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In the first article, “Using Jenkins with Kubernetes AWS, Part 1,” on automating Kubernetes installation with Jenkins, we installed Jenkins on CoreOS, created the pre-requisite artifacts for installing Kubernetes, and created a Jenkins node. In the second article, “Using Jenkins with Kubernetes AWS, Part 2,” we configured a Jenkinsfile and created a Jenkins pipeline. In this article, we shall run the Jenkins pipeline to install Kubernetes and subsequently test the Kubernetes cluster. This article has the following sections:
Running the Jenkins Pipeline
Click Build Now to run the Jenkins Pipeline, as shown in Figure 1.
Figure 1: Build Now starts the Jenkins Pipeline
The Jenkins Pipeline gets started and a progress bar indicates the progress of the pipeline. A Stage View for the various stages in the pipeline also gets displayed, as shown in Figure 2. The Kube-aws render stage in the Stage View has a “paused” link because we requested user input for worker count (and instance type user input, which shall be prompted for subsequently) in the Jenkinsfile. Click the “paused” link.
Figure 2: Obtaining the Public IP Address
In the Console Output for the Jenkins Pipeline, click the Input requested link, as shown in Figure 3.
Figure 3: Input requested for number of nodes
A Number of Nodes dialog gets displayed, prompting for user input for the number of nodes, as shown in Figure 4. A default value as configured in the Jenkinsfile is also set. Click Proceed after specifying a value.
Figure 4: Specifying Number of Nodes
The Pipeline continues to run and again gets paused at another input request for the instance type. Click Input requested, as shown in Figure 5.
Figure 5: Input Requested for Instance Type
The Instance Type dialog gets displayed (see Figure 6). Select the default value (or specify a different value) and click Proceed.
Figure 6: Specifying Instance Type
The pipeline continues to run. In the Deploy Cluster stage, another Input requested link is presented, as shown in Figure 7. Click the link.
Figure 7: Input Requested for Should Cluster be Deployed
In the Should Deploy Cluster? dialog, select the default value of “yes” and click Proceed, as shown in Figure 8.
Figure 8: Should Deploy Cluster?
The pipeline continues to run. Creating the AWS resources for a Kubernetes cluster could take a while, as indicated by the message in the Console Output shown in Figure 9.
Figure 9: Creating AWS Resources
The pipeline runs to completion. A “SUCCESS” message indicates that the pipeline has run successfully, as shown in Figure 10.
Figure 10: Jenkins Pipeline Run completed Successfully
The Stage View for the Jenkins Pipeline displays the various stages of the pipeline having completed, as shown in Figure 11. The Stage view includes links for Last build, Last stable build, Last successful build, and Last completed build.
Figure 11: Stage View
Click Full Stage View to display the full stage view separately, as shown in Figure 12.
Figure 12: Selecting Full Stage View
The Full Stage View gets displayed, as shown in Figure 13.
Figure 13: Full Stage View
In the Dashboard, the icon adjacent to the Jenkins Pipeline turns green to indicate successful completion, as shown in Figure 14.
Figure 14: Jenkins Dashboard with Jenkins Pipeline listed as having completed Successfully
To display the console output, select Console Output for the Build, as shown in Figure 15.
Figure 15: Build History>Console Output
The Console Output gets displayed (see Figure 16).
Figure 16: Console Output
A more detailed Console Output is listed in the following code segment:
Started by user Deepak Vohra
[Pipeline] node
Running on jenkins in /var/jenkins/workspace/install-kubernetes
[Pipeline] {
[Pipeline] stage (set env)
Using the 'stage' step without a block argument is deprecated
Entering stage set env
Proceeding
[Pipeline] sh
[install-kubernetes] Running shell script
+ sudo yum install gnupg2
Loaded plugins: priorities, update-motd, upgrade-helper
Package gnupg2-2.0.28-1.30.amzn1.x86_64 already installed and
latest version
Nothing to do
[Pipeline] sh
[install-kubernetes] Running shell script
+ gpg2 --keyserver pgp.mit.edu --recv-key FC8A365E
gpg: directory '/home/ec2-user/.gnupg' created
gpg: new configuration file '/home/ec2-user/.gnupg/gpg.conf'
created
...
...
[Pipeline] sh
[install-kubernetes] Running shell script
+ gpg2 --fingerprint FC8A365E
pub 4096R/FC8A365E 2016-03-02 [expires: 2021-03-01]
Key fingerprint = 18AD 5014 C99E F7E3 BA5F 6CE9 50BD
D3E0 FC8A 365E
uid [ unknown] CoreOS Application Signing Key
<security@coreos.com>
sub 2048R/3F1B2C87 2016-03-02 [expires: 2019-03-02]
sub 2048R/BEDDBA18 2016-03-08 [expires: 2019-03-08]
sub 2048R/7EF48FD3 2016-03-08 [expires: 2019-03-08]
[Pipeline] sh
[install-kubernetes] Running shell script
+ wget https://github.com/coreos/coreos-kubernetes/releases/
download/v0.7.1/kube-aws-linux-amd64.tar.gz
--2016-11-29 21:22:04-- https://github.com/coreos/
coreos-kubernetes/releases/download/v0.7.1/
kube-aws-linux-amd64.tar.gz
Resolving github.com (github.com)... 192.30.253.112,
192.30.253.113
Connecting to github.com (github.com)|192.30.253.112|:443...
connected.
