Agenda 
  • Introduction to DevSecOps 
  • Demystifying Basics of Docker & Kubernetes 
  • TerraScan - Cloud Native Security Tool

 

tools
DevSecOps
skills
Culture
Development software releases 
& updates
Operation
​Reliability 
performance 
scaling
Security
​Reliability 
performance 
scaling
DevSecOps 
  • Integrate Security Tools 
  • Create Security  as Code Culture 
  • Promote Cross

Secure Software Development lifecycle 

Docker

kubernetes 

Terrascan - Cloud Native Security Tool

Key features

https://github.com/accurics/terrascan.git

support project by giving a gitstar ! 

Demo :-

 K8s Creating Pod - Declarative Way (With Yaml File)

apiVersion: v1      
kind: Pod                         # type of K8s object: Pod
metadata:
  name: firstpod                  # name of pod
  labels:
    app: frontend                 # label pod with "app:frontend"   
spec:
  containers: 
  - name: nginx                   
    image: nginx:latest           # image name:image version, nginx downloads from DockerHub
    ports:
    - containerPort: 80           # open ports in the container
    env:                          # environment variables
      - name: USER
        value: "username"

 K8s Creating Pod - K8s Creating Pod - Imperative Way

minikube start 

kubectl run firstpod --image=ngnix --restart=Never 
kubectl get pod -o wide 
kubectl decsribe pods firstpod
kubectl logs fisrtpod 
kubectl exec firstpod -- hostname 
kubectl exec firstpod -- ls
kubectl get pods -o wide 
kubectl delete pods fisrtpod

MultiContainer Pod , Init Container 

  • Best Practice: 1 Container runs in 1 Pod normally, because the smallest element in K8s is Pod (Pod can be scaled up/down).
  • Multicontainers run in the same Pod when containers are dependent of each other.
  • Multicontainers in one Pod have following features:
    • Multi containers that run on the same Pod run on the same Node.
    • Containers in the same Pod run/pause/deleted at the same time.
    • Containers in the same Pod communicate with each other on localhost, there is not any network isolation.
    • Containers in the same Pod use one volume commonly and they can reasch same files in the volume.

 

 

apiVersion: v1
kind: Pod
metadata:
  name: initcontainerpod
spec:
  containers:
  - name: appcontainer            # after initcontainer closed successfully, appcontainer starts.
    image: busybox
    command: ['sh', '-c', 'echo The app is running! && sleep 3600']
  initContainers:
  - name: initcontainer
    image: busybox                # init container starts firstly and look up myservice is up or not in every 2 seconds, if there is myservice available, initcontainer closes. 
    command: ['sh', '-c', "until nslookup myservice; do echo waiting for myservice; sleep 2; done"]
# save as service.yaml and run after pod creation
apiVersion: v1
kind: Service
metadata:
  name: myservice
spec:
  ports:
  - protocol: TCP
    port: 80
    targetPort: 9376
apiVersion: v1
kind: Pod
metadata:
  name: multicontainer
spec:
  containers:
  - name: webcontainer                           # container name: webcontainer
    image: nginx                                 # image from nginx
    ports:                                       # opening-port: 80
      - containerPort: 80
    volumeMounts:
    - name: sharedvolume                          
      mountPath: /usr/share/nginx/html          # path in the container
  - name: sidecarcontainer
    image: busybox                              # sidecar, second container image is busybox
    command: ["/bin/sh"]                        # it pulls index.html file from github every 15 seconds
    args: ["-c", "while true; do wget -O /var/log/index.html https://raw.githubusercontent.com/sangam14/bugtroncon-demo/main/index.html/; sleep 15; done"]
    volumeMounts:
    - name: sharedvolume
      mountPath: /var/log
  volumes:                                      # define emptydir temporary volume, when the pod is deleted, volume also deleted
  - name: sharedvolume                          # name of volume 
    emptyDir: {}                                # volume type emtpydir: creates empty directory where the pod is runnning
Kubectl apply -f multicontainer.yaml
kubectl get pods
kubectl get pods -w

create muticontainer on the pod ( web container and sidecarcontainer)

Connect ( bin/sh of the web container and install net-tools to show ethernet interface 

Kubectl exec -it muticontainer -c webcontainer -- /bin/sh 
# apt update 
# apt install net-tools 
# ifconfig 

