This document contains the detailed description of all generated annotations of the k8s-dogu-operator.
This section contains all annotations attached to K8s services, if needed.
The k8s-dogu-operator.cloudogu.com/ces-services annotation contains information about one or more CES services.
Each CES service defines an external service of the system that is accessible through the web server. The annotation is automatically
generated for each dogu that is marked as a webapp. It is also possible to customize the behavior of the services by
specifying a custom URL through which the service can be reached.
How do I mark my dogu as a webapp?
The requirement for your Dogu is that the Dockerfile provides at least one port. The dogu is marked as a webapp via
an environment variable. If the Dockerfile provides only one port, you have to set the
SERVICE_TAGS=webapp environment variable. If the Dockerfile contains multiple ports, it is necessary to specify the destination port of the webapp
in the environment variable. For example, we consider the exposed ports 8080,8081 and want to mark port 8081 as a
webapp. Then we need to set the environment variable SERVICE_8081_TAGS=webapp instead of SERVICE_TAGS=webapp.
Example of a simple webapp.
We consider the following setup:
Dockerfile
...
ENV SERVICE_TAGS=webapp
EXPOSE 8080
...dogu.json
...
"Name": "my-dogu-namespace/my-dogu-name"
...The Dogu operator would create a service with the following annotation "k8s-dogu-operator.cloudogu.com/ces-services":
...
k8s-dogu-operator.cloudogu.com/ces-services: '[{"name": "my-dogu-name", "port":8080, "location":"/my-dogu-name", "pass":"/my-dogu-name"}]'
...Each k8s-dogu-operator.cloudogu.com/ces-services entry contains an array of ces-service JSON objects. Each
ces-service object contains the following information:
- name: The name of the CES service. Used to identify the resulting ingress in the cluster.
- port: The destination port of the target service. In our case, the target service is the generated Dogu service.
- location: the URL where the CES service is accessible. Our CES service would be available in the browser as.
http(s)://<fqdn>/my-dogu-name. - pass: the URL to target in the destination server. The location is exposed. The pass is used when the request is redirected to the target server. Sometimes it is necessary to change the context path of a request prior to sending it to the actual endpoint, e.g., the dogus are configured to listen to localhost:\context-path instead of localhost:
Example for a webapp with additional services.
Sometimes it is necessary to customize the ces-service information or even add additional services for a dogu. The
following examples explain the necessary steps. We will consider the following setup:
Dockerfile
...
ENV SERVICE_TAGS=webapp
ENV SERVICE_8080_NAME=superapp-ui
ENV SERVICE_8080_LOCATION=superapp
ENV SERVICE_ADDITIONAL_SERVICES='[{"name": "superapp-api", "port": 8080, "location": "api", "pass": "my-dogu-name/api/v2"}]'
8080,8081 EXPOSE
...dogu.json
...
"Name": "my-dogu-namespace/my-dogu-name"
...The Dogu operator would create a service with the following annotation "k8s-dogu-operator.cloudogu.com/ces-services":
...
k8s-dogu-operator.cloudogu.com/ces-services: '[{"name": "superapp-ui", "port":8080, "location":"/superapp", "pass":"/my-dogu-name"},{"name": "superapp-api", "port":8080, "location":"/api", "pass":"/my-dogu-name/api/v2"}]'
...The environment variables in the form SERVICE_<PORT>_<PROPERTY> allow overriding the default behavior. As in our
example, the SERVICE_8080_NAME=superapp-ui causes the Dogu operator to create a CES service named superapp-ui
instead of my-dogu-name, which is the name of the dogu. Accepted properties are NAME, LOCATION, and PASS.
Besides overriding the default CES service, it is possible to add additional services. These are defined with the
environment variable SERVICE_ADDITIONAL_SERVICES. These can contain ces-service JSON objects, which are passed in the
CES-service annotation.