Merge pull request #3 from rojanjose/master

Lab 1 instructions

Author: jzaccone

workshop/Lab0/README.md

@@ -1,9 +1,40 @@
-# Pre-work
-
+# Lab 0: Pre-work
 
 ## 1. Setup Kubernetes environment
 
 Run through the instructions listed [here](https://github.com/IBM/kube101/tree/master/workshop/Lab0)
 
-## 2. Download or clone the repo
+## 2. Cloud shell login.
+
+## 3. Docker hub account.
+
+Create a [dockerhub](https://hub.docker.com/) user and set the environment variable.
+```
+DOCKERUSER=<dockerhub useid>
+```
+
+## 4. Set the cluster name
+
+```
+ibmcloud ks clusters
+
+OK
+Name                               ID                     State     Created        Workers   Location          Version                 Resource Group Name        Provider
+user001-workshop                      bseqlkkd0o1gdqg4jc10   normal    3 months ago   5         Dallas            4.3.38_1544_openshift   default                    classic
+
+
+CLUSTERNAME=use001-workshop 
+```
+or
+
+```
+CLUSTERNAME=`ibmcloud ks clusters | grep Name -A 1 | awk '{print $1}' | grep -v Name`
+
+echo $CLUSTERNAME
+user001-workshop
+```
+
+
+
+
 

workshop/Lab1/README.md

@@ -1,13 +1,306 @@
-# Lab 1. Container storage and Kubernetes
+# Lab 1: Non-persistent storage with Kubernetes
 
-Expolore how local storage works on the pods.
-Mount it on Docker.
+Storing data in containers or worker nodes are considered as the [non-persistent](https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/#local-ephemeral-storage) forms of data storage.
+In this lab, we will explore storage options on the IBM Kubernetes worker nodes. Follow this [lab](https://github.com/remkohdev/docker101/tree/master/workshop/lab-3) is you are interested in learning more about container-based storage.
 
-The application is the [Guestbook App](https://github.com/IBM/guestbook), which is a sample multi-tier web application.
+The lab covers the following topics:
+- Create and claim IBM Kubernetes [non-persistent](https://cloud.ibm.com/docs/containers?topic=containers-storage_planning#non_persistent_overview) storage based on the primary and secondary storage available on the worker nodes.
+- Make the volumes available in the `Guestbook` application.
+- Use the volumes to store application cache and debug information.
+- Access the data from the guestbook container using the Kubernetes CLI.
+- Assess the impact of losing a pod on data retention.
+- Claim back the storage resources and clean up.
 
