Add OpenAI usage metrics

app/Cargo.toml

@@ -19,17 +19,16 @@ icalendar = { version = "0.16.13", features = [
 ] }
 moka = { version = "0.12.10", features = ["future"] }
 openai = { version = "1.1.0", default-features = false, features = ["rustls"] }
-opentelemetry = { version = "0.28.0", features = ["trace"] }
+opentelemetry = { version = "0.28.0", features = ["trace", "metrics"] }
 opentelemetry-http = "0.28.0"
 opentelemetry-otlp = { version = "0.28.0", features = [
   "grpc-tonic",
   "metrics",
   "trace",
 ] }
-opentelemetry-prometheus = "0.28.0"
 opentelemetry-semantic-conventions = "0.28.0"
 opentelemetry-stdout = "0.28.0"
-opentelemetry_sdk = { version = "0.28.0", features = ["rt-async-std", "trace"] }
+opentelemetry_sdk = { version = "0.28.0", features = ["rt-async-std", "trace", "metrics"] }
 poem = { version = "3.1.7", features = [
   "opentelemetry",
   "rustls",
@@ -72,6 +71,7 @@ tracing = { version = "0.1.40", features = ["attributes"] }
 tracing-opentelemetry = { version = "0.29.0" }
 tracing-subscriber = { version = "0.3.19", features = ["env-filter", "fmt"] }
 uuid = { version = "1.17.0", features = ["v4", "serde"] }
+once_cell = "1.19.0"
 jsonwebtoken = "9.3.0"
 urlencoding = "2.1.3"
 url = "2.5.4"

app/compose.yml

@@ -16,6 +16,54 @@ services:
       timeout: 5s
       retries: 5
 
+  # OpenTelemetry Collector - receives OTLP data from your Rust app
+  otel-collector:
+    image: otel/opentelemetry-collector-contrib:latest
+    command: ["--config=/etc/otel-collector-config.yaml"]
+    volumes:
+      - ./docker/otel-collector-config.yaml:/etc/otel-collector-config.yaml
+    ports:
+      - "4317:4317"   # OTLP gRPC receiver
+      - "4318:4318"   # OTLP HTTP receiver
+      - "8889:8889"   # Prometheus metrics endpoint
+    depends_on:
+      - prometheus
+
+  # Prometheus - stores metrics
+  prometheus:
+    image: prom/prometheus:latest
+    command:
+      - '--config.file=/etc/prometheus/prometheus.yml'
+      - '--storage.tsdb.path=/prometheus'
+      - '--web.console.libraries=/etc/prometheus/console_libraries'
+      - '--web.console.templates=/etc/prometheus/consoles'
+      - '--storage.tsdb.retention.time=200h'
+      - '--web.enable-lifecycle'
+    volumes:
+      - ./docker/prometheus.yml:/etc/prometheus/prometheus.yml
+      - prometheus-data:/prometheus
+    ports:
+      - "9090:9090"
+
+  # Grafana - visualizes metrics
+  grafana:
+    image: grafana/grafana:latest
+    environment:
+      - GF_SECURITY_ADMIN_PASSWORD=admin
+      - GF_USERS_ALLOW_SIGN_UP=false
+    volumes:
+      - grafana-data:/var/lib/grafana
+      - ./docker/grafana/dashboards:/var/lib/grafana/dashboards
+      - ./docker/grafana/provisioning:/etc/grafana/provisioning
+    ports:
+      - "3001:3000"
+    depends_on:
+      - prometheus
+
 volumes:
   pg-data:
-   driver: local
+    driver: local
+  prometheus-data:
+    driver: local
+  grafana-data:
+    driver: local

app/docker/README.md

@@ -0,0 +1,66 @@
+# OpenTelemetry Observability Stack
+
+This Docker Compose setup provides a complete observability stack for monitoring your Ethereum Forum application's OpenAI usage metrics.
+
+## Services
+
+### OpenTelemetry Collector
+- **Port**: 4317 (gRPC), 4318 (HTTP)
+- **Purpose**: Receives OTLP data from your Rust application
+- **Config**: `otel-collector-config.yaml`
+
+### Prometheus  
+- **Port**: 9090
+- **Purpose**: Stores metrics data
+- **Config**: `prometheus.yml`
+- **URL**: http://localhost:9090
+
+### Grafana
+- **Port**: 3001
+- **Purpose**: Visualizes metrics with dashboards
+- **Credentials**: admin/admin
+- **URL**: http://localhost:3001
+
+## Getting Started
+
+1. **Start the stack:**
+   ```bash
+   docker compose up -d
+   ```
+
+2. **Configure your Rust app** to send OTLP data to `localhost:4317` (gRPC) or `localhost:4318` (HTTP)
+
+3. **Access Grafana** at http://localhost:3001 (admin/admin)
+   - The "OpenAI Usage Metrics" dashboard is automatically provisioned
+   - View real-time token usage, rates, and user breakdowns
+
+4. **Access Prometheus** at http://localhost:9090 for raw metric queries
+
+## Metrics Available
+
+Your Rust application exports these OpenAI usage metrics:
+- `openai_prompt_tokens_total` - Total prompt tokens used
+- `openai_completion_tokens_total` - Total completion tokens used  
+- `openai_total_tokens_total` - Total tokens used (prompt + completion)
+
+Each metric includes a `user_id` label for per-user tracking.
+
+## Environment Variables for Rust App
+
+Make sure your Rust application is configured to send OTLP data:
+
+```bash
+OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4317
+OTEL_SERVICE_NAME=ethereum-forum
+```
+
+## Stopping the Stack
+
+```bash
+docker compose down
+```
+
+To also remove volumes:
+```bash
+docker compose down -v
+```