[openwrt/openwrt] imagebuilder: fix local packages/ folder

[LEDE Commits]

jow pushed a commit to openwrt/openwrt.git, branch openwrt-21.02:
https://git.openwrt.org/6d266ef158840b9f9e2b18153f3b789ad220e559

commit 6d266ef158840b9f9e2b18153f3b789ad220e559
Author: Paul Spooren <mail at aparcar.org>
AuthorDate: Tue Oct 12 15:36:33 2021 -1000

    imagebuilder: fix local packages/ folder
    
    This commit fixes commit "2999f810ff: build,IB: include kmods only in
    local builds" which cause the local packages/ folder only to be added
    for local builds but no longer for ImageBuilder created by the Buildbot.
    
    The commits intention was to use remote kmods repositories rather than
    storing them locally. Accidentally the entire handling of the local
    `packages/` was removed.
    
    Re-add the folder and include a README describing what it can be used
    for.
    
    Signed-off-by: Paul Spooren <mail at aparcar.org>
    (cherry picked from commit 15e55a2190ba087679b24b8844a51a6e4d512cf3)
    Fixes: #5068
    Signed-off-by: Jo-Philipp Wich <jo at mein.io>
---
 target/imagebuilder/Makefile        |  6 +++++-
 target/imagebuilder/files/README.md | 11 +++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/target/imagebuilder/Makefile b/target/imagebuilder/Makefile
index 0580e41c57..8607a2d709 100644
--- a/target/imagebuilder/Makefile
+++ b/target/imagebuilder/Makefile
@@ -46,12 +46,16 @@ ifeq ($(CONFIG_IB_STANDALONE),)
 	$(VERSION_SED_SCRIPT) $(PKG_BUILD_DIR)/repositories.conf
 endif
 
-ifeq ($(CONFIG_BUILDBOT),)
 	$(INSTALL_DIR) $(PKG_BUILD_DIR)/packages
+	# create an empty package index so `opkg` doesn't report an error
+	touch $(PKG_BUILD_DIR)/packages/Packages
+	$(INSTALL_DATA) ./files/README.md $(PKG_BUILD_DIR)/packages/
+
 	echo ''                                                        >> $(PKG_BUILD_DIR)/repositories.conf
 	echo '## This is the local package repository, do not remove!' >> $(PKG_BUILD_DIR)/repositories.conf
 	echo 'src imagebuilder file:packages'                          >> $(PKG_BUILD_DIR)/repositories.conf
 
+ifeq ($(CONFIG_BUILDBOT),)
   ifeq ($(CONFIG_IB_STANDALONE),)
 	$(FIND) $(call FeedPackageDir,libc) -type f \
 		\( -name 'libc_*.ipk' -or -name 'kernel_*.ipk' -or -name 'kmod-*.ipk' \) \
diff --git a/target/imagebuilder/files/README.md b/target/imagebuilder/files/README.md
new file mode 100644
index 0000000000..9a9616d06d
--- /dev/null
+++ b/target/imagebuilder/files/README.md
@@ -0,0 +1,11 @@
+# ./packages folder
+
+Add `.ipk` packages to this folder will allow the ImageBuilder to install them.
+
+For more complex setups consider adding a custom feed containing packages.
+
+    src custom file:///path/to/packages
+
+Whenever the ImageBuilder builds a firmware image this folder will be reloaded
+and a new package index created. In case signature checks are enabled the
+`./packages/Packages` index will be signed with a locally generated key pair.