Merge "Add block-device defaults"

diskimage_builder/elements/block-device-efi/README.rst

@@ -0,0 +1,11 @@
+================
+Block Device EFI
+================
+
+This provides a block-device configuration for the ``vm`` element to
+get a single-partition disk suitable for EFI booting.
+
+Note on x86 this provides the extra `BIOS boot partition
+<https://en.wikipedia.org/wiki/BIOS_boot_partition>`__ and a EFI boot
+partition for maximum compatability.
+

diskimage_builder/elements/block-device-efi/block-device-default.yaml

@@ -0,0 +1,30 @@
+- local_loop:
+    name: image0
+
+- partitioning:
+    base: image0
+    label: gpt
+    partitions:
+      - name: ESP
+        type: 'EF00'
+        size: 8MiB
+        mkfs:
+          type: vfat
+          mount:
+            mount_point: /boot/efi
+            fstab:
+              options: "defaults"
+              fsck-passno: 1
+      - name: BSP
+        type: 'EF02'
+        size: 8MiB
+      - name: root
+        type: '8300'
+        size: 100%
+        mkfs:
+          type: ext4
+          mount:
+            mount_point: /
+            fstab:
+              options: "defaults"
+              fsck-passno: 1

diskimage_builder/elements/block-device-efi/element-provides

@@ -0,0 +1 @@
+block-device

diskimage_builder/elements/block-device-gpt/README.rst

@@ -2,10 +2,10 @@
 Block Device GPT
 ================
 
-This is an override for the default block-device configuration
+This provides a block-device configuration for the ``vm`` element to
-provided in the ``vm`` element to get a GPT based single-partition
+get a GPT based single-partition disk.
-disk, rather than the default MBR.
 
-Note this provides the extra `BIOS boot partition
+Note on x86 this provides the extra `BIOS boot partition
 <https://en.wikipedia.org/wiki/BIOS_boot_partition>`__ as required for
 non-EFI boot environments.
+

diskimage_builder/elements/block-device-gpt/block-device-ppc64el.yaml

@@ -0,0 +1,32 @@
+# Default GPT block device setup for PPC
+# --------------------------------------
+#
+# Details (extracted from [1])
+#
+# Power Firmware (OFW) scans chosen (nvram value boot-device) device,
+# for either PReP* partition or vfat.
+#
+# PReP is raw and small (8M max) partition which caries only stage1
+# binary.
+#
+# [1] https://www.ibm.com/developerworks/community/wikis/home?lang=en#!/wiki/W51a7ffcf4dfd_4b40_9d82_446ebc23c550/page/PowerLinux%20Boot%20howto
+
+- local_loop:
+    name: image0
+
+- partitioning:
+    base: image0
+    label: gpt
+    partitions:
+      - name: boot
+        type: '0x4100'
+        size: 8MiB
+      - name: root
+        size: 100%
+        mkfs:
+          type: ext4
+          mount:
+            mount_point: /
+            fstab:
+              options: "defaults"
+              fsck-passno: 1

diskimage_builder/elements/block-device-gpt/element-provides

@@ -0,0 +1 @@
+block-device

diskimage_builder/elements/block-device-mbr/README.rst

@@ -0,0 +1,7 @@
+================
+Block Device MBR
+================
+
+This provides the default legacy block-device configuration for the
+"vm" element.  This configures a single partition and is suitable for
+a MBR based bootloader.

diskimage_builder/elements/block-device-mbr/element-provides

@@ -0,0 +1 @@
+block-device

diskimage_builder/elements/ubuntu-minimal/test-elements/xenial-build-succeeds/element-deps

@@ -1,2 +1,3 @@
+block-device-mbr
 openstack-ci-mirrors
 vm

diskimage_builder/elements/ubuntu/test-elements/xenial-build-succeeds/element-deps

