Package module: fix packages-could-be-objects code

- Check for 'list' when it's actually a 'dict' is strange.
   Reverse logic to consider 'str' a package name and everything
   else is special.
 - Refactor to handle the difference between package names and
   packages-with-script-data in one place.
 - Add code and config documentation.
 - Switch sample configurations to dummy-backend.

src/modules/packages/main.py

@@ -42,13 +42,26 @@ class PackageManager(metaclass=abc.ABCMeta):
 
     @abc.abstractmethod
     def install(self, pkgs, from_local=False):
+        """
+        Install a list of packages (named) into the system.
+        Although this handles lists, in practice it is called
+        with one package at a time.
+
+        @param pkgs: list[str]
+            list of package names
+        @param from_local: bool
+            if True, then these are local packages (on disk) and the
+            pkgs names are paths.
+        """
         pass
 
     @abc.abstractmethod
     def remove(self, pkgs):
-        """ Removes packages.
+        """
+        Removes packages.
 
-        :param pkgs:
+        @param pkgs: list[str]
+            list of package names
         """
         pass
 
@@ -60,6 +73,23 @@ class PackageManager(metaclass=abc.ABCMeta):
         if script != "":
             check_target_env_call(script.split(" "))
 
+    def install_package(self, packagedata, from_local=False):
+        """
+        Install a package from a single entry in the install list.
+        This can be either a single package name, or an object
+        with pre- and post-scripts.
+
+        @param packagedata: str|dict
+        @param from_local: bool
+            see install.from_local
+        """
+        if isinstance(packagedata, str):
+            self.install([packagedata], from_local=from_local)
+        else:
+            self.run(packagedata["pre-script"])
+            self.install([packagedata["package"]], from_local=from_local)
+            self.run(packagedata["post-script"])
+
 
 class PMPackageKit(PackageManager):
     backend = "packagekit"
@@ -126,7 +156,7 @@ class PMDnf(PackageManager):
 
 
 class PMUrpmi(PackageManager):
-    backend = "urpmi";
+    backend = "urpmi"
 
     def install(self, pkgs, from_local=False):
         check_target_env_call(["urpmi", "--download-all", "--no-suggests",
@@ -215,6 +245,9 @@ class PMDummy(PackageManager):
     def update_db(self):
         libcalamares.utils.debug("Updating DB")
 
+    def run(self, script):
+        libcalamares.utils.debug("Running script '" + str(script) + "'")
+
 
 backend_managers = [
     (c.backend, c)
@@ -247,32 +280,17 @@ def run_operations(pkgman, entry):
     for key in entry.keys():
         entry[key] = subst_locale(entry[key])
         if key == "install":
-            if isinstance(entry[key], list):
             for package in entry[key]:
-                    pkgman.run(package["pre-script"])
-                    pkgman.install([package["package"]])
-                    pkgman.run(package["post-script"])
-            else:
-                pkgman.install(entry[key])
+                pkgman.install_package(package)
         elif key == "try_install":
             # we make a separate package manager call for each package so a
             # single failing package won't stop all of them
             for package in entry[key]:
-                if isinstance(package, str):
                 try:
-                        pkgman.install([package])
+                    pkgman.install_package(package)
                 except subprocess.CalledProcessError:
                     warn_text = "WARNING: could not install package "
-                        warn_text += package
-                        libcalamares.utils.debug(warn_text)
-                else:
-                    try:
-                        pkgman.run(package["pre-script"])
-                        pkgman.install([package["package"]])
-                        pkgman.run(package["post-script"])
-                    except subprocess.CalledProcessError:
-                        warn_text = "WARNING: could not install packages "
-                        warn_text += package["package"]
+                    warn_text += str(package)
                     libcalamares.utils.debug(warn_text)
         elif key == "remove":
             pkgman.remove(entry[key])

src/modules/packages/packages.conf

@@ -10,9 +10,13 @@
 #  - pacman      - Pacman
 #  - portage     - Gentoo package manager
 #  - entropy     - Sabayon package manager
+#  - dummy       - Dummy manager, only logs
 #
-backend: packagekit
+backend: dummy
 
+# If set to true, a package-manager specific update procedure
+# is run first (only if there is internet) to update the list
+# of packages and dependencies.
 update_db: true
 
 #

src/modules/packages/test.yaml

@@ -1,5 +1,6 @@
+backend: dummy
 rootMountPoint: /tmp/mount
-packageOperations:
+operations:
   - install:
     - pre-script: touch /tmp/foo
       package: vi