[NixTuto] Channels

slides.tex

@@ -140,9 +140,9 @@ The running environment should be explicit:
 
   \begin{itemize}
       \item the running environment should be defined
-        \note[itemize]{
-          \item How(had-hoc script, complex runtime etc),
-          \item Where(your laptop, your old laptop etc) you run you experiment.}
+        \note{
+          How(had-hoc script, complex runtime etc),
+          Where(your laptop, your old laptop etc) you run you experiment.}
 
       \item Documenting how to run the experiment.
         \note{The input, the running scripts etc \\}
@@ -304,49 +304,110 @@ The running environment should be explicit:
 \end{frame}
 
 \begin{frame}[fragile]{Derivations}
-  \only<1>{
+  \begin{onlyenv}<1>
     \note{https://nixos.org/nixos/nix-pills/our-first-derivation.html\\}
-    Nix refers to \texbf{derivation} instead of packages. \\
+    Nix refers to \textbf{derivation} instead of package. \\
+
+    \vspace{1em}
+    From the Nix point of view, a derivation is a build action, \\
+    described by a Nix set.
+
+    \vspace{1em}
+    Once built, a  derivation is located into a common place\\
+    the \textbf{Nix store}.
+
     \vspace{1em}
-    Derivation are the building block of Nix, from a file system point of view.
+
+    A derivation is identified with a unique hash as follows:
+
+  \begin{lstlisting}[language=Nix,basicstyle=\small]
+        /nix/store/hash-name
+  \end{lstlisting}
+
     \note{A derivation is a set of attributes describing a building process \\}
-  }
+
+  \end{onlyenv}
+
   \begin{onlyenv}<2>
   %\begin{adjustbox}{width=\textwidth,height=\textheight,keepaspectratio}
   \vspace{-1em}
 
-  \begin{lstlisting}[language=Nix,basicstyle=\Small]
-{ stdenv, fetchurl , cmake, simgrid, boost }:
-  stdenv.mkDerivation rec {
-
-  name = "chord-vprez";
+  \begin{lstlisting}[language=Nix,basicstyle=\small]
+{
+  name = "chord";
 
   src = fetchurl {
     url = "https://gitlab.com/me/chord.tar.gz";
-    sha256 = "1h2jgq5pspyiskffq777nhi5rf0y8hg...";
+    sha256 = "1h2jgq5pspyiskffq777nhi5rf0y8h...";
   };
 
-  cmakeFlags= " -Denable_debug=on";
+  builder = "build.sh";
   buildInputs = [ simgrid boost cmake ];
 
   meta = ..;
 }
+
   \end{lstlisting}
-  %\end{adjustbox}
+   \end{onlyenv}
+\end{frame}
 
-  \end{onlyenv}
 
-\end{frame}
+\begin{frame}[fragile]{Store}
+
+  All build derivations are stored in the nix store: \texttt{/nix/store}.\\
+
+  \vspace{1em}
 
-\begin{frame}{Store}
-  Packages are stored in the nix store: \texttt{/nix/store}.\\
   They are identified with a sha-256 hash of the source nix file and
-  its "inputs".\\
-  \texttt{/nix/store/an9dli66ng2jzvqf13b2i230mm9fq7qk-cdo-1.7.2}\\
-  changing a flag alters the inputs produce new packages: \\
-  \texttt{/nix/store/srf6grrfy9vkc9fsplk8xk292lm8jvz5-cdo-1.7.2}
+  its "inputs".
+
+  \begin{lstlisting}[basicstyle=\small]
+/nix/store/wi199j9qz9n1z3f4inlnx4rdxja54vg2-vim/bin/vim
+  \end{lstlisting}
+
+  \vspace{1em}
+
+  Changing the inputs changes the path:
+  \note{Here I changed my vimrc}
+
+  \begin{lstlisting}[basicstyle=\small]
+/nix/store/58gs3qxyqb2xh03jkai7cmph8086d2dd-vim/bin/vim
+  \end{lstlisting}
+
+\end{frame}
+
+\begin{frame}[plain]{Channels}
+
+  \only<1>{
+  \textbf{NixPkgs} is a git repository containing the code of all \emph{official} derivations.
+
+  \vspace{1em}
+
+  A \textbf{channel} is link to  branch of NixPkgs tested with continuous integration.
+
+  \vspace{1em}
+
+  \begin{itemize}
+    \item nixpkgs-unstable (feeling lucky?)
+    \item nixpkgs-19.03 (current stable)
+    \item nixpkgs-18.09 (outdated)
+  \end{itemize}
+  }
+
+  \only<2>{
+
+    Channels are not fully reproducible, as they are subject to updates.
+
+  }
+
 \end{frame}
 
+% \begin{frame}[fragile]{}
+% 
+%   A derivation is identified with a hash of its inputs (\emph{sources}, and \emph{derivations})
+% 
+% \end{frame}
+
 \begin{frame}[plain,noframenumbering]
   \center Thanks. Question Time.
 \end{frame}