Tomcat Operator

The purpose of this repository is to showcase a proof of concept of a simple Openshift Operator to manage tomcat Images.

Building the Operator

Requirements

To build the operator, you will first need to install the following tools:

• Go with $GOPATH set to $HOME/go
• Docker
• Operator-sdk

Procedure

1. Clone the repository under your $GOPATH

$ git clone https://github.com/web-servers/tomcat-operator.git $GOPATH/src/github.com/tomcat-operator

2. Change to the source directory

$ cd $GOPATH/src/github.com/tomcat-operator

3. Compile and build the Tomcat Operator

$ make build

4. Push it to docker (docker.io/${USER}/tomcat-operator:version)

$ make push

Deploy to an Openshift Cluster

1. Login to your Openshift Server using oc login and use it to create a new project

$ oc new-project tomcat-operator

2. Now deploy the operator

$ make run-openshift

Deploy your Web Application

Once the Tomcat Operator has been deployed, you can now deploy your own webapps via the operator custom resources.

From Sources using Source-To-Image (s2i)

1. Build your Web Application using Source-To-Image and git it a name prefixed with your container registry access user

$ s2i build [GIT_URL] ${USER}/tomcat-s2i docker.io/${USER}/tomcat-app

2. Push the image

$ docker push docker.io/${USER}/tomcat-app

3. Configure your Custom Resource

apiVersion: tomcat.apache.org/v1alpha1
kind: Tomcat
metadata:
  name: example-tomcat
spec:
  applicationName: tomcat-app
  applicationImage: docker.io/${USER}/tomcat-app
  size: 3

4. Deploy the Custom Resource

$ oc apply -f path/to/your/custom_resource.yaml

5. Finally, to access the newly deployed application, simply create a route using the Openshift UI

From a WAR

If you would like to deploy an existing WAR, you will have to build your container image using the tomcat-maven module of Tomcat:

1. Build the maven fat jar for tomcat

$ git clone https://github.com/apache/tomcat
$ cd tomcat
$ ant
$ CATALINA_HOME=`pwd`
$ cd $CATALINA_HOME/res/tomcat-maven
$ mvn install

2. Copy your WAR file into the $CATALINA_HOME/res/tomcat-maven/webapps directory

$ mkdir -p $CATALINA_HOME/res/tomcat-maven/webapps
$ cd $CATALINA_HOME/res/tomcat-maven/webapps
$ cp path/to/war .

3. Copy your configuration files to the $CATALINA_HOME/res/tomcat-maven directory

$ mkdir -p $CATALINA_HOME/res/tomcat-maven/conf
$ mkdir -p $CATALINA_HOME/res/tomcat-maven/conf/Catalina
$ chmod g+w $CATALINA_HOME/res/tomcat-maven/conf/Catalina
$ cd $CATALINA_HOME/res/tomcat-maven
$ cp $CATALINA_HOME/output/build/conf/server.xml conf
$ cp $CATALINA_HOME/output/build/conf/logging.properties conf
$ cp $CATALINA_HOME/output/build/conf/tomcat-users.xml conf

4. Build the container image using a tag to access your docker registry and push it

$ docker build . -t <registry>/<username>/tomcat-demo
$ docker push <registry>/<username>/tomcat-demo

Make sure that your registry is accessible by your Openshift Cluster.

5. Configure your Custom Resource

apiVersion: tomcat.apache.org/v1alpha1
kind: Tomcat
metadata:
  name: example-tomcat
spec:
  applicationName: tomcat-app
  applicationImage: <registry>/<username>/tomcat-demo
  size: 3

6. Deploy the Custom Resource

$ oc apply -f path/to/your/custom_resource.yaml

7. Create a route using the Openshift UI to access your application.