-## Scenario 1: Deploy the application using `kubectl`
+
+The primary storage maps to the volume type `hostPath` and the secondary storage maps to `emptyDir`. Learn more about Kubernetes volume types [here](https://Kubernetes.io/docs/concepts/storage/volumes/).
+
+## Reserve Persistent Volumes
+
+From the cloud shell prompt, run the following commands to get the guestbook application and the kubernetes configuration needed for the storage labs.
 
 ```bash
-git clone https://github.com/IBM/workshop-template
-cd workshop-template
+cd $HOME
+git clone --branch fs https://github.com/IBM/guestbook-nodejs.git
+git clone --branch storage https://github.com/rojanjose/guestbook-config.git
+cd $HOME/guestbook-config/storage
+```
+
+Let's start with reserving the Persistent volume from the primary storage.
+Review the yaml file `pv-hostpath.yaml`. Note the values set for `type`, `storageClassName` and `hostPath`.
+
+```console
+apiVersion: v1
+kind: PersistentVolume
+metadata:
+  name: guestbook-primary-pv
+  labels:
+    type: local
+spec:
+  storageClassName: manual
+  capacity:
+    storage: 10Gi
+  accessModes:
+    - ReadWriteOnce
+  hostPath:
+    path: "/mnt/data"
+```
+
+Create the persistent volume as shown in the command below:
+```
+kubectl create -f pv-hostpath.yaml
+persistentvolume/guestbook-primary-pv created
+
+kubectl get pv
+NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM                   STORAGECLASS       REASON   AGE
+guestbook-primary-pv                       10Gi       RWO            Retain           Available                           manual                      13s
+```
+
+Next 
+PVC yaml:
+```
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+ name: guestbook-local-pvc
+spec:
+  storageClassName: manual
+  accessModes:
+    - ReadWriteMany
+  resources:
+    requests:
+      storage: 3Gi
+```
+
+Create PVC:
+
+```
+kubectl create -f guestbook-local-pvc.yaml
+persistentvolumeclaim/guestbook-local-pvc created
+❯ kubectl get pvc
+NAME                  STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS       AGE
+guestbook-local-pvc   Bound    guestbook-local-pv                         10Gi       RWX            manual             6s
+```
+
+
+## Guestbook application using storage
+
+The application is the [Guestbook App](https://github.com/IBM/guestbook-nodejs), which is a simple multi-tier web application built using the loopback framework.
+
+Change to the guestbook application source directory:
+
+```
+cd $HOME/guestbook-nodejs/src
+```
+Review the source `common/models/entry.js`. The application uses storage allocated using `hostPath` to store data cache in the file `data/cache.txt`. The file `logs/debug.txt` records debug messages provisioned using the `emptyDir` storage type.
+
+```source
+module.exports = function(Entry) {
+
+    Entry.greet = function(msg, cb) {
+
+        // console.log("testing " + msg);
+        fs.appendFile('logs/debug.txt', "Received message: "+ msg +"\n", function (err) {
+            if (err) throw err;
+            console.log('Debug stagement printed');
+        });
+
+        fs.appendFile('data/cache.txt', msg+"\n", function (err) {
+            if (err) throw err;
+            console.log('Saved in cache!');
+        });
+
+...
+```
+
+Run the commands listed below to build the guestbook image and copy into the docker hub registry:
+
+```
+cd $HOME/guestbook-nodejs/src
+docker build -t $DOCKERUSER/guestbook-nodejs:storage .
+docker login -u $DOCKERUSER
+docker push $DOCKERUSER/guestbook-nodejs:storage
+```
+
+Review the deployment yaml file `guestbook-deplopyment.yaml` prior to deploying the application into the cluster.
+
+```
+cd $HOME/guestbook-config/storage/lab1
+cat guestbook-deployment.yaml
+```
+
+Replace the first part of `image` name with your docker hub user id.
+The section `spec.volumes` lists `hostPath` and `emptyDir` volumes. The section `spec.containers.volumeMounts` lists the mount paths that the application uses to write in the volumes.
+
+```
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: guestbook-v1
+  labels:
+    app: guestbook
+ ...
+    spec:
+      containers:
+        - name: guestbook
+          image: rojanjose/guestbook-nodejs:storage
+          imagePullPolicy: Always
+          ports:
+          - name: http-server
+            containerPort: 3000
+          volumeMounts:
+          - name: guestbook-primary-volume
+            mountPath: /home/node/app/data
+          - name: guestbook-secondary-volume
+            mountPath: /home/node/app/logs
+      volumes:
+      - name: guestbook-primary-volume
+        persistentVolumeClaim:
+          claimName: guestbook-primary-pvc
+      - name: guestbook-secondary-volume
+        emptyDir: {}
+  
+
+...
+```
+
+Deploy the Guestbook application:
+
+```
+kubectl create -f guestbook-deployment.yaml
