#+TITLE: Démystifions Git, Github, Gitlab
#+AUTHOR: @@latex:{\large Arnaud Legrand} \\ \vspace{0.2cm}Grenoble Alpes University and CNRS\\ \vspace{0.2cm} \texttt{arnaud.legrand@imag.fr}@@
#+OPTIONS: H:2 tags:nil
#+EXCLUDE_TAGS: noexport
#+LANGUAGE: fr
#+SELECT_TAGS: export
#+LATEX_COMPILER: lualatex
#+LATEX_CLASS: beamer
#+LATEX_CLASS_OPTIONS: [presentation,bigger]
#+LATEX_HEADER: \usepackage[normalem]{ulem}

#+LATEX_HEADER: \usepackage{tikz}
#+LATEX_HEADER: \usetikzlibrary{babel}
#+LATEX_HEADER: \usetikzlibrary{positioning}
#+LATEX_HEADER: \usetikzlibrary{fit}
#+LATEX_HEADER: \usepackage{gitdags}

#+LATEX_HEADER:\usepackage[strict=true,french=guillemets]{csquotes}

# #+LATEX_HEADER: \usetikzlibrary{arrows}
# #+LATEX_HEADER: \usetikzlibrary{graphs}
# #+LATEX_HEADER: \usetikzlibrary{trees}
# #+LATEX_HEADER: \usetikzlibrary{graphdrawing}
# #+LATEX_HEADER: \usegdlibrary{layered}
# #+LATEX_HEADER: \usetikzlibrary{arrows, graphs, graphs.standard, trees, graphdrawing, quotes, positioning, shadows, shapes, mindmap}
#+BEAMER_HEADER: \setbeamercovered{invisible}
#+BEAMER_HEADER: \AtBeginSection[]{\begin{frame}<beamer>\frametitle{Où en sommes nous ?}\tableofcontents[currentsection]\end{frame}}
#+BEAMER_HEADER: \beamertemplatenavigationsymbolsempty
#+STARTUP: beamer
#+COLUMNS: %45ITEM %10BEAMER_ENV(Env) %10BEAMER_ACT(Act) %4BEAMER_COL(Col) %8BEAMER_OPT(Opt)
#+STARTUP: indent
#+PROPERTY: header-args :eval no-export

#+LaTeX: \newcommand<>\gd[1]{\only#2{\gitDAG[grow up=1, branch right=1]{#1}};}
#+LaTeX: \newcommand<>\gc[2]{\only#3{\gitcontent{#1}{#2}}}
#+LaTeX: \newcommand<>\ga[2]{\only#3{\node[DAGref,fill = white, align=center, font = \normalsize, #2] () {#1};}}

* Contexte
** Aaah... l'informatique
*** Problème
#+ATTR_BEAMER: :overlay <+->
- Mon ordinateur a planté!
- Ce document était bien mieux hier!
- Vous n'avez pas travaillé sur la bonne version du document. Comment fusionner?
- Mais qui a écrit ça ? Et pourquoi ?
*** Solution ?
#+ATTR_BEAMER: :overlay <+->
- Sauvegarde régulière avec une notion d'historique\smallskip

  #+BEGIN_EXPORT latex
  \footnotesize\enquote{\texttt{SE15\_PPT\_16x9\_Template\_Arial\only<+->{\_FINAL\only<+->{\_FINAL\only<+->{\_0925}}}.pptx}}
  #+END_EXPORT
- Travailler tout seul!
- Passer son temps à (s')envoyer des mails!
** Gestionnaire de versions
Les gestionnaires de version datent du début des années 70
*** Fonctionnalités essentielles
- Conserve un historique des modifications sans dupliquer les dossiers
  de sauvegardes
- Sauvegarde les données (avec l’historique) sur des ordinateurs
  distants
- Fusion "automatique" des fichiers édités par plusieurs personnes.
*** \includegraphics[height=.6cm]{img_git/Logo_Git.pdf}
#+LaTeX: \begin{columns}
#+LaTeX:   \begin{column}{.8\linewidth}
- 2005: créé pour le développement du noyau Linux par Linus Torvalds
  - $> 20$ millions de lignes de code
  - $\approx 14\,000$ developeurs
    # #+ATTR_LaTeX: :width .3\linewidth
    # file:img_git/Logo_Git.pdf
# #+BEGIN_QUOTE
# Only wimps use tape backup: _real_ men just upload their important stuff on
# ftp, and let the rest of the world mirror it ;)\flushright
#                                  -- Linus Torvalds
# #+END_QUOTE
#+LaTeX:   \end{column}
#+LaTeX:   \begin{column}{.2\linewidth}
#+ATTR_LaTeX: :width \linewidth
file:img_git/linus.jpg
#+LaTeX:   \end{column}
#+LaTeX: \end{columns}
** Objectif de cet exposé
  #+BEGIN_EXPORT latex
  \begin{overlayarea}{\linewidth}{0cm}
    \begin{flushright}
    \null\vspace{-2.0cm}%
    \includegraphics[height=0.55\paperheight]{img_git/Git_Xkcd.png}
    \end{flushright}
  \end{overlayarea}
  #+END_EXPORT
- +Apprendre à utiliser =git=+ \vspace{.8cm} \pause

