhost:3000> in a web
+browser and look at the dashboards in the `Alloy` folder.
+
+> **NOTE**: It can take up to a minute for Alloy metrics and profiles to start
+> appearing.

example/compose.yaml

@@ -0,0 +1,32 @@
+name: alloy-example
+
+include:
+  - ./grafana.yaml
+  - ./databases.yaml
+
+services:
+  alloy:
+    image: grafana/alloy:v1.0.0
+    pull_policy: always
+    profiles: ["alloy"]
+    restart: on-failure
+    volumes:
+      - ./config/alloy:/etc/alloy
+    environment:
+      REMOTE_WRITE_HOST: mimir:9009
+      LOKI_HOST: loki:3100
+      TEMPO_HOST: tempo:4317
+      PYROSCOPE_HOST: pyroscope:4040
+    depends_on:
+      - mimir
+      - loki
+      - tempo
+      - pyroscope
+    command:
+      - run
+      - /etc/alloy/config.alloy
+      - --storage.path=/var/lib/alloy/data
+      - --server.http.listen-addr=0.0.0.0:12345
+      - --stability.level=experimental # Enable all functionality
+    ports:
+      - "12345:12345"

example/config/alloy/config.alloy

@@ -0,0 +1,74 @@
+// This file serves as an example Alloy configuration to interact with the
+// Docker Compose environment.
+//
+// This configuration works whether you are running Alloy locally or within the
+// Docker Compose environment when the `alloy` profile is enabled.
+
+logging {
+	level = "debug"
+
+	// Forward internal logs to the local Loki instance.
+	write_to = [loki.write.loki.receiver]
+}
+
+tracing {
+	// Write all spans. Don't do this in production!
+	sampling_fraction = 1.0
+
+	// Forward internal spans to the local Tempo instance.
+	write_to = [otelcol.exporter.otlp.tempo.input]
+}
+
+// Collect metrics from the local running Alloy instance and forward to
+// Prometheus.
+prometheus.exporter.self "alloy" {}
+prometheus.scrape "alloy" {
+	targets    = prometheus.exporter.self.alloy.targets
+	forward_to = [prometheus.remote_write.mimir.receiver]
+}
+
+// Collect profiles from the local running Alloy instance and forward to
+// Pyroscope.
+pyroscope.scrape "default" {
+  targets = [
+    {"__address__" = "localhost:12345", "service_name" = "alloy"},
+  ]
+  forward_to = [pyroscope.write.pyroscope.receiver]
+}
+
+prometheus.remote_write "mimir" {
+	endpoint {
+		url = format(
+			"http://%s/api/v1/push",
+			coalesce(env("REMOTE_WRITE_HOST"), "localhost:9009"),
+		)
+	}
+}
+
+loki.write "loki" {
+	endpoint {
+		url = format(
+			"http://%s/loki/api/v1/push",
+			coalesce(env("LOKI_HOST"), "localhost:3100"),
+		)
+	}
+}
+
+otelcol.exporter.otlp "tempo" {
+	client {
+		endpoint = coalesce(env("TEMPO_HOST"), "localhost:4317")
+
+		tls {
+			insecure = true
+		}
+	}
+}
+
+pyroscope.write "pyroscope" {
+	endpoint {
+		url = format(
+			"http://%s",
+			coalesce(env("PYROSCOPE_HOST"), "localhost:4040"),
+		)
+	}
+}

example/config/grafana/datasources/datasource.yml

@@ -0,0 +1,53 @@
+apiVersion: 1
+
+deleteDatasources:
+  - name: Mimir
+
+datasources:
+- name: Mimir
+  type: prometheus
+  access: proxy
+  orgId: 1
+  url: http://mimir:9009/prometheus
+  basicAuth: false
+  isDefault: false
+  version: 1
+  editable: true
+  jsonData:
+    # The recommended scrape interval is 60s.
+    timeInterval: '60s'
+- name: Loki
+  type: loki
+  access: proxy
+  orgId: 1
+  url: http://loki:3100
+  basicAuth: false
+  isDefault: false
+  version: 1
+  editable: true
+  jsonData:
+    derivedFields:
+      - datasourceUid: tempo
+        matcherRegex: tid=(\w+)
+        name: TraceID
+        url: $${__value.raw}
+- name: Tempo
+  type: tempo
+  access: proxy
+  orgId: 1
+  url: http://tempo:3200
+  basicAuth: false
+  isDefault: false
+  version: 1
+  editable: true
+  apiVersion: 1
+  uid: tempo
+- name: Pyroscope
+  type: grafana-pyroscope-datasource
+  access: proxy
+  orgId: 1
+  url: http://pyroscope:4040/
+  basicAuth: false
+  isDefault: false
+  version: 1
+  editable: true

