Add Guix buildpack

Author: Hugo Lecomte

docs/source/config_files.rst

@@ -231,6 +231,27 @@ to produce a reproducible environment.
 To see an example repository visit
 `nix binder example <https://github.com/binder-examples/nix>`_.
 
+.. _manifest.scm:
+
+``manifest.scm`` - the Guix package manager
+===========================================
+
+Specify packages to be installed by the `Guix package manager <https://guix.gnu.org/>`_.
+All packages specified in |manifest|_ will be installed in a container using |guix_package|_. In addition, you can use different `channels <https://guix.gnu.org/manual/en/html_node/Channels.html>`_ rather
+than the ones available by default (official channels of GNU Guix 1.3.0).
+You must describe such channels in a ``channels.scm`` file which will be used
+alongside ``manifest.scm`` with the |guix_time-machine|_ command. Furthermore, using a ``channels.scm`` file lets you `pin a specific revision <https://guix.gnu.org/manual/en/html_node/Replicating-Guix.html>`_ of Guix, allowing you to unambiguously specific the software environment to reproduce.
+
+For more information about Guix please read the `manual <https://guix.gnu.org/manual/en/guix.html>`_.
+
+.. |manifest| replace:: ``manifest.scm``
+.. _manifest: https://guix.gnu.org/manual/en/html_node/Invoking-guix-package.html#index-profile-manifesthy
+
+.. |guix_package| replace:: ``guix package``
+.. _guix_package: https://guix.gnu.org/manual/en/html_node/Invoking-guix-package.html#Invoking-guix-package
+
+.. |guix_time-machine| replace:: ``guix time-machine``
+.. _guix_time-machine: https://guix.gnu.org/manual/en/html_node/Invoking-guix-time_002dmachine.html
 
 ``Dockerfile`` - Advanced environments
 ======================================

repo2docker/app.py

@@ -37,6 +37,7 @@
     PipfileBuildPack,
     PythonBuildPack,
     RBuildPack,
+    GuixBuildPack,
 )
 from . import contentproviders
 from .utils import ByteSpecification, chdir
@@ -99,6 +100,7 @@ def _default_log_level(self):
             CondaBuildPack,
             PipfileBuildPack,
             PythonBuildPack,
+            GuixBuildPack,
         ],
         config=True,
         help="""

repo2docker/buildpacks/__init__.py

@@ -8,3 +8,4 @@
 from .legacy import LegacyBinderDockerBuildPack
 from .r import RBuildPack
 from .nix import NixBuildPack
+from .guix import GuixBuildPack

repo2docker/buildpacks/base.py

@@ -718,3 +718,4 @@ def get_start_script(self):
             # the only path evaluated at container start time rather than build time
             return os.path.join("${REPO_DIR}", start)
         return None
+

repo2docker/buildpacks/guix/__init__.py

@@ -0,0 +1,74 @@
+"""BuildPack for guix environments"""
+import os
+
+from ..base import BuildPack, BaseImage
+
+
+class GuixBuildPack(BaseImage):
+    """A guix Package Manager BuildPack"""
+
+    def get_path(self):
+        """Return paths to be added to PATH environment variable"""
+        return super().get_path() + ["/home/${NB_USER}/.guix-profile/bin"]
+
+
+    def get_build_scripts(self):
+        """
+        Install guix package manager version 1.3.0.x86_64-linux, using
+        an unmodified installation script found at
+        https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh
+        """
+        return super().get_build_scripts() + [
+            (
+                "root",
+                """
+                yes | BIN_VER=1.3.0.x86_64-linux \
+                bash /home/${NB_USER}/.local/bin/guix-install.bash
+                """,
+            ),
+
+        ]
+
+    def get_build_script_files(self):
+
+        """Copying guix installation script on the image"""
+        return {
+            "guix/guix-install.bash":
+                "/home/${NB_USER}/.local/bin/guix-install.bash",
+        }
+
+    def get_assemble_scripts(self):
+        """
+        Wake up the guix daemon with root permission, set guix environnement
+        variables, make sure we never use debian's python by error by
+        renaming it, then, as an user install packages listed in
+        manifest.scm, use guix time-machine if channels.scm file exists
+        """
+        assemble_script ="""
+                 /var/guix/profiles/per-user/root/current-guix/bin/guix-daemon \
+                 --build-users-group=guixbuild --disable-chroot & \
+                 mv /usr/bin/python /usr/bin/python.debian && \
+                 su - $NB_USER -c '{}' && \
+                 echo 'GUIX_PROFILE="$HOME/.guix-profile" ; \
+                 source "$GUIX_PROFILE/etc/profile"'>> ~/.bash_profile
+                 """
+
+        if os.path.exists(self.binder_path("channels.scm")):
+            assemble_script = assemble_script.format(
+                "guix time-machine -C  " + self.binder_path("channels.scm") +
+                " -- package -m "  + self.binder_path("manifest.scm")
+            )
+        else:
+            assemble_script = assemble_script.format(
+                "guix package -m " + self.binder_path("manifest.scm")
+            )
+        return super().get_assemble_scripts() + [
+            ( "root",
+              assemble_script,
+             )
+        ]
+
+    def detect(self):
+        """Check if current repo should be built with the guix BuildPack"""
+        return os.path.exists(self.binder_path("manifest.scm"))
+