Base squeleton for blueprinting script

blueprinting.py

@@ -0,0 +1,7 @@
+#!/usr/bin/env python3
+import pacman
+
+
+if __name__ == "__main__":
+    packages = pacman.list_installed_packages()
+    config_files = pacman.list_modified_config_files()

pacman.py

@@ -0,0 +1,138 @@
+#!/usr/bin/env python3
+import os
+import subprocess
+import sys
+
+PACKAGE_BASE_PATH = "/var/cache/pacman/pkg/"
+ARCH = "x86_64"
+
+
+def is_installed(package):
+    """
+    Check whether the specified package is installed or not.
+    """
+    try:
+        subprocess.check_output(["pacman", "-Qs", package])
+        return True
+    except subprocess.CalledProcessError:
+        return False
+
+
+def get_file_from_package(file):
+    """
+    Get the specified file from the corresponding package archive from pacman
+    cache.
+
+    Returns None and print an error message if unable to find the archive in the
+    pacman cache.
+    """
+    # /var/cache/pacman/pkg/lvm2-2.02.116-1-x86_64.pkg.tar.xz
+    # Find the package
+    try:
+        pacman_raw = subprocess.check_output(["pacman", "-Qo", file])
+        pacman_raw = pacman_raw.decode("utf-8").strip()
+        package, version = pacman_raw.split(" ")[-2:]
+    except subprocess.CalledProcessError:
+        print("Unable to find a package owning file " + file + ".",
+              file=sys.stderr)
+        return None
+    # Remove leading / if present
+    file = file.lstrip("/")
+    # Get the path to the package
+    package_archive = package + "-" + version + "-" + ARCH + ".pkg.tar.xz"
+    package_path = PACKAGE_BASE_PATH + package_archive
+    # Untar the package file
+    try:
+        raw = subprocess.check_output(["bsdtar", "-xOf", package_path, file],
+                                      stderr=open(os.devnull, 'w'))
+        raw = raw.decode("utf-8")
+    except subprocess.CalledProcessError:
+        try:
+            package_path = package_path.replace(ARCH, "any")
+            raw = subprocess.check_output(["bsdtar", "-xOf", package_path, file],
+                                          stderr=open(os.devnull, 'w'))
+            raw = raw.decode("utf-8")
+        except subprocess.CalledProcessError:
+            print("Unable to untar package archive " + package_path + ".",
+                file=sys.stderr)
+            return None
+    return raw
+
+
+def list_packages_in_group(group):
+    """
+    List all the packages member of a given group.
+    """
+    pacman_raw = subprocess.check_output(["pacman", "-Sg", group])
+    pacman_raw = pacman_raw.decode("utf-8").strip()
+    return [i.split(" ")[1] for i in pacman_raw.split("\n")]
+
+
+
+def list_modified_config_files(packages=[]):
+    """
+    List all the manually modified configuration files.
+
+    packages is an optionnal filtering list of packages. Defaults to [] which
+    means "all the packages".
+
+    Returns a dict with modified configuration files as keys and diffs as
+    values.
+    """
+    pacman_raw = subprocess.check_output(["pacman", "-Qii"] + packages)
+    pacman_raw = pacman_raw.decode("utf-8").strip()
+    modified_list = [i.split("\t")[1]
+                     for i in pacman_raw.split("\n")
+                     if i.startswith("MODIFIED")]
+    modified_files = {}
+    for i in modified_list:
+        package_file = get_file_from_package(i)
+        with open(i, 'r') as fh:
+            fs_file = fh.read()
+        modified_files[i] = None
+    return modified_files
+
+
+def list_installed_packages():
+    """
+    List all the installed packages (native, not AUR).
+
+    If a group of packages is completely installed, those packages will be
+    replaced by the matching group name.
+    """
+    # Get a list of all the explicitly installed packages
+    pacman_packages_raw = subprocess.check_output(["pacman", "-Qenq"])
+    pacman_packages_raw = pacman_packages_raw.decode("utf-8").strip()
+    packages_list = pacman_packages_raw.split("\n")
+    # Get a list of all the explicitly installed packages, part of a group
+    pacman_groups_raw = subprocess.check_output(["pacman", "-Qgenq"])
+    pacman_groups_raw = pacman_groups_raw.decode("utf-8").strip()
+    # Store the installed packages of each group
+    groups_packages = {}
+    for i in pacman_groups_raw.split("\n"):
+        group, package = i.split(" ")
+        if group in groups_packages:
+            groups_packages[group] += [package]
+        else:
+            groups_packages[group] = [package]
+    # Check if the whole group has been installed
+    for group in groups_packages:
+        # List of packages in the group not explicitly installed
+        diff = set(list_packages_in_group(group)).difference(
+            set(groups_packages[group]))
+        # Check that they are installed anyway
+        diff_are_all_installed = True
+        for package in diff:
+            if not is_installed(package):
+                diff_are_all_installed = False
+                break
+        if diff_are_all_installed:
+            # If the whole group has been installed, replace its packages in
+            # the packages list by itself
+            for package in groups_packages[group]:
+                try:
+                    packages_list.remove(package)
+                except ValueError:
+                    pass
+            packages_list.append(group)
+    return packages_list