Jsonnet support

[ngtuna]

This supports deploy kubeapps components via the kubeapps.jsonnet file.

$ d=$PWD/kubeapps-manifest
$ git clone --recurse-submodules /~https://github.com/kubeapps/manifest $d
$ export KUBECFG_JPATH=$d/lib:$d/vendor/kubecfg/lib:$d/vendor/ksonnet-lib
$ kubeapps up --file $d/kubeapps.jsonnet
$ kubeapps down --file $d/kubeapps.jsonnet

[anguslees]

There's nothing wrong with this PR, but I'm confused where the kubeapps/installer codebase is going. We seem to have too many features for experimentation (imo) compared to the final goal as a single-file, just-works installer.

Is the final version going to support external, or internal embedded files? as YAML, or jsonnet?
Is it intended as a platform for us as devs to easily experiment with new files, or for end users? (does it offer anything beyond what a simple shell script would do for experimentation?)

[ngtuna]

There's nothing wrong with this PR, but I'm confused where the kubeapps/installer codebase is going. We seem to have too many features for experimentation (imo) compared to the final goal as a single-file, just-works installer.

That's true. However, this is not the final state of the kubeapps/installer. I am adding support for kubeapps.jsonnet file only for development purpose that means we can update the file and easily try kubeapps up. We won't embed the content of it into the installer code at this stage IMO until we release it.

Is the final version going to support external, or internal embedded files? as YAML, or jsonnet?
Is it intended as a platform for us as devs to easily experiment with new files, or for end users? (does it offer anything beyond what a simple shell script would do for experimentation?)

The final version is for end users and we are already clear about the UX. Right now I am just trying to go over the scope for testing both yaml and jsonnet files. We haven't decided to go with YAML or jsonnet or both yet. I am fine with those options. I won't merge this PR until we agree on supporting jsonnet, otherwise I will just close it.

[sebgoa]

@ngtuna we should embed the manifests right now.

it should be a very simple tool with two (maximum three commands): up and dashboard

The up just applys the manifests that are embedded. I don't know if we can embed jsonnet manifests from kubeapps/manifests or if those need to be expanded prior to being embedded.

Then we need some minimal testing

[ngtuna]

Should be closed now. We can open this discussion and implement in future if we think it's worth to use jsonnet file.