Files
openstapps/examples/minimal-deployment

Minimal deployment

This is an example for how a deployment for StApps can look like. The project also shows why we decided to use Docker for the deployment on all universities. With help of Docker's virtualization you don't have to install and configure anything beyond docker and docker compose itself.

A complete StApps deployment consists of following projects:

|*****|        |*******|        |*********|        |**********|
| app | <----> | proxy | <----> | backend | <----> | database |
|*****|        |*******|        |*********|        |**********|
                                     ^
                                     |
                               |************|
                               | connectors |
                               |************|

This project shows a very fast way to deploy backend, database and api (to copy some data from an existing deployment of the TU Berlin).

With a running backend and database you should be able to run the app with your deployment.

Step by step to your own deployment

At first you need to install docker and docker-compose. Then clone or download this repository. To download the docker images from GitLab you have to be authenticated against GitLabs container registry. Please execute docker login registry.gitlab.com. The requested credentials are the same as for GitLab. docker login stores the credentials the users home directory. If you plan to execute docker commands only from root or via sudo you should run docker login with root or sudo as well.

On Linux machines you should be able to proceed on Execution on Linux otherwise follow me step by step.

Be sure to execute all the following commands in the repository and with root privileges or access to the Docker daemon.

Start the database

Our current database is Elasticsearch and most configuration is contained in the Docker image. Since Docker is not a full virtualization it uses the hosts kernel. That's why on some systems you may need to increase your virtual memory to get Elasticsearch to work. (documentation for increasing your virtual memory)

To start the database

# let the elasticsearch user and group be the owner of the folder
chown 100:101 database

# start the database container
docker-compose up -d database

# have a look at the logs of the database
docker-compose logs database

As stated in the docker-compose.yml the database will expose port 9200 to other services in the same deployment (all services in the file).

Start the backend

The backend is providing an interface to search and bulk index data into the database. Simply run:

# start the backend container
docker-compose up -d backend

# have a look at the logs of the backend
docker-compose logs backend

The backend will find the database on http://database:9200 inside the deployment network. As stated in the docker-compose.yml the backend will expose port 3000 on the host. You should be able to request the backend for it's configuration on http://localhost:3000 (or http://MY-IP-ADDRESS:3000).

Now you have a running backend that can be queried by the app. You could already try to the install the app and use it with your local deployment. That is pretty boring, because the backend doesn't provide any data by now.

There is no public deployment for the app version 2.0.0 by now. But you could copy some data from there.

To import some SCPlace's you could run:

docker-compose run --rm api copy --appVersion 2.0.0 place <url-of-public-deployment> http://backend:3000 20

This will copy data using the api from the deployment of the TU Berlin to your deployment.

Execution on Linux

On Linux you can execute a simple shell script that will run you through steps above and copy some data in your deployment:

sh start.sh

Where to go from here

Writing your own connector

You now have your own deployment and can import some data from your university into the backend. To write your own program to import data you should checkout the minimal-connector This is a small program that shows the usage of the api and imports some example data from TypeScript code. Feel free to fork the minimal-connector and write your own connector with it.

Add your connector

You may want to integrate your connectors in the docker-compose.yml to deploy your whole StApps-backend-environment in a single command. Use the systemd directory in this project as an example of how to deploy your connector(s) and configure systemd services and timers.

The service will try to restart a named container. That means for successful execution the container needs to be started once before with the appropriate command.

docker-compose up minimal-connector

To enable the service that runs the connector periodically execute:

systemctl --now enable /absolute/path/minimal-deployment/minimal-connector/minimal-connector.service /absolute/path/minimal-deployment/minimal-connector/minimal-connector.timer

This command will immediately start the service on execution.

Round off your deployment with the proxy

The backend is exposed on the port 3000 now. This means anyone can import data into your backend and you can only run one version of the backend at a time. Have a look at the proxy to secure and round off your deployment. The proxy will add a layer of security, allowing you to run multiple deployments for different app version on one server and provide some static data like images for your university.

Explore docker capabilities

Docker is a great tool with many great features. Have a look at the docker cli documentation or our docker cheat sheet to learn more about it.