helm-to-carvel-conversion-tool

A tool for converting any Helm Repository into a Carvel Package Repository including support for air gapped scenarios

Synopsis

One of the key strengths of the Carvel Packaging is that it is not only for YTT and KAPP rather can also manage things like helm.
In you will find a script that will generate a package repository and all the needed files from a helm repository which can be used in air gapped environments
This will also enable you to utilize these charts in an air gapped environment

Options for running the tool

Run the script on a linux machine directly

This gives the most flexibility but requires a lot of pre reqs on your system which are mentioned bellow in the Script based execution section

Utilize the Docker image ghcr.io/terasky-oss/helm-airgaping-tool:0.1.0

This allows for a very simple process to generate such a repo and can also be run on MAC (Windwos is also possible but requires some changes to the alias command)

Running the container

You will need docker installed on your machine
Login to the destination oci registry with docker CLI on your machine - the docker config.json with creds is mapped into the container to ease passing in credentials

If your docker config is using a command line tool like gcloud as a credential helper this will not work out of the box and will need manipulation of the alias command as those utils are not passed into the container.

docker login <REGISTRY FQDN>

Make sure that PWD and HOME env variables are set

echo $PWD
echo $HOME

Create a sub folder in your current directory called output

mkdir output

Create an alias for running the container easily with all needed mounts

alias helm-to-pkg="docker run -i -v $HOME/.docker/config.json:/root/.docker/config.json -v $PWD/output:/output ghcr.io/terasky-oss/helm-airgaping-tool:0.1.0"

OPTIONAL - If you want to supply a list of charts to package instead of the entire repo create a file named chart-list.txt in the current directory and update the alias from step 4

touch chart-list.txt
alias helm-to-pkg="docker run -i -v $HOME/.docker/config.json:/root/.docker/config.json -v $PWD/output:/output -v $PWD/chart-list.txt:/app/chart-list.txt ghcr.io/terasky-oss/helm-airgaping-tool:0.1.0"

Now fill in the chart names in the format <REPO NAME>/<CHART NAME> one per line
When running the tool you must pass the flag "--chart-list-file-path" with the value "/app/chart-list.txt"

Run the following to see detailed help menu on how to run the tool

helm-to-pkg --help

BASH Autocompletion - run the following commands to get bash auto completion for flags

source <(helm-to-pkg --bash-completion)

The outputted manifests will be available in the output directory you created above

Running the script

in order to run the script you will need to have pre installed:

jq - https://stedolan.github.io/jq/download/
yq - https://github.com/kislyuk/yq
readme-generator - https://github.com/bitnami-labs/readme-generator-for-helm
helm - helm v3+ - https://github.com/helm/helm
json2yml - https://www.npmjs.com/package/json2yaml
kbld and imgpkg - https://carvel.dev
helm schema-gen plugin - helm plugin https://github.com/karuppiah7890/helm-schema-gen

Once this is all installed run the following to see the commandline flags:

./helm-to-pkg --help

Example Usage:

./helm-to-pkg.sh \
    --helm-repo-name bitnami \
    --helm-repo-url https://charts.bitnami.com/bitnami \
    --number-of-chart-versions 4 \
    --package-repository-name bitnami-oss \
    --oci-image-repository bitnami-charts \
    --oci-registry-fqdn harbor.example.com \
    --package-domain-suffix bitnami.charts

Parameterized instructions for using the generated repo will be printed at the end of the script execution.

General Usage Instructions

Installing the package repo in a non air gapped environment

You can choose either of the following options:

Add as a global package to your tanzu cluster with default settings:

    tanzu package repository add <PACKAGE REPOSITORY NAME> --url <PACKAGE REPOSITORY URL> --namespace tanzu-package-repo-global

Add as a global package to your tanzu cluster with custom sync interval:

    ## If run with the docker mode 
    # cd output
    ## If run via script directly run:
    # cd /tmp/carvel-bitnami-packages/

    ## For both cases run
    kubectl apply -n tanzu-package-repo-global -f package-repository-manifest.yaml

Air Gapped Instructions

Run the following command to copy all packages and images into a tar ball on your machine:

    imgpkg copy -b harbor.example.com/bitnami-charts/bitnami-oss:latest --to-tar /tmp/bitnami-oss.tar --registry-verify-certs=false

Import the Tar file to the airgapped environment
Run the following to import the artifacts to an OCI registry in your air gapped environment:

    imgpkg copy --tar /tmp/bitnami-oss.tar --to-repo <AIR GAPPED REGISTRY>/<AIR GAPPED REPO> --registry-verify-certs=false

Add the repo to your cluster with either of the following options:

Add as a global package to your tanzu cluster with default settings:

    tanzu package repository add <PACKAGE REPOSITORY NAME> --url <AIR GAPPED REGISTRY>/<AIR GAPPED REPO>:<PACKAGE REPO TAG> --namespace tanzu-package-repo-global

Add as a global package to your tanzu cluster with custom sync interval:
** edit the generated manifest package-repository-manifest.yaml and change the image reference to your airgapped environment
** add the repo to your cluster

    kubectl apply -n tanzu-package-repo-global -f package-repository-manifest.yaml

TeraSky-OSS/helm-to-carvel-conversion-tool