nix: Move shell hook: default.nix -> shell.nix and set custom prompt.

When using multiple dev envs with nix-shell it's good to have a unique
shell propt to distinguish them.

default.nix

@@ -1,250 +1,238 b''
 # Nix environment for the community edition
 #
 # This shall be as lean as possible, just producing the Enterprise
 # derivation. For advanced tweaks to pimp up the development environment we use
 # "shell.nix" so that it does not have to clutter this file.
 
 args@
 { pythonPackages ? "python27Packages"
 , pythonExternalOverrides ? self: super: {}
 , doCheck ? true
 , ...
 }:
 
 let
 
   # Use nixpkgs from args or import them. We use this indirect approach
   # through args to be able to use the name `pkgs` for our customized packages.
   # Otherwise we will end up with an infinite recursion.
   nixpkgs = args.pkgs or (import <nixpkgs> { });
 
   # johbo: Interim bridge which allows us to build with the upcoming
   # nixos.16.09 branch (unstable at the moment of writing this note) and the
   # current stable nixos-16.03.
   backwardsCompatibleFetchgit = { ... }@args:
     let
       origSources = nixpkgs.fetchgit args;
     in
     nixpkgs.lib.overrideDerivation origSources (oldAttrs: {
       NIX_PREFETCH_GIT_CHECKOUT_HOOK = ''
         find $out -name '.git*' -print0 | xargs -0 rm -rf
       '';
     });
 
   # Create a customized version of nixpkgs which should be used throughout the
   # rest of this file.
   pkgs = nixpkgs.overridePackages (self: super: {
     fetchgit = backwardsCompatibleFetchgit;
   });
 
   # Evaluates to the last segment of a file system path.
   basename = path: with pkgs.lib; last (splitString "/" path);
 
   # source code filter used as arugment to builtins.filterSource.
   src-filter = path: type: with pkgs.lib;
     let
       ext = last (splitString "." path);
     in
       !builtins.elem (basename path) [
         ".git" ".hg" "__pycache__" ".eggs"
         "bower_components" "node_modules"
         "build" "data" "result" "tmp"] &&
       !builtins.elem ext ["egg-info" "pyc"] &&
       # TODO: johbo: This check is wrong, since "path" contains an absolute path,
       # it would still be good to restore it since we want to ignore "result-*".
       !hasPrefix "result" path;
 
   basePythonPackages = with builtins; if isAttrs pythonPackages
     then pythonPackages
     else getAttr pythonPackages pkgs;
 
   buildBowerComponents =
     pkgs.buildBowerComponents or
     (import ./pkgs/backport-16.03-build-bower-components.nix { inherit pkgs; });
 
   sources = pkgs.config.rc.sources or {};
   version = builtins.readFile ./rhodecode/VERSION;
   rhodecode-enterprise-ce-src = builtins.filterSource src-filter ./.;
 
   nodeEnv = import ./pkgs/node-default.nix {
     inherit pkgs;
   };
   nodeDependencies = nodeEnv.shell.nodeDependencies;
 
   bowerComponents = buildBowerComponents {
     name = "enterprise-ce-${version}";
     generated = ./pkgs/bower-packages.nix;
     src = rhodecode-enterprise-ce-src;
   };
 
   pythonGeneratedPackages = self: basePythonPackages.override (a: {
     inherit self;
   })
   // (scopedImport {
     self = self;
     super = basePythonPackages;
     inherit pkgs;
     inherit (pkgs) fetchurl fetchgit;
   } ./pkgs/python-packages.nix);
 
   pythonOverrides = import ./pkgs/python-packages-overrides.nix {
     inherit
       basePythonPackages
       pkgs;
   };
 
   pythonLocalOverrides = self: super: {
     rhodecode-enterprise-ce =
       let
         linkNodeAndBowerPackages = ''
           echo "Export RhodeCode CE path"
           export RHODECODE_CE_PATH=${rhodecode-enterprise-ce-src}
           echo "Link node packages"
           rm -fr node_modules
           mkdir node_modules
           # johbo: Linking individual packages allows us to run "npm install"
           # inside of a shell to try things out. Re-entering the shell will
           # restore a clean environment.
           ln -s ${nodeDependencies}/lib/node_modules/* node_modules/
 