example/config/grafana/grafana.ini

@@ -0,0 +1,9 @@
+[analytics]
+reporting_enabled = false
+[auth.anonymous]
+enabled = true
+org_role = Admin
+[explore]
+enabled = true
+[users]
+default_theme = dark

example/config/mimir/mimir.yaml

@@ -0,0 +1,63 @@
+# Do not use this configuration in production.
+# It is for demonstration purposes only.
+multitenancy_enabled: false
+
+activity_tracker: {}
+
+alertmanager: {}
+
+alertmanager_storage:
+  backend: local
+
+server:
+  http_listen_port: 9009
+
+  # Configure the server to allow messages up to 100MB.
+  grpc_server_max_recv_msg_size: 104857600
+  grpc_server_max_send_msg_size: 104857600
+  grpc_server_max_concurrent_streams: 1000
+
+distributor:
+  pool:
+    health_check_ingesters: true
+
+ingester_client:
+  grpc_client_config:
+    grpc_compression: gzip
+    max_recv_msg_size: 104857600
+    max_send_msg_size: 104857600
+
+ingester:
+  ring:
+    final_sleep: 0s
+    kvstore:
+      store: inmemory
+    min_ready_duration: 0s
+    num_tokens: 512
+    replication_factor: 1
+
+blocks_storage:
+  backend: filesystem
+  bucket_store:
+    sync_dir: /tmp/mimir/tsdb-sync
+  filesystem:
+    dir: /tmp/mimir/blocks
+  tsdb:
+    dir: /tmp/mimir/tsdb
+
+compactor:
+  sharding_ring:
+    kvstore:
+      store: inmemory
+
+ruler:
+  enable_api: true
+
+ruler_storage:
+  backend: filesystem
+  local:
+    directory: /tmp/mimir/rules
+
+limits:
+  ingestion_burst_size: 500000
+  ingestion_rate: 250000

example/databases.yaml

@@ -0,0 +1,35 @@
+services:
+  mimir:
+    image: grafana/mimir:2.12.0
+    restart: on-failure
+    command:
+      - -config.file=/etc/mimir-config/mimir.yaml
+    volumes:
+      - ./config/mimir:/etc/mimir-config
+    ports:
+      - "9009:9009"
+
+  loki:
+    image: grafana/loki:3.0.0
+    restart: on-failure
+    ports:
+      - "3100:3100"
+
+  tempo:
+    image: grafana/tempo:2.4.1
+    restart: on-failure
+    command:
+      - "-storage.trace.backend=local"                  # tell tempo where to permanently put traces
+      - "-storage.trace.local.path=/tmp/tempo/traces"
+      - "-storage.trace.wal.path=/tmp/tempo/wal"        # tell tempo where to store the wal
+      - "-auth.enabled=false"                           # disables the requirement for the X-Scope-OrgID header
+      - "-server.http-listen-port=3200"
+    ports:
+      - "3200:3200"
+      - "4317:4317"
+
+  pyroscope:
+    image: grafana/pyroscope:1.5.0
+    restart: on-failure
+    ports:
+      - "4040:4040"

example/grafana.yaml

@@ -0,0 +1,47 @@
+services:
+  grafana:
+    image: grafana/grafana:10.1.9
+    restart: on-failure
+    command:
+      - --config=/etc/grafana-config/grafana.ini
+    volumes:
+      - ./config/grafana:/etc/grafana-config
+      - ./config/grafana/datasources:/etc/grafana/provisioning/datasources
+    ports:
+      - "3000:3000"
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://localhost:3000/healthz"]
+      interval: 1s
+      start_interval: 0s
+      timeout: 10s
+      retries: 5
+
+  # Provision alloy-mixin after Grafana is healthy and running.
+  provision-dashboards:
+    build: images/grizzly
+    restart: on-failure
+    depends_on:
+      grafana:
+        condition: service_healthy
+    environment:
+      - GRAFANA_URL=http://grafana:3000
+    volumes:
+      - ../operations/alloy-mixin:/etc/alloy-mixin
+    working_dir: /etc/alloy-mixin
+    command: grr apply grizzly/dashboards.jsonnet
+
+  # Watch dashboards for changes and apply them to Grafana.
+  watch-dashboards:
+    build: images/grizzly
+    restart: on-failure
+    depends_on:
+      grafana:
+        condition: service_healthy
+    environment:
+      - GRAFANA_URL=http://grafana:3000
+    volumes:
+      - ../operations/alloy-mixin:/etc/alloy-mixin
+    working_dir: /etc/alloy-mixin
+    command: grr watch dashboards/ grizzly/dashboards.jsonnet
+
+

example/images/grizzly/Dockerfile

@@ -0,0 +1,2 @@
+FROM golang:1.22-alpine
+RUN go install github.com/grafana/grizzly/cmd/[email protected]