+deployment.apps/guestbook-v1 created
+
+kubectl get pods
+NAME                            READY   STATUS    RESTARTS   AGE
+guestbook-v1-6f55cb54c5-jb89d   1/1     Running   0          14s
+
+kubectl create -f guestbook-service.yaml
+service/guestbook created
+```
+
+Find the URL for the guestbook application by joining the worker node external IP and service node port.
+
+```
+HOSTNAME=`ibmcloud ks workers --cluster $CLUSTERNAME | grep Ready | head -n 1 | awk '{print $2}'`
+SERVICEPORT=`kubectl get svc guestbook -o=jsonpath='{.spec.ports[0].nodePort}'`
+echo "http://$HOSTNAME:$SERVICEPORT"
+```
+
+Open the URL in a browser and create guest book entries.
+
+![Guestbook entries](images/lab1-guestbook-entries.png)
+
+Log into the pod:
+
+```
+kubectl exec -it guestbook-v1-6f55cb54c5-jb89d bash
+
+kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl kubectl exec [POD] -- [COMMAND] instead.
+
+root@guestbook-v1-6f55cb54c5-jb89d:/home/node/app# ls -al
+total 256
+drwxr-xr-x   1 root root   4096 Nov 11 23:40 .
+drwxr-xr-x   1 node node   4096 Nov 11 23:20 ..
+-rw-r--r--   1 root root     12 Oct 29 21:00 .dockerignore
+-rw-r--r--   1 root root    288 Oct 29 21:00 .editorconfig
+-rw-r--r--   1 root root      8 Oct 29 21:00 .eslintignore
+-rw-r--r--   1 root root     27 Oct 29 21:00 .eslintrc
+-rw-r--r--   1 root root    151 Oct 29 21:00 .gitignore
+-rw-r--r--   1 root root     30 Oct 29 21:00 .yo-rc.json
+-rw-r--r--   1 root root    105 Oct 29 21:00 Dockerfile
+drwxr-xr-x   2 root root   4096 Nov 11 03:40 client
+drwxr-xr-x   3 root root   4096 Nov 10 23:04 common
+drwxr-xr-x   2 root root   4096 Nov 11 23:16 data
+drwxrwxrwx   2 root root   4096 Nov 11 23:44 logs
+drwxr-xr-x 439 root root  16384 Nov 11 23:20 node_modules
+-rw-r--r--   1 root root 176643 Nov 11 23:20 package-lock.json
+-rw-r--r--   1 root root    830 Nov 11 23:20 package.json
+drwxr-xr-x   3 root root   4096 Nov 10 23:04 server
+
+root@guestbook-v1-6f55cb54c5-jb89d:/home/node/app# cat data/cache.txt
+Hello Kubernetes!
+Hola Kubernetes!
+Zdravstvuyte Kubernetes!
+Nǐn hǎo Kubernetes!
+Goedendag Kubernetes!
+
+root@guestbook-v1-6f55cb54c5-jb89d:/home/node/app# cat logs/debug.txt
+Received message: Hello Kubernetes!
+Received message: Hola Kubernetes!
+Received message: Zdravstvuyte Kubernetes!
+Received message: Nǐn hǎo Kubernetes!
+Received message: Goedendag Kubernetes!
+
+
+root@guestbook-v1-6f55cb54c5-jb89d:/home/node/app# df -h
+Filesystem               Size  Used Avail Use% Mounted on
+overlay                   98G  3.5G   90G   4% /
+tmpfs                     64M     0   64M   0% /dev
+tmpfs                    7.9G     0  7.9G   0% /sys/fs/cgroup
+/dev/mapper/docker_data   98G  3.5G   90G   4% /etc/hosts
+shm                       64M     0   64M   0% /dev/shm
+/dev/xvda2                25G  3.6G   20G  16% /home/node/app/data
+tmpfs                    7.9G   16K  7.9G   1% /run/secrets/kubernetes.io/serviceaccount
+tmpfs                    7.9G     0  7.9G   0% /proc/acpi
+tmpfs                    7.9G     0  7.9G   0% /proc/scsi
+tmpfs                    7.9G     0  7.9G   0% /sys/firmware
+
+```
+
+Kill the pod to see the impact of deleting the pod on data.
+
+```
+kubectl get pods
+NAME                            READY   STATUS    RESTARTS   AGE
+guestbook-v1-6f55cb54c5-jb89d   1/1     Running   0          12m
+
+kubectl delete pod guestbook-v1-6f55cb54c5-jb89d
+pod "guestbook-v1-6f55cb54c5-jb89d" deleted
+
+kubectl get pods
+NAME                            READY   STATUS    RESTARTS   AGE
+guestbook-v1-5cbc445dc9-sx58j   1/1     Running   0          86s
+```
+
+![Guestbook delete data](images/lab1-guestbook-data-deleted.png)
+
+Enter new data:
+![Guestbook reload](images/lab1-guestbook-data-reload.png)
+
+Log into the pod to view the state of the data.
+
+```
+kubectl get pods
+NAME                            READY   STATUS    RESTARTS   AGE
+guestbook-v1-5cbc445dc9-sx58j   1/1     Running   0          86s
+
+kubectl exec -it guestbook-v1-5cbc445dc9-sx58j bash
+kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl kubectl exec [POD] -- [COMMAND] instead.
+
+root@guestbook-v1-5cbc445dc9-sx58j:/home/node/app# cat data/cache.txt
+Hello Kubernetes!
+Hola Kubernetes!
+Zdravstvuyte Kubernetes!
+Nǐn hǎo Kubernetes!
+Goedendag Kubernetes!
+Bye Kubernetes!
+Aloha Kubernetes!
+Ciao Kubernetes!
+Sayonara Kubernetes!
+
+root@guestbook-v1-5cbc445dc9-sx58j:/home/node/app# cat logs/debug.txt
+Received message: Bye Kubernetes!
+Received message: Aloha Kubernetes!
+Received message: Ciao Kubernetes!
+Received message: Sayonara Kubernetes!
+root@guestbook-v1-5cbc445dc9-sx58j:/home/node/app#
+```
+
+This shows that the storage type `emptyDir` loose data on a pod restart whereas `hostPath` data lives until the worker node or cluster is deleted.
+
+
+## Clean up
+
 ```
+cd $HOME/guestbook-config/storage/lab1
+kubectl delete -f .
+```