docs: add installation instructions

Largely, this mirrors the README, but provides more information about
installing and upgrading from pip vs. using the git checkout directly.

Signed-off-by: Konstantin Ryabitsev <konstantin@linuxfoundation.org>

1 files changed, 67 insertions, 1 deletions

diff --git a/docs/installing.rst b/docs/installing.rst
index 82a8f54..e19baf3 100644
--- a/docs/installing.rst
+++ b/docs/installing.rst
@@ -1,4 +1,70 @@
 Installing b4
 =============
+B4 is packaged for many distributions, so chances are that you will be
+able to install it using your regular package installation commands,
+e.g.::
 
-Stub.
+    # dnf install b4
+
+or::
+
+    # apt install b4
+
+Note, that b4 is under heavy development, so it is possible that the
+version packaged for your distribution is not as recent as you'd like.
+If that is the case, you can install it from other sources.
+
+Installing with pip
+-------------------
+To install from pypi::
+
+    python3 -m pip install --user b4
+
+This will install b4 locally and pull in any required dependencies. If
+you are not able to execute ``b4 --version`` after pip completes, check
+that your ``~/.local/bin/`` is in your ``$PATH``.
+
+Upgrading
+~~~~~~~~~
+If you have previously installed from pypi, you can upgrade using pip as
+well::
+
+    python3 -m pip install --user --upgrade b4
+
+Running from the checkout dir
+-----------------------------
+If you want to run the latest development version of b4, you can run it
+directly from the git repository::
+
+    git clone https://git.kernel.org/pub/scm/utils/b4/b4.git
+    cd b4
+    git submodule update --init
+    pip install --user -r requirements.txt
+
+You can then either symlink the ``b4.sh`` script to your user-bin
+directory::
+
+    ln -sf $HOME/path/to/b4.sh ~/bin/b4
+
+or you can add an alias to your shell's RC file::
+
+    alias b4="$HOME/path/to/b4/b4.sh"
+
+Using a stable branch
+~~~~~~~~~~~~~~~~~~~~~
+If you don't want to use the master branch (which may not be stable),
+you can switch to a stable branch instead, e.g.::
+
+    git switch stable-0.9.y
+
+Updating the git checkout
+~~~~~~~~~~~~~~~~~~~~~~~~~
+It should be sufficient to just turn ``git pull``::
+
+    git pull origin master
+    git submodule update
+
+If you notice that ``requirements.txt`` has been updated, you may wish
+to run the pip command again::
+
+    pip install --user -r requirements.txt