fedora-cosmic: drop hardware/VM packages not needed on the target host

Trim NVIDIA, Intel GPU/audio/platform, other wireless vendors and VM guest
packages from the cloned upstream manifests, and block linux-firmware's
recommends of them via a generated exclude list. Keeps amd-gpu-firmware,
amd-ucode-firmware, iwlwifi-mvm-firmware (AX200) and alsa-sof-firmware.

build.sh

@@ -83,6 +83,45 @@ gpgcheck=0
 EOF
 }
 
+# Drop packages listed in a blocklist from the cloned upstream package
+# manifests. rpm-ostree refuses (fatally) to exclude a package that an included
+# manifest declares, so remove those lines at the source instead.
+trim_upstream_packages() {
+  local root="$1"
+  local blocklist="$2"
+  local f
+  for f in "${root}"/packages/*.yaml; do
+    [[ -f "${f}" ]] || continue
+    awk '
+      NR == FNR {
+        if ($0 ~ /^[[:space:]]*#/ || $0 ~ /^[[:space:]]*$/) next
+        skip[$0] = 1
+        next
+      }
+      {
+        line = $0
+        sub(/^[[:space:]]*-[[:space:]]*/, "", line)
+        if (line in skip) next
+        print
+      }
+    ' "${blocklist}" "${f}" > "${f}.tmp"
+    mv "${f}.tmp" "${f}"
+  done
+}
+
+# Generate an exclude-packages snippet from the same blocklist. This blocks the
+# removed packages from being pulled back in as recommends (e.g. linux-firmware
+# recommends the split firmware packages).
+generate_exclude_yaml() {
+  local blocklist="$1"
+  local out="$2"
+  {
+    echo "# Generated by build.sh from $(basename "${blocklist}") - do not edit."
+    echo "exclude-packages:"
+    grep -vE '^[[:space:]]*(#|$)' "${blocklist}" | sed 's/^/  - /'
+  } > "${out}"
+}
+
 case "${BUILD_MODE}" in
   upstream)
     [[ -n "${UPSTREAM_REPO}" ]] || { echo "UPSTREAM_REPO not set in ${CONF}" >&2; exit 1; }
@@ -106,6 +145,12 @@ case "${BUILD_MODE}" in
       setup_token2_repo "${BUILD_DIR}/upstream"
     fi
 
+    if [[ -f "${IMAGE_DIR}/upstream-exclude.txt" ]]; then
+      trim_upstream_packages "${BUILD_DIR}/upstream" "${IMAGE_DIR}/upstream-exclude.txt"
+      generate_exclude_yaml "${IMAGE_DIR}/upstream-exclude.txt" \
+        "${BUILD_DIR}/upstream/hardware-exclude.yaml"
+    fi
+
     MANIFEST="${BUILD_DIR}/upstream/manifest.yaml"
     ;;
   standalone)