  =git= est "explicite" (à la différence \newline de dropbox et
  autres)\newline
  Heureusement, il y a des interfaces \vspace{1.2cm}
- Notions essentielles pour utiliser les interfaces à =git=
  - Historique distribué
  - Branche
  - Conflit et fusion
  - L'écosystème
    #+LaTeX: \raisebox{-.3em}{\includegraphics[height=.5cm]{img_git/Logo_Git.pdf}}\smallskip

    #+BEGIN_EXPORT latex
    \includegraphics[height=.5cm]{img_git/Logo_GitHub.pdf}
    \includegraphics[height=.5cm]{img_git/Octocat.jpg} \quad
    \resizebox{!}{.5cm}{GitLab} \includegraphics[height=.5cm]{img_git/Logo_GitLab.png}
    #+END_EXPORT
#+LaTeX: \vfill
* L'historique quand on est tout seul
** Son propre projet
Accès à un certain nombre de fichiers.
- Temps continu
- Checkpoint/snapshot: conserver les moments clés du projet pour
  pouvoir y revenir
  - \bgroup\tt git \textbf{add}\egroup pour indiquer quelles modifications ont souhaite conserver
  - \bgroup\tt git \textbf{commit}\egroup pour faire le checkpoint (date, commentaire)

** Une histoire simple
#+BEGIN_EXPORT latex
\begin{overlayarea}{\linewidth}{8cm}
\begin{tikzpicture}
  \useasboundingbox (0,0) rectangle (5,8);
  % \draw (current bounding box.north east) -- (current bounding box.north west) -- (current bounding box.south west) -- (current bounding box.south east) -- cycle;
  \tikzset{DAGcommit/.append style={minimum height = 1em, minimum width=1em},
    DAGedge/.append style={thin},
    DAGrefedge/.append style={thin},
    special commit/.style={DAGcommit,fill= solarized-red!20}}
  \node[anchor=south west](simple) at (.5,0) {\tikz{
%    \node[DAGcommit, at (3,0)] (v0) {v0};
    \gd<+>{ v0 }
    \gc<.->{article.md img/fig1.jpg}{left=of v0}
    \gd<+>{ v0 -- v1 }
    \gc<.->{article.md}{left=of v1}
    \gd<+>{ v0 -- v1 -- v2 }
    \gc<.->{article.md img/fig2.jpg}{left=of v2}
    \gd<+>{ v0 -- v1 -- v2 -- v3 }
    \gc<.->{article.md}{left=of v3}
    \gd<+>{ v0 -- v1 -- v2 --v3 -- v4 -- v5}
    \gc<.->{article.md img/me.jpg}{left=of v4}
    \gc<.>{article.md}{left=of v5}
    \gd<+>{ v0 -- v1 -- v2 --v3 -- v4 -- {{[nodes=unreachable] v5}}}
    \only<.>{\draw[->,-Latex] (v5) to[out=0,in=0] (v4);}
    \gd<+>{ v0 -- v1 -- v2 --v3 -- v4 -- {{[nodes=unreachable] v5}, v5'}}
    \gd<+->{ v0 -- v1 -- v2 --v3 -- v4 -- {{[nodes=unreachable] v5}, v5' -- v6 -- v7}}
    \ga<+>{git {\bf add} ... ; git {\bf commit}}{right=of v0}
    \ga<.>{Chaque version du projet\\ (appelée \emph{commit} ou \emph{révision})\\ est identifiée par un SHA1}{right=of v3} %text width=3cm, 
    \ga<.>{Un \textbf{historique} \\à la granularité\\ du \sout{fichier} projet}{right=of v6} %text width=3cm, 
    \only<+>{\draw[<->,Latex-Latex, dashed] (v7) to[out=0,in=0] (v3);}
    \ga<.>{git {\bf diff} v3..v7}{right=of v6}
    \only<+>{\draw[->,-Latex] (v7) to[out=0,in=0] (v5');}
    \ga<.>{git {\bf checkout} v5'}{right=of v6}
    \ga<+>{Tout ce qui a été commité\\est sauvegardé et accessible}{right=of v3}
    \ga<.>{Cet historique est\\ \textbf{local}!}{right=of v1}
  }};
  % % HEAD reference
  % \gitHEAD
  % {left=of master}
  % {master}
\end{tikzpicture}
\end{overlayarea}
#+END_EXPORT
# https://tikzit.github.io/
# dot2tex... bof
# https://pdfs.semanticscholar.org/bb76/d0dc3b4a38a15dcf5c4572a5cf9f121fef7e.pdf
# /usr/share/doc/texlive-doc/generic/pgf/pgfmanual.pdf 
#     - 5. Tutorial: Diagrams as Simple Graphs 
** Backup sur un server distant
#+BEGIN_EXPORT latex
\pgfdeclarelayer{background}
\pgfdeclarelayer{foreground}
\pgfsetlayers{background,main,foreground}

