Additions

.gitignore

@@ -1 +1,2 @@
 Kubernetes-Dont's.key
+.DS_Store

Demo-1/01 - stats.sh

@@ -1,5 +1,8 @@
 #!/bin/sh
 
+# The next line is for a minikube environment
+eval $(minikube -p minikube docker-env)
+
 # https://docs.docker.com/engine/reference/commandline/stats/
 
 docker stats --format "table {{.Name}}\t{{.MemUsage}}\t{{.MemPerc}}"

Demo-1/02 - events.sh

@@ -1,3 +1,3 @@
 #!/bin/bash
 
-kubectl get events -w
+kubectl get events -w -A

Demo-1/03 - deploy.sh

@@ -1,3 +1,3 @@
 #!/bin/bash
 
-kubectl apply -f depolyment.yaml
+kubectl apply -f memory-waster.yaml

Demo-1/06 - cleanup.sh

@@ -1,3 +1,3 @@
 #!/bin/bash
 
-kubectl delete -f deployment.yaml
+kubectl delete -f memory-waster.yaml

Demo-1/README.md

@@ -0,0 +1,7 @@
+# This demo will show resource settings
+
+Using the provided scripts it will be made visible how resource limits limit the number of pods that can be deployed on a cluster.
+
+This demo will deploy as many nginx pods that each will have a reservation of 512Mb.
+
+Run the different scripts in different terminals to get the full picture.

Demo-2/01 - stats.sh

@@ -0,0 +1,20 @@
+#!/bin/sh
+
+# The next line is for a minikube environment
+eval "$(minikube -p minikube docker-env)"
+
+# https://docs.docker.com/engine/reference/commandline/stats/
+
+docker stats --format "table {{.Name}}\t{{.MemUsage}}\t{{.MemPerc}}"
+
+exit
+
+# .Container	Container name or ID (user input)
+# .Name	Container name
+# .ID	Container ID
+# .CPUPerc	CPU percentage
+# .MemUsage	Memory usage
+# .NetIO	Network IO
+# .BlockIO	Block IO
+# .MemPerc	Memory percentage (Not available on Windows)
+# .PIDs	Number of PIDs (Not available on Windows)

Demo-2/02 - events.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+kubectl get events -w  -A

Demo-2/03 - deploy.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+kubectl create namespace mem-example
+
+kubectl apply -f memory-request-limit-1.yaml

Demo-2/04 - deploy.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+kubectl create namespace mem-example
+
+kubectl delete -f memory-request-limit-1.yaml
+kubectl apply -f memory-request-limit-2.yaml

Demo-2/05 - deploy.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+kubectl create namespace mem-example
+
+kubectl delete -f memory-request-limit-2.yaml
+kubectl apply -f memory-request-limit-3.yaml

Demo-2/06- cleanup.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+kubectl delete -f memory-request-limit-3.yaml
+kubectl delete namespace mem-example
+

Demo-2/memory-request-limit-1.yaml

@@ -0,0 +1,27 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: memory-waster
+  namespace: mem-example
+  labels:
+    app: memory-waster
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: memory-waster
+  template:
+    metadata:
+      labels:
+        app: memory-waster
+    spec:
+      containers:
+      - name: memory-demo-ctr
+        image: polinux/stress
+        resources:
+          limits:
+            memory: "200Mi"
+          requests:
+            memory: "100Mi"
+        command: ["/bin/sh"] 
+        args: ["-c", "sleep 1; stress --vm 1 --vm-bytes 150M --vm-hang 1"]

Demo-2/memory-request-limit-2.yaml

@@ -0,0 +1,27 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: memory-waster
+  namespace: mem-example
+  labels:
+    app: memory-waster
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: memory-waster
+  template:
+    metadata:
+      labels:
+        app: memory-waster
+    spec:
+      containers:
+      - name: memory-demo-ctr
+        image: polinux/stress
+        resources:
+          limits:
+            memory: "200Mi"
+          requests:
+            memory: "100Mi"
+        command: ["/bin/sh"] 
+        args: ["-c", "sleep 1; stress --vm 1 --vm-bytes 250M --vm-hang 1"]