@@ -1,2 +1,4 @@
+block-device-mbr
 openstack-ci-mirrors
 vm
+

diskimage_builder/elements/vm/element-deps

@@ -1 +1,2 @@
+block-device
 bootloader

diskimage_builder/lib/common-functions

@@ -239,9 +239,52 @@ function run_d() {
     check_break after-$1 bash
 }
 
+function _arg_defaults_hack() {
+    # The block-device configuration looks in all elements for a
+    # "block-device-default.yaml" file.  The "vm" element used to
+    # provide the default block-device, which was fine when there was
+    # only one option; but now we have mbr, gpt & efi versions.
+    #
+    # So now the vm element has a dependency on the block-device
+    # element, which several different elements can provide.  However,
+    # for backwards compatability we need to ensure you can still
+    # build without specifying it.  Thus if we see the vm element, but
+    # no block-device-* element, we will automatically add the old
+    # default MBR.
+    #
+    # Note that you can still override this by setting
+    # DIB_BLOCK_DEVICE_CONFIG; any value there will be taken over the
+    # element defaults.  In this case you'd have "block-device-mbr" as
+    # an element, but it wouldn't actually be used for configuration.
+    #
+    # XXX: if this is becoming a common problem, we could have some
+    # sort of "element-defaults" that maps a "element-deps" entry to a
+    # default.
+    local vm_seen
+    local blockdev_seen
+    local elements
+
+    for arg do
+        if [[ "$arg" =~ "vm" ]]; then
+            vm_seen=1
+        elif [[ "$arg" =~ "block-device-" ]]; then
+            blockdev_seen=1
+        fi
+        elements="$elements $arg"
+    done
+
+    if [[ -n "${vm_seen}" && -z "${blockdev_seen}" ]]; then
+        elements="$elements block-device-mbr"
+    fi
+
+    echo $elements
+}
+
 function arg_to_elements() {
   for arg do IMAGE_ELEMENT="$IMAGE_ELEMENT $arg" ; done
 
+  IMAGE_ELEMENT="$(_arg_defaults_hack $IMAGE_ELEMENT)"
+
   if [ "$SKIP_BASE" != "1" ]; then
     IMAGE_ELEMENT="base $IMAGE_ELEMENT"
   fi

doc/source/user_guide/building_an_image.rst

@@ -67,54 +67,24 @@ on.
 
 There are currently two defaults:
 
-* When using the `vm` element a MBR based partition layout is created
+* When using the ``vm`` element, an element that provides
-  with exactly one partition that fills up the whole disk and used as
+  ``block-device`` should be included.  Available ``block-device-*``
-  root device.
+  elements cover the common case of a single partition that fills up
-* When not using the `vm` element a plain filesystem image, without
+  the whole disk and used as root device.  Currently there are MBR,
+  GPT and EFI versions.  For example, to use a GPT disk you could
+  build with ::
+
+    disk-image-create -o output.qcow vm block-device-gpt ubuntu-minimal
+
+* When not using the ``vm`` element a plain filesystem image, without
   any partitioning, is created.
 
-The user can overwrite the default handling by setting the environment
+If you wish to customise the top-level ``block-device-default.yaml``
+file from one of the ``block-device-*`` elements, set the environment
 variable `DIB_BLOCK_DEVICE_CONFIG`.  This variable must hold YAML
 structured configuration data or be a ``file://`` URL reference to a
 on-disk configuration file.
 
-The default when using the `vm` element is:
-
-.. code-block:: yaml
-
-    DIB_BLOCK_DEVICE_CONFIG='
-      - local_loop:
-          name: image0
-
-      - partitioning:
-          base: image0
-          label: mbr
-          partitions:
-            - name: root
-              flags: [ boot, primary ]
-              size: 100%
-              mkfs:
-                mount:
-                  mount_point: /
-                  fstab:
-                    options: "defaults"
-                    fsck-passno: 1'
-
-The default when not using the `vm` element is:
-
-.. code-block:: yaml
-
-    DIB_BLOCK_DEVICE_CONFIG='
-      - local_loop:
-          name: image0
-          mkfs:
-            name: mkfs_root
-            mount:
-              mount_point: /
-              fstab:
-                options: "defaults"
-                fsck-passno: 1'
-
 There are a lot of different options for the different levels.  The
 following sections describe each level in detail.