\begin{overlayarea}{\linewidth}{5cm}
\begin{tikzpicture}
  \useasboundingbox (0,0) rectangle (6cm,5cm);
%  \draw (current bounding box.north east) -- (current bounding box.north west) -- (current bounding box.south west) -- (current bounding box.south east) -- cycle;
  \tikzset{DAGcommit/.append style={minimum height = 1em, minimum width=1em},
    DAGedge/.append style={thin},
    DAGrefedge/.append style={thin},
    special commit/.style={DAGcommit,fill= solarized-red!20},
    every node/.style={transform shape}}

%  \tikzset{res/.style={ellipse,draw,minimum height=0.5cm,minimum width=0.8cm}}
%  \tikzset{literal/.style={rectangle,draw,minimum height=0.5cm,minimum width=0.8cm,text width = 1.2 cm, align = center}}
  \tikzset{hfit/.style={rounded rectangle, inner xsep=0pt},
           vfit/.style={rounded corners}}


  \begin{scope}[scale = .5]
    \gd<1>{ v0 }
    \ga<1>{\LARGE git {\bf clone}}{right=of v0}
    \begin{pgfonlayer}{background}
      \node<1>[fit=(v0), fill=green!30, ellipse, opacity=.8] {};
    \end{pgfonlayer}
    \gd<2-3>{ v0 -- v1 -- v2 --v3 }
    \ga<2>{\Large Alice working locally}{right=of v0}
    \ga<3>{\LARGE git {\bf push}}{right=of v0}
    \begin{pgfonlayer}{background}
      \node<3>[fit=(v0)(v3), fill=green!30, ellipse] {};
    \end{pgfonlayer}
    \gd<4-6>{ v0 -- v1 -- v2 --v3 -- v4 -- {{[nodes=unreachable] v5}, v5' -- v6 -- v7}}
    \ga<4>{\Large Alice working locally}{right=of v0}
    \ga<5>{\LARGE git {\bf push}}{right=of v0}
    \begin{pgfonlayer}{background}
      \node<5>[fit=(v4)(v7), fill=green!30,ellipse,rotate=-30] {};
    \end{pgfonlayer}
    \node[DAGref,fill = white, below=of v0,remember picture] (alice) {\includegraphics[width=2cm]{img_git/alice.jpg}};    
  \end{scope}
  
  \begin{scope}[scale = .5, xshift = 8cm, yshift = 3cm, every node/.style={transform shape}]
    \gd<1-2>{ v0 }
    \begin{pgfonlayer}{background}
      \node<1>[fit=(v0), fill=green!30, ellipse] {};
    \end{pgfonlayer}
    \gd<3-4>{ v0 -- v1 -- v2 --v3 }
    \begin{pgfonlayer}{background}
      \node<3>[fit=(v0)(v3), fill=green!30, ellipse] {};
    \end{pgfonlayer}
    \gd<5-6>{ v0 -- v1 -- v2 --v3 -- v4 -- v5' -- v6 -- v7}
    \begin{pgfonlayer}{background}
      \node<5>[fit=(v4)(v7), fill=green!30, ellipse, opacity=.8] {};
%      \filldraw<5>[fill=green!20!white, draw=green!50!black] v4.east -- v7 -- (-1,-3) -- cycle;
    \end{pgfonlayer}
    \node[DAGref,fill = white, below=of v0, remember picture] (gitlab) {\includegraphics[width=2cm]{img_git/Logo_GitLab.png}};
  \end{scope}

  \only<1>{\draw[->,-Latex] (gitlab) to[out=180,in=0] (alice);}
  \only<3>{\draw[->,-Latex] (alice) to[out=0,in=180] (gitlab);}
  \only<5>{\draw[->,-Latex] (alice) to[out=0,in=180] (gitlab);}

  \ga<6>{On synchronise des \textbf{branches}\\ en échangeant \\des morceaux d'historiques}{right=of v6}