Demo-2/memory-request-limit-3.yaml

@@ -0,0 +1,28 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: memory-waster
+  namespace: mem-example
+  labels:
+    app: memory-waster
+spec:
+  replicas: 15
+  selector:
+    matchLabels:
+      app: memory-waster
+  template:
+    metadata:
+      labels:
+        app: memory-waster
+    spec:
+      terminationGracePeriodSeconds: 5
+      containers:
+      - name: memory-demo-ctr
+        image: polinux/stress
+        resources:
+          limits:
+            memory: "200Mi"
+          requests:
+            memory: "50Mi"
+        command: ["/bin/sh"] 
+        args: ["-c", "sleep 30; stress --vm 1 --vm-bytes 150M --vm-hang 1"]

Demo-3/01 - start.sh

@@ -0,0 +1,4 @@
+#!/bin/bash
+
+kubectl create namespace probes
+kubectl apply -f configmap-probes.yaml

Demo-3/02 - deploy-1.sh

@@ -0,0 +1,4 @@
+#!/bin/bash
+
+kubectl apply -f deployment-1.yaml
+kubectl apply -f service.yaml

Demo-3/03 - deploy-2.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+kubectl apply -f deployment-2.yaml

Demo-3/04 - port forward.sh

@@ -0,0 +1,4 @@
+#!/bin/bash
+
+kill $(ps -ef | grep kube | grep port-forward | awk '{print $2}')
+kubectl -n probes port-forward service/probes 9876:80 &

Demo-3/05 - browser.sh

@@ -0,0 +1,9 @@
+#!/bin/bash
+
+# https://github.com/mhausenblas/simpleservice
+
+# On a Mac this will open a browser session
+/Applications//Google\ Chrome.app/Contents/MacOS/Google\ Chrome http://127.0.0.1:9876/env
+/Applications//Google\ Chrome.app/Contents/MacOS/Google\ Chrome http://127.0.0.1:9876/info
+/Applications//Google\ Chrome.app/Contents/MacOS/Google\ Chrome http://127.0.0.1:9876/health
+/Applications//Google\ Chrome.app/Contents/MacOS/Google\ Chrome http://127.0.0.1:9876/endpoint0

Demo-3/06 - scale.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+kubectl -n probes scale deployment --replicas=10 probes

Demo-3/07 - clean up.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+kubectl delete namespaces probes
+
+pkill -f port-forward

