churl (chart museum curl) is a utility for interacting with a Helm chart museum.
The default chart museum deployment does not include a kubernetes ingress, meaning that it's only accessible from within the kubernetes cluster, perhaps using it's service address (i.e., http://cm-chartmuseum.chartmuseum:8080/index.yaml). churl will create a kubernetes port-forwarding tunnel from a local machine and issue HTTP requests to retrieve charts and chart archives.
The Chart Museum is installed as a helm package, and the version of helm used makes no difference, however, the tests assume the usage of version 3.
churl is not meant to add, remove, or alter charts or chart archives. It's recommended to use helm commands for that purpose.
This project has several goals. First and foremost is to create a tool that helps me access a protected chart museum. There are several secondary goals:
In order to better understand the OneFlow branching stragey, it will be applied here. Reading about it does not impart the same level of undestanding as using it.
Github has made a number of CI/CD tools available to open source developers.
churl started as a bash script. The following is a much simplified version of the script.
#!/usr/bin/env bash
QUERY=$1
shift 1
# Set up the port forward to run in the background, but grab the PID so that we
# can terminate the forwarding when we're done.
kubectl port-forward svc/cm-chartmuseum 9000:8080 --address localhost --context "minikube" --namespace chartmuseum > /dev/null 2>&1 &
KUBEPID=$!
# Ensure that the port-forwarding process dies with this script.
closePortForward() {
kill $KUBEPID
}
trap closePortForward EXIT
sleep 10
curl -sL "http://localhost:9000/$QUERY"The port forward currently lives as long as the churl executable, however it is probably common to perform multiple requests. An improvement might be to spawn a long-lived background process that manages the port-forward, and closes after a period of inactivity. In this arrangement, the user's request is routed to the background process, which performs the actual request.
churl is tested with a local kubernetes & helm installation:
helm repo add stable https://kubernetes-charts.storage.googleapis.com
helm install stable/chartmuseum --name cm