[RFC] scripts/oe-replicate-build: add a script that packages and replicates a yocto build elsewhere

diff --git a/meta/files/replica-shar-extract.sh b/meta/files/replica-shar-extract.sh
new file mode 100644
index 00000000000..78bb6a524ff
--- /dev/null
+++ b/meta/files/replica-shar-extract.sh
@@ -0,0 +1,56 @@ 
+#!/bin/bash
+
+verbose=0
+listcontents=0
+prepare_buildsystem="yes"
+while getopts "Dl" OPT; do
+        case $OPT in
+        D)
+                verbose=1
+                ;;
+        l)
+                listcontents=1
+                ;;
+        n)
+                prepare_buildsystem="no"
+                ;;
+        *)
+                echo "Usage: $(basename "$0") [-D] [-l] [-n]"
+                echo "  -D         Use set -x to see what is going on"
+                echo "  -l         list files that will be extracted"
+                echo "  -n         Extract files but do not prepare the build system"
+                exit 1
+                ;;
+        esac
+done
+
+if [ $verbose = 1 ] ; then
+        set -x
+fi
+
+payload_offset=$(($(grep -na -m1 "^MARKER:$" "$0"|cut -d':' -f1) + 1))
+
+if [ "$listcontents" = "1" ] ; then
+    tail -n +$payload_offset "$0"| tar tv || exit 1
+    exit
+fi
+
+
+tail -n +$payload_offset "$0"| tar mx --checkpoint=.2500 || exit 1
+
+if [ $prepare_buildsystem = "no" ] ; then
+        exit
+fi
+
+target_dir=$(basename "$0" .sh)
+pushd $target_dir
+./setup-layers --destdir layers
+TEMPLATECONF=$(pwd)/meta-build-config/conf/templates/replica . layers/poky/oe-init-build-env
+popd
+
+echo "Each time you wish to use build in a new shell session, you need to source the environment setup script e.g."
+echo " \$ . $target_dir/layers/poky/oe-init-build-env $target_dir/build"
+
+exit 0
+
+MARKER:
diff --git a/scripts/oe-replicate-build b/scripts/oe-replicate-build
new file mode 100755
index 00000000000..96e69c0c92e
--- /dev/null
+++ b/scripts/oe-replicate-build
@@ -0,0 +1,56 @@ 
+#!/usr/bin/env python3
+#
+# Copyright OpenEmbedded Contributors
+#
+# SPDX-License-Identifier: MIT
+#
+
+import argparse
+import json
+import os
+import subprocess
+
+def _do_replica(args):
+    replicadir = args.output_prefix or "build-replica"
+    print("Preparing items for the bundle in {}/ ...".format(replicadir))
+    os.mkdir(replicadir)
+
+    subprocess.check_output("bitbake -S lockedsigs {}".format(args.targets), shell=True, cwd=replicadir)
+    sstate_dir = subprocess.check_output("bitbake-getvar --value SSTATE_DIR", shell=True).decode().strip()
+    if not args.no_sstate:
+        subprocess.check_output("gen-lockedsig-cache {} {} {} {}".format("locked-sigs.inc", sstate_dir, "build/sstate-cache", "''"), shell=True, cwd=replicadir)
+
+    layerdir = "meta-build-config"
+    subprocess.check_output("bitbake-layers create-layer --add-layer {}".format(layerdir), shell=True, cwd=replicadir)
+    subprocess.check_output("bitbake-layers save-build-conf {} replica".format(layerdir), shell=True, cwd=replicadir)
+    subprocess.check_output("bitbake-layers remove-layer {}".format(layerdir), shell=True, cwd=replicadir)
+
+    # meta-build-config is then in bblayers.conf.sample, and should be removed from it as it wasn't in the actual build
+    bblayers = os.path.join(replicadir, layerdir, 'conf/templates/replica/bblayers.conf.sample')
+    with open(bblayers) as f:
+        lines = f.readlines()
+        lines = [l for l in lines if os.path.join(replicadir, layerdir) not in l]
+    with open(bblayers,'w') as f:
+        f.write(''.join(lines))
+
+    subprocess.check_output("bitbake-layers create-layers-setup {}".format(replicadir), shell=True)
+
+    print("Making a bundle tarball in {}.tar ...".format(replicadir))
+    subprocess.check_output("tar cf {}.tar {}".format(replicadir, replicadir), shell=True)
+
+    print("Making a self-extracting bundle archive in {}.sh ...".format(replicadir))
+    corebase = subprocess.check_output("bitbake-getvar --value COREBASE", shell=True).decode().strip()
+    subprocess.check_output("cp {}/meta/files/replica-shar-extract.sh {}.sh".format(corebase, replicadir), shell=True)
+    subprocess.check_output("cat {}.tar >> {}.sh".format(replicadir, replicadir), shell=True)
+    subprocess.check_output("chmod +x {}.sh".format(replicadir), shell=True)
+
+parser = argparse.ArgumentParser(description="A script that bundles up everything needed to replicate a yocto build elsewhere (including appropriate portions of sstate cache) into a self-contained shell archive.")
+
+parser.add_argument('--targets', help="Bitbake targets that the replica bundle should be made for.")
+parser.add_argument('--output-prefix', help='File name prefix for the output files, if the default (build-replica) is undesirable.')
+parser.add_argument('--no-sstate', action='store_true', help='Do not include sstate cache into the replica bundle.')
+
+args = parser.parse_args()
+
+_do_replica(args)
+