docs: better docs, mv doxygen to sphinx

This patch refactors the VPP sphinx docs
in order to make it easier to consume
for external readers as well as VPP developers.

It also makes sphinx the single source
of documentation, which simplifies maintenance
and operation.

Most important updates are:

- reformat the existing documentation as rst
- split RELEASE.md and move it into separate rst files
- remove section 'events'
- remove section 'archive'
- remove section 'related projects'
- remove section 'feature by release'
- remove section 'Various links'
- make (Configuration reference, CLI docs,
  developer docs) top level items in the list
- move 'Use Cases' as part of 'About VPP'
- move 'Troubleshooting' as part of 'Getting Started'
- move test framework docs into 'Developer Documentation'
- add a 'Contributing' section for gerrit,
  docs and other contributer related infos
- deprecate doxygen and test-docs targets
- redirect the "make doxygen" target to "make docs"

Type: refactor

Change-Id: I552a5645d5b7964d547f99b1336e2ac24e7c209f
Signed-off-by: Nathan Skrzypczak <nathan.skrzypczak@gmail.com>
Signed-off-by: Andrew Yourtchenko <ayourtch@gmail.com>

1 files changed, 121 insertions, 0 deletions

diff --git a/docs/gettingstarted/running/index.rst b/docs/gettingstarted/running/index.rst
new file mode 100644
index 00000000000..626be6c7deb
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+++ b/docs/gettingstarted/running/index.rst
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+.. _running:
+
+Running VPP
+===========
+
+.. toctree::
+
+Usergroup
+---------
+
+When VPP is installed, a new usergroup *'vpp'* is created. To avoid running the
+VPP CLI (vppctl) as root, add any existing users to the new group that need to
+interact with VPP:
+
+.. code-block:: console
+
+    $ sudo usermod -a -G vpp user1
+
+Update your current session for the group change to take effect:
+
+.. code-block:: console
+
+    $ newgrp vpp
+
+
+Systemd File vpp.service
+------------------------
+
+When the VPP is installed, a systemd service files is also installed. This
+file, vpp.service (Ubuntu: /lib/systemd/system/vpp.service and CentOS:
+/usr/lib/systemd/system/vpp.service), controls how VPP is run as a service. For
+example, whether or not to restart on failure and if so, with how much delay.
+Also, which UIO driver should be loaded and location of the *'startup.conf'*
+file.
+
+.. code-block:: console
+
+    $ cat /usr/lib/systemd/system/vpp.service
+    [Unit]
+    Description=Vector Packet Processing Process
+    After=syslog.target network.target auditd.service
+
+    [Service]
+    ExecStartPre=-/bin/rm -f /dev/shm/db /dev/shm/global_vm /dev/shm/vpe-api
+    ExecStartPre=-/sbin/modprobe uio_pci_generic
+    ExecStart=/usr/bin/vpp -c /etc/vpp/startup.conf
+    Type=simple
+    Restart=on-failure
+    RestartSec=5s
+
+    [Install]
+    WantedBy=multi-user.target
+
+.. note::
+
+    Some older versions of the *'uio_pci_generic'* driver don't bind all
+    the supported NICs properly, so the *'igb_uio'* driver built from DPDK
+    needs to be installed. This file controls which driver is loaded at boot.
+    *'startup.conf'* file controls which driver is used.
+
+Huge Pages
+----------
+
+VPP requires *hugepages* to run during VPP operation, to manage large pages of memory.
+During VPP installation, VPP will overwrite the existing hugepage settings.
+By default, VPP sets the number of hugepages on a system to 1024 2M hugepages.
+This is the number of hugepages on the system, not just used by VPP.
+
+When VPP is installed, the following configuration file is copied to the system. The
+hugepage settings are applied in the VPP installation and on system reboots. To set
+the hugepage settings, perform the following commands:
+
+.. code-block:: console
+
+    $ cat /etc/sysctl.d/80-vpp.conf
+    # Number of 2MB hugepages desired
+    vm.nr_hugepages=1024
+
+    # Must be greater than or equal to (2 * vm.nr_hugepages).
+    vm.max_map_count=3096
+
+    # All groups allowed to access hugepages
+    vm.hugetlb_shm_group=0
+
+    # Shared Memory Max must be greater or equal to the total size of hugepages.
+    # For 2MB pages, TotalHugepageSize = vm.nr_hugepages * 2 * 1024 * 1024
+    # If the existing kernel.shmmax setting  (cat /sys/proc/kernel/shmmax)
+    # is greater than the calculated TotalHugepageSize then set this parameter
+    # to current shmmax value.
+    kernel.shmmax=2147483648
+
+Depending on how the system is being used, this configuration file can be updated to adjust
+the number of hugepages reserved on a system. Below are some examples of
+possible settings.
+
+For a small VM with minimal workload:
+
+.. code-block:: console
+
+    vm.nr_hugepages=512
+    vm.max_map_count=2048
+    kernel.shmmax=1073741824
+
+For a large system running multiple VMs, each needing its own set of hugepages:
+
+.. code-block:: console
+
+    vm.nr_hugepages=32768
+    vm.max_map_count=66560
+    kernel.shmmax=68719476736
+
+
+.. note::
+
+    If VPP is being run in a Virtual Machine (VM), the VM must have hugepage
+    backing. When VPP is installed, it will attempt to overwrite existing the
+    hugepage setting. If the VM does not have hugepage backing, the install will fail,
+    but the failure may go unnoticed. When the VM is rebooted, on system startup,
+    *'vm.nr_hugepages'* will be reapplied, and will fail, and the VM will abort kernel
+    boot, locking up the VM. To avoid this scenario, ensure the VM has enough
+    hugepage backing.