### you can check same for sidecarcontainer 

Kubectl exec -it muticontainer -c sidecarcontainer -- /bin/sh 
kuectl logs -f multicontainer -c sidecarcontainer 
kubectl port-forward pod/multicontainer 8080:80 

kubectl delete -f multicontainer.yaml 
apiVersion: v1 
kind: pod 
metadata:
  name: firstpod
  labels:
    app: frontend 
    tier: frontend
    mycluster.local/team: team1 
spec:
   containers:
     - name: ngnix 
       image: ngnix:latest 
       ports:
         - containerPort: 80
       env: 
         - name: USER
           value: "username"  


           
kubectl label pods pod1 team=development  #adding label team=development on pod1
kubectl get pods --show-labels
kubectl label pods pod1 team-  #remove team (key:value) from pod1
kubectl label --overwrite pods pod1 team=test #overwrite/change label on pod1
kubectl label pods --all foo=bar  # add label foo=bar for all pods

Label & Selector , Annotation ,

Namespace 

imperative way to add label to the pod

Selector

we can select/filter pod with Kubectl command 

kubectl get pods -l "app=firstapp" --show-labels
kubectl get pods -l "app=firstapp,tier=frontend" --show-labels
kubectl get pods -l "app=firstapp,tier!=frontend" --show-labels
kubectl get pods -l "app,tier=frontend" --show-labels #equality-based selector
kubectl get pods -l "app in (firstapp)" --show-labels  #set-based selector
kubectl get pods -l "app not in (firstapp)" --show-labels  #set-based selector
kubectl get pods -l "app=firstapp,app=secondapp" --show-labels # comma means and => firstapp and secondapp
kubectl get pods -l "app in (firstapp,secondapp)" --show-labels # it means or => firstapp or secondapp

apiVersion: v1 
kind: pod 
metadata:
  name: firstpod
  labels:
    app: frontend 
spec:
   containers:
     - name: ngnix 
       image: ngnix:latest 
       ports:
         - containerPort: 80
       nodeSelector:
         hddtype: ssd

NodeSelector

kubectl apply -f podnode.yaml
kubectl get pods -w #always watch
kubectl label nodes minikube hddtype=ssd 
#after labelling node, pod11 configuration can run, because node is labelled with hddtype:ssd 

apiVersion: v1 
kind: pod 
metadata:
  name: annotationpod
  annotations:
    owner: "sangam "
    notificatin-email: "owner@email.com"
    realesedate: "1.1.2022"
    ngnix.ingress.kubenetes.io/force-ssl-redirect: "true"
spec:
   containers:
     - name: annotationcontainer
       image: ngnix:latest 
       ports:
         - containerPort: 80
       env: 
         - name: USER
           value: "username"

annotation

kubectl apply -f podannotation.yaml
kubectl describe pod annotationpod
kubectl annotate pods annotationpod foo=bar #imperative way
kubectl delete -f podannotation.yaml
  • Namespaces provides a mechanism for isolating groups of resources within a single cluster. It provides a scope for names.
  • Namespaces cannot be nested inside one another and each Kubernetes resource can only be in one namespace.
  • Kubectl commands run on default namespaces if it is not determined in the command.
kubectl get pods --namespaces kube-system  #get all pods in the kube-system namespaces
kubectl get pods --all-namespaces  # get pods from all namespaces
kubectl create namespace development  #create new development namespace in imperative way
kubectl get pods -n development  # get pods from all namespace
apiVersion: v1 
kind : Namespace 
metadata:
  name: developement 
---
apiVersion: v1 
kind: pod 
metadata:
   namespace: developement
   name: naespacepod 
spec:
  containers:
    - name: namespacecontainer 
      image: ngnix:latest 
      ports:
        - containerPort: 80   
kubectl apply -f namespace.yaml
kubectl get pods -n development  #get pods in the development namespace
kubectl exec -it namespacedpod -n development -- /bin/sh  
#run namespacepod in development namespace

kubectl config set-context --current  --namespace=development  #now default namespace is development
kubectl get pods     #returns pods in the development namespace  
kubectl config set-context --current  --namespace=default  #now namespace is default 
kubectl delete namespaces development  #delete development namespace

