Update how-to guide for offline installation (#5440)

* Update how-to guide for offline installation

* Update site/content/docs/latest/howto/offline-installation.md

site/content/docs/latest/howto/offline-installation.md

@@ -1,64 +1,100 @@
 # Offline Installation of Kubeapps
 
-Since the version 1.10.1 of Kubeapps (Chart version 3.7.0), it's possible to successfully install Kubeapps in an offline environment. To be able to able to install Kubeapps without Internet connection, it's necessary to:
+## Table of Contents
 
-- Pre-download the Kubeapps chart.
+1. [Introduction](#introduction)
+2. [Pre-requisites](#pre-requisites)
+3. [Step 1. Download the Kubeapps chart](#step-1-download-the-kubeapps-chart)
+4. [Step 2. Mirror Kubeapps images](#step-2-mirror-kubeapps-images)
+5. [Step 3. [Optional] Prepare an offline Package Repository](#step-3-optional-prepare-an-offline-package-repository)
+6. [Step 4. Install Kubeapps](#step-4-install-kubeapps)
+
+## Introduction
+
+[Kubeapps](https://kubeapps.dev/) provides a cloud-native solution to browse, deploy and manage the lifecycle of applications on a Kubernetes cluster. It is a one-time install that gives you many important benefits, including the ability to:
+
+- browse and deploy packaged applications from public or private repositories
+- customize deployments through an intuitive user interface
+- upgrade, manage and delete the applications that are deployed in your Kubernetes cluster
+- expose an API to manage your package repositories and your applications
+
+This guide explains in detail how to **install Kubeapps in an air-gapped environment**.
+
+## Pre-requisites
+
+To be able to able to install Kubeapps without an Internet connection, it's necessary to:
+
+- Kubernetes cluster (air-gapped).
+- Pre-download the Kubeapps Helm chart.
 - Mirror Kubeapps images so they are accessible within the cluster.
 - [Optional] Have one or more offline Package Repositories.
 
-## 1. Download the Kubeapps chart
+> **Note**: Internet connection is necessary at this point to download charts and images for an offline installation
+
+## Step 1. Download the Kubeapps chart
 
-First, download the tarball containing the Kubeapps chart from the publicly available repository maintained by Bitnami. Note that Internet connection is necessary at this point:
+First, download the tarball containing the Kubeapps chart from the publicly available repository maintained by Bitnami.
 
 ```bash
-helm pull --untar https://charts.bitnami.com/bitnami/kubeapps-4.0.4.tgz
+helm pull --untar https://charts.bitnami.com/bitnami/kubeapps-x.y.z.tgz
 helm dep update ./kubeapps
 ```
 
-> Latest version of this chart available at the Bitnami Chart [Repository](https://github.com/bitnami/charts/blob/master/bitnami/kubeapps/Chart.yaml#L3)
+> Notice `x.y.z` must be replaced by the latest version of the Kubeapps chart available at the [Bitnami Chart Repository](https://github.com/bitnami/charts/blob/master/bitnami/kubeapps/Chart.yaml#L3)
 
-## 2. Mirror Kubeapps images
+## Step 2. Mirror Kubeapps images
 
-In order to be able to install Kubeapps, it's necessary to either have a copy of all the images that Kubeapps requires in each node of the cluster or push these images to an internal Docker registry that Kubernetes can access. You can obtain the list of images by checking the `values.yaml` of the chart. For example:
+To be able to install Kubeapps, it's necessary to either have a copy of all the images that Kubeapps requires in each node of the cluster or push these images to an internal Docker registry that Kubernetes can access. You can obtain the list of images by checking the [`values.yaml` file](https://github.com/bitnami/charts/blob/master/bitnami/kubeapps/values.yaml) of the chart. For example:
 
 ```yaml
 registry: docker.io
 repository: bitnami/nginx
 tag: 1.19.2-debian-10-r32
 ```
 
