FastAPI OpenTelemetry Project

Summary

This project demonstrates how to effectively integrate FastAPI with OpenTelemetry to achieve enhanced observability. By combining FastAPI with OpenTelemetry and Grafana, you gain several advantages:

Simplified Instrumentation: The project includes minimal customized instrumentation with OpenTelemetry, showcasing how easy it is to get started.
Flexibility: The setup allows for flexible and extensible monitoring infrastructure management, enabling easy adjustments and scalability.
Enhanced Observability: Leverage distributed tracing and monitoring to gain deep insights into your application's performance and behavior.
Near Real-time Visualization: Use Grafana dashboards to visualize metrics and traces in real-time, providing quick feedback and alerting capabilities.

Prerequisites
Infrastructure Setup
Seceret management
oTelCol deployment
Service Deployment
Monitoring and Tracing
To do

Prerequisites

Before you begin, ensure you have the following installed:

Infrastructure Setup

Authenticate with GCP:

gcloud auth login
gcloud auth application-default login

Set Environment Variables:

Export the necessary environment variables for Terraform:

export TF_VAR_gcp_credentials_json="path/to/your/credentials.json"
export TF_VAR_project_id="your-gcp-project-id"
export TF_VAR_region="your-gcp-region"

Initialize Terraform:

terraform init -backend-config="gke-infra/terraform/backend_configs/staging-backend-config.hcl"

Create Infrastructure:
```
terraform apply -var-file="gke-infra/terraform/envs/staging.tfvars"
```
This will create the necessary GKE cluster, deploy the OpenTelemetry Collector and the Grafana instance.

Secret Management

Before deploying the FastAPI service, create the necessary secrets to pass them as variables to the service.

Create Secrets (example using kubectl):
In this repo, all the gke resources are build namespace otel-col. You could use your own namespace, such as monitoring-demo.

kubectl create secret generic otel-endpoint --from-literal=OTEL_EXPORTER_OTLP_ENDPOINT=<your otel-collector endpoind>
--namespace=otel-col

kubectl create secret generic grafana-auth --from-literal=username="<your-grafana-cloud-instant-name>" --from-literal=password="<your grafana access token>" -n <your-name-space>

note: the otel-col endpoint is ..svc.cluster.local

Deploy otel-collector daemonset

```
helm repo add open-telemetry https://open-telemetry.github.io/opentelemetry-helm-charts
helm install otel-collector open-telemetry/opentelemetry-collector -f values.yaml
```
Verify if the pods are created.
```
./check_pod_all_logs.sh 
```

Service Deployment

Build and Push Docker Image:

docker build --platform linux/amd64 -t fastapi-otel:v2.0 .
docker tag fastapi-otel:v2.0 <your-artifact-registry-rep>/<your-service-name:version>
docker push <your-artifact-registry-rep>/<your-service-name:version>

Deploy to GKE Cluster: Update the deployment.yaml file to include the correct image path from Google Artifactory.
```
cd gke-infra/deploy/fast_api
kubectl apply -f deployment.yaml
```
deploy debug pod with traffic simulation script
```
kubectl apply -f alpine-pod.yaml
kubectl apply -f traffic-simulation-configmap.yaml
```
login to the pod
```
kubectl exec -it apline-curl -n otel-col -- sh
cd script
traffic_simulation.sh
```
You should see some 200 and 422 responses from service. To check details you could check the log of the service pod. The metics which we custimised with open-telemetry export also to pod log, for debuging purpose.
```
kubectl logs -f <name-of-fast-api-service-pod>  -n otel-col
```

Monitoring and Tracing

The FastAPI service is instrumented with OpenTelemetry, allowing for distributed tracing and monitoring.

Configure OpenTelemetry Collector:

See gke-infra/deploy/otel-collector/values.yaml
Access Metrics in Grafana cloud:

Assume you have already Grafana Cloud set up. Stack created, credential set up, enabled OpenTelemetry Connection Reference documentation: https://grafana.com/docs/grafana-cloud/send-data/otlp/send-data-otlp/
Configure Grafana Datasource:
- There will be datasource automatically available based on the connection set in pervious step.
- For metrics, go to default datasource connection, details see below image.
Create Dashboards: You can now create custom dashboards in Grafana to visualize the metrics collected by OpenTelemetry.

To do

Set up alert via Grafana API.
Customised more instrumentation for fastapi as well as for possible backends, such as postgress, redis, rocksdb.
Migrate all GCP deployment to terraform.