ledgermonolith

Ledger Monolith Service

Reads and writes transactions belonging to the bank ledger.

Implemented in Java with Spring Boot and Guava.

Endpoints

Endpoint	Type	Auth?	Description
/balances/<accountid>	GET	🔒	Get the account balance if owned by the currently authenticated user.
/healthy	GET		Liveness probe endpoint. Monitors health of background thread.
/ready	GET		Readiness probe endpoint.
/transactions	POST	🔒	Submits a transaction to be appended to the ledger.
/transactions/<accountid>	GET	🔒	Return the account transaction list if authenticated to access the account.
/version	GET		Returns the contents of $VERSION

Environment Variables

Located in init/ledgermonolith.env

• Required
  • VERSION
    • a version string for the service
  • PORT
    • the port for the webserver
  • JVM_OPTS
    • settings for the JVM. Used to obey container memory limits
  • LOCAL_ROUTING_NUM
    • the routing number for our bank
  • PUB_KEY_PATH
    • the path to the JWT signer's public key, mounted as a secret
  • POSTGRES_DB
    • URL of the service
  • POSTGRES_USER
    • username for the database
  • POSTGRES_PASSWORD
    • password for the database
  • SPRING_DATASOURCE_URL
    • URL of the database service
  • SPRING_DATASOURCE_USERNAME
    • username for the database
  • SPRING_DATASOURCE_PASSWORD
    • password for the database
  • USE_DEMO_DATA
    • Set to "True" to initialize the bank ledger with demo data
• Optional
  • POLL_MS
    • the number of milliseconds to wait in between polls to the database
    • optional. Defaults to 100
  • CACHE_SIZE
    • the max number of HTTP requests to cache
    • optional. Defaults to 1,000
  • CACHE_MINUTES
    • the expiry time for the cache in minutes
    • optional. Defaults to 60
  • HISTORY_LIMIT
    • the number of past transactions to store for each user
    • optional. Defaults to 100
  • EXTRA_LATENCY_MILLIS
    • add fake extra latency in milliseconds to transaction history requests
    • optional. Defaults to 0

Scripts

• scripts/deploy-monolith.sh: deploys service to a VM on Google Compute Engine
• scripts/teardown-monolith.sh: teardown service from Google Compute Engine
• scripts/build-artifacts.sh: pushes build artifacts to Google Cloud Storage
• scripts/delete-artifacts.sh: deletes build artifacts in Google Cloud Storage

Quickstart

To deploy Bank of Anthos with a monolith service:

# In the root directory of the project repo
export PROJECT_ID=<your-project-id>
export ZONE=<your-gcp-zone>
make cluster && \
make monolith-fw-rule && \
make monolith

Deploys the full Bank of Anthos application with a Java monolith service running on a Google Compute Engine VM and all other microservices running on Kubernetes.

Deploying the Monolith

Option 1 - From Canonical Artifacts

Deploy the canonical version of the monolith to a Google Compute Engine VM. Use canonical build artifacts hosted on Google Cloud Storage at gs://bank-of-anthos-ci/monolith.

# In the root directory of the project repo
export PROJECT_ID=<your-project-id>
export ZONE=<your-gcp-zone>
make monolith-deploy

Option 2 - With Custom-built Artifacts

Deploy a custom version of the monolith to a Google Compute Engine VM. Compile and build artifacts locally and push them to Google Cloud Storage (GCS).

Specify the GCS location with environment variable GCS_BUCKET. Artifacts will be pushed to gs://{GCS_BUCKET}/monolith.

# In the root directory of the project repo
export PROJECT_ID=<your-project-id>
export ZONE=<your-gcp-zone>
export GCS_BUCKET=<your-gcs-bucket>
make monolith-build
make monolith-deploy

Checking the Monolith

Startup Script Logs

The output of the monolith VM startup procedure is logged.

1. Go to the Google Compute Engine instances page.
2. Select View logs under the ... options button for the monolith VM: ledgermonolith-service.
3. Search for "startup-script" in the search bar of the Logs Viewer.

App Build Artifacts

Build artifacts for the monolith VM should be saved to /opt/monolith.

1. Go to the Google Compute Engine instances page.
2. Click the SSH button on the monolith VM: ledgermonolith-service.
3. Enter ls /opt/monolith in the shell prompt.

Java App Logs

Runtime logs for the java app are piped to /var/log/monolith.log.

1. Go to the Google Compute Engine instances page.
2. Click the SSH button on the monolith VM: ledgermonolith-service.
3. Enter tail -f /var/log/monolith.log in the shell prompt.

Serving HTTP Requests

The monolith service can be queried via HTTP from a client on the same Google Cloud network that also has the monolith network tag.

1. Go to the Google Compute Engine instances page.
2. Note the internal ip address of the monolith VM: ledgermonolith-service.
3. Create a VM instance on the monolith network - default - and add the network tag monolith.
4. Click the SSH button on the instance after it has successfully started.
5. Enter curl ledgermonolith-service.c.[PROJECT_ID].internal:8080/version in the shell prompt, replacing PROJECT_ID with your GCP project id.
6. If you see a version string like v#.#.#, the ledgermonolith is correctly serving HTTP requests

Running Bank of Anthos with the Monolith

To run the full Bank of Anthos application you also need to configure and deploy the microservices that are not part of the ledgermonolith service. This directory (src/ledgermonolith) includes a custom config.yaml file. The config.yaml along with the associated manifests in the kubernetes-manifests directory located in the repository's root folder will deploy the other supporting microservices (including the frontend), plus the accounts database. To deploy, run the following commands from this directory:

1. Set environment variables

CLUSTER=<your-cluster-name>
PROJECT_ID=<your-project-id>
ZONE=<your-gcp-zone>

2. Create a GKE cluster.

gcloud container clusters create ${CLUSTER} \
  --machine-type=e2-standard-4 \
  --num-nodes=4 \
  --project=${PROJECT_ID} \
  --subnetwork=default \
  --zone=${ZONE}

3. Create a firewall rule to allow the cluster to talk to the monolith.

CLUSTER_POD_CIDR=$(gcloud container clusters describe ${CLUSTER} --format="value(clusterIpv4Cidr)" --project ${PROJECT_ID} --zone=${ZONE}) && \
gcloud compute firewall-rules create monolith-gke-cluster \
  --allow TCP:8080 \
  --project=${PROJECT_ID} \
  --source-ranges ${CLUSTER_POD_CIDR} \
  --target-tags monolith

4. Replace [PROJECT_ID] with your $PROJECT_ID in src/ledgermonolith/config.yaml.

5. Get credentials for the cluster

gcloud container clusters get-credentials ${CLUSTER} \
  --project=${PROJECT_ID} \
  --zone ${ZONE}

6. Run the following commands from the root of this repository, to deploy your custom config alongside the other Bank of Anthos services.

kubectl apply -f src/ledgermonolith/config.yaml
kubectl apply -f extras/jwt/jwt-secret.yaml
kubectl apply -f kubernetes-manifests/accounts-db.yaml
kubectl apply -f kubernetes-manifests/userservice.yaml
kubectl apply -f kubernetes-manifests/contacts.yaml
kubectl apply -f kubernetes-manifests/frontend.yaml
kubectl apply -f kubernetes-manifests/loadgenerator.yaml