-> This list includes but is not limited to: `bitnami/kubeapps-apprepository-controller`, `bitnami/kubeapps-asset-syncer`, `bitnami/kubeapps-dashboard`, `bitnami/kubeapps-pinniped-proxy`, `bitnami/kubeapps-apis`, `bitnami/nginx`, `bitnami/oauth2-proxy`, `bitnami/postgresql`.
+> The list of images to download includes (could change in time):
+>
+> - `bitnami/nginx`
+> - `bitnami/kubeapps-dashboard`
+> - `bitnami/kubeapps-apprepository-controller`
+> - `bitnami/kubeapps-asset-syncer`
+> - `bitnami/oauth2-proxy`
+> - `bitnami/kubeapps-pinniped-proxy`
+> - `bitnami/kubeapps-apis`
+> - `bitnami/postgresql`
 
-For simplicity, in this guide, we use a single-node cluster created with [Kubernetes in Docker (`kind`)](https://github.com/kubernetes-sigs/kind). In this environment, as the images have to be preloaded, we first have to pull the images (`docker pull`) and next load them into the cluster (`kind load docker-image`):
+For simplicity, in this guide, use a single-node cluster created with [Kubernetes in Docker (`kind`)](https://github.com/kubernetes-sigs/kind), using a namespace called "kubeapps". In this environment, the images have to be pre-loaded: - first, pull the images (`docker pull`), - next load them into the cluster (`kind load docker-image`).
 
 ```bash
 docker pull bitnami/nginx:1.19.2-debian-10-r32
 kind load docker-image bitnami/nginx:1.19.2-debian-10-r32
 ```
 
-In case you are using a private Docker registry, you will need to re-tag the images and push them:
+> **Note**: tags must be updated according to the version of the images in the [`values.yaml` file](https://github.com/bitnami/charts/blob/master/bitnami/kubeapps/values.yaml)
+
+In case you are using a private Docker registry, you need to re-tag the images and push them:
 
 ```bash
 docker pull bitnami/nginx:1.19.2-debian-10-r32
 docker tag bitnami/nginx:1.19.2-debian-10-r32 REPO_URL/bitnami/nginx:1.19.2-debian-10-r32
 docker push REPO_URL/bitnami/nginx:1.19.2-debian-10-r32
 ```
 
-You will need to follow a similar process for every image present in the values file.
+Follow the same process for every image present in the values file.
 
-## 3. [Optional] Prepare an offline Package Repository
+## Step 3. [Optional] Prepare an offline Package Repository
 
-By default, Kubeapps install the `bitnami` Package Repository. Since, in order to sync that repository, it's necessary to have Internet connection, you will need to mirror it or create your own repository (e.g. using Harbor) and configure it when installing Kubeapps.
+By default, Kubeapps install the `bitnami` Package Repository. Since, to sync that repository, it's necessary to have an Internet connection, you will need to mirror it or create your repository (e.g. using Harbor) and configure it when installing Kubeapps.
 
-For more information about how to create a private repository, follow this [guide](./private-app-repository.md).
+For more information about how to create a private repository, follow this [how-to guide](./private-app-repository.md).
 
-## 4. Install Kubeapps
+## Step 4. Install Kubeapps
 
 Now that you have everything pre-loaded in your cluster, it's possible to install Kubeapps using the chart directory from the first step:
 
-**NOTE**: If during step 2), you were using a private docker registry, it's necessary to modify the global value used for the registry. This can be set by specifying `--set global.imageRegistry=REPO_URL`.
-If this registry, additionally, needs an ImagePullSecret, specify it with `--set global.imagePullSecrets[0]=SECRET_NAME`.
-
 ```bash
-helm install kubeapps ./kubeapps [OPTIONS]
+helm install kubeapps [OPTIONS] ./kubeapps
 ```
+
+**NOTE**: If during step 2), you were using a private docker registry, it's necessary to modify the global value used for the registry. This can be set by specifying `--set global.imageRegistry=REPO_URL`.
+If this registry, additionally, needs an ImagePullSecret, specify it with `--set global.imagePullSecrets[0]=SECRET_NAME`.