Continuous Deployment to Kubernetes with Dynamic Jenkins Slave and Docker

Fasten your safety belt, and departing …..

1. Create a pipeline job.
2. Setup your SCM and build from Jenkinsfile (sample provided below).

Jenkins slave is docker, and we will use it to build our docker images, which means we will need to have a docker engine inside Jenkins slave docker (a.k.a docker in docker). Since I’m not able to make use of ready made docker image available @ docker hub as my jenkins slave (I need jdk, maven, kubectl… too as my jenkins slave) , so I created my own based on jenkins/jnlp-slave image.
To achieve DoD, we map the docker.sock from the host to our container (‘dockersock’ in k8s-jnlp-slave.yml).

3. Install plugins as below:
4.Create jenkins kubernetes plugin by adding new entry.

5. Fill in configuration according to your kubernetes cluster or use your kube config file by adding credential as highlighted below:

6. Regardless you configure manually or using your customize kube config file, you need to test the connection.
7. Build your job and you should see a new node created and start building.
Source available @ github.

Credits to authors and websites below:


Run Jenkins JLNP Slave In Kubernetes

  3. Take note on text highlighted in red as they are parameters use to spawn container in kubernetes later.
  4. Then go to your terminal and run your kubectl command as below (assume you have exported your kubeconfig).
    Note: Replace all environment variables we captured just now as images above.
  5. Refresh your slave node page and you will see it’s now up and running.

Example demonstrate above use Docker container from


Backup & Restore Keycloak Easy Way

Finding solution this morning and figure out this can be pretty handy.

  1. Run command below:

    In my case, i override few parameter as my keycloak is running.

  2. Once you get the backup file, you can selectively import from your admin console.

source from:


Deploy Keycloak With Custom Context Path in Kubernetes With Ingress

New to this and spend a day to figured out, perhaps this will help some of you.

1. Prepare your k8s template yaml.

2. Update web-context in <KEYCLOAK_HOME>/standalone/configuration/standalone.xml, standalone-ha.xml, or domain.xml depending on your operating mode.

3. Add proxy-address-forwarding under http-listerner in <KEYCLOAK_HOME>/standalone/configuration/standalone.xml, standalone-ha.xml, or domain.xml depending on your operating mode.

4. Update index.html in <KEYCLOAK_HOME>welcome-content/index.html



Keycloak Invalid parameter: redirect_uri

In case you also facing the same issue, may try 2 approaches as below:

1. If you are using Ingress in Kubernetes, you may need to add proxy-address-forwarding as below in standalone.xml, standalone-ha.xml, or domain.xml depending on your operating mode.

2. Set ‘*” for Valid Redirect URL (this is temporary hack, still figuring out why)

Credit to


Simple Yet Descriptive

Youtube pitch deck from Alexander Jarvis

AirBnB Pitch Deck from Malcolm Lewis


  Photographer: Lay


AWS Glacier CLI Command

Archived some of my files in Glacier for cold storage, jot down some note which I think useful.

To Download

Response as below, “InProgress” indicate it’s currently retrieving your vault information.

OK, tried few hours later and it showed “Succeeded”, go on…

Get archive list with command below which will lead to output written in archive.json.

Then create a json file with sample content below indicate which archive to download (I use download.json in this case)

Then execute command below:

You get response as:

Check the status job status:

Come back few hours/minutes, check the status and it’s now turn to “Succeeded”

Finally you can download your file with command below:

To Upload

To Delete


Credit to: &


Docker: exec user process caused “no such file or directory”

Have no idea why Docker showing this (un-friendly) error message.
In fact, it caused by the bash script file created in Windows having different line ending and cannot run properly in Linux container.

Here is the fix using Notepad++.
First show the linefeed symbol.

You will see this.

Convert the linefeed from Windows to Unix.

You will get this, and save it 🙂


Weird Spring Boot Behavior

Encountered a weird behavior when running my Spring Boot + JSF (PrimeFaces) application in Docker container (using java -jar xxx.jar as ENTRYPOINT). It keep complaining “xhtml Not Found in ExternalContext as a Resource” when I access the page, in fact that runs well either using java -jar command or mvn spring:run in host machine.

After some hard time,  manage to figure out why…….. phew….
… it was caused by wrong jar packaging structure, and correct structure should look as below:

Credit to BalusC @ stackoverflow