[ WARNING ] This is a small project that I've created to try some libraries and frameworks for study purposes, don't use it in production without review and configure everything properly.

Why chainsaw? Nothing special, was a github suggestion. =)

Here you'll find:

• Spring-boot application with spring-cloud-config-client, actuator, google jib (docker img creator), oauth2 client.
• Quarkus application (need improvements)
• Spring cloud config server.
• Helm chart for the applications
• Keycloak installed with helm charts

What I'm planning to add

• Add Prometheus for monitoring
• GraphQL as Backend For Frontend (BFF)
• ArchUnit to keep architecture consistent
• Migrate to Helm 3
• Support for openshift
• Keycloak cluster
• Upgrade to OpenJDK 11

Follow the recipe and should work, otherwise drop an issue:

• openJDK 8

• Maven

• VirtualBox

• Minikube / Kind

  motivation: basic kubernetes env. to run applications locally

  Minikube installation: https://kubernetes.io/docs/tasks/tools/install-minikube/

  Kind installation: https://kind.sigs.k8s.io/docs/user/quick-start/

  ** Additional steps for Minikube:

  # start a new kubernetes cluster with minikube
  minikube start --cpus 2 --memory 8192
  
  # first steps
  kubectl config use minikube
  
  # config to use internal docker environment
  eval $(minikube docker-env)
  

• Helm charts V3+:

  motivation: easy to deploy containers and stateful services into kubernetes and also have a good catalog of ready-to-use charts and configurations.

  installation: https://helm.sh/docs/intro/install/

• Keycloak operator

  motivation: provides a great management interface, openID support and it has a great development and support community

  1. Install Operator Lifecycle Manager (OLM), a tool to help manage the Operators running on your cluster.

     $ curl -sL https://github.com/operator-framework/operator-lifecycle-manager/releases/download/0.14.1/install.sh | bash -s 0.13.0

  2. Install the operator by running the following command:What happens when I execute this command?

     $ kubectl create -f https://operatorhub.io/install/keycloak-operator.yaml

  3. This Operator will be installed in the "my-keycloak-operator" namespace and will be usable from this namespace only.

  After install, watch your operator come up using next command.

  $ kubectl get csv -n my-keycloak-operator

  4. Create a Keycloak instance:

  ** You can download and customize the keycloak.yaml as you need.

  kubectl apply -f https://raw.githubusercontent.com/keycloak/keycloak-operator/master/deploy/examples/keycloak/keycloak.yaml

  To use it, checkout the custom resource definitions (CRDs) introduced by this operator to start using it.

  IMPORTANT:

  There's some step to configure on keycloak:

  1. From the "Realm Setting" > "Keys" click on the public key button and copy the public key to be used on the chainsaw-config-server as is configured on this Github repo: https://github.com/brunojensen/chainsaw-kube-config
  2. Create a new client called "bank-platform" with "Client Protocol"="openid connect".

  Optionally, we could also install keycloak-gatekeeper to work as a side-car to app pod and provide authentication out-of-shelf

• Service discovery comes off-the-shelf with kubernetes

  motivation: kubernetes provides a way to identify services and balance the request between the multiple instances of the application.

• Monitoring with spring actuator and kubernetes liveness/readness probe

  motivation: as a quick solution to monitor the health of the application and configure the environment to restore in case of failure

• Spring-boot Services

  motivation: spring-boot provides an easy-to-go template generation for microservices. One good alternative was to use the quarkus project, but I didn't want to go that far and the requirements of this code challenge is to use spring. But to create the docker image I decide to use a google container tool called jib.

  # pre-defined bash script to run maven and helm to package and install the application on the local environment
  chmod +x app.sh && ./app.sh install
  

• Postgres operator

  how to install via helm

  helm install postgres-operator ./charts/postgres-operator

  how to create a postgres instance

  kubectl create -f k8s-config/postgres-manifest/minimal-postgres-manifest.yaml

  Obs.: change to the service type to NodePort

  how to get host/port/user/password

  export HOST_PORT=$(minikube service acid-minimal-cluster --url | sed 's,.*/,,')
  export PGHOST=$(echo $HOST_PORT | cut -d: -f 1)
  export PGPORT=$(echo $HOST_PORT | cut -d: -f 2)
  export PGPASSWORD=$(kubectl get secret postgres.acid-minimal-cluster.credentials -o 'jsonpath={.data.password}' | base64 -d)'
  

• Application evaluation

  # requires "jq" -> https://stedolan.github.io/jq/download/
  # use this script to run tests on the APIs.
  ./app.sh
  

• kubectl tips:

  https://kubernetes.io/docs/reference/kubectl/overview/