[OE-core] [PATCH] core-image.bbclass: Add empty-root-password IMAGE_FEATURE

[Ben Shelton]

From: Bill Pittman <bill.pittman at ni.com>

In some cases, it may be desirable to build an image that has an empty
root password but that is not built with the full set of development-
specific changes that may be made by 'debug-tweaks' now or in the
future.  An example is a user-programmable embedded target that is
shipped with an empty root password that the customer is expected to
change when the target is configured.

To enable this use case, add an 'empty-root-password' IMAGE_FEATURE that
will allow an empty root password (e.g. not zap it during the image
creation step).

Signed-off-by: Bill Pittman <bill.pittman at ni.com>
Signed-off-by: Alejandro del Castillo <alejandro.delcastillo at ni.com>
Signed-off-by: Ben Shelton <ben.shelton at ni.com>
---
 meta/classes/core-image.bbclass |  7 +++++--
 meta/classes/image.bbclass      |  4 ++--
 meta/conf/local.conf.sample     | 28 +++++++++++++++-------------
 3 files changed, 22 insertions(+), 17 deletions(-)

diff --git a/meta/classes/core-image.bbclass b/meta/classes/core-image.bbclass
index 62363fb..cfced2b 100644
--- a/meta/classes/core-image.bbclass
+++ b/meta/classes/core-image.bbclass
@@ -27,6 +27,7 @@ LIC_FILES_CHKSUM = "file://${COREBASE}/LICENSE;md5=4d92cd373abda3937c2bc47fbc49d
 # - hwcodecs            - Install hardware acceleration codecs
 # - package-management  - installs package management tools and preserves the package manager database
 # - debug-tweaks        - makes an image suitable for development, e.g. allowing passwordless root logins
+# - empty-root-password - allows passwordless root logins, but does not enable other debug-tweaks
 # - dev-pkgs            - development packages (headers, etc.) for all installed packages in the rootfs
 # - dbg-pkgs            - debug symbol packages for all installed packages in the rootfs
 # - doc-pkgs            - documentation packages for all installed packages in the rootfs
@@ -73,8 +74,10 @@ inherit image
 # Create /etc/timestamp during image construction to give a reasonably sane default time setting
 ROOTFS_POSTPROCESS_COMMAND += "rootfs_update_timestamp ; "
 
-# Zap the root password if debug-tweaks feature is not enabled
-ROOTFS_POSTPROCESS_COMMAND += '${@bb.utils.contains("IMAGE_FEATURES", "debug-tweaks", "", "zap_empty_root_password ; ",d)}'
+# Zap the root password if empty-root-password feature is not enabled
+EMPTY_ROOT_PASSWORD_SUPPORT := '${@bb.utils.contains("IMAGE_FEATURES", "debug-tweaks", "empty-root-password", "",d)}'
+IMAGE_FEATURES  += '${EMPTY_ROOT_PASSWORD_SUPPORT}'
+ROOTFS_POSTPROCESS_COMMAND += '${@bb.utils.contains("IMAGE_FEATURES", "empty-root-password", "", "zap_empty_root_password ; ",d)}'
 
 # Tweak the mount options for rootfs in /etc/fstab if read-only-rootfs is enabled
 ROOTFS_POSTPROCESS_COMMAND += '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", "read_only_rootfs_hook; ", "",d)}'
diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
index fc08653..bc14f89 100644
--- a/meta/classes/image.bbclass
+++ b/meta/classes/image.bbclass
@@ -22,7 +22,7 @@ inherit ${TESTIMAGECLASS}
 # IMAGE_FEATURES may contain any available package group
 IMAGE_FEATURES ?= ""
 IMAGE_FEATURES[type] = "list"
-IMAGE_FEATURES[validitems] += "debug-tweaks read-only-rootfs"
+IMAGE_FEATURES[validitems] += "debug-tweaks read-only-rootfs empty-root-password"
 
 # rootfs bootstrap install
 ROOTFS_BOOTSTRAP_INSTALL = "${@bb.utils.contains("IMAGE_FEATURES", "package-management", "", "${ROOTFS_PKGMANAGE_BOOTSTRAP}",d)}"
@@ -158,7 +158,7 @@ inherit ${IMAGE_CLASSES}
 IMAGE_POSTPROCESS_COMMAND ?= ""
 MACHINE_POSTPROCESS_COMMAND ?= ""
 # Allow dropbear/openssh to accept logins from accounts with an empty password string if debug-tweaks is enabled
-ROOTFS_POSTPROCESS_COMMAND += '${@bb.utils.contains("IMAGE_FEATURES", "debug-tweaks", "ssh_allow_empty_password; ", "",d)}'
+ROOTFS_POSTPROCESS_COMMAND += '${@bb.utils.contains("IMAGE_FEATURES", "empty-root-password", "ssh_allow_empty_password; ", "",d)}'
 # Enable postinst logging if debug-tweaks is enabled
 ROOTFS_POSTPROCESS_COMMAND += '${@bb.utils.contains("IMAGE_FEATURES", "debug-tweaks", "postinst_enable_logging; ", "",d)}'
 # Write manifest
diff --git a/meta/conf/local.conf.sample b/meta/conf/local.conf.sample
index 6b5250a..a1a828e 100644
--- a/meta/conf/local.conf.sample
+++ b/meta/conf/local.conf.sample
@@ -97,19 +97,21 @@ PACKAGE_CLASSES ?= "package_ipk"
 # The EXTRA_IMAGE_FEATURES variable allows extra packages to be added to the generated 
 # images. Some of these options are added to certain image types automatically. The
 # variable can contain the following options:
-#  "dbg-pkgs"       - add -dbg packages for all installed packages
-#                     (adds symbol information for debugging/profiling)
-#  "dev-pkgs"       - add -dev packages for all installed packages
-#                     (useful if you want to develop against libs in the image)
-#  "ptest-pkgs"     - add -ptest packages for all ptest-enabled packages
-#                     (useful if you want to run the package test suites)
-#  "tools-sdk"      - add development tools (gcc, make, pkgconfig etc.)
-#  "tools-debug"    - add debugging tools (gdb, strace)
-#  "eclipse-debug"  - add Eclipse remote debugging support
-#  "tools-profile"  - add profiling tools (oprofile, exmap, lttng, valgrind)
-#  "tools-testapps" - add useful testing tools (ts_print, aplay, arecord etc.)
-#  "debug-tweaks"   - make an image suitable for development
-#                     e.g. ssh root access has a blank password
+#  "dbg-pkgs"              - add -dbg packages for all installed packages
+#                            adds symbol information for debugging/profiling)
+#  "dev-pkgs"              - add -dev packages for all installed packages
+#                            (useful if you want to develop against libs in the image)
+#  "ptest-pkgs"            - add -ptest packages for all ptest-enabled packages
+#                            (useful if you want to run the package test suites)
+#  "tools-sdk"             - add development tools (gcc, make, pkgconfig etc.)
+#  "tools-debug"           - add debugging tools (gdb, strace)
+#  "eclipse-debug"         - add Eclipse remote debugging support
+#  "tools-profile"         - add profiling tools (oprofile, exmap, lttng, valgrind)
+#  "tools-testapps"        - add useful testing tools (ts_print, aplay, arecord etc.)
+#  "debug-tweaks"          - make an image suitable for development
+#                            e.g. ssh root access has a blank password
+#  "empty-root-password"   - allow passwordless root logins, but don't enable
+#                            other debug-tweaks
 # There are other application targets that can be used here too, see
 # meta/classes/image.bbclass and meta/classes/core-image.bbclass for more details.
 # We default to enabling the debugging tweaks.
-- 
2.1.3