A solution for Account Balance based on a Event-Driven architecture with DDD and CQRS. The full solution contains three applications.
- A Web API which receives Commands to produces Domain Events also receives Queries to return JSON.
- A Consumer App that reads the Event Stream and do a projection to a MongoDB database.
- A Web API for authentication and JWT generation.
My Account Balance API Source Code on GitHub
Requirements
Environment setup
If you already have valid connections strings for Kafka and MongoDB you could skip this topic and go to the Running the applications topic.
- Run the
./up-kafka-mongodb.sh
script to run Kafka and MongoDB as Docker Containers. Please wait until the ~800mb download to be complete.
$ ./up-kafka-mongodb.sh
Pulling mongodb (mongo:latest)...
latest: Pulling from library/mongo
Digest: sha256:2c55bcc870c269771aeade05fc3dd3657800540e0a48755876a1dc70db1e76d9
Status: Downloaded newer image for mongo:latest
Pulling kafka (spotify/kafka:latest)...
latest: Pulling from spotify/kafka
Digest: sha256:cf8f8f760b48a07fb99df24fab8201ec8b647634751e842b67103a25a388981b
Status: Downloaded newer image for spotify/kafka:latest
Creating setup_mongodb_1 ...
Creating setup_kafka_1 ...
Creating setup_mongodb_1
Creating setup_mongodb_1 ... done
- Check if the data layer is ready with the following commands:
$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
mongo latest d22888af0ce0 17 hours ago 361MB
spotify/kafka latest a9e0a5b8b15e 11 months ago 443MB
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
32452776153f spotify/kafka "supervisord -n" 2 days ago Up 2 days 0.0.0.0:2181->2181/tcp, 0.0.0.0:9092->9092/tcp setup_kafka_1
ba28cf144478 mongo "docker-entrypoint..." 2 days ago Up 2 days 0.0.0.0:27017->27017/tcp setup_mongodb_1
If Kafka is running good it will be working with the 10.0.75.1:9092
connection string and if MongoDB is running good it will be working at mongodb://10.0.75.1:27017
.
Running the applications
You have two options to run the three applications, one is by opening on Visual Studio 2017 and another is by dotnet core commands.
Option 1 - Running with Visual Studio 2017
Open the three solutions with three Visual Studio 2017 them run the following projects.
BearerAuthAPI.Infrastructure
MyAccountAPI.Consumer.Infrastructure
MyAccountAPI.Producer.Infrastructure
.
Option 2 - Running with dotnet commands
How to run the Bearer Authencation API
- Run the command
dotnet run
atsource\BearerAuthAPI\BearerAuthAPI.Infrastructure
folder.
$ dotnet run
Using launch settings from D:\git\myaccountbalanceapi\source\BearerAuthAPI\BearerAuthAPI.Infrastructure\Properties\launchSettings.json...
Hosting environment: Development
Content root path: D:\git\myaccountbalanceapi\source\BearerAuthAPI\BearerAuthAPI.Infrastructure
Now listening on: http://localhost:15878
Application started. Press Ctrl+C to shut down.
- Navigate to Swagger UI at (eg. http://localhost:15878/swagger).
- Post the following credentials:
{
"username": "ivanpaulovich",
"password": "mysecret"
}
- Store the Bearer Token because you will need the token value later to log on Producer API.
{
"token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJqdGkiOiJhYzA4MmE3OS1lMWY3LTQ4MTktYmU1Mi1hOTQwMTBkM2VjZTciLCJzdWIiOiJzdHJpbmciLCJleHAiOjE1MTI0Nzg5ODgsImlzcyI6Imh0dHA6Ly9teWFjY291bnRhcGkiLCJhdWQiOiJodHRwOi8vbXlhY2NvdW50YXBpIn0.9YKGmKaptLBDcExHhPOQ3_j9TsdbkcRf8ZtvIkdq8Go",
"expiration": "2017-12-05T13:03:08Z"
}
How to run the Consumer API
- At
source\MyAccountBalanceAPI\MyAccountAPI.Consumer.Infrastructure
folder, update the appsettings.json with the appropriate connections strings or leave with the default values:
{
"MongoDB": {
"ConnectionString": "mongodb://10.0.75.1:27017",
"Database": "MyAccountAPIv05"
},
"ServiceBus": {
"ConnectionString": "10.0.75.1:9092",
"Topic": "MyAccountAPIv05"
}
}
- Run the command
dotnet run
atsource\MyAccountBalanceAPI\MyAccountAPI.Consumer.Infrastructure
folder
$ dotnet run
11/5/2017 11:17:20 AM Waiting for events..
11/5/2017 11:18:20 AM Waiting for events..
11/5/2017 11:19:20 AM Waiting for events..
11/5/2017 11:20:20 AM Waiting for events..
11/5/2017 11:21:20 AM Waiting for events..
11/5/2017 11:22:20 AM Waiting for events..
- Attention: keep the Console App running for events processing.
How to run the Producer API
- At
source\MyAccountBalanceAPI\MyAccountAPI.Producer.Infrastructure
folder, update the appsettings.json with the appropriate connections strings or leave with the default values:
{
"MongoDB": {
"ConnectionString": "mongodb://10.0.75.1:27017",
"Database": "MyAccountAPIv05"
},
"ServiceBus": {
"ConnectionString": "10.0.75.1:9092",
"Topic": "MyAccountAPIv05"
}
}
- Run the command
dotnet run
at thesource\MyAccountBalanceAPI\MyAccountAPI.Producer.Infrastructure
folder.
$ dotnet run
Using launch settings from D:\git\myaccountbalanceapi\source\MyAccountBalanceAPI\MyAccountAPI.Producer.Infrastructure\Properties\launchSettings.json...
Hosting environment: Development
Content root path: D:\git\myaccountbalanceapi\source\MyAccountBalanceAPI\MyAccountAPI.Producer.Infrastructure
Now listening on: http://localhost:14398
Application started. Press Ctrl+C to shut down.
- Navigate to the Swagger UI (eg. http://localhost:14398/swagger). Following a few sample requests:
POST api/Customers
{
"pin": "08724050601",
"name": "Ivan Paulovich",
"initialAmount": 1600
}
returns
{
"customerId": "f5ea8e65-d9e1-4b33-aad5-b5ca022bc183",
"ssn": "08724050601",
"name": "Ivan Paulovich",
"accountId": "f78c4764-5df2-4ad9-a6c8-210871e03313",
"currentBalance": {
"value": 1600
}
}
GET api/Customers will returns
[
{
"_id": "f5ea8e65-d9e1-4b33-aad5-b5ca022bc183",
"_version": 1,
"name": {
"Text": "Ivan Paulovich"
},
"pin": {
"Text": "08724050601"
}
}
]
GET api/Accounts will returns
[
{
"_id": "f78c4764-5df2-4ad9-a6c8-210871e03313",
"_version": 1,
"currentBalance": {
"Value": 1600
},
"transactions": null,
"customerId": "f5ea8e65-d9e1-4b33-aad5-b5ca022bc183"
}
]
PATCH /api/Accounts/Deposit
{
"customerId": "f5ea8e65-d9e1-4b33-aad5-b5ca022bc183",
"accountId": "f78c4764-5df2-4ad9-a6c8-210871e03313",
"amount": 350
}
PATCH /api/Accounts/Withdraw
{
"customerId": "f5ea8e65-d9e1-4b33-aad5-b5ca022bc183",
"accountId": "f78c4764-5df2-4ad9-a6c8-210871e03313",
"amount": 670
}