The first goal is to create a set of Docker containers properly packaged to run all processes related to the application.
If the application is already packaged as a Docker container by the original developers and is already available on a container registry like Docker Hub, you can use that directly and skip this step.
While there are various different ways to create a container in Docker, within SLATE we recommended using a Dockerfile. This allows a third party, such as the SLATE app curators, to easily follow and understand the contents of a Docker container. You can look at the Best practices for writing Dockerfiles for examples and guidance.
Each SLATE application should reside in a separate Git repository in the GitHub slateci group. The name of the repository should be container-appname. The directory structure should look like:
├── app
│ ├── <content>
│ ├── entrypoint.sh
├── local-test
│ ├── <content>
├── build
├── build.sh
├── run.sh
├── Dockerfile
├── LICENSE
├── README.md
└── .gitignore
app: Contains all the sources for the application. The main script should be called entrypoint.sh where appropriate.local-test: Contains the deployment for a local minikube.build: Contains build.sh to build the images and run.sh to start the app in minikube.As a base image, we recommend CentOS 7+ or Ubuntu.
Each application should include a ‘README.md’ that documents how to use the container. In particular, it should include a table with all the ways in which the container can be configured in the following format:
| Type | Description | Example | |
|---|---|---|---|
MY_PARAM | Conf param (ENV) | A parameter passed through an environment variable. | -e MY_PARAM=value |
/etc/myapp/myapp.conf | Conf file (VOLUME) | A configuration file passed through volumes. | -v ${PWD}/myapp.conf:/etc/myapp/myapp.conf |
/var/data/myapp | Data dir (VOLUME) | Persistent storage that must survive redeployment. | -v /storage/data/myapp:/var/data/myapp |
/var/cache/myapp | Cache dir (VOLUME) | Storage space that is preferable to survive between redeployment but can be deleted. | -v /tmp/cache/myapp:/var/cache/squid |
/var/scratch | Temp dir (VOLUME) | Temporary storage space that can be deleted when done. | -v /tmp/scratch:/var/scratch |
Each image should be published through a container registry of your choice:
Use the template below for single-image repositories in the chosen container registry:
slateci/appname
In the case where your repository has more than one image use the following template instead:
slateci/appname-componentname