We can avoid -n for all command by changing of default namespace 

  • A Deployment provides declarative updates for Pods and ReplicaSets.
  • We define states in the deployment, deployment controller compares desired state and take necessary actions to keep desire state.
  • Deployment object is the higher level K8s object that controls and keeps state of single or multiple pods automatically.
kubectl create deployment firstdeployment --image=nginx:latest --replicas=2 
kubectl get deployments
kubectl get pods -w    #on another terminal
kubectl delete pods <oneofthepodname> #we can see another terminal, new pod will be created (to keep 2 replicas)  
kubectl scale deployments firstdeployment --replicas=5
kubectl delete deployments firstdeployment 
apiVersion: apps/v1
kind: Deployment
metadata:
  name: firstdeployment
  labels:
    team: development
spec:
  replicas: 3
  selector:                        # deployment selector
    matchLabels:                   # deployment selects "app:frontend" pods, monitors and traces these pods 
      app: frontend                # if one of the pod is killed, K8s looks at the desire state (replica:3), it recreats another pods to protect number of replicas
  template:
    metadata:
      labels:                      # pod labels, if the deployment selector is same with these labels, deployment follows pods that have these labels         
        app: frontend              # key: value        
    spec:                                   
      containers:
      - name: nginx                
        image: nginx:latest        # image download from DockerHub
        ports:
        - containerPort: 80        # open following ports
kubectl apply -f deployement1.yaml 
kubectl get pods 
kubectl delete pods <podname> 
kubectl get pods 
kubectl scale deployements firstdeployement --replicas=5 
kubectl get deployements 
kubectl scale deployements firstdeployement --replicas=3 
kubectl get pods -o wide 
kubectl exec -it -c <podname> -- bash
# apt get update 
# apt install net-tools 
# apt install iputils-ping 
# ipconfig 
kubectl port-forward <podname> 8085:80 
kubectl delete -f deployment1.yaml

Rollout - Rollback

apiVersion: apps/v1
kind: Deployment
metadata:
  name: rcdeployment
  labels:
    team: development
spec:
  replicas: 5                        # create 5 replicas
  selector:
    matchLabels:                     # labelselector of deployment: selects pods which have "app:recreate" labels
      app: recreate
  strategy:                          # deployment roll up strategy: recreate => Delete all pods firstly and create Pods from scratch.
    type: Recreate
  template:
    metadata:
      labels:                        # labels the pod with "app:recreate" 
        app: recreate
    spec:
      containers:
      - name: nginx
        image: nginx
        ports:
        - containerPort: 80
kuectl apply -f recrete-deployement.yaml 
kubectl get pods 
kubectl get rs
kubectl set image deployement rcdeplotemnt ngnix=httpd
kubectl get pod 
kubectl get rs 
kubectl delete -f recreate-deplotment.yaml 
kubectl apply -f rolling-deployment.yaml --record 
kubcetl get pods 
kubectl get rs 
kubectl edit deployment rolldeployment --record 
kubectl get pods 
kubectl get rs 
kubectl set image deployment rolldeployment ngnix=httpd:alpine --record-true 
kubectl rollout history deployment rolldeployment 
kubectl delete -f rolling-deployment.yaml

Terrascan - Cloud Native Security Tool 

Install Terrascan  

$ curl -L "$(curl -s https://api.github.com/repos/accurics/terrascan/releases/latest | grep -o 
-E "https://.+?_Darwin_x86_64.tar.gz")" > terrascan.tar.gz
$ tar -xf terrascan.tar.gz terrascan && rm terrascan.tar.gz
$ install terrascan /usr/local/bin && rm terrascan
$ terrascan

Install terrascan via brew

$ brew install terrascan

Docker Image

$ docker run accurics/terrascan

push images

Source Code Repository

CI/CD pipeline

git action

pre-commit

Container Registry

Atlantis

GitOps repo

Sync changes

test

Dev

Prod

commit code

GitOps namespace

Kubernetes  Cluster

pull images

Pre-Sync Hook

Terraform Pull Request Automation

Kubernetes API

etcd

persistent to database ( if valid)

Custom Security Policies

Kubernetes API Response

 Deployment Creation Request

Webhook

validation decision

validating

Admission

admission Controller

terrascan CLI

terrascan as Server

DockerFile

Kubernetes

Helm

terraform

Github

Slack Notification 

$ terrascan scan -i <IaC provider> --find-vuln

kustomize

Thank You ! 

sangam14

Demo Code:-https://github.com/sangam14/bugtroncon-demo

Introduction to DevSecOps , K8s , Docker, Terrascan

By Sangam Biradar

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Introduction to DevSecOps , K8s , Docker, Terrascan

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