  \ga<6>{Changer l'ellipse d'Alice}{right=of v0}
  % % HEAD reference
  % \gitHEAD
  % {left=of master}
  % {master}
\end{tikzpicture}
\end{overlayarea}
#+END_EXPORT
*** cruft                                                        :noexport:
#+BEGIN_EXPORT latex

\begin{tikzpicture}[
    rotate=180,
    nodes={
      text height=.7em,
      text depth=.2em,
      draw=black!20,
      thick, 
      fill=white, 
      font=\footnotesize
    },
    >=stealth',
    rounded corners,
    semithick
  ] 
  \graph [
%    simple necklace layout, % circular
%    spring layout, % force
    layered layout, % layered
%    tree layout, % trees
%   binary tree layout, % trees
    level distance=1cm,
    sibling sep=.5em,
    sibling distance=1cm
  ] {
%    AA -- {BB -- {CC, CC3 -- {DD1, DD2}},AAA};
    "merge" -> {head -- v0,b} -- c -- d;
  };
\end{tikzpicture}

\begin{tikzpicture}
%    \usegdlibrary{layered}
% Commit DAG
\graph[layered layout,grow up sep = 2em]{
   AA -- {BB -- {CC, CC3 -- {DD1, DD2}},AAA};
   merge <- {head -- v0,b} -- c -- d;
   A  -- B -- { 
      C,
      D -- E,
   };
 };

 \draw[red, dashed] (1, 0.5) -- (1, -5);

\end{tikzpicture}

#+END_EXPORT

* Travailler à plusieurs
** Collaborer = gérer un historique distribué                     :noexport:
#+BEGIN_EXPORT latex
\pgfdeclarelayer{background}
\pgfdeclarelayer{foreground}
\pgfsetlayers{background,main,foreground}

\begin{overlayarea}{\linewidth}{5cm}
\begin{tikzpicture}
  \useasboundingbox (0,0) rectangle (6cm,5cm);
%  \draw (current bounding box.north east) -- (current bounding box.north west) -- (current bounding box.south west) -- (current bounding box.south east) -- cycle;
  \tikzset{DAGcommit/.append style={minimum height = 1em, minimum width=1em},
    DAGedge/.append style={thin},
    DAGrefedge/.append style={thin},
    special commit/.style={DAGcommit,fill= solarized-red!20},
    every node/.style={transform shape}}

%  \tikzset{res/.style={ellipse,draw,minimum height=0.5cm,minimum width=0.8cm}}
%  \tikzset{literal/.style={rectangle,draw,minimum height=0.5cm,minimum width=0.8cm,text width = 1.2 cm, align = center}}
  \tikzset{hfit/.style={rounded rectangle, inner xsep=0pt},
           vfit/.style={rounded corners}}

  \begin{scope}[scale = .5]
    \gd<1>{ v0 }
    \ga<1>{\LARGE git {\bf clone}}{right=of v0}
    \begin{pgfonlayer}{background}
      \node<1>[fit=(v0), fill=green!30, ellipse, opacity=.8] {};
    \end{pgfonlayer}
    \gd<2-3>{ v0 -- v1 -- v2 --v3 }
    \ga<2>{\Large Alice working locally}{right=of v0}
    \ga<3>{\LARGE git {\bf push}}{right=of v0}
    \begin{pgfonlayer}{background}
      \node<3>[fit=(v0)(v3), fill=green!30, ellipse] {};
    \end{pgfonlayer}
    \gd<4-5>{ v0 -- v1 -- v2 --v3 -- v4 -- {{[nodes=unreachable] v5}, v5' -- v6 -- v7}}
    \ga<4>{\Large Alice working locally}{right=of v0}
    \ga<5>{\LARGE git {\bf push}}{right=of v0}
    \begin{pgfonlayer}{background}
      \node<5>[fit=(v4)(v7), fill=green!30,ellipse,rotate=-30] {};
    \end{pgfonlayer}
    \node[DAGref,fill = white, below=of v0,remember picture] (linus) {\includegraphics[width=2cm]{img_git/alice.jpg}};    
  \end{scope}
  
  \begin{scope}[scale = .5, xshift = 5cm, yshift = 5cm, every node/.style={transform shape}]
    \gd<1-2>{ v0 }
    \begin{pgfonlayer}{background}
      \node<1>[fit=(v0), fill=green!30, ellipse] {};
    \end{pgfonlayer}
    \gd<3-4>{ v0 -- v1 -- v2 --v3 }
    \begin{pgfonlayer}{background}
      \node<3>[fit=(v0)(v3), fill=green!30, ellipse] {};
    \end{pgfonlayer}
    \gd<5->{ v0 -- v1 -- v2 --v3 -- {
                      v4 -- v5' -- v6 ,
                      v4'' -- v5''} 
               -- {Merge}
           }
    \begin{pgfonlayer}{background}
      \node<5>[fit=(v4)(v7), fill=green!30, ellipse, opacity=.8] {};
%      \filldraw<5>[fill=green!20!white, draw=green!50!black] v4.east -- v7 -- (-1,-3) -- cycle;
    \end{pgfonlayer}
    \node[DAGref,fill = white, below=of v0, remember picture] (gitlab) {\includegraphics[width=2cm]{img_git/Logo_GitLab.png}};
  \end{scope}

