Once installed, create a new Repository under the test account.

For this example, the repository name should be docker-http-server

This repository will be populated with example code and as our build source in the next steps.

The next stage is to configure the Drone build. Login to Drone with the same username/password as defined within the Gogs setup.

https://[[HOST_SUBDOMAIN]]-80-[[KATACODA_HOST]].environments.katacoda.com

User: test Password: test

You should see a list of your Gogs projects. Active the project build using the Toggle.

When new changes are pushed to the repository, Drone will automatically start the build pipeline. The pipeline will be defined in the next steps.

The final part of the infrastructure is the Docker Registry.

The Docker Registry is where Images are stored and allow them to be distributed to staging/production environments.

There are many options available to run a Docker Registry, with hosted options available from cloud providers. In this example, we'll run the official open source version made available by Docker.

docker run -p 5000:5000 -d registry:2

For production, a username/password should be defined for the Registry. This is discussed at https://katacoda.com/courses/docker-production/launch-private-registry

A sample Golang HTTP server is available at https://github.com/katacoda/golang-http-server.

This project has a Dockerfile created to build the binary and a Docker Image. This is what our Drone CI/CD process will use.

Clone the project locally using git clone https://github.com/katacoda/golang-http-server && cd golang-http-server

Drone build pipelines are configured by including a .drone.yml file (cat .drone.yml). This file defines the steps required to build the artefacts.

The aim is to build a Docker Image. The existing Drone plugin manages this and will push to the registry once the image has been created.

For Docker to know which private registry is being used, it is required to be included as part of the Docker Image name. The command below will update the Drone configuration to add the path to the private registry.

sed -i 's|docker-http-server|[[HOST_SUBDOMAIN]]-5000-[[KATACODA_HOST]].environments.katacoda.com/test/docker-http-server|g' .drone.yml

Once configured, push the changes to the private Gogs instance.

git remote add gogs http://test:[email protected][[HOST_SUBDOMAIN]]-3000-[[KATACODA_HOST]].environments.katacoda.com/test/docker-http-server.git && \ git commit -am 'Updated Repo Path' && \ git push gogs master

The push will trigger the Drone build.

View the build pipeline status at https://[[HOST_SUBDOMAIN]]-80-[[KATACODA_HOST]].environments.katacoda.com/test/docker-http-server

Under the covers, Drone is running its own Docker Instance that is being used to build the Image.

Because the Dockerfile (cat Dockerfile) is building the binary, the Drone agent doesn't need to be configured with Golang or other dependencies.

Once the built has finished, the Docker Image will be pushed to the Docker Registry. The results of the Registry can be viewed at the API.

The _catalog endpoint returns all the images within the registry.

curl [[HOST_SUBDOMAIN]]-5000-[[KATACODA_HOST]].environments.katacoda.com/v2/_catalog

Querying a particular Image returns the tags (versions) available.

curl [[HOST_SUBDOMAIN]]-5000-[[KATACODA_HOST]].environments.katacoda.com/v2/test/docker-http-server/tags/list

Once the Image has been built, it can be deployed onto the required Docker Hosts.

Like when pushing the Image to the registry, to pull from the private registry the URL needs to be included.

Below will pull the latest Image tag and launch the container.

docker run -d -p 8080:80 [[HOST_SUBDOMAIN]]-5000-[[KATACODA_HOST]].environments.katacoda.com/test/docker-http-server

The results can be viewed via curl localhost:8080

Congratulations!! You have created an entire CI/CD Docker process using Open Source On-Premise projects.