Removing extra docs

Author: tapaswenipathak

docs/builds.rst

@@ -172,6 +172,104 @@ If you're having trouble getting your version to build, try wiping out the exist
 Build environment
 -----------------
 
+Build environments use `Docker`_ to handle container virtualization. To perform
+any development on the Docker build system, you will need to set up `Docker`_ on
+your host system. Setup of Docker will vary by system, and so is out of the
+scope of this documentation.
+
+Once you have Docker set up, you will need to pull down our build image. These
+images are found on our `Docker Hub repository`_, the source comes from our
+`container image repo`_.
+
+.. note:: The size of the Docker images is around 5 to 9 GB.
+
+To get started using Docker for build environments, you'll need to pull down at
+least one build image. For example, to pull down our latest image::
+
+    docker pull readthedocs/build:latest
+
+The default image used by our build servers is :djangosetting:`DOCKER_IMAGE`.
+This would be a good place to start testing as the ``latest`` version could
+operate differently. See ``DOCKER_IMAGE`` below for setting this configuration
+option.
+
+After this image is downloaded, you can update your settings to use the new
+image -- see `Configuration`_.
+
+.. _`Docker`: http://docker.com
+.. _`Docker Hub repository`: https://hub.docker.com/r/readthedocs/build/
+.. _`container image repo`: https://github.com/readthedocs/readthedocs-docker-images
+
+Configuration
+-------------
+
+There are several settings used to configure usage of virtual machines:
+
+DOCKER_ENABLE
+    True/False value used to enable the Docker build environment.
+
+    Default: :djangosetting:`DOCKER_ENABLE`
+
+DOCKER_LIMITS
+    A dictionary of limits to virtual machines. These limits include:
+
+        time
+            An integer representing the total allowed time limit (in
+            seconds) of build processes. This time limit affects the parent
+            process to the virtual machine and will force a virtual machine
+            to die if a build is still running after the allotted time
+            expires.
+
+        memory
+            The maximum memory allocated to the virtual machine. If this
+            limit is hit, build processes will be automatically killed.
+            Examples: '200m' for 200MB of total memory, or '2g' for 2GB of
+            total memory.
+
+    Default: :djangosetting:`DOCKER_LIMITS`
+
+DOCKER_IMAGE
+    Tag of a Docker image to use as a base image.
+
+    Default: :djangosetting:`DOCKER_IMAGE`
+
+DOCKER_SOCKET
+    URI of the socket to connect to the Docker daemon. Examples include:
+    ``unix:///var/run/docker.sock`` and ``tcp://127.0.0.1:2375``.
+
+    Default: :djangosetting:`DOCKER_SOCKET`
+
+DOCKER_VERSION
+    Version of the API to use for the Docker API client.
+
+    Default: :djangosetting:`DOCKER_VERSION`
+
+
+Local development
+-----------------
+
+On Linux development environments, it's likely that your UID and GID do not
+match the ``docs`` user that is set up as the default user for builds. In this
+case, it's necessary to make a new image that overrides the UID and GID for the
+normal container user::
+
+    contrib/docker_build.sh latest
+
+This will create a new image, ``readthedocs/build-dev:latest``. To build a
+different image, you can instead specify a version to build::
+
+    contrib/docker_build.sh 5.0
+
+This will create a new image, ``readthedocs/build-dev:5.0``.
+
+You can set a ``local_settings.py`` option to automatically patch the image
+names to the development image names that are built here:
+
+DOCKER_USE_DEV_IMAGES
+    If set to ``True``, replace the normal Docker image name used in building
+    ``readthedocs/build`` with the image name output for these commands,
+    ``readthedocs/build-dev``.
+
 The *Sphinx* and *Mkdocs* builders set the following RTD-specific environment variables when building your documentation:
 
 .. csv-table::
@@ -188,3 +286,6 @@ The *Sphinx* and *Mkdocs* builders set the following RTD-specific environment va
    In case extra environment variables are needed to the build process (like secrets, tokens, etc),
    you can add them going to :guilabel:`Admin` > :guilabel:`Environment Variables` in your project.
    See :doc:`guides/environment-variables`.
+
+
+