isar-bootstrap-host: Introduce HOST_DISTRO_BOOTSTRAP_KEYS

Analogously to DISTRO_BOOTSTRAP_KEYS, this allows to override the key
used for bootstrapping the host distro. This is required when using
custom repos e.g.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

doc/user_manual.md

@@ -318,6 +318,7 @@ Some other variables include:
  - `HOST_ARCH` - The Debian architecture of SDK root filesystem (e.g., `amd64`). By default set to current Debian host architecture. This variable is optional.
  - `HOST_DISTRO_APT_SOURCES` - List of apt source files for SDK root filesystem. This variable is optional.
  - `HOST_DISTRO_APT_PREFERENCES` - List of apt preference files for SDK root filesystem. This variable is optional.
+ - `HOST_DISTRO_BOOTSTRAP_KEYS` - Analogously to DISTRO_BOOTSTRAP_KEYS: List of gpg key URIs used to verify apt bootstrap repo for the host.
  - `DISTRO_APT_PREMIRRORS` - The preferred mirror (append it to the default URI in the format `ftp.debian.org my.preferred.mirror`. This variable is optional.
  - `THIRD_PARTY_APT_KEYS` - List of gpg key URIs used to verify apt repos for apt installation after bootstrapping
 

meta/recipes-core/isar-bootstrap/isar-bootstrap-host.bb

@@ -12,8 +12,9 @@ DEPLOY_ISAR_BOOTSTRAP = "${DEPLOY_DIR_BOOTSTRAP}/${HOST_DISTRO}-${HOST_ARCH}-${D
 ISAR_BOOTSTRAP_LOCK = "${DEPLOY_DIR_BOOTSTRAP}/${HOST_DISTRO}-${HOST_ARCH}-${DISTRO_ARCH}.lock"
 
 require isar-bootstrap.inc
-# We only build debian host buildchroot environments
-DISTRO_BOOTSTRAP_KEYS = ""
+
+HOST_DISTRO_BOOTSTRAP_KEYS ?= ""
+DISTRO_BOOTSTRAP_KEYS = "${HOST_DISTRO_BOOTSTRAP_KEYS}"
 
 do_apt_config_prepare[dirs] = "${WORKDIR}"
 do_apt_config_prepare[vardeps] += "\