#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
apiVersion: v1
kind: ConfigMap
metadata:
  name: zeppelin-server-conf
data:
  # 'serviceDomain' is a Domain name to use for accessing Zeppelin UI.
  # Should point IP address of 'zeppelin-server' service.
  #
  # Wildcard subdomain need to be point the same IP address to access service inside of Pod (such as SparkUI).
  # i.e. if service domain is 'local.zeppelin-project.org', DNS configuration should make 'local.zeppelin-project.org' and '*.local.zeppelin-project.org' point the same address.
  #
  # Default value is 'local.zeppelin-project.org' while it points 127.0.0.1 and `kubectl port-forward zeppelin-server` will give localhost to connects.
  # If you have your ingress controller configured to connect to `zeppelin-server` service and have a domain name for it (with wildcard subdomain point the same address), you can replace serviceDomain field with your own domain.
  serviceDomain: local.zeppelin-project.org:8080
  sparkContainerImage: spark:2.4.0
  nginx.conf: |
    daemon off;
    worker_processes auto;
    events {
      worker_connections 1024;
    }
    http {
      map $http_upgrade $connection_upgrade {
        default upgrade;
        '' close;
      }

      # first server block will be default. Proxy zeppelin server.
      server {
        listen 80;
        location / {
          proxy_pass http://localhost:8080;
          proxy_set_header Host $host;
          proxy_http_version 1.1;
          proxy_set_header Upgrade $http_upgrade;
          proxy_set_header Connection $connection_upgrade;
          proxy_redirect http://localhost $scheme://SERVICE_DOMAIN;
        }
      }

      # match request domain [port]-[service].[serviceDomain]
      # proxy extra service such as spark-ui
      server {
        listen 80;
        server_name "~(?<svc_port>[0-9]+)-(?<svc_name>[^.]*)\.(.*)";
        location / {
          resolver 127.0.0.1:53 ipv6=off;
          proxy_pass http://$svc_name.NAMESPACE.svc:$svc_port;
          proxy_set_header Host $host;
          proxy_http_version 1.1;
          proxy_set_header Upgrade $http_upgrade;
          proxy_set_header Connection $connection_upgrade;
          proxy_redirect http://localhost $scheme://SERVICE_DOMAIN;

          # redirect rule for spark ui. 302 redirect response misses port number of service domain
          proxy_redirect ~(http:[/]+[0-9]+[-][^-]+[-][^.]+)[^/]+(\/jobs.*) $1.SERVICE_DOMAIN$2;
        }
      }
    }
---
kind: Pod
apiVersion: v1
metadata:
  name: zeppelin-server
  labels:
    app: zeppelin-server
spec:
  automountServiceAccountToken: true
  containers:
  - name: zeppelin-server
    image: apache/zeppelin:0.9.0-SNAPSHOT
    command: ["sh", "-c", "$(ZEPPELIN_HOME)/bin/zeppelin.sh"]
    lifecycle:
      preStop:
        exec:
          # SIGTERM triggers a quick exit; gracefully terminate instead
          command: ["sh", "-c", "ps -ef | grep org.apache.zeppelin.server.ZeppelinServer | grep -v grep | awk '{print $2}' | xargs kill"]
    env:
    - name: ZEPPELIN_K8S_CONTAINER_IMAGE
      value: apache/zeppelin:0.9.0-SNAPSHOT
    - name: ZEPPELIN_HOME
      value: /zeppelin
    - name: ZEPPELIN_SERVER_RPC_PORTRANGE
      value: 12320:12320
    - name: POD_UID
      valueFrom:
        fieldRef:
          apiVersion: v1
          fieldPath: metadata.uid
    - name: POD_NAME
      valueFrom:
        fieldRef:
          apiVersion: v1
          fieldPath: metadata.name
    - name: ZEPPELIN_K8S_SPARK_CONTAINER_IMAGE
      valueFrom:
        configMapKeyRef:
          name: zeppelin-server-conf
          key: sparkContainerImage
    - name: SERVICE_DOMAIN
      valueFrom:
        configMapKeyRef:
          name: zeppelin-server-conf
          key: serviceDomain
    - name: MASTER   # default value of master property for spark interpreter.
      value: k8s://https://kubernetes.default.svc
    # volumeMounts:
    #  - name: zeppelin-server-notebook-volume     # configure this to persist notebook
    #    mountPath: /zeppelin/notebook
    #  - name: zeppelin-server-conf                # configure this to persist Zeppelin configuration
    #    mountPath: /zeppelin/conf
    #  - name: zeppelin-server-custom-k8s          # configure this to mount customized Kubernetes spec for interpreter
    #    mountPath: /zeppelin/k8s
  - name: zeppelin-server-gateway
    image: nginx:1.14.0
    command: ["/bin/sh", "-c"]
    args:
      - cp -f /tmp/conf/nginx.conf /etc/nginx/nginx.conf;
        sed -i -e "s/SERVICE_DOMAIN/$(cat /tmp/conf/serviceDomain)/g" /etc/nginx/nginx.conf;
        sed -i -e "s/NAMESPACE/$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace)/g" /etc/nginx/nginx.conf;
        cat /etc/nginx/nginx.conf;
        /usr/sbin/nginx
    volumeMounts:
      - name: zeppelin-server-conf-volume
        mountPath: /tmp/conf
    lifecycle:
      preStop:
        exec:
          # SIGTERM triggers a quick exit; gracefully terminate instead
          command: ["/usr/sbin/nginx", "-s", "quit"]
  - name: dnsmasq  # nginx requires dns resolver for dynamic dns resolution
    image: "janeczku/go-dnsmasq:release-1.0.5"
    args:
      - --listen
      - "127.0.0.1:53"
      - --default-resolver
      - --append-search-domains
      - --hostsfile=/etc/hosts
      - --verbose
  volumes:
  - name: zeppelin-server-conf-volume
    configMap:
      name: zeppelin-server-conf
      items:
      - key: nginx.conf
        path: nginx.conf
      - key: serviceDomain
        path: serviceDomain
---
kind: Service
apiVersion: v1
metadata:
  name: zeppelin-server    # keep Service name the same to Pod name.
spec:
  ports:
    - name: http
      port: 80
    - name: rpc            # port name is referenced in the code. So it shouldn't be changed.
      port: 12320
  selector:
    app: zeppelin-server
---
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: zeppelin-server-role
rules:
- apiGroups: [""]
  resources: ["pods", "services"]
  verbs: ["create", "get", "update", "patch", "list", "delete", "watch"]
- apiGroups: ["rbac.authorization.k8s.io"]
  resources: ["roles", "rolebindings"]
  verbs: ["bind", "create", "get", "update", "patch", "list", "delete", "watch"]
---
kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: zeppelin-server-role-binding
subjects:
- kind: ServiceAccount
  name: default
roleRef:
  kind: Role
  name: zeppelin-server-role
  apiGroup: rbac.authorization.k8s.io