Demo-3/configmap-probes.yaml

@@ -0,0 +1,97 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: probes
+  namespace: probes
+data:
+  readinessprobe.sh: |-
+    #!/bin/bash
+    
+    # This script is used to check the readiness of a POD.
+    # If a pod works fine the script exits with exit code 0
+    # otherwise, a non exit code is used.
+    #
+    # Add the following (or similar) code to the helm chart
+    # files in order to use it.
+    #
+    #   readinessProbe:
+    #     periodSeconds: 3
+    #     successThreshold: 1
+    #     failureThreshold: 2
+    #     initialDelaySeconds: 30
+    #     timeoutSeconds: 5
+    #     exec:
+    #      command:
+    #         - /bin/bash 
+    #         - /probes/readinessprobe.sh
+    #
+    # Consider various tests such as availability of certain filesystems, environment variables
+    # or connectivity/responses from/to (web)servers.
+    
+    function probe_log() {
+        echo "$( date +%D-%T ): ${1}" > /proc/1/fd/1
+        exit 1
+    }
+    #
+    # Debug checks:
+    #
+    # Report a NOT READY status if the file /tmp/notready does exist:
+    cat /tmp/notready > /dev/null 2>&1 && probe_log "File /tmp/notready exists"
+    
+    # Report A NOT READY status if the file /etc/passwd does NOT exist:
+    cat /etc/passwd > /dev/null 2>&1 || probe_log "File /etc/passwd does not exist"
+    
+    # Check if the following filesystem exist.
+    df /dev > /dev/null 2>&1 || probe_log "Filesystem /dev not found"
+        
+    # If we reached this point we can assume that everything is fine.
+    # Exit with an okay status
+    exit 0
+  livenessprobe.sh: |-
+    #!/bin/bash
+    
+    # This script is used to check the readiness of a POD.
+    # If a pod works fine the script exits with exit code 0
+    # otherwise, a non exit code is used.
+    #
+    # Add the following (or similar) code to the helm chart
+    # files in order to use it.
+    #
+    #   livenessProbe:
+    #     periodSeconds: 1
+    #     successThreshold: 1
+    #     failureThreshold: 2
+    #     initialDelaySeconds: 30
+    #     timeoutSeconds: 5
+    #     exec:
+    #       command:
+    #       - /bin/bash 
+    #       - /probes/livenessprobe.sh
+    #
+    # Consider various tests such as availability of certain filesystems, environment variables
+    # or connectivity/responses from/to (web)servers.
+    
+    function probe_log() {
+        echo "$( date +%D-%T ): ${1}" > /proc/1/fd/1
+        exit 1
+    }
+    
+    # Check the local health page
+    # Use wget and not curl... wget has easier exit codes!
+    wget  http://localhost:9876/health -o /dev/null || probe_log "Restarting because healt page is not responding"
+    
+    #
+    # Debug checks:
+    #
+    # Report a NOT ALIVE status if the file /tmp/notready does exist:
+    cat /tmp/notalive > /dev/null 2>&1 && probe_log "File /tmp/notalive exists"
+    
+    # Report A NOT ALIVE status if the file /etc/passwd does NOT exist:
+    cat /etc/passwd > /dev/null 2>&1 || probe_log "File /etc/passwd does not exist"
+    
+    # Check if the following filesystem exist.
+    df /dev > /dev/null 2>&1 || probe_log "Filesystem /dev not found"
+    
+    # If we reached this point we can assume that everything is fine.
+    # Exit with an okay status
+    exit 0

Demo-3/deployment-1.yaml

@@ -0,0 +1,34 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  labels:
+    app: probes
+  name: probes
+  namespace: probes
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: probes
+  strategy: {}
+  template:
+    metadata:
+      labels:
+        app: probes
+    spec:
+      containers:
+      - image: mhausenblas/simpleservice:0.5.0
+      # https://github.com/mhausenblas/simpleservice
+        name: simpleservice
+        resources:
+          limits:
+            memory: "200Mi"
+        volumeMounts:
+        - name: probes
+          mountPath: "/probes"
+          readOnly: true  
+      volumes:
+        - name: probes
+          configMap:
+            name: probes
+status: {}

Demo-3/deployment-2.yaml

@@ -0,0 +1,54 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  labels:
+    app: probes
+  name: probes
+  namespace: probes
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: probes
+  strategy: {}
+  template:
+    metadata:
+      labels:
+        app: probes
+    spec:
+      containers:
+      - image: mhausenblas/simpleservice:0.5.0
+      # https://github.com/mhausenblas/simpleservice
+        name: simpleservice
+        resources:
+          limits:
+            memory: "200Mi"
+        livenessProbe:
+          periodSeconds: 1
+          successThreshold: 1
+          failureThreshold: 2
+          initialDelaySeconds: 30
+          timeoutSeconds: 5
+          exec:
+            command:
+              - /bin/bash
+              - /probes/livenessprobe.sh
+        readinessProbe:
+          periodSeconds: 3
+          successThreshold: 1
+          failureThreshold: 2
+          initialDelaySeconds: 30
+          timeoutSeconds: 5
+          exec:
+           command:
+              - /bin/bash
+              - /probes/readinessprobe.sh
+        volumeMounts:
+        - name: probes
+          mountPath: "/probes"
+          readOnly: true  
+      volumes:
+        - name: probes
+          configMap:
+            name: probes
+status: {}

Demo-3/service.yaml

@@ -0,0 +1,18 @@
+apiVersion: v1
+kind: Service
+metadata:
+  labels:
+    app: probes
+  name: probes
+  namespace: probes
+spec:
+  ports:
+  - name: tcp-9876
+    port: 80
+    protocol: TCP
+    targetPort: 9876
+  selector:
+    app: probes
+  type: ClusterIP
+status:
+  loadBalancer: {}