dockcross: Add support for per-project configuration

README.rst

@@ -210,8 +210,8 @@ convenience target ``display_images`` could be used::
   done
 
 
-Configuration
+Dockcross configuration
--------------
+-----------------------
 
 The following environmental variables and command-line options are used. In
 all cases, the command-line option overrides the environment variable.
@@ -238,6 +238,18 @@ Extra arguments to pass to the ``docker run`` command. Quote the entire set of
 args if they contain spaces.
 
 
+Pre-project dockcross configuration
+-----------------------------------
+
+If a shell script named ``.dockcross`` is found in the current directory where
+the dockcross script is started, it is executed before the dockcross script
+``command`` argument.  The shell script is expected to have a shebang like
+``#!/bin/bash``.
+
+For example, commands like ``git config --global advice.detachedHead false`` can
+be added to this script.
+
+
 Examples
 --------
 

imagefiles/entrypoint.sh

@@ -35,6 +35,11 @@ if [[ -n $BUILDER_UID ]] && [[ -n $BUILDER_GID ]]; then
         /dockcross/pre_exec.sh
     fi
 
+    # Execute project specific pre execution hook
+    if [[ -e /work/.dockcross ]]; then
+       chpst -u :$BUILDER_UID:$BUILDER_GID /work/.dockcross
+    fi
+
     # Run the command as the specified user/group.
     exec chpst -u :$BUILDER_UID:$BUILDER_GID "$@"
 else