           echo "DONE: Link node packages"
 
           echo "Link bower packages"
           rm -fr bower_components
           mkdir bower_components
 
           ln -s ${bowerComponents}/bower_components/* bower_components/
           echo "DONE: Link bower packages"
         '';
       in super.rhodecode-enterprise-ce.override (attrs: {
 
       inherit
         doCheck
         version;
       name = "rhodecode-enterprise-ce-${version}";
       releaseName = "RhodeCodeEnterpriseCE-${version}";
       src = rhodecode-enterprise-ce-src;
 
       buildInputs =
         attrs.buildInputs ++
         (with self; [
           pkgs.nodePackages.bower
           pkgs.nodePackages.grunt-cli
           pkgs.subversion
           pytest-catchlog
           rhodecode-testdata
         ]);
 
       propagatedBuildInputs = attrs.propagatedBuildInputs ++ (with self; [
         rhodecode-tools
       ]);
 
       # TODO: johbo: Make a nicer way to expose the parts. Maybe
       # pkgs/default.nix?
       passthru = {
         inherit
           bowerComponents
           linkNodeAndBowerPackages
           myPythonPackagesUnfix
           pythonLocalOverrides;
         pythonPackages = self;
       };
 
       LC_ALL = "en_US.UTF-8";
       LOCALE_ARCHIVE =
         if pkgs.stdenv ? glibc
         then "${pkgs.glibcLocales}/lib/locale/locale-archive"
         else "";
 
-      # Somewhat snappier setup of the development environment
-      # TODO: move into shell.nix
-      # TODO: think of supporting a stable path again, so that multiple shells
-      #       can share it.
-      shellHook = ''
-        tmp_path=$(mktemp -d)
-        export PATH="$tmp_path/bin:$PATH"
-        export PYTHONPATH="$tmp_path/${self.python.sitePackages}:$PYTHONPATH"
-        mkdir -p $tmp_path/${self.python.sitePackages}
-        python setup.py develop --prefix $tmp_path --allow-hosts ""
-      '' + linkNodeAndBowerPackages;
-
       preCheck = ''
         export PATH="$out/bin:$PATH"
       '';
 
       postCheck = ''
         rm -rf $out/lib/${self.python.libPrefix}/site-packages/pytest_pylons
         rm -rf $out/lib/${self.python.libPrefix}/site-packages/rhodecode/tests
       '';
 
       preBuild = linkNodeAndBowerPackages + ''
         grunt
         rm -fr node_modules
       '';
 
       postInstall = ''
         # python based programs need to be wrapped
         ln -s ${self.supervisor}/bin/supervisor* $out/bin/
         ln -s ${self.gunicorn}/bin/gunicorn $out/bin/
         ln -s ${self.PasteScript}/bin/paster $out/bin/
         ln -s ${self.channelstream}/bin/channelstream $out/bin/
         ln -s ${self.pyramid}/bin/* $out/bin/  #*/
 
         # rhodecode-tools
         # TODO: johbo: re-think this. Do the tools import anything from enterprise?
         ln -s ${self.rhodecode-tools}/bin/rhodecode-* $out/bin/
 
         # note that condition should be restricted when adding further tools
         for file in $out/bin/*; do  #*/
           wrapProgram $file \
               --prefix PYTHONPATH : $PYTHONPATH \
               --prefix PATH : $PATH \
               --set PYTHONHASHSEED random
         done
 
         mkdir $out/etc
         cp configs/production.ini $out/etc
 
         echo "Writing meta information for rccontrol to nix-support/rccontrol"
         mkdir -p $out/nix-support/rccontrol
         cp -v rhodecode/VERSION $out/nix-support/rccontrol/version
         echo "DONE: Meta information for rccontrol written"
 
