docs: mention client repository and rework client installation

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

docs/installation.rst

@@ -113,9 +113,9 @@ Client Installation
 Install `Proxmox Backup`_ Client on Debian
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-Proxmox ships as a set of Debian packages to be installed on
-top of a standard Debian installation. After configuring the
-:ref:`sysadmin_package_repositories`, you need to run:
+Proxmox ships as a set of Debian packages to be installed on top of a standard
+Debian installation. After configuring the :ref:`package_repositories_client_only_apt`,
+you need to run:
 
 .. code-block:: console
 
@@ -123,12 +123,6 @@ top of a standard Debian installation. After configuring the
   # apt-get install proxmox-backup-client
 
 
-Installing from source
-~~~~~~~~~~~~~~~~~~~~~~
+.. note:: The client-only repository should be useable by most recent Debian
+   and Ubuntu derivatives.
 
-.. todo:: Add section "Installing from source"
-
-Installing statically linked binary
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-.. todo:: Add section "Installing statically linked binary"

docs/package-repositories.rst

@@ -29,6 +29,8 @@ update``.
 In addition, you need a package repository from Proxmox to get Proxmox Backup
 updates.
 
+.. _package_repos_secure_apt:
+
 SecureApt
 ~~~~~~~~~
 
@@ -139,3 +141,40 @@ You can access this repository by adding the following line to
   :caption: sources.list entry for ``pbstest``
 
   deb http://download.proxmox.com/debian/pbs buster pbstest
+
+.. _package_repositories_client_only:
+
+Proxmox Backup Client-only Repository
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If you want to :ref:`use the the Proxmox Backup Client <client_creating_backups>`
+on systems using a Linux distribution not based on Proxmox projects, you can
+use the client-only repository.
+
+Currently there's only a client-repository for APT based systems.
+
+.. _package_repositories_client_only_apt:
+
+APT-based Proxmox Backup Client Repository
+++++++++++++++++++++++++++++++++++++++++++
+
+For modern Linux distributions using `apt` as package manager, like all Debian
+and Ubuntu Derivative do, you may be able to use the APT-based repository.
+
+This repository is tested with:
+
+- Debian Buster
+- Ubuntu 20.04 LTS
+
+It may work with older, and should work with more recent released versions.
+
+In order to configure this repository you need to first :ref:`setup the Proxmox
+release key <package_repos_secure_apt>`. After that, add the repository URL to
+the APT sources lists.
+Edit the file ``/etc/apt/sources.list.d/pbs-client.list`` and add the following
+snipped
+
+.. code-block:: sources.list
+  :caption: File: ``/etc/apt/sources.list``
+
+  deb http://download.proxmox.com/debian/pbs-client buster main

www/OnlineHelpInfo.js

@@ -5,7 +5,7 @@ const proxmoxOnlineHelpInfo = {
   },
   "client-repository": {
     "link": "/docs/backup-client.html#client-repository",
-    "title": "Repository Locations"
+    "title": "Backup Repository Locations"
   },
   "client-creating-backups": {
     "link": "/docs/backup-client.html#client-creating-backups",
@@ -51,10 +51,22 @@ const proxmoxOnlineHelpInfo = {
     "link": "/docs/package-repositories.html#sysadmin-package-repositories",
     "title": "Debian Package Repositories"
   },
+  "package-repos-secure-apt": {
+    "link": "/docs/package-repositories.html#package-repos-secure-apt",
+    "title": "SecureApt"
+  },
   "sysadmin-package-repos-enterprise": {
     "link": "/docs/package-repositories.html#sysadmin-package-repos-enterprise",
     "title": "`Proxmox Backup`_ Enterprise Repository"
   },
+  "package-repositories-client-only": {
+    "link": "/docs/package-repositories.html#package-repositories-client-only",
+    "title": "Proxmox Backup Client-only Repository"
+  },
+  "package-repositories-client-only-apt": {
+    "link": "/docs/package-repositories.html#package-repositories-client-only-apt",
+    "title": "APT-based Proxmox Backup Client Repository"
+  },
   "get-help": {
     "link": "/docs/introduction.html#get-help",
     "title": "Getting Help"