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bruce-mig/simple-bank

A production grade banking system in Go using gRPC, protobuf, asynq redis message broker, gin, docker and k8s

asynq backend ci-cd docker gin go golang grpc grpc-go http-server kubernetes message-queue redis

Simple bank service

The service provides APIs for the frontend to do following things:

Create and manage bank accounts, which are composed of owner’s name, balance, and currency.
Record all balance changes to each of the account. So every time some money is added to or subtracted from the account, an account entry record will be created.
Perform a money transfer between 2 accounts. This should happen within a transaction, so that either both accounts’ balance are updated successfully or none of them are.

Setup local development

Install tools

npm install -g @dbml/cli
dbml2sql --version

Sqlc
```
brew install sqlc
```

go install github.com/golang/mock/mockgen@v1.6.0

Setup infrastructure

Create the bank-network
```
make network
```
Start postgres container:
```
make postgres
```
Create simple_bank database:
```
make createdb
```
Run db migration up all versions:
```
make migrateup
```
Run db migration up 1 version:
```
make migrateup1
```
Run db migration down all versions:
```
make migratedown
```
Run db migration down 1 version:
```
make migratedown1
```

Documentation

Generate DB documentation:
```
make db_docs
```
Access the DB documentation at this address. Password: secret

How to generate code

Generate schema SQL file with DBML:
```
make db_schema
```
Generate SQL CRUD with sqlc:
```
make sqlc
```
Generate DB mock with gomock:
```
make mock
```

Create a new db migration:

make new_migration name=<migration_name>

How to run

Run server:
```
make server
```
Run test:
```
make test
```

Deploy to minikube kubernetes cluster

Start minikube:

Minikube and kubectl must be installed as prerequisites.
Then start minikube
```
minikube start
```
To view minikube dashboard, use the command minikube dashboard or use k9s with the command k9s.
Pod deployments:

Use the command kubectl apply -f <file-name>.yml
Running Postgres and Redis on the host machine:

To spin up database on local machine, run the following command
```
docker-compose -f database.yml up -d
```
To connect to database from minikube, change the host from localhost to host.minikube.internal in the deployment.yaml file.

Install nginx ingress controller:

Enable ingress add-ons

minikube addons enable ingress
minikube addons enable ingress-dns

Apply ingress

kubectl apply -f k8s/ingress-nginx.yaml
kubectl apply -f k8s/ingress-http.yaml
kubectl apply -f k8s/ingress-grpc.yaml
kubectl get ingress

Configure ingress:

Add ingress host to /etc/hosts as follows
```
sudo vi /etc/hosts
```
Append to the file
```
127.0.0.1       api.simplebank.test
127.0.0.1       gapi.simplebank.test
```
Create a minikube tunnel
```
minikube tunnel
```
The app is now available at http://api.simplebank.test in the browser.

Test ingress by running
```
nslookup simplebank.test
```

Install cert-manager:

kubectl apply -f https://github.com/jetstack/cert-manager/releases/download/v1.4.0/cert-manager.yaml

Deploy to kubernetes cluster

Install nginx ingress controller:

kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v0.48.1/deploy/static/provider/aws/deploy.yaml

Install cert-manager:

kubectl apply -f https://github.com/jetstack/cert-manager/releases/download/v1.4.0/cert-manager.yaml

Setup gRPC

Generate files

NOTE: You should add the protoc-gen-go-grpc to your PATH
```
PATH="${PATH}:${HOME}/go/bin"
```
```
make proto
```

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Contributors

Created December 6, 2023

Updated May 21, 2025

bruce-mig/simple-bank | GitHunt