  \begin{scope}[scale = .5, xshift = 10cm, yshift = 0cm, every node/.style={transform shape}]
    \gd<1-2>{ v0 }
    \begin{pgfonlayer}{background}
      \node<1>[fit=(v0), fill=green!30, ellipse] {};
    \end{pgfonlayer}
    \gd<3-4>{ v0 -- v1 -- v2 --v3 }
    \begin{pgfonlayer}{background}
      \node<3>[fit=(v0)(v3), fill=green!30, ellipse] {};
    \end{pgfonlayer}
    \gd<5->{ v0 -- v1 -- v2 --v3 -- { v4''[fill=blue]  -- v5''}}
    \begin{pgfonlayer}{background}
%      \node<5>[fit=(v4)(v7), fill=green!30, ellipse, opacity=.8] {};
%      \filldraw<5>[fill=green!20!white, draw=green!50!black] v4.east -- v7 -- (-1,-3) -- cycle;
    \end{pgfonlayer}
    \node[DAGref,fill = white, below=of v0, remember picture] (baby) {\includegraphics[width=2cm]{img_git/baby1.jpg}};
  \end{scope}

  \only<1>{\draw[->,-Latex] (gitlab) to[out=0,in=0] (linus);}
  \only<3>{\draw[->,-Latex] (linus) to[out=0,in=0] (gitlab);}
  \only<5>{\draw[->,-Latex] (linus) to[out=0,in=0] (gitlab);}
  % % HEAD reference
  % \gitHEAD
  % {left=of master}
  % {master}
\end{tikzpicture}
\end{overlayarea}
#+END_EXPORT
** Collaborer = gérer un historique distribué
#+BEGIN_EXPORT latex
\scalebox{.75}{
    \begin{tikzpicture}[remember picture]
      \tikzset{DAGcommit/.append style={minimum height = 1em, minimum width=1em},
          DAGedge/.append style={thin},
          DAGrefedge/.append style={thin},
          special commit/.style={DAGcommit,fill= solarized-red!20}}

      % Chloé
      \node (historique de Chloe) at (0,0) {\tikz[remember picture]{
              % Commit DAG
              \onslide<1-3>{
                  \gitDAG[grow up=0.75, branch left=0.75]{
                      A -- B -- C
                  };
                  % Branch
                  \gitbranch
                  {master}
                  {left=of C}
                  {C}
                  % HEAD reference
                  \gitHEAD
                  {left=of master}
                  {master}
              }
              \onslide<4>{
                  \gitDAG[grow up=0.75, branch left=0.75]{
                      A -- B -- C -- D -- E
                  };
                  % Branch
                  \gitbranch
                  {master}
                  {left=of E}
                  {E}
                  % HEAD reference
                  \gitHEAD
                  {left=of master}
                  {master}
              }
              \onslide<5-8>{
                  \gitDAG[grow up=0.75, branch left=0.75]{
                      A -- B -- C -- D -- E -- F1[as=F]
                  };
                  % Branch
                  \gitbranch
                  {master}
                  {left=of F1}
                  {F1}
                  % HEAD reference
                  \gitHEAD
                  {left=of master}
                  {master}
              }
              \onslide<9>{
                  \gitDAG[grow up=0.75, branch left=0.75]{
                      A -- B -- C -- D -- E -- {
                          G,
                          F,
                      } -- H
                  };
                  % Branch
                  \gitbranch
                  {master}
                  {left=of H}
                  {H}
                  % HEAD reference
                  \gitHEAD
                  {left=of master}
                  {master}
              }
              % Tag reference
              \gittag
              [v0p1]
              {v0.1}
              {left=of A}
              {A}

              \node[DAGref,fill = white, below= of A] {\includegraphics[height=10mm]{img_git/alice.jpg}};
          }
      };

