feat(coreos-sanity): add some checks to ensure that coreos policies are not overwritted

.gitignore

@@ -1,4 +1,6 @@
 build/
 vscode-bitbake-build/
 documentation/_build/
+documentation/oe-logs
+documentation/oe-workdir
 

documentation/ref-manual/classes.rst

@@ -21,12 +21,26 @@ The ``coreos_metadata_scm`` is automatically inherited if ``DISTRO`` is set to
 ``belden-coreos`` or to any distro based on ``belden-coreos``.
 
 .. _ref-classes-coreos-image:
-.. index:: coreos_image.bbclass
+.. index:: coreos-image.bbclass
 
-``coreos_image.bbclass``
+``coreos-image.bbclass``
 ========================
 
 The ``coreos-image`` class provides common definitions for the
 ``coreos-image-*`` image recipes, such as support for additional
 :extern:ref:`IMAGE_FEATURE <ref-features-image>`.
 
+.. _ref-classes-coreos-sanity:
+.. index:: coreos-sanity.class
+
+``coreos-sanity.bbclass``
+========================
+
+The ``coreos-sanity`` class is inherited inside the CoreOS layer
+configuration file to add some sanity checks. Theses check ensure that the 
+policies of CoreOS are followed.
+
+Currently, this add check to ensure:
+  - that the distro is based on CoreOS
+  - that SystemD is used as ``INIT_MANAGER``
+  - that glibc is used as the default C library

layers/meta-belden-coreos/classes/coreos-sanity.bbclass

@@ -0,0 +1,33 @@
+# This class add some sanity checks to ensure that distribution based on
+# CoreOS only use the subset of openembedded-core that is supported by the
+# CoreOS team.
+
+
+SANITY_COREOS_COMPATIBLE ??= "0"
+
+addhandler check_coreos_sanity_eventhandler
+check_coreos_sanity_eventhandler[eventmask] = "bb.event.SanityCheck"
+python check_coreos_sanity_eventhandler() {
+
+    if e.data.getVar('SANITY_COREOS_COMPATIBLE') != "1":
+            bb.fatal(
+            "The CoreOS layer is only compatible with distribution based on "
+            "conf/distro/belden-core.conf.\n"
+            "Please ensure that your distribution configuration file contains "
+            " `require conf/distro/belden-core.conf`"
+        )
+
+    if e.data.getVar('VIRTUAL-RUNTIME_init_manager') != "systemd":
+        bb.fatal(
+            "systemd is not set as `INIT_MANAGER`. "
+            "Using SystemD is mandatory on CoreOS based distribution"
+        )
+    
+    if e.data.getVar("TCLIBC") != "glibc":
+        bb.fatal(
+            "glibc is not set as `TCLIBC`. "
+            "Using glibc is mandatory on CoreOS based distribution"
+        )
+
+    return
+}

layers/meta-belden-coreos/conf/distro/belden-coreos.conf

@@ -31,6 +31,10 @@ SANITY_TESTED_DISTROS ?= " \
             debian-11 \n \
             "
 
+# This variable is used to ensure that any distribution using the CoreOS layer
+# include this file. This is checked by the coreos-sanity class
+SANITY_COREOS_COMPATIBLE ?= "1"
+
 require conf/distro/include/no-static-libs.inc
 require conf/distro/include/yocto-uninative.inc
 require conf/distro/include/security_flags.inc

layers/meta-belden-coreos/conf/layer.conf

@@ -11,3 +11,8 @@ BBFILE_PRIORITY_meta-belden-coreos = "6"
 
 LAYERDEPENDS_meta-belden-coreos = "core"
 LAYERSERIES_COMPAT_meta-belden-coreos = "kirkstone"
+
+# Sanity Checks
+# ==============================================================================
+
+INHERIT += "coreos-sanity"