New to Kubepack? Please start here.

Scenario-8

This docs explain how Pack works inside cluster.

In this scenario, we’ll do following things.

1. Create a git repository.

   • This repository requires test-kubed through dependency-list.yaml file.
   • Run $ pack dep -f . to get the dependencies and $ pack edit -f . -p <filepath> to make desired changes.
   • Then, run $ pack up -f . to final version under manifests/output folder.
   • Last, commit our changes to git repository.

2. Now, I write a pod yaml, you can see it here. In this pod, our above git repository mounted as volume path. Image a8uhnf/git-mount:1.0.0 checks the mounted path. If there is an manifest/output folder then it’ll apply $ kubectl apply -R -f <manifest/output folder path>.

Step by Step Guide

First, create a git repository

Create a dependency-list.yaml file in your git repository. Your dependency-list.yaml file will look like below.

    $ cat dependency-list.yaml

items:
 - package: github.com/kubepack/test-kubed
   branch: master

It depends on test-kubed’s master branch.

Now, run $ pack dep -f .. This command will get all the dependencies and place under manifests/vendor folder.

    $ tree manifests/vendor/

    manifests/vendor/
    └── github.com
        └── kubepack
            └── test-kubed
                ├── dependency-list.yaml
                └── manifests
                    └── app
                        ├── deployment.yaml
                        ├── kubed-config.yaml
                        └── service.yaml
    
    5 directories, 4 files

Now, you have all the dependencies.

Now, suppose you want to edit deployment.yaml file and make the replicas from 1 to 2.

Below command will open the deployment.yaml file in editor. Then made the changes.

    $ pack edit -f . -p manifests/vendor/github.com/kubepack/test-kubed/manifests/app/deployment.yaml

This command will generate a patch file under manifests/patch folder.

    $ tree manifests/patch/

    manifests/patch/
    └── github.com
        └── kubepack
            └── test-kubed
                └── kubed-operator.deployment.extensions.yaml
    
    3 directories, 1 file

Then, run $ pack up -f ., which will combine original and patch file and place under manifests/output folder.

    $ tree manifests/output/

    manifests/output/
    └── github.com
        └── kubepack
            └── test-kubed
                └── manifests
                    └── app
                        ├── deployment.yaml
                        ├── kubed-config.yaml
                        └── service.yaml
    
    5 directories, 3 files

Now, last step, commit the whole thing and push it git repository.

Now, see below this yaml file.

    apiVersion: v1
    kind: Pod
    metadata:
      name: server
    spec:
      containers:
      - image: a8uhnf/git-mount:1.0.0
        imagePullPolicy: Always
        name: git-mount
        resources: {}
        volumeMounts:
        - mountPath: /mypath
          name: git-volume
      volumes:
      - gitRepo:
          repository: YOUR_GIT_REPO_LOCATION # https://github.com/kubepack/kube-a.git
          revision: GIT_REPO_REVISION_NUMBER # c90e98d6c0a6143c19a6e3a575befbdfa170fa00
        name: git-volume
    status: {}

change the above yaml file’s gitRepo.repository and gitRepo.revision to your repository location and revision.

    $ kubectl apply -f https://raw.githubusercontent.com/kubepack/kubepack/master/docs/_testdata/test-8/pod.yaml
    pod "server" created

This pod mount your git repository in /mypath in the container and if their is exist any manifests/output folder, then it’ll $ kubectl apply -R -f <output filepath>. You can check actual implementation here.

Now, you can see the all the desired kubernetes object in your cluster.

Next Steps

• Want to publish apps using Kubepack? Please visit here.
• Want to consume apps published using Kubepack? Please visit here.
• To learn about dependency-list.yaml file, please visit here.
• Learn more about pack cli from here.