      % Origin/master commun
      \onslide<1-2>{
          % Remote branch
          \gitremotebranch
          [origmaster1]
          {origin/master}
          {right=of C}
          {C}
      }
      \onslide<3>{
          % Remote branch
          \gitremotebranch
          [origmaster1]
          {origin/master}
          {right=of C,opacity=0.5}
          {C}
      }
      \onslide<4-5>{
          % Remote branch
          \gitremotebranch
          [origmaster2]
          {origin/master}
          {right=of E}
          {E}
      }
      \onslide<6-7>{
          % Remote branch
          \gitremotebranch
          [origmaster]
          {origin/master}
          {right=of F1}
          {F1}
      }
      \onslide<8>{
          % Remote branch
          \gitremotebranch
          [origmaster]
          {origin/master}
          {right=of F1,opacity=0.5}
          {F1}
      }
      \onslide<9>{
          % Remote branch
          \gitremotebranch
          [origmaster3]
          {origin/master}
          {right=of H}
          {H}
      }

      % Benoît
      \node[right=2.25 of historique de Chloe.south east,anchor=south west] (historique de Benoit) {\tikz[remember picture]{
              % Commit DAG
              \onslide<1>{
                  \gitDAG[grow up=0.75, branch right=0.75]{
                      A -- B -- C
                  };
                  % Branch
                  \gitbranch
                  {master}
                  {right=of C}
                  {C}
                  % HEAD reference
                  \gitHEAD
                  {right=of master}
                  {master}
              }
              \onslide<2-4>{
                  \gitDAG[grow up=0.75, branch right=0.75]{
                      A -- B -- C -- D -- E
                  };
                  % Branch
                  \gitbranch
                  {master}
                  {right=of E}
                  {E}
                  % HEAD reference
                  \gitHEAD
                  {right=of master}
                  {master}
              }
              \onslide<5-6>{
                  \gitDAG[grow up=0.75, branch right=0.75]{
                      A -- B -- C -- D -- E -- G
                  };
                  % Branch
                  \gitbranch
                  {master}
                  {right=of G}
                  {G}
                  % HEAD reference
                  \gitHEAD
                  {right=of master}
                  {master}
              }
              \onslide<7-9>{
                  \gitDAG[grow up=0.75, branch right=0.75]{
                      A -- B -- C -- D -- E -- {
                          G,
                          F,
                      } -- H
                  };
                  % Branch
                  \gitbranch
                  {master}
                  {right=of H}
                  {H}
                  % HEAD reference
                  \gitHEAD
                  {right=of master}
                  {master}
              }
              % Tag reference
              \gittag
              [v0p1]
              {v0.1}
              {right=of A}
              {A}
              % 
              \node[DAGref,fill = white, below= of A] {\includegraphics[height=10mm]{img_git/bob.jpg}};
          }
      };

      % Liens de Benoît avec Origin/master
      \draw<1-2>[DAGrefedge] (C) -- (origmaster1);
      \draw<4-5>[DAGrefedge] (E) -- (origmaster2);
      \draw<9>[DAGrefedge] (H) -- (origmaster3);

      % Dépôt origin
      \node[font=\fontfamily{lmtt}\selectfont\small, above=0.35 of current bounding box.north,above] (origin) {\tikz[scale = .3, every node/.style={transform shape}, remember picture]{
         % Commit DAG
              \onslide<1-3>{
                  \gitDAG[grow up=0.75, branch left=0.75]{
                      A -- B -- C
                  };
                  % Branch
                  \gitbranch
                  {master}
                  {left=of C}
                  {C}
                  % HEAD reference
                  \gitHEAD
                  {left=of master}
                  {master}
              }
              \onslide<4>{
                  \gitDAG[grow up=0.75, branch left=0.75]{
                      A -- B -- C -- D -- E
                  };
                  % Branch
                  \gitbranch
                  {master}
                  {left=of E}
                  {E}
                  % HEAD reference
                  \gitHEAD
                  {left=of master}
                  {master}
              }
              \onslide<5-8>{
                  \gitDAG[grow up=0.75, branch left=0.75]{
                      A -- B -- C -- D -- E -- F1[as=F]
                  };
                  % Branch
                  \gitbranch
                  {master}
                  {left=of F1}
                  {F1}
                  % HEAD reference
                  \gitHEAD
                  {left=of master}
                  {master}
              }
              \onslide<9>{
                  \gitDAG[grow up=0.75, branch left=0.75]{
                      A -- B -- C -- D -- E -- {
                          G,
                          F,
                      } -- H
                  };
                  % Branch
                  \gitbranch
                  {master}
                  {left=of H}
                  {H}
                  % HEAD reference
                  \gitHEAD
                  {left=of master}
                  {master}
              }
              % Tag reference
              \gittag
              [v0p1]
              {v0.1}
              {left=of A}
              {A}

              \node[DAGref,fill = white, below= of A] {\includegraphics[height=2cm]{img_git/Logo_GitLab.png}};
          }}

