Add more document and fix dockerfile for CentOS

Add how to build container from dockerfile and add missing config
for CentOS dockerfile. This fix is verified that functest/yeardstick
are called successfully under debug/proposed_tests testsuite.

Change-Id: Icb31331ecd78b8fccd69ac960c24340b605e54bf
Signed-off-by: Tomofumi Hayashi <tohayash@redhat.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/docs/dovetailtool/dovetail.tool.installation.rst b/docs/dovetailtool/dovetail.tool.installation.rst
index 29ebe895..7826f33f 100644
--- a/docs/dovetailtool/dovetail.tool.installation.rst
+++ b/docs/dovetailtool/dovetail.tool.installation.rst
@@ -115,8 +115,16 @@ Pull Dovetail Docker image from public Dockerhub
 
 <Tag> here is the version, 'latest' is used for the master branch.
 
-As an alternative way, you can build own docker image from Dockfile(s) under ``docker/`` directory,
-``Dockerfile`` is based on ubuntu system and ``Dockerfile.centos7`` is for centos7.
+(Optional) Create Docker image from Dockerfile
+-----------------------------------------------
+Instead of an official Docker image, you can build your own Docker image from
+Dockerfile(s) located under the ``docker/`` directory. The ``Dockerfile``
+is based on Ubuntu and the ``Dockerfile.centos7`` file is for a CentOS based
+Docker image.
+
+::
+
+  sudo docker build -t <your_new_image_name> -f <your_Dockerfile> .
 
 Dovetail Docker container creation
 ----------------------------------