\documentclass[slidestop]{beamer}

\title{Git and remote repositories}
\providecommand{\myConference}{Git course}
\providecommand{\myDate}{Monday, October 14, 2013}
\author{Martijn Vermaat}
\providecommand{\myGroup}{Leiden Genome Technology Center}
\providecommand{\myDepartment}{Department of Human Genetics}
\providecommand{\myCenter}{Center for Human and Clinical Genetics}
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\usetheme{lumc}

\lstset{
  basicstyle=\ttfamily,
  language=none,
  frame=none,
  numbers=none,
  numbersep=0
}

\AtBeginSection[]
{
  \begin{frame}
    \frametitle{Table of contents}
    \tableofcontents[currentsection]
  \end{frame}
}

\begin{document}

% This disables the \pause command, handy in the editing phase.
%\renewcommand{\pause}{}

% Make the title page.
\bodytemplate


\section{Remote repositories}

\begin{frame}
  \frametitle{Distributed Git}
  Repositories can reference each other:
  \begin{itemize}
    \item A repository can be on a server, your desktop, your coworker's
      laptop, etc.
    \item Technically, no repository is `special'.
    \item We call a reference to another repository a {\em remote}.
  \end{itemize}
  \pause
  \bigskip
  \includegraphics[width=6cm]{images/repositories}
\end{frame}

\begin{frame}[fragile]
  \frametitle{Listing remotes}
  \begin{lstlisting}
$ git remote
gitlab
  \end{lstlisting}
  \bigskip
  We are on \bt{aida} and have one remote, \bt{gitlab}, defined.
  \pause
  \bigskip
  \begin{lstlisting}[basicstyle=\ttfamily\footnotesize]
$ git remote -v
gitlab  https://git.lumc.nl/m.vermaat.hg/tv-series.git (fetch)
gitlab  https://git.lumc.nl/m.vermaat.hg/tv-series.git (push)
  \end{lstlisting}
  \bigskip
  \bt{-v}: Include remote location.\\
  \vspace{1cm}
  We see that communication with \bt{gitlab} is over HTTPS.
\end{frame}

\begin{frame}[fragile]
  \frametitle{Adding a remote: \bt{git remote add}}
  \begin{lstlisting}
$ git remote add hue 192.168.0.8:projects/tv-series
  \end{lstlisting}
  \bigskip
  This adds a reference to the remote repository \bt{hue} using communication
  over SSH.
  \pause
  \bigskip
  \begin{lstlisting}[basicstyle=\ttfamily\footnotesize]
$ git remote -v
gitlab  https://git.lumc.nl/m.vermaat.hg/tv-series.git (fetch)
gitlab  https://git.lumc.nl/m.vermaat.hg/tv-series.git (push)
hue     192.168.0.8:projects/tv-series (fetch)
hue     192.168.0.8:projects/tv-series (push)
  \end{lstlisting}
\end{frame}

\begin{frame}
  \frametitle{Remote branches}
  You see code from remotes as {\em remote branches}:
  \begin{itemize}
    \item Remote branches are just branches prefixed with the remote name.
    \item Communicate with remotes to update the remote branches.
    \item You can setup a local branch to {\em track} a remote branch.
  \end{itemize}
  \pause
  \bigskip
  \includegraphics[width=10cm]{images/example}
\end{frame}

\begin{frame}[fragile]
  \frametitle{Listing remote branches: \bt{git branch}}
  \begin{lstlisting}
$ git branch -v
* master  f1ef19c State character preference
  \end{lstlisting}
  \bigskip
  This shows only our local branches.
  \pause
  \bigskip
  \begin{lstlisting}[basicstyle=\ttfamily\footnotesize]
$ git branch -v -a
* master                f1ef19c State character preference
  remotes/gitlab/master f1ef19c State character preference
  \end{lstlisting}
  \bigskip
  \bt{-a}: Include remote branches.
\end{frame}

\begin{frame}[fragile]
  \frametitle{Updating remote branches: \bt{git fetch}}
  \begin{lstlisting}
$ git fetch hue
remote: Counting objects: 5, done.
remote: Compressing objects: 100% (2/2), done.
remote: Total 3 (delta 0), reused 0 (delta 0)
Unpacking objects: 100% (3/3), done.
From 192.168.0.8:projects/tv-series
 * [new branch]      master     -> hue/master
 * [new branch]      simpsons   -> hue/simpsons
  \end{lstlisting}
  \pause
  \bigskip
  \includegraphics[width=10cm]{images/example-hue}
\end{frame}

\begin{frame}[fragile]
  \frametitle{Merging remote branches: \bt{git merge}}
  We can merge remote branches just like normal branches.
  \bigskip
  \begin{lstlisting}
$ git merge hue/simpsons
...
  \end{lstlisting}
  \pause
  \bigskip
  Alternatively, we could continue the work of a remote branch.
\end{frame}