      % Actions
      % Push de Benoît
      \draw<3>[->,-Latex] (historique de Benoit) to[out=90,in=0] node[midway,font=\scriptsize,above right]{\texttt{git push}} (origin);
      \onslide<3>{
          % Remote branch
          \gitremotebranch
          [origmaster]
          {origin/master}
          {left=of E}
          {E}
      }

      % Pull de Chloé
      \draw<4>[->,-Latex] (origin) to[out=180,in=90] node[midway,font=\scriptsize,above left]{\texttt{git pull}} (historique de Chloe);

      % Push de Chloé
      \draw<6>[->,-Latex] (historique de Chloe) to[out=90,in=180] node[midway,font=\scriptsize,above left]{\texttt{git push}} (origin);
      \onslide<6>{
          % Remote branch
          \gitremotebranch
          [origmaster]
          {origin/master}
          {left=of E,opacity=0.5}
          {E}
      }

      % Pull de Benoît
      \draw<7>[->,-Latex] (origin) to[out=0,in=90] node[midway,font=\scriptsize,above right]{\texttt{git pull}} (historique de Benoit);
      \onslide<7>{
          % Remote branch
          \gitremotebranch
          [origmaster]
          {origin/master}
          {right=of F}
          {F}
      }

      % Push de Benoît
      \draw<8>[->,-Latex] (historique de Benoit) to[out=90,in=0] node[midway,font=\scriptsize,above right]{\texttt{git push}} (origin);
      \onslide<8>{
          % Remote branch
          \gitremotebranch
          [origmaster]
          {origin/master}
          {left=of H}
          {H}
      }

      % Pull de Chloé
      \draw<9>[->,-Latex] (origin) to[out=180,in=90] node[midway,font=\scriptsize,above left]{\texttt{git pull}} (historique de Chloe);
    \end{tikzpicture}}
#+END_EXPORT
** À RAJOUTER
- Git push interdit si pas à jour, pas cohérent
- Au fait, le serveur de backup ne sert à rien, Alice et Bob
  pourraient échanger directement leur historique. Git est
  complètemnet décentralisé, chacun a une copie complète de tout
  l'historique du projet (et pas juste de la dernière version...).
  - Très résilient. 
** Le conflit
Au moment du pull, il se peut que le merge ne soit pas possible et
qu'un conflit apparaisse.

- Rien de grave, ne pas paniquer. Rien n'est perdu, tout est dans
  votre historique local!


- Git travaille à la granularité du fichier et de la ligne
  - \to modulariser si possible
- Il y aura conflit dans un fichier si la même ligne a été modifiée
  de chaque côté
  - La modification peut sembler sans importance (des espaces ou un
    nouveau saut de ligne au milieu d'un ligne...)
  - Réindenter un texte peut conduire à de véritables cauchemards
  - \to Bien séparer dans ses commits les modifications de fonds et
    celle de forme
- Les fichier binaires n'ont pas de lignes... La fusion est souvent
  impossible et il faudrat choisir.
  - \to Préférer le format texte

#+BEGIN_CENTER
Démonstration !
#+END_CENTER
** En conclusion, git:
- Ça versionne !
- Ça facilite le travail collaboratif (fusion) !
- Ça permet de stocker ses modifications localement (« commit ») !
- Ça permet de partager ses modifications quand on le souhaite (« push ») !

Mais alors, comment mettre ça en place ?
* L'écosystème
** Collaborative development platforms
- GitHub, GitLab, et les autres!
  - Hébergement
  - Interfaces web (navigation, preview, édition en ligne)
  - Gestion des permissions (lecture/écriture, public/privé) et des utilisateurs
- Un réseau social des développeurs
  - Issues et revue de code
  - Statistiques, émulation, gestion de communauté
  - Le "fork" et la "pull request"
- Des tas de fonctionnalités incroyables
  - Intégration Continue \hfill[\to MOOC RR advanced]
  - Déversement vers des archives (Zenodo, SWH) \hfill[\to MOOC RR advanced]
** Interfaces graphiques
- Jupyterlab
- Rstudio
- GitTruc
** Managing large files (dans le module de RR2)
- Refer to zenodo of figshare from the beginning
- git annex and git lfs (deployed on github, bitbucket, and recent
  versions of gitlab) \hfill[\to MOOC RR advanced]
- Push to Zenodo ?

