support for managing GPT partitions

Specifically, this is to support Azure's G-series VMs (which come with
disks up to 6500GB).

3 files changed, 102 insertions, 34 deletions

diff --git a/ChangeLog b/ChangeLog
index 127bc361..a3694737 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -21,7 +21,9 @@
  - hostname: on first boot apply hostname to be same as is written for
    persistent hostname.  (LP: #1246485)
  - remove usage of dmidecode on linux in favor of /sys interface [Ben Howard]
- - python3 support [Barry Warsaw, Daniel Watson, Josh Harlow] (LP: #1247132)
+ - python3 support [Barry Warsaw, Daniel Watkins, Josh Harlow] (LP: #1247132)
+ - support managing gpt partitions in disk config [Daniel Watkins]
+ - Azure: utilze gpt support for ephemeral formating [Daniel Watkins]
 0.7.6:
  - open 0.7.6
  - Enable vendordata on CloudSigma datasource (LP: #1303986)
diff --git a/cloudinit/config/cc_disk_setup.py b/cloudinit/config/cc_disk_setup.py
index 1660832b..d8553167 100644
--- a/cloudinit/config/cc_disk_setup.py
+++ b/cloudinit/config/cc_disk_setup.py
@@ -27,6 +27,7 @@ frequency = PER_INSTANCE
 # Define the commands to use
 UDEVADM_CMD = util.which('udevadm')
 SFDISK_CMD = util.which("sfdisk")
+SGDISK_CMD = util.which("sgdisk")
 LSBLK_CMD = util.which("lsblk")
 BLKID_CMD = util.which("blkid")
 BLKDEV_CMD = util.which("blockdev")
@@ -151,7 +152,7 @@ def enumerate_disk(device, nodeps=False):
         name: the device name, i.e. sda
     """
 
-    lsblk_cmd = [LSBLK_CMD, '--pairs', '--out', 'NAME,TYPE,FSTYPE,LABEL',
+    lsblk_cmd = [LSBLK_CMD, '--pairs', '--output', 'NAME,TYPE,FSTYPE,LABEL',
                  device]
 
     if nodeps:
@@ -315,22 +316,6 @@ def is_disk_used(device):
     return False
 
 
-def get_hdd_size(device):
-    """
-    Returns the hard disk size.
-    This works with any disk type, including GPT.
-    """
-
-    size_cmd = [SFDISK_CMD, '--show-size', device]
-    size = None
-    try:
-        size, _err = util.subp(size_cmd)
-    except Exception as e:
-        raise Exception("Failed to get %s size\n%s" % (device, e))
-
-    return int(size.strip())
-
-
 def get_dyn_func(*args):
     """
     Call the appropriate function.
@@ -358,6 +343,30 @@ def get_dyn_func(*args):
         raise Exception("No such function %s to call!" % func_name)
 
 
+def get_mbr_hdd_size(device):
+    size_cmd = [SFDISK_CMD, '--show-size', device]
+    size = None
+    try:
+        size, _err = util.subp(size_cmd)
+    except Exception as e:
+        raise Exception("Failed to get %s size\n%s" % (device, e))
+
+    return int(size.strip())
+
+
+def get_gpt_hdd_size(device):
+    out, _ = util.subp([SGDISK_CMD, '-p', device])
+    return out.splitlines()[0].split()[2]
+
+
+def get_hdd_size(table_type, device):
+    """
+    Returns the hard disk size.
+    This works with any disk type, including GPT.
+    """
+    return get_dyn_func("get_%s_hdd_size", table_type, device)
+
+
 def check_partition_mbr_layout(device, layout):
     """
     Returns true if the partition layout matches the one on the disk
@@ -393,6 +402,36 @@ def check_partition_mbr_layout(device, layout):
                     break
 
             found_layout.append(type_label)
+    return found_layout
+
+
+def check_partition_gpt_layout(device, layout):
+    prt_cmd = [SGDISK_CMD, '-p', device]
+    try:
+        out, _err = util.subp(prt_cmd)
+    except Exception as e:
+        raise Exception("Error running partition command on %s\n%s" % (
+                        device, e))
+
+    out_lines = iter(out.splitlines())
+    # Skip header
+    for line in out_lines:
+        if line.strip().startswith('Number'):
+            break
+
+    return [line.strip().split()[-1] for line in out_lines]
+
+
+def check_partition_layout(table_type, device, layout):
+    """
+    See if the partition lay out matches.
+
+    This is future a future proofing function. In order
+    to add support for other disk layout schemes, add a
+    function called check_partition_%s_layout
+    """
+    found_layout = get_dyn_func(
+        "check_partition_%s_layout", table_type, device, layout)
 
     if isinstance(layout, bool):
         # if we are using auto partitioning, or "True" be happy
@@ -417,18 +456,6 @@ def check_partition_mbr_layout(device, layout):
     return False
 
 
-def check_partition_layout(table_type, device, layout):
-    """
-    See if the partition lay out matches.
-
-    This is future a future proofing function. In order
-    to add support for other disk layout schemes, add a
-    function called check_partition_%s_layout
-    """
-    return get_dyn_func("check_partition_%s_layout", table_type, device,
-                        layout)
-
-
 def get_partition_mbr_layout(size, layout):
     """
     Calculate the layout of the partition table. Partition sizes
@@ -481,6 +508,29 @@ def get_partition_mbr_layout(size, layout):
     return sfdisk_definition
 
 
+def get_partition_gpt_layout(size, layout):
+    if isinstance(layