docs: cleaning up VPP documents by deleting unnecessary info.

- cleaned up the 'build/run VPP' docs

Type: docs

Signed-off-by: Saima Yunus <yunus.saima.99@gmail.com>
Change-Id: I9dbddbe1932804b8d507cb2f1631cd7116e59072

2 files changed, 111 insertions, 2 deletions

diff --git a/docs/developer/build-run-debug/building.rst b/docs/developer/build-run-debug/building.rst
index 1df838abf84..d01eff7bf8f 100644
--- a/docs/developer/build-run-debug/building.rst
+++ b/docs/developer/build-run-debug/building.rst
@@ -3,11 +3,95 @@
 .. toctree::
 
 Building VPP
-============
+=====================
 
 To get started developing with VPP, you need to get the required VPP sources and then build the packages.
 For more detailed information on the build system please refer to :ref:`buildsystem`.
 
+.. _makesureinstalled:
+
+VPP for Ubuntu: Environment Setup
+-------------------------------------------
+
+If you are not downloading VPP on Ubuntu with WSL (Windows Subsystem for Linux), please disregard this section
+and jump to 'Get the VPP Sources'.
+
+Before starting on VPP for Ubuntu, make sure WSL2 and Ubuntu are installed.
+
+To install WSL2 and Ubuntu, run Windows PowerShell as an administrator and enter this in the terminal:
+
+.. code-block:: console
+
+    $ wsl --install
+
+Next, go to the 'resolv.conf' file in Ubuntu's '/etc' folder.
+It should have been automatically generated when Ubuntu was installed; if it doesn't exist, create it.
+Please use 'sudo' to avoid "File resolv.conf is unwritable" errors.
+
+.. code-block:: console
+
+    $ cd /etc
+    $ sudo nano resolv.conf
+
+In the file, add the following content in place of the current 'nameserver X.X.X.X' line:
+
+.. code-block:: console
+
+    nameserver 8.8.8.8
+
+This replaces the DNS nameserver on your machine with the Google DNS service,
+resolving any DNS Internet connection issues.
+
+Note: by default, the 'resolv.conf' file regenerates every time you restart Ubuntu, so your changes won't be saved.
+To keep your changes, run the following command to make 'resolv.conf' immutable:
+
+.. code-block:: console
+
+    $ sudo chattr +i /etc/resolv.conf
+
+
+Now copy the following lines from 'resolv.conf':
+
+.. code-block:: console
+
+    [network]
+    generateResolvConf = false
+
+Then, go to the 'wsl.conf' file in '/etc' and paste the lines there.
+Please use 'sudo' here as well to avoid "File wsl.conf is unwritable" errors.
+
+.. code-block:: console
+
+    $ sudo nano wsl.conf
+
+In order to test your DNS server connection, please ping 8.8.8.8 on the terminal:
+
+.. code-block:: console
+
+    $ ping 8.8.8.8
+    PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
+    64 bytes from 8.8.8.8: icmp_seq=1 ttl=116 time=9.58 ms
+    64 bytes from 8.8.8.8: icmp_seq=2 ttl=116 time=45.8 ms
+    64 bytes from 8.8.8.8: icmp_seq=3 ttl=116 time=9.62 ms
+    64 bytes from 8.8.8.8: icmp_seq=4 ttl=116 time=11.4 ms
+    64 bytes from 8.8.8.8: icmp_seq=5 ttl=116 time=12.2 ms
+    64 bytes from 8.8.8.8: icmp_seq=6 ttl=116 time=8.69 ms
+    64 bytes from 8.8.8.8: icmp_seq=7 ttl=116 time=52.4 ms
+    64 bytes from 8.8.8.8: icmp_seq=8 ttl=116 time=11.0 ms
+    ...
+
+While still in /etc, run the following commands:
+
+.. code-block:: console
+
+    $ sudo apt-get update
+    $ sudo apt-get dist-upgrade
+    $ sudo apt-get install --reinstall ca-certificates
+    $ sudo update-ca-certificates
+
+
+Finally, head back to your home directory and jump to 'Get the VPP Sources'.
+
 .. _setupproxies:
 
 Set up Proxies
@@ -45,6 +129,13 @@ installed, by entering the following commands:
 
 There should be no output, or no packages shown after the above commands are run.
 
+Please make sure **make** is installed before running the next command.
+If it is not installed, run the following command first:
+
+.. code-block:: console
+
+    $ sudo apt install make
+
 Run the following **make** command to install the dependencies for FD.io VPP.
 
 If the download hangs at any point, then you may need to
@@ -119,9 +210,19 @@ Use the following **make** command below to build the release version of FD.io V
 
     $ make build-release
 
+Installing External Dependencies
+-------------------------------------------
+At this point, there are still some VPP external dependencies left to install. They could be installed
+using 'make-build', but this only installs them locally in the VPP tree, not in the operating system.
+In order to fix this and save time, run the following command:
+
+.. code-block:: console
+
+    $ make install-ext-deps
 
+-------------------------------------------
 Building Necessary Packages
---------------------------------------------
+-------------------------------------------
 
 The package that needs to be built depends on the type system VPP will be running on:
 
diff --git a/docs/developer/build-run-debug/running_vpp.rst b/docs/developer/build-run-debug/running_vpp.rst
index 9b33e53ec60..2c9725727da 100644
--- a/docs/developer/build-run-debug/running_vpp.rst
+++ b/docs/developer/build-run-debug/running_vpp.rst
@@ -33,6 +33,13 @@ _________________________
 
 With the following commands you can run VPP and then be dropped into the GDB prompt.
 
+Before running either command, please make sure that the 'gdb' package is installed.
+If it's not installed, run the following command first:
+
+.. code-block:: console
+
+   $ sudo apt install gdb
+
 Running the release image:
 
 .. code-block:: console
@@ -46,3 +53,4 @@ Running the debug image:
 
    # make debug
    (gdb)
+