feat: Rewrite the Tensorboards Web App charm following the sidecar pattern

.github/workflows/integrate.yaml

@@ -60,7 +60,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        charm: [tensorboard-controller]
+        charm: [tensorboard-controller, tensorboards-web-app]
 
     steps:
       - name: Check out code

.gitignore

@@ -4,3 +4,4 @@ build/
 __pycache__
 *.charm
 .idea
+.vscode

README.md

@@ -14,13 +14,13 @@ To get started, install Kubeflow lite bundle (See [Quick start guide](https://ch
 
 Then, deploy Tensorboard Controller and Tensorboard Web App with
 ```bash
-juju deploy tensorboard-controller --channel=latest/edge
-juju deploy tensorboards-web-app --channel=latest/edge
+juju deploy tensorboard-controller --channel=latest/edge --trust
+juju deploy tensorboards-web-app --channel=latest/edge --trust
 ```
 And Create the following relations
 ```bash
 juju relate istio-pilot:ingress tensorboards-web-app:ingress
-juju relate istio-pilot:gateway tensorboard-controller:gateway
+juju relate istio-pilot:gateway-info tensorboard-controller:gateway-info
 ```
 For a quick example on using Tensorboard, see https://charmed-kubeflow.io/docs/kubeflow-basics
 For more information, see https://juju.is/docs

charms/tensorboards-web-app/CONTRIBUTING.md

@@ -0,0 +1,71 @@
+# Contributing
+
+## Overview
+
+This document explains the processes and practices recommended for contributing enhancements to
+this operator.
+- Generally, before developing enhancements to this charm, you should consider [opening an issue
+  ](https://github.com/canonical/kubeflow-tensorboards-operator/issues) explaining your use case.
+- If you would like to chat with us about your use-cases or proposed implementation, you can reach
+  us at [Canonical Mattermost public channel](https://chat.charmhub.io/charmhub/channels/charm-dev) or [Discourse](https://discourse.charmhub.io/).
+- Familiarising yourself with the [Charmed Operator Framework](https://juju.is/docs/sdk) library will help you a lot when working on new features or bug fixes.
+- All enhancements require review before being merged. Code review typically examines
+  - code quality
+  - test coverage
+  - user experience for Juju administrators of this charm.
+- Please help us out in ensuring easy to review branches by rebasing your pull request branch onto
+  the `main` branch. This also avoids merge commits and creates a linear Git commit history.
+
+## Developing
+
+You can use the environments created by `tox` for development:
+
+```shell
+tox --notest -e unit
+source .tox/unit/bin/activate
+```
+
+### Testing
+
+```shell
+tox -e lint          # code style
+tox -e unit          # unit tests
+tox -e integration   # integration tests
+tox                  # runs 'lint' and 'unit' environments
+```
+
+## Build charm
+
+Build the Tensorboards Web App charm using:
+
+```shell
+charmcraft pack
+```
+
+## Upgrade manifests
+The charm uses Jinja2 templates in order to store manifests that need to be applied during its deployment. The process for upgrading them is:
+
+### Spot the differences between versions of a manifest file
+
+1. Install `kustomize` using the official documentation [instructions](https://kubectl.docs.kubernetes.io/installation/kustomize/)
+2. Clone [Kubeflow manifests](https://github.com/kubeflow/manifests) repo locally
+3. `cd` into the repo and checkout to the branch or tag of the target version.
+4. Build the manifests with `kustomize` and save the file:
+
+`kustomize build apps/tensorboard/tensorboards-web-app/upstream/overlays/istio >> rendered_manifest_vX.yaml`
+
+5. Checkout to the branch or tag of the version of the current manifest
+6. Build the manifest with `kustomize` (see step 4) and save the file
+7. Compare both files to spot the differences (e.g. using diff)
+
+### Introduce changes
+
+Once the comparison is done, add any changes to the relevant ClusterRoles and ClusterRoleBindings to the
+  `templates/auth_manifests.yaml.j2` file and remember to:
+  * Use the current model as the namespace
+  * Use the application name as the name of any ClusterRoles, ClusterRoleBindings, or ServiceAccounts.
+
+
+## Canonical Contributor Agreement
+
+Canonical welcomes contributions to the Charmed Training Operator. Please check out our [contributor agreement](https://ubuntu.com/legal/contributors) if you're interested in contributing to the solution.# Contributing

charms/tensorboards-web-app/README.md

@@ -1,17 +1,13 @@
-## Kubeflow Tensorboards Operator
+## Tensorboards Web App Operator
 
 ### Overview
-This charm encompasses the Kubernetes Python operator for Kubeflow Tensorboards (see
-[CharmHub](https://charmhub.io/?q=kubeflow-tensorboards)).
+This charm encompasses the Kubernetes Python operator for Kubeflow's Tensorboards Web App(see
+[CharmHub](https://charmhub.io/tensorboards-web-app)).
 
-The Kubeflow Tensorboards operator is a Python script that wraps the latest released version
-of Kubeflow Tensorboards, providing lifecycle management and handling events such as install,
+The Tensorboards Web App charmed operator is a Python script that wraps the latest released version
+of Kubeflow's Tensorboards Web App, providing lifecycle management and handling events such as install,
 upgrade, integrate, and remove.
 
-## Install
+## Usage
 
-To install Kubeflow Tensorboards, run:
-
-    juju deploy kubeflow-tensorboards
-
-For more information, see https://juju.is/docs
+This charm is an integral part of the Kubeflow Tensorboards Operator bundle. In order to install and use the whole bundle, please refer to the instructions [here](../../README.md#usage).

charms/tensorboards-web-app/config.yaml

@@ -1,14 +1,10 @@
-# Copyright 2021 Canonical Ltd.
+# Copyright 2023 Canonical Ltd.
 # See LICENSE file for licensing details.
 
 options:
-  port:
-    type: int
-    default: 5000
-    description: HTTP port
   backend-mode:
     type: string
-    default: development
+    default: production
     description: Which mode out of `development` or `production` the backend server should use
   secure-cookies:
     type: boolean