HTTP request sent, awaiting response... 302 Found
Location: https://github-cloud.s3.amazonaws.com/releases/
41458519/309e294a-29b1-
...
...
2016-11-29 21:22:05 (62.5 MB/s) - 'kube-aws-linux-amd64.tar.gz'
saved [4655969/4655969]
[Pipeline] sh
[install-kubernetes] Running shell script
+ wget https://github.com/coreos/coreos-kubernetes/releases/
download/v0.7.1/kube-aws-linux-amd64.tar.gz.sig
--2016-11-29 21:22:05-- https://github.com/coreos/
coreos-kubernetes/releases/download/v0.7.1/kube-aws-linux-
amd64.tar.gz.sig
Resolving github.com (github.com)... 192.30.253.113,
192.30.253.112
Connecting to github.com (github.com)|192.30.253.113|:443...
connected.
HTTP request sent, awaiting response... 302 Found
Location: https://github-cloud.s3.amazonaws.com/releases/
41458519/0543b716-2bf4-
...
...
Saving to: 'kube-aws-linux-amd64.tar.gz.sig'
0K 100% 9.21M=0s
2016-11-29 21:22:05 (9.21 MB/s) -
'kube-aws-linux-amd64.tar.gz.sig' saved [287/287]
[Pipeline] sh
[install-kubernetes] Running shell script
+ gpg2 --verify kube-aws-linux-amd64.tar.gz.sig kube-aws-
linux-amd64.tar.gz
gpg: Signature made Mon 06 Jun 2016 09:32:47 PM UTC using RSA
key ID BEDDBA18
gpg: Good signature from "CoreOS Application Signing Key
<security@coreos.com>" [unknown]
gpg: WARNING: This key is not certified with a trusted
signature!
gpg: There is no indication that the signature belongs to the
owner.
Primary key fingerprint: 18AD 5014 C99E F7E3 BA5F 6CE9 50BD
D3E0 FC8A 365E
Subkey fingerprint: 55DB DA91 BBE1 849E A27F E733 A6F7
1EE5 BEDD BA18
[Pipeline] sh
[install-kubernetes] Running shell script
+ tar zxvf kube-aws-linux-amd64.tar.gz
linux-amd64/
linux-amd64/kube-aws
[Pipeline] sh
[install-kubernetes] Running shell script
+ sudo mv linux-amd64/kube-aws /usr/local/bin
[Pipeline] sh
[install-kubernetes] Running shell script
...
...
[Pipeline] sh
[install-kubernetes] Running shell script
+ aws ec2 create-volume --availability-zone us-east-1c
--size 10 --volume-type gp2
{
"AvailabilityZone": "us-east-1c",
"Encrypted": false,
"VolumeType": "gp2",
"VolumeId": "vol-b325332f",
"State": "creating",
"Iops": 100,
"SnapshotId": "",
"CreateTime": "2016-11-29T21:22:07.949Z",
"Size": 10
}
[Pipeline] sh
[install-kubernetes] Running shell script
+ aws ec2 create-key-pair --key-name kubernetes-coreos
--query KeyMaterial --output text
[Pipeline] sh
[install-kubernetes] Running shell script
+ chmod 400 kubernetes-coreos.pem
[Pipeline] stage (Kube-aws init)
Using the 'stage' step without a block argument is deprecated
Entering stage Kube-aws init
Proceeding
[Pipeline] deleteDir
[Pipeline] sh
[install-kubernetes] Running shell script
+ mkdir coreos-cluster
[Pipeline] sh
[install-kubernetes] Running shell script
+ cd coreos-cluster
[Pipeline] sh
[install-kubernetes] Running shell script
+ kube-aws init --cluster-name=kubernetes-coreos-cluster
--external-dns-name=NOSQLSEARCH.COM --region=us-east-1
--availability-zone=us-east-1c --key-name=kubernetes-coreos
--kms-key-arn=arn:aws:kms:us-east-1:672593526685:key/
c9748fda-2ac6-43ff-a267-d4edc5b21ad9
Success! Created cluster.yaml
Next steps:
1. (Optional) Edit cluster.yaml to parameterize the cluster.
2. Use the "kube-aws render" command to render the stack
template.
[Pipeline] stage (Kube-aws render)
Using the 'stage' step without a block argument is deprecated
Entering stage Kube-aws render
Proceeding
[Pipeline] input
Input requested
Approved by Deepak Vohra
[Pipeline] input
Input requested
Approved by Deepak Vohra
[Pipeline] sh
[install-kubernetes] Running shell script
+ kube-aws render
Success! Stack rendered to stack-template.json.
