Remove netronome and amdgpu firmware by default

Allow customizing which firmware to remove this way.

Change-Id: I714c0771c565814714881b979daaa4c83a15db1d

dib/ironic-python-agent-ramdisk/environment.d/10-defaults.bash

@@ -0,0 +1 @@
+export IPA_REMOVE_FIRMWARE=${IPA_REMOVE_FIRMWARE:-amdgpu,netronome}

dib/ironic-python-agent-ramdisk/post-install.d/99-remove-extra-packages

@@ -8,6 +8,10 @@ set -o pipefail
 
 rm -rf /tmp/ironic-python-agent
 
+for item in ${IPA_REMOVE_FIRMWARE//,/ }; do
+    rm -rf /usr/lib/firmware/$item
+done
+
 # TODO(dtantsur): implement the same for debian-based systems
 case "$DISTRO_NAME" in
     fedora|centos|centos7|rhel|rhel7)

doc/source/admin/dib.rst

@@ -158,6 +158,15 @@ required for instance image or deploy image.
 .. _dynamic-login: https://docs.openstack.org/diskimage-builder/latest/elements/dynamic-login/README.html
 .. _devuser: https://docs.openstack.org/diskimage-builder/latest/elements/devuser/README.html
 
+Firmware Removal
+~~~~~~~~~~~~~~~~
+
+By default the element removes some firmware blobs to reduce the image size.
+Specifically, firmware from ``netronome`` and ``amdgpu`` is removed. If you
+want to override this, change the ``IPA_REMOVE_FIRMWARE`` environment variable
+to a comma-separated list of directories or files under ``/usr/lib/firmware``.
+Set it to an empty string to disable firmware removal.
+
 Available Elements
 ------------------
 

releasenotes/notes/no-firmware-e2cb953037a3be8f.yaml

@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    Firmware for netronome and amdgpu is now removed by default. Set
+    ``IPA_REMOVE_FIRMWARE`` to override.