[ci] Publish package checksums #149

Add make package/index to generate Packages file with SHA256 checksums.
Filter to only include openwisp packages and save as Packages.sha256.checksum
following OpenWRT's standard format.

Fixes #149

Author: shubhamk0205

runbuild

@@ -52,6 +52,15 @@ fi
 
 make -j"$CORES" package/openwisp-config/compile || make -j1 V=s package/openwisp-config/compile || exit 1
 
+# Generate package index with checksums
+cd "$BUILD_DIR"/openwrt
+make package/index
+
+# Filter Packages file to include only openwisp packages and save as checksum file
+awk '/^Package: openwisp/,/^$/' \
+	"$BUILD_DIR"/openwrt/bin/packages/"$COMPILE_TARGET"/Packages \
+	>"$BUILD_DIR"/openwrt/bin/packages/"$COMPILE_TARGET"/openwisp/Packages.sha256.checksum
+
 mv "$BUILD_DIR"/openwrt/bin/packages/"$COMPILE_TARGET"/openwisp "$VERSIONED_DIR"
 
 rm "$LATEST_LINK" || true