         # TODO: johbo: Make part of ac-tests
         if [ ! -f rhodecode/public/js/scripts.js ]; then
           echo "Missing scripts.js"
           exit 1
         fi
         if [ ! -f rhodecode/public/css/style.css ]; then
           echo "Missing style.css"
           exit 1
         fi
       '';
 
     });
 
     rhodecode-testdata = import "${rhodecode-testdata-src}/default.nix" {
     inherit
       doCheck
       pkgs
       pythonPackages;
     };
 
   };
 
   rhodecode-testdata-src = sources.rhodecode-testdata or (
     pkgs.fetchhg {
       url = "https://code.rhodecode.com/upstream/rc_testdata";
       rev = "v0.9.0";
       sha256 = "0k0ccb7cncd6mmzwckfbr6l7fsymcympwcm948qc3i0f0m6bbg1y";
   });
 
   # Apply all overrides and fix the final package set
   myPythonPackagesUnfix = with pkgs.lib;
     (extends pythonExternalOverrides
     (extends pythonLocalOverrides
     (extends pythonOverrides
              pythonGeneratedPackages)));
   myPythonPackages = (pkgs.lib.fix myPythonPackagesUnfix);
 
 in myPythonPackages.rhodecode-enterprise-ce

shell.nix

@@ -1,57 +1,70 b''
 { pkgs ? (import <nixpkgs> {})
 , vcsserverPath ? "./../rhodecode-vcsserver"
 , vcsserverNix ? "shell.nix"
 , doCheck ? true
 }:
 
 let
 
   # Convert vcsserverPath to absolute path.
   vcsserverAbsPath =
     if pkgs.lib.strings.hasPrefix "/" vcsserverPath then
       builtins.toPath "${vcsserverPath}"
     else
       builtins.toPath ("${builtins.getEnv "PWD"}/${vcsserverPath}");
 
   # Import vcsserver if nix file exists, otherwise set it to null.
   vcsserver =
     let
       nixFile = "${vcsserverAbsPath}/${vcsserverNix}";
     in
       if pkgs.lib.pathExists "${nixFile}" then
         builtins.trace
           "Using local vcsserver from ${nixFile}"
           import "${nixFile}" {inherit pkgs;}
       else
           null;
 
   hasVcsserver = !isNull vcsserver;
 
-  enterprise = import ./default.nix {
+  enterprise-ce = import ./default.nix {
     inherit pkgs doCheck;
   };
 
-  pythonPackages = enterprise.pythonPackages;
+  ce-pythonPackages = enterprise-ce.pythonPackages;
 
-in enterprise.override (attrs: {
+in enterprise-ce.override (attrs: {
   # Avoid that we dump any sources into the store when entering the shell and
   # make development a little bit more convenient.
   src = null;
 
   buildInputs =
     attrs.buildInputs ++
     pkgs.lib.optionals (hasVcsserver) vcsserver.propagatedNativeBuildInputs ++
-    (with pythonPackages; [
+    (with ce-pythonPackages; [
       bumpversion
       invoke
       ipdb
     ]);
 
-  shellHook = attrs.shellHook +
+  # Somewhat snappier setup of the development environment
+  # TODO: think of supporting a stable path again, so that multiple shells
+  #       can share it.
+  postShellHook = ''
+    # Custom prompt to distinguish from other dev envs.
+    export PS1="\n\[\033[1;32m\][CE-shell:\w]$\[\033[0m\] "
+
+    tmp_path=$(mktemp -d)
+    export PATH="$tmp_path/bin:$PATH"
+    export PYTHONPATH="$tmp_path/${ce-pythonPackages.python.sitePackages}:$PYTHONPATH"
+    mkdir -p $tmp_path/${ce-pythonPackages.python.sitePackages}
+    python setup.py develop --prefix $tmp_path --allow-hosts ""
+    '' + enterprise-ce.linkNodeAndBowerPackages +
     pkgs.lib.strings.optionalString (hasVcsserver) ''
       # Setup the vcsserver development egg.
       pushd ${vcsserverAbsPath}
       python setup.py develop --prefix $tmp_path --allow-hosts ""
       popd
     '';
+
 })