* Tikz                                                             :noexport:
** From the doc                                                   :noexport:
#+BEGIN_EXPORT latex
\scalebox{.8}{\begin{tikzpicture}[nodes={text height=.7em, text depth=.2em,
  draw=black!20, thick, fill=white, font=\footnotesize},
  >=spaced stealth', rounded corners, semithick]
  \graph[layered layout, level distance=1cm, sibling sep=.5em, sibling distance=1cm] {
    "5th Edition" -> { "6th Edition", "PWB 1.0" };
    "6th Edition" -> { "LSX" [>child anchor=45], "1 BSD", "Mini Unix", "Wollongong", "Interdata" };
    "Interdata" -> { "Unix/TS 3.0", "PWB 2.0", "7th Edition" };
    "7th Edition" -> { "8th Edition", "32V", "V7M", "Ultrix-11", "Xenix", "UniPlus+" };
    "V7M" -> "Ultrix-11";
    "8th Edition" -> "9th Edition";
    "1 BSD" -> "2 BSD" -> "2.8 BSD" -> { "Ultrix-11", "2.9 BSD" };
    "32V" -> "3 BSD" -> "4 BSD" -> "4.1 BSD" -> { "4.2 BSD", "2.8 BSD", "8th Edition" };
    "4.2 BSD" -> { "4.3 BSD", "Ultrix-32" };
    "PWB 1.0" -> { "PWB 1.2" -> "PWB 2.0", "USG 1.0" -> { "CB Unix 1", "USG 2.0" }};
    "CB Unix 1" -> "CB Unix 2" -> "CB Unix 3" -> { "Unix/TS++", "PDP-11 Sys V" };
    { "USG 2.0" -> "USG 3.0", "PWB 2.0", "Unix/TS 1.0" } -> "Unix/TS 3.0";
    { "Unix/TS++", "CB Unix 3", "Unix/TS 3.0" } -> "TS 4.0" -> "System V.0" -> "System V.2" -> "System V.3";
  };  
\end{tikzpicture}}
#+END_EXPORT

** Historiques
#+BEGIN_EXPORT latex
    \centering
    \begin{tikzpicture}
      % Commit DAG
      \gitDAG[grow right sep = 2em]{
        A -- B -- { 
          C,
          D -- E,
        }
      };
      % Tag reference
      \gittag
        [v0p1]       % node name
        {v0.1}       % node text
        {above=of A} % node placement
        {A}          % target
      % Remote branch
      \gitremotebranch
        [origmaster]    % node name
        {origin/master} % node text
        {above=of C}    % node placement
        {C}             % target
      % Branch
      \gitbranch
        {master}     % node name and text 
        {above=of E} % node placement
        {E}          % target
      % HEAD reference
      \gitHEAD
        {above=of master} % node placement
        {master}          % target
    \end{tikzpicture}

    \begin{tikzpicture}
      \gitDAG[grow right sep = 2em]{
        A -- B -- { 
          C -- D' -- E',
          {[nodes=unreachable] D -- E },
        }
      };
      % Tag reference
      \gittag
        [v0p1]       % node name
        {v0.1}       % node text
        {above=of A} % node placement
        {A}          % target
      % Remote branch
      \gitremotebranch
        [origmaster]    % node name
        {origin/master} % node text
        {above=of C}    % node placement
        {C}             % target
      % Branch
      \gitbranch
        {master}      % node name and text 
        {above=of E'} % node placement
        {E'}          % target
      % HEAD reference
      \gitHEAD
        {above=of master} % node placement
        {master}          % target
    \end{tikzpicture}
#+END_EXPORT
** Historiques
#+BEGIN_EXPORT latex
    \centering
    \begin{tikzpicture}
      % Commit DAG
      \gitDAG[grow up sep = 2em, branch right = 4em]{
        A -- B -- { 
           C
           \onslide<2>{,D -- E}
        }
      };
      % Tag reference
      \gittag
        [v0p1]       % node name
        {v0.1}       % node text
        {right=of A} % node placement
        {A}          % target
      % Remote branch
      \gitremotebranch
        [origmaster]    % node name
        {origin/master} % node text
        {left=of C}    % node placement
        {C}             % target
      % Branch
\onslide<2>{
      \gitbranch
        {master}     % node name and text 
        {right=of E} % node placement
        {E}          % target
      % HEAD reference
      \gitHEAD
        {right=of master} % node placement
        {master}          % target
}
    \end{tikzpicture}
#+END_EXPORT

** Historiques
# http://www.texample.net/media/tikz/examples/TEX/beamer-arrows.tex
#+BEGIN_EXPORT latex
    \centering
    \begin{tikzpicture}
      % Commit DAG
      \gitDAG[grow up sep = 2em, branch right = 4em]{
        "" -- A -- B -- C -- {[nodes=unreachable] D};
        {[nodes=placeholder] "" -- NAA -- NBB -- NCC } --[draw opacity = 0,fill opacity = 0] E -- F;
        C -- E;
      };
      % Tag reference
    \end{tikzpicture}
#+END_EXPORT