add mksquashfs config params

Allow mksquashfs overrides for thread count and compression algorithm.

Apply all rootfs-level overrides uniformly in Makefile.

Change-Id: I9dfb9fac63a6efcad42bc73242929e52ff1f9344

image-builder/Makefile

@@ -51,8 +51,16 @@ images: build generate_iso package_qcow
 
 build:
 	set -ex
-	# Apply any user-defined overrides to multistrap playbook
-	cp $(WORKDIR)/rootfs/multistrap-vars.yaml assets/playbooks/roles/multistrap/vars/main.yaml
+	# Apply any user-defined rootfs overrides to playbooks
+	if [ -f $(WORKDIR)/rootfs/multistrap-vars.yaml ]; then
+	  cp $(WORKDIR)/rootfs/multistrap-vars.yaml assets/playbooks/roles/multistrap/vars/main.yaml
+	fi
+	if [ -f $(WORKDIR)/rootfs/osconfig-vars.yaml ]; then
+	  cp $(WORKDIR)/rootfs/osconfig-vars.yaml assets/playbooks/roles/osconfig/vars/main.yaml
+	fi
+	if [ -f $(WORKDIR)/rootfs/livecdcontent-vars.yaml ]; then
+	  cp $(WORKDIR)/rootfs/livecdcontent-vars.yaml assets/playbooks/roles/livecdcontent/vars/main.yaml
+	fi
 ifneq ($(PROXY), )
 	sudo -E ./tools/docker_proxy.sh $(PROXY) $(NO_PROXY)
 	export http_proxy=$(PROXY)

image-builder/assets/playbooks/roles/livecdcontent/defaults/main.yaml

@@ -1,2 +1,5 @@
 root_chroot: build
 root_image: build
+# Additional flags for mksquashfs
+mksquashfs_compression: lz4
+mksquashfs_threads: "{{ ansible_processor_vcpus }}"

image-builder/assets/playbooks/roles/livecdcontent/tasks/squashfs.yaml

@@ -15,5 +15,6 @@
         mksquashfs \
             "{{ root_chroot }}" \
             "{{ root_image }}/live/filesystem.squashfs" \
-            -processors {{ ansible_processor_vcpus }} \
+            -processors {{ mksquashfs_threads }} \
+            -comp {{ mksquashfs_compression }} \
             -e boot

image-builder/config/qcow-control-plane/osconfig-control-plane-vars.yaml

@@ -1,10 +1,5 @@
 # Custom user-defined overrides to the `osconfig` playbook can be placed here.
-# Example, writing an extra file to the OS:
-#files:
-#    - name: /test.sh
-#      file_content: |
-#          #!/bin/bash
-#          echo hello world
-#      permissions: '0755'
-#      owner: root
-#      group: root
+#
+# You would only use this if you needed to apply some settings uniques to this
+# type of image (control-plane or data-plane). Ex: kernel boot params specific
+# to workers vs non-worker nodes.

image-builder/config/rootfs/livecdcontent-vars.yaml

@@ -0,0 +1,3 @@
+# user-defined overrides for livecdcontent playbook
+#
+#mksquashfs_threads = 1

image-builder/config/rootfs/osconfig-vars.yaml

@@ -0,0 +1,10 @@
+# Custom user-defined overrides to the `osconfig` playbook can be placed here.
+# Example, writing an extra file to the OS:
+#files:
+#    - name: /test.sh
+#      file_content: |
+#          #!/bin/bash
+#          echo hello world
+#      permissions: '0755'
+#      owner: root
+#      group: root