Next steps:
1. (Optional) Validate your changes to cluster.yaml with
"kube-aws validate"
2. (Optional) Further customize the cluster by modifying
stack-template.json or files in ./userdata.
3. Start the cluster with "kube-aws up".
[Pipeline] sh
[install-kubernetes] Running shell script
+ sed -i 's/#workerCount: 1/workerCount: 3/' cluster.yaml
[Pipeline] sh
[install-kubernetes] Running shell script
+ sed -i 's/#workerInstanceType: m3.medium/
workerInstanceType: t2.micro/' cluster.yaml
[Pipeline] sh
[install-kubernetes] Running shell script
+ kube-aws validate
Validating UserData...
UserData is valid.
Validating stack template...
Validation Report: {
Capabilities: ["CAPABILITY_IAM"],
CapabilitiesReason: "The following resource(s) require
capabilities: [AWS::IAM::Role]",
Description: "kube-aws Kubernetes cluster
kubernetes-coreos-cluster"
}
stack template is valid.
Validation OK!
[Pipeline] stage (Archive CFN)
Using the 'stage' step without a block argument is deprecated
Entering stage Archive CFN
Proceeding
[Pipeline] step
Archiving artifacts
Recording fingerprints
[Pipeline] stage (Deploy Cluster)
Using the 'stage' step without a block argument is deprecated
Entering stage Deploy Cluster
Proceeding
[Pipeline] input
Input requested
Approved by Deepak Vohra
[Pipeline] echo
Deploying Kubernetes cluster
[Pipeline] sh
[install-kubernetes] Running shell script
+ kube-aws up
Creating AWS resources. This should take around 5 minutes.
Success! Your AWS resources have been created:
Cluster Name: kubernetes-coreos-cluster
Controller IP: 34.193.183.134
The containers that power your cluster are now being downloaded.
You should be able to access the Kubernetes API once the
containers finish downloading.
[Pipeline] sh
[install-kubernetes] Running shell script
+ kube-aws status
Cluster Name: kubernetes-coreos-cluster
Controller IP: 34.193.183.134
[Pipeline] step
Archiving artifacts
Recording fingerprints
[Pipeline] }
[Pipeline] // Node
[Pipeline] End of Pipeline
Finished: SUCCESS
Testing the Kubernetes Cluster
Having installed Kubernetes, next we shall test the cluster by running some application. First, we need to configure the Controller Ip on the Public DNS Name (the nosqlsearch.com domain). Copy the Controller IP from the Console Output, as shown in Figure 17.
Figure 17: Obtaining the Public IP Address
The Kubernetes Controller Ip may also be obtained from the EC2 Console, as shown in Figure 18.
Figure 18: Obtaining the Kubernetes Controller Ip
Add an A (Host) entry to the DNS Zone file for the nosqlsearch.com domain at the hosting provider, as shown in Figure 19. Adding an A record would be slightly different for different hosting providers.
Figure 19: Obtaining the Public IP Address
SSH Log in to the Kubernetes Master using the Master’s Ip.
ssh -i "kubernetes-coreos.pem" core@34.193.178.55
The CoreOS command prompt gets displayed, as shown in Figure 20.
Figure 20: Obtaining the Public IP Address
Install the kubectl binaries:
sudo wget https://storage.googleapis.com/kubernetes-release/ release/v1.3.0/bin/linux/amd64/./kubectl sudo chmod +x ./kubectl
List the nodes:
./kubectl get nodes
The Kubernetes cluster nodes get listed (see Figure 21).
Figure 21: Obtaining the Public IP Address
To test the cluster, create a deployment for nginx consisting of three replicas.
kubectl run nginx --image=nginx --replicas=3
Subsequently, list the deployments:
kubectl get deployments
The “nginx” deployment should get listed, as shown in Figure 22.
Figure 22: Obtaining the Public IP Address
List the cluster-wide Pods:
kubectl get pods -o wide
Create a service of type LoadBalancer from the nginx deployment:
kubectl expose deployment nginx --port=80 --type=LoadBalancer
List the services:
kubectl get services
The cluster-wide Pods get listed, as shown in Figure 23. The “nginx” service gets created and listed including cluster ip and the external Ip.
Figure 23: Obtaining the Public IP Address
Invoke the nginx service at the cluster ip. The nginx service output HTML markup gets displayed, as shown in Figure 24.
Figure 24: Obtaining the Public IP Address
Conclusion
In three articles, we discussed installing Kubernetes cluster using a Jenkins project. We created a Jenkins Pipeline project with a Jenkinsfile to install the cluster. A Jenkins pipeline automates Kubernetes installation, and the same Jenkins pipeline may be modified as required and re-run to create multiple Kubernetes clusters.
