# Database as a service repository

This repository containes all the needed elements to deploy database as a service to kubernetes

## Architecture

Redis is the chosen database technology and the final product will deploy autonomous
redis cluster. Supported deployment options are standalone Redis server and HA
(Sentinel) Redis deployment. Either deployment option won't provide data persistency.

## Subsystem structure

**docker** Contains dockerfiles to produce dbaas / testapplication container images
**charts** Contais helm charts to deploy dbaas service / testapplication
**testapplication** Contains dbaas test applications with various languages such as go, ..

## Container image creation

The images must be built at subsystem root level

To produce dbaas service image:
```
docker build --file docker/Dockerfile.redis --tag redis-standalone .
```

To produce testapplication image:
```
docker build --file docker/Dockerfile.testapp --tag dbaas-test .
```

## Deployment

### DBaaS service

Dbaas service is realized either with single container running redis database
or with HA deployment implemented by a redis sentinel solution.
Standalone dbaas database is configured to be non-persistent and
non-redundant. HA dbaas provides redundancy but it is also configured to be
non-persistent.

After dbaas service is installed, environment variables **DBAAS_SERVICE_HOST**,
**DBAAS_SERVICE_PORT** and **DBAAS_NODE_COUNT** are exposed to application
containers. In the case of HA dbaas deployment also environment variables
**DBAAS_MASTER_NAME** and **DBAAS_SERVICE_SENTINEL_PORT** are exposed to
application containers. SDL library will automatically use these environment
variables.

The service is installed via helm by using dbaas-service chart. Modify the
values accordingly before installation (repository location, image name, ..)

```
helm install ./dbaas-service
```

### SDLCLI
There is a pre-installed `sdlcli` tool in DBaaS container. With this tool user
can see statistics of database backend (Redis), check healthiness of DBaaS
database backend, list database keys and get and set values into database.
To get more information about available commands and how to use them, please
check help instructions: `sdlcli --help`.

### DBaaS test application

Test application is installed via helm by using dbaas-test chart. Modify the
values accordingly before installation (repository location, image name, ..)

```
helm install ./dbaas-test
```

## Testing

Make sure that dbaas-service and dbaas-test application are deployed:
```
>>helm ls
NAME            REVISION  UPDATED                    STATUS     CHART                   APP VERSION	NAMESPACE
angry-greyhound	1         Thu Mar 21 11:36:23 2019   DEPLOYED	dbaas-test-0.1.0	1.0             default
loitering-toad  1         Thu Mar 21 11:35:21 2019   DEPLOYED	dbaas-0.1.0             1.0             default
```

Check the deployed pods
```
>>kubectl get pods
NAME                                READY   STATUS    RESTARTS   AGE
dbaas-test-app-7695dbb9ff-qn8c2     1/1     Running   0          5s
redis-standalone-78978f4c6f-54b2s   1/1     Running   0          66s
```

Connect to the test application container:
```
kubectl exec -it dbaas-test-app-7695dbb9ff-qn8c2 -- /bin/bash
```

In test application container:
```
The environment variables for database backend should be set:

>>printenv
DBAAS_SERVICE_HOST=10.108.103.51
DBAAS_SERVICE_PORT=6379
DBAAS_NODE_COUNT=1

Go test application using preliminary go SDL-API should be able to perform reads and writes:

>>./testapp
key1:data1
key3:%!s(<nil>)
key2:data2
num1:1
num2:2
-------------
mix2:2
num1:1
num2:2
pair1:data1
array1:adata1
mix1:data1
mix3:data3
mix4:4
arr1:
key1:data1
key2:data2
pair2:data2
array2:adata2


Redis server can be pinged with redis-cli:

>>redis-cli -h $DBAAS_SERVICE_HOST -p $DBAAS_SERVICE_PORT ping
PONG
```

## License
This project is licensed under the Apache License 2.0 - see the [LICENSE.md](LICENSE.md) file for details