Make our docker-image more user-friendly

- move from ubuntu:14.04 base image to ubuntu:16.04 .
  Ubuntu 16.04 is current/latest LTS release. Let's use it.

- pre-install vim
  It is a "feaute request". Users like to experiment and modify samples
  inside container.

- pre-install bash-completion
  Rally provides bash-completion script, but uit doesn't work without
  installed `bash-completion` package.

- remove '-e' from execution of `echo`.
  This flag is not required, even more it is redundant.

- add sudo rights to rally user
  Rally is a pluggable framework. External plugins can require installation
  of additional python or system packages.

Change-Id: I9540343adbb48fded5531bd3c819396cdb7328df

Dockerfile

@@ -1,8 +1,8 @@
-FROM ubuntu:14.04
+FROM ubuntu:16.04
 MAINTAINER Sergey Skripnick <sskripnick@mirantis.com>
 
 # install prereqs
-RUN apt-get update && apt-get install --yes wget python
+RUN apt-get update && apt-get install --yes wget python vim bash-completion
 
 # ubuntu's pip is too old to work with the version of requests we
 # require, so get pip with get-pip.py
@@ -11,7 +11,10 @@ RUN wget https://bootstrap.pypa.io/get-pip.py && \
   rm -f get-pip.py
 
 # create rally user
-RUN useradd -u 65500 -m rally && \
+RUN apt-get install sudo && \
+  useradd -u 65500 -m rally && \
+  usermod -aG sudo rally && \
+  echo "rally ALL=(ALL) NOPASSWD:ALL" > /etc/sudoers.d/00-rally-user && \
   ln -s /opt/rally/doc /home/rally/rally-docs
 
 # install rally. the COPY command below frequently invalidates
@@ -25,7 +28,7 @@ RUN ./install_rally.sh --system --verbose --yes \
   # TODO(andreykurilin): build docs to rst before move, since we have several
   # extensions.
   mv certification/ samples/ doc/ /opt/rally/ && \
-  chmod -R u=rwX,go=rX /opt/rally /etc/rally && \
+  chown -R rally /opt/rally /etc/rally && \
   rm -rf /tmp/* && \
   apt-get -y remove \
     build-essential \
@@ -37,13 +40,16 @@ RUN ./install_rally.sh --system --verbose --yes \
   apt-get clean
 
 RUN echo '[ ! -z "$TERM" -a -r /etc/motd ] && cat /etc/motd' \
-            >> /etc/bash.bashrc; echo -e 'Welcome to Rally Docker container!\n\
-    Rally certification tasks, samples and docs are located at /opt/rally/\n\
-    Rally at readthedocs - http://rally.readthedocs.org\n\
-    How to contribute - http://rally.readthedocs.org/en/latest/contribute.html\n\
-    If you have any questions, you can reach the Rally team by:\n\
-      * e-mail - openstack-dev@lists.openstack.org with tag [Rally] in subject\n\
-      * irc - "#openstack-rally" channel at freenode.net' > /etc/motd
+            >> /etc/bash.bashrc; echo '\
+╔═════════════════════════════════════════════════════════════════════════════╗\n\
+║ Welcome to Rally Docker container!                                          ║\n\
+║  Rally certification tasks, samples and docs are located at /opt/rally/     ║\n\
+║  Rally at readthedocs - http://rally.readthedocs.org                        ║\n\
+║  How to contribute - http://rally.readthedocs.org/en/latest/contribute.html ║\n\
+║  If you have any questions, you can reach the Rally team by:                ║\n\
+║    * e-mail - openstack-dev@lists.openstack.org with tag [Rally] in subject ║\n\
+║    * irc - "#openstack-rally" channel at freenode.net                       ║\n\
+╚═════════════════════════════════════════════════════════════════════════════╝\n' > /etc/motd
 
 VOLUME ["/home/rally"]