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diff --git a/categories/devops.md b/categories/devops.md
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--- a/categories/devops.md
+++ b/categories/devops.md
@@ -6,12 +6,139 @@
 - Travis
 - Buildkite
 
-## Everything is code
-- Infrastructure as code
-- CI config as code
-- Dockerfile
+### Scaleable Jenkins architecture
+
+![declarative jobs](https://raw.githubusercontent.com/wahyd4/knowledge-mind-mapping/master/assets/images/declareative-config.png)
+![scaleable jenkins](https://raw.githubusercontent.com/wahyd4/knowledge-mind-mapping/master/assets/images/scaleable-jenkins.png)
+
+
+- Use external storage plugin to host artifacts
+- Store job/pipeline configurations in code repository
+- Use Docker container for each stage, which means to need to install various dependencies on agents
+- Scale up/down(On-demand) agents when needed to save costs.
+
+### A sample jenkins job configuration file
+
+From <https://github.com/GoogleCloudPlatform/continuous-deployment-on-kubernetes/blob/master/sample-app/Jenkinsfile>
+
+```
+pipeline {
+
+  environment {
+    PROJECT = "REPLACE_WITH_YOUR_PROJECT_ID"
+    APP_NAME = "gceme"
+    FE_SVC_NAME = "${APP_NAME}-frontend"
+    CLUSTER = "jenkins-cd"
+    CLUSTER_ZONE = "us-east1-d"
+    IMAGE_TAG = "gcr.io/${PROJECT}/${APP_NAME}:${env.BRANCH_NAME}.${env.BUILD_NUMBER}"
+    JENKINS_CRED = "${PROJECT}"
+  }
+
+  agent {
+    kubernetes {
+      label 'sample-app'
+      defaultContainer 'jnlp'
+      yaml """
+apiVersion: v1
+kind: Pod
+metadata:
+labels:
+  component: ci
+spec:
+  # Use service account that can deploy to all namespaces
+  serviceAccountName: cd-jenkins
+  containers:
+  - name: golang
+    image: golang:1.10
+    command:
+    - cat
+    tty: true
+  - name: gcloud
+    image: gcr.io/cloud-builders/gcloud
+    command:
+    - cat
+    tty: true
+  - name: kubectl
+    image: gcr.io/cloud-builders/kubectl
+    command:
+    - cat
+    tty: true
+"""
+}
+  }
+  stages {
+    stage('Test') {
+      steps {
+        container('golang') {
+          sh """
+            ln -s `pwd` /go/src/sample-app
+            cd /go/src/sample-app
+            go test
+          """
+        }
+      }
+    }
+    stage('Build and push image with Container Builder') {
+      steps {
+        container('gcloud') {
+          sh "PYTHONUNBUFFERED=1 gcloud builds submit -t ${IMAGE_TAG} ."
+        }
+      }
+    }
+    stage('Deploy Canary') {
+      // Canary branch
+      when { branch 'canary' }
+      steps {
+        container('kubectl') {
+          // Change deployed image in canary to the one we just built
+          sh("sed -i.bak 's#gcr.io/cloud-solutions-images/gceme:1.0.0#${IMAGE_TAG}#' ./k8s/canary/*.yaml")
+          step([$class: 'KubernetesEngineBuilder',namespace:'production', projectId: env.PROJECT, clusterName: env.CLUSTER, zone: env.CLUSTER_ZONE, manifestPattern: 'k8s/services', credentialsId: env.JENKINS_CRED, verifyDeployments: false])
+          step([$class: 'KubernetesEngineBuilder',namespace:'production', projectId: env.PROJECT, clusterName: env.CLUSTER, zone: env.CLUSTER_ZONE, manifestPattern: 'k8s/canary', credentialsId: env.JENKINS_CRED, verifyDeployments: true])
+          sh("echo http://`kubectl --namespace=production get service/${FE_SVC_NAME} -o jsonpath='{.status.loadBalancer.ingress[0].ip}'` > ${FE_SVC_NAME}")
+        }
+      }
+    }
+    stage('Deploy Production') {
+      // Production branch
+      when { branch 'master' }
+      steps{
+        container('kubectl') {
+        // Change deployed image in canary to the one we just built
+          sh("sed -i.bak 's#gcr.io/cloud-solutions-images/gceme:1.0.0#${IMAGE_TAG}#' ./k8s/production/*.yaml")
+          step([$class: 'KubernetesEngineBuilder',namespace:'production', projectId: env.PROJECT, clusterName: env.CLUSTER, zone: env.CLUSTER_ZONE, manifestPattern: 'k8s/services', credentialsId: env.JENKINS_CRED, verifyDeployments: false])
+          step([$class: 'KubernetesEngineBuilder',namespace:'production', projectId: env.PROJECT, clusterName: env.CLUSTER, zone: env.CLUSTER_ZONE, manifestPattern: 'k8s/production', credentialsId: env.JENKINS_CRED, verifyDeployments: true])
+          sh("echo http://`kubectl --namespace=production get service/${FE_SVC_NAME} -o jsonpath='{.status.loadBalancer.ingress[0].ip}'` > ${FE_SVC_NAME}")
+        }
+      }
+    }
+    stage('Deploy Dev') {
+      // Developer Branches
+      when {
+        not { branch 'master' }
+        not { branch 'canary' }
+      }
+      steps {
+        container('kubectl') {
+          // Create namespace if it doesn't exist
+          sh("kubectl get ns ${env.BRANCH_NAME} || kubectl create ns ${env.BRANCH_NAME}")
+          // Don't use public load balancing for development branches
+          sh("sed -i.bak 's#LoadBalancer#ClusterIP#' ./k8s/services/frontend.yaml")
+          sh("sed -i.bak 's#gcr.io/cloud-solutions-images/gceme:1.0.0#${IMAGE_TAG}#' ./k8s/dev/*.yaml")
+          step([$class: 'KubernetesEngineBuilder',namespace: "${env.BRANCH_NAME}", projectId: env.PROJECT, clusterName: env.CLUSTER, zone: env.CLUSTER_ZONE, manifestPattern: 'k8s/services', credentialsId: env.JENKINS_CRED, verifyDeployments: false])
+          step([$class: 'KubernetesEngineBuilder',namespace: "${env.BRANCH_NAME}", projectId: env.PROJECT, clusterName: env.CLUSTER, zone: env.CLUSTER_ZONE, manifestPattern: 'k8s/dev', credentialsId: env.JENKINS_CRED, verifyDeployments: true])
+          echo 'To access your environment run `kubectl proxy`'
+          echo "Then access your service via http://localhost:8001/api/v1/proxy/namespaces/${env.BRANCH_NAME}/services/${FE_SVC_NAME}:80/"
+        }
+      }
+    }
+  }
+}
+```
 
 ## CD
+
+### Tools Comparision
+
 ![OSI Models](https://raw.githubusercontent.com/wahyd4/knowledge-mind-mapping/master/assets/images/iac.png)
 
 ### An example CI/CD flow
@@ -28,6 +155,20 @@ F --Manual/Auto trigger--> G[Update manifest]
 G --> H((Deploy to Next env))
 ```
 
+### Spinnaker
+
+Spinnaker is an open-source, multi-cloud continuous delivery platform that helps you release software changes with high velocity and confidence. Spinnaker provides two core sets of features:
+
+	application management
+
+	application deployment
+
+## Everything is code
+
+- Infrastructure as code
+- CI config as code
+- Dockerfile
+
 ## Automation tools
 
 ### Capistrano