Monday, November 30, 2020

Code error 403 when trying to access Kubernetes cluster | Jenkins Kubernetes Deployment Error

When ever you are doing deployment from Jenkins to EKS cluster, you may get this error:

Api call failed with code 403, detailed message: {
  "kind": "Status",
  "apiVersion": "v1",
  "metadata": {

"status": "Failure",
  "message": "namespaces is forbidden: User \"system:anonymous\" cannot list namespaces at the cluster scope",
  "reason": "Forbidden",
  "details": {
    "kind": "namespaces"
  "code": 403 
Work around or the fix: 

You get this error because you're getting blocked by RBAC policies. Basically, RBAC policies set to restrict the resources you use and limits a few of your action. 

There are two possibilities, either you haven't created an RBAC or it's somehow restricting the cluster access.

By default, your clusterrolebinding has system:anonymous set which blocks the cluster access.

Execute the following command, it will set a clusterrole as cluster-admin which will give you the required access.

kubectl create clusterrolebinding cluster-system-anonymous --clusterrole=cluster-admin --user=system:anonymous


Friday, November 20, 2020

How to fix Jenkins Error | Incorrect Java 11 version

You may have this issue when trying to install Jenkins with default JDK version(Java 11) in Ubuntu 18.0.4. We need to fix by installing JDK 8.

Remove Jenkins first.

sudo apt-get remove jenkins -y

Install Java 8 version

sudo apt-get install openjdk-8-jdk -y

Now choose which version to select from both Java 11 and Java 8 
sudo update-alternatives --config java
type 2 to choose Java 8 version.

Check Java version after setting:

Install Jenkins

sudo apt-get install jenkins -y

Now try to access Jenkins in the browser.

Thursday, November 19, 2020

Slack Azure DevOps Integration | How to Integrate Slack with Azure DevOps | Send push notifications from Azure pipelines to Slack

Slack is popular collaboration tool used at work by many companies. Slack can be integrated with CI tools such as Jenkins, Azure DevOps(VSTS). We will see how to integrate with Azure Build pipelines. 

1. Azure pipelines setup
2. Slack channel setup
Azure DevOps & Slack integration steps
1. Go to and sign in to workspace.
2. Go to channel where you would like to receive push notification from Azure DevOps. Click on more and Add apps

3. Add Visual Studio Team Services App

4. Add Configuration

5.  And then select channel to post notification and add the channel

6. In Azure DevOps Dashboard, click on Project settings.
7. Click on Service Hooks tab and then click create subscriptions button to add a new service hook.

8. Select Slack from the list of services, and press the Next button.

9. On the Trigger screen, choose the event that you’d like to trigger the notification, and add any filters. Press the Next button to continue.

10. On the Action screen, add the URL as the Slack Webhook URL and press Finish when you are done.

Now whenever Azure pipelines runs any builds, it will send push notifications to the Slack channel. Please watch the above steps in YouTube channel:

Monday, November 16, 2020

How to Install TeamCity on AWS Ubuntu EC2 | How to setup TeamCity on Ubuntu 18.0.4 with PostgreSQL?

TeamCity is one of the CI tools, It is open source and Java based tool. It can be configured easily.

Please find below steps for installing TeamCity on Ubuntu:

Make sure Ubuntu instance has at least 4 GB RAM
Open port 8111 in security firewall.

We need to setup database for storing all the build information. We will be using PostgreSQL.

PostgreSQL Installation
sudo sh -c 'echo "deb `lsb_release -cs`-pgdg main" >> /etc/apt/sources.list.d/pgdg.list'

sudo wget -q -O - | sudo apt-key add -

sudo apt-get -y install postgresql postgresql-contrib

sudo systemctl start postgresql
sudo systemctl enable postgresql

Login as postgres user
sudo su - postgres

Now create a user below
createuser teamcity

Switch to sql shell by entering

Execute the below three lines (one by one)
ALTER USER teamcity WITH ENCRYPTED password 'password';
CREATE DATABASE teamcity OWNER teamcity;

type exit to come out of postgres user.

TeamCity Installation

Download Java
sudo apt-get update && sudo apt-get install default-jdk -y

Download TeamCity


Extract TeamCity
tar -xvf TeamCity-2020.1.5.tar.gz
sudo mkdir /opt/JetBrains
sudo mv TeamCity /opt/JetBrains/TeamCity
cd /opt/JetBrains/TeamCity
Create service file

sudo nano /etc/init.d/teamcity
(copy the whole text colored in green)
# Provides:          TeamCity autostart
# Required-Start:    $remote_fs $syslog
# Required-Stop:     $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Start teamcity daemon at boot time
# Description:       Enable service provided by daemon.
# /etc/init.d/teamcity -  startup script for teamcity

#  Ensure you enter the  right  user name that  TeamCity will run  under

export TEAMCITY_DATA_PATH="/opt/JetBrains/TeamCity/.BuildServer"

case $1 in

  start-stop-daemon --start  -c $USER --exec /opt/JetBrains/TeamCity/bin/ start
  start-stop-daemon --start -c $USER  --exec  /opt/JetBrains/TeamCity/bin/ stop

exit 0

Ctrl + O enter
Ctrl + X enter
sudo chmod +x /etc/init.d/teamcity
sudo update-rc.d teamcity defaults
sudo /etc/init.d/teamcity start

Access logs files
cat /opt/JetBrains/TeamCity/buildAgent/logs/teamcity-agent.log

Now access Teamcity UI

Open browser and access team city url in the browser

Click on Proceed.
Select database type as jdbc driver as Postgres SQL from the dropdown and Click on Proceed.

now you need to download the jdbc driver at below location.
cd /opt/JetBrains/TeamCity/.BuildServer/lib/jdbc
sudo wget

Select database type as PostgreSQL
Refresh JDBC driver
You should see like this —> Loaded PostgreSQL JDBC driver version: 9.4

Now provide the below info
Enter database Host - localhost
Enter database name - teamcity
User name - teamcity
Password - password
Click on Proceed

please wait and watch..As It may take a few mins…

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