\begin{frame}[fragile]
  \frametitle{Creating a local tracking branch: \bt{git checkout}}
  Remote branches are `read-only':
  \begin{itemize}
    \item We cannot directly continue work on a remote branch.
    \item But we can setup a local {\em tracking branch}.
  \end{itemize}
  \bigskip
  \begin{lstlisting}
$ git checkout simpsons
Branch simpsons set up to track remote branch
simpsons from hue.
Switched to a new branch 'simpsons'
  \end{lstlisting}
  \bigskip
  What happened here?
  \begin{itemize}
    \item There was no branch \bt{simpsons}.
    \item But there was a remote branch of the same name.
    \item So Git creates a new branch based on that (and switches to it).
  \end{itemize}
\end{frame}

\begin{frame}[fragile]
  \frametitle{Working on a tracking branch}
  Let's continue working on branch \bt{simpsons}.
  \begin{lstlisting}[basicstyle=\ttfamily\footnotesize]
$ emacs FACTS.md
$ git commit -am 'Edit character presence'
[simpsons 0676334] Edit character presence
 1 file changed, 1 insertion(+), 1 deletion(-)
$ git status
# On branch simpsons
# Your branch is ahead of 'hue/simpsons' by 1 commit.
#
nothing to commit (working directory clean)
  \end{lstlisting}
  \bigskip
  \includegraphics[width=9cm]{images/example-commit}
\end{frame}

\begin{frame}[fragile]
  \frametitle{Pushing changes to a remote: \bt{git push}}
  \begin{lstlisting}
$ git push hue simpsons
Counting objects: 5, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (2/2), done.
Writing objects: 100% (3/3), 303 bytes, done.
Total 3 (delta 1), reused 0 (delta 0)
To hue.remote:projects/tv-series
   0535b7e..0676334  simpsons -> simpsons
\end{lstlisting}
  \bigskip
  Our work on branch \bt{simpsons} is now available on remote \bt{hue} too.
\end{frame}

\begin{frame}[fragile]
  \frametitle{Cloning an existing repository}
  Instead of creating repositories using \bt{git init}, you can create a local
  {\em clone} of an existing (remote) repository.
  \bigskip
  \begin{lstlisting}[basicstyle=\ttfamily\footnotesize]
$ git clone https://git.lumc.nl/m.vermaat.hg/tv-series.git
Cloning into 'tv-series'...
remote: Counting objects: 6, done.
remote: Compressing objects: 100% (4/4), done.
remote: Total 6 (delta 1), reused 0 (delta 0)
Unpacking objects: 100% (6/6), done.
  \end{lstlisting}
  \pause
  \bigskip
  A remote called \bt{origin} is added for the original repository and branch
  \bt{master} is setup to track the original \bt{master}.
  \bigskip
  \begin{lstlisting}[basicstyle=\ttfamily\footnotesize]
$ cd tv-series/
$ git remote -v
origin  https://git.lumc.nl/m.vermaat.hg/tv-series.git (fetch)
origin  https://git.lumc.nl/m.vermaat.hg/tv-series.git (push)
  \end{lstlisting}
\end{frame}

\begin{frame}[fragile]
  \frametitle{Shortcuts for tracking branches}
  If a local branch is setup to track a remote branch, there are shortcuts for
  synchronizing them.\\
  \pause
  \vspace{1cm}
  For example, say \bt{HEAD} is on \bt{simpsons} which is tracking
  \bt{origin/simpsons}.
  \bigskip
  \begin{lstlisting}
$ git push    ==>    $ git push origin simpsons
  \end{lstlisting}
  \bigskip
  \begin{lstlisting}
$ git pull    ==>    $ git fetch origin
                     $ git merge origin/simpsons
  \end{lstlisting}
\end{frame}


\section{Working with GitLab}

\begin{frame}
  \frametitle{Using a central server}
  Git can be used by a team completely decentralized.\\
  \vspace{0.5cm}
  However, often a central server is used:
  \begin{itemize}
    \item It can be easier to communicate via the server.
    \item It can be convenient to have a canonical repository.
    \item Services such as {\em GitLab} and {\em GitHub} add many features on
      top of Git.
  \end{itemize}
\end{frame}

\begin{frame}
  \frametitle{GitLab}
  Our GitLab server is at \bt{https://git.lumc.nl/}\\
  \vspace{0.5cm}
  \begin{itemize}
    \item Coupled to your LUMC account.
    \item All users can create projects.
    \item Browse repositories and edit files online.
    \item Control access for other users.
    \item Track bugs/issues/tickets.
    \item Create merge requests and do code reviews.
  \end{itemize}
\end{frame}

% todo: create gitlab project, clone gitlab project

\section{Questions?}
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\begin{frame}
  \begin{center}
    Acknowledgements:
    \bigskip
    \bigskip

    Jeroen Laros

    Zuotian Tatum

    % https://www.atlassian.com/git

  \end{center}
\end{frame}

\end{document}