image.bbclass: Make unneeded packages for a read-only rootfs configurable

Previously the list of packages that are considered unneeded for a
read-only rootfs was hardcoded. This made it impossible to, e.g., have
shadow installed on a system with a read-only rootfs, but where /etc
is mounted writable.

This also lists ${VIRTUAL-RUNTIME_update-alternatives} rather than
update-alternatives (as was previously the case) since this should
actually remove the intended package.

Signed-off-by: Peter Kjellerstedt <peter.kjellerstedt@axis.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 10 insertions, 19 deletions

diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
index 62ff07e2e7..894ff993cc 100644
--- a/meta/classes/image.bbclass
+++ b/meta/classes/image.bbclass
@@ -33,6 +33,10 @@ IMAGE_GEN_DEBUGFS ?= "0"
 # rootfs bootstrap install
 ROOTFS_BOOTSTRAP_INSTALL = "${@bb.utils.contains("IMAGE_FEATURES", "package-management", "", "${ROOTFS_PKGMANAGE_BOOTSTRAP}",d)}"
 
+# These packages will be removed from a read-only rootfs after all other
+# packages have been installed
+ROOTFS_RO_UNNEEDED = "update-rc.d base-passwd shadow ${VIRTUAL-RUNTIME_update-alternatives} ${ROOTFS_BOOTSTRAP_INSTALL}"
+
 # packages to install from features
 FEATURE_INSTALL = "${@' '.join(oe.packagegroup.required_packages(oe.data.typed_value('IMAGE_FEATURES', d), d))}"
 FEATURE_INSTALL[vardepvalue] = "${FEATURE_INSTALL}"
@@ -114,7 +118,7 @@ def rootfs_variables(d):
                  'IMAGE_ROOTFS_MAXSIZE','IMAGE_NAME','IMAGE_LINK_NAME','IMAGE_MANIFEST','DEPLOY_DIR_IMAGE','RM_OLD_IMAGE','IMAGE_FSTYPES','IMAGE_INSTALL_COMPLEMENTARY','IMAGE_LINGUAS',
                  'MULTILIBRE_ALLOW_REP','MULTILIB_TEMP_ROOTFS','MULTILIB_VARIANTS','MULTILIBS','ALL_MULTILIB_PACKAGE_ARCHS','MULTILIB_GLOBAL_VARIANTS','BAD_RECOMMENDATIONS','NO_RECOMMENDATIONS',
                  'PACKAGE_ARCHS','PACKAGE_CLASSES','TARGET_VENDOR','TARGET_ARCH','TARGET_OS','OVERRIDES','BBEXTENDVARIANT','FEED_DEPLOYDIR_BASE_URI','INTERCEPT_DIR','USE_DEVFS',
-                 'COMPRESSIONTYPES', 'IMAGE_GEN_DEBUGFS']
+                 'COMPRESSIONTYPES', 'IMAGE_GEN_DEBUGFS', 'ROOTFS_RO_UNNEEDED']
     variables.extend(rootfs_command_variables(d))
     variables.extend(variable_depends(d))
     return " ".join(variables)
diff --git a/meta/lib/oe/rootfs.py b/meta/lib/oe/rootfs.py
index 0f835d311b..bfae1d8e89 100644
--- a/meta/lib/oe/rootfs.py
+++ b/meta/lib/oe/rootfs.py
@@ -238,28 +238,13 @@ class Rootfs(object):
                                       self.d.getVar('IMAGE_ROOTFS', True),
                                       "run-postinsts", "remove"])
 
-        runtime_pkgmanage = bb.utils.contains("IMAGE_FEATURES", "package-management",
-                         True, False, self.d)
-        sysvcompat_in_distro = bb.utils.contains("DISTRO_FEATURES", [ "systemd", "sysvinit" ],
-                         True, False, self.d)
         image_rorfs = bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs",
-                         True, False, self.d)
-        if sysvcompat_in_distro and not image_rorfs:
-            pkg_to_remove = ""
-        else:
-            pkg_to_remove = "update-rc.d"
+                                        True, False, self.d)
         if image_rorfs:
             # Remove components that we don't need if it's a read-only rootfs
+            unneeded_pkgs = self.d.getVar("ROOTFS_RO_UNNEEDED", True).split()
             pkgs_installed = image_list_installed_packages(self.d)
-            pkgs_to_remove = list()
-            for pkg in pkgs_installed:
-                if pkg in ["update-rc.d",
-                        "base-passwd",
-                        "shadow",
-                        "update-alternatives", pkg_to_remove,
-                        self.d.getVar("ROOTFS_BOOTSTRAP_INSTALL", True)
-                        ]:
-                    pkgs_to_remove.append(pkg)
+            pkgs_to_remove = [pkg for pkg in pkgs_installed if pkg in unneeded_pkgs]
 
             if len(pkgs_to_remove) > 0:
                 self.pm.remove(pkgs_to_remove, False)
@@ -273,6 +258,8 @@ class Rootfs(object):
         post_uninstall_cmds = self.d.getVar("ROOTFS_POSTUNINSTALL_COMMAND", True)
         execute_pre_post_process(self.d, post_uninstall_cmds)
 
+        runtime_pkgmanage = bb.utils.contains("IMAGE_FEATURES", "package-management",
+                                              True, False, self.d)
         if not runtime_pkgmanage:
             # Remove the package manager data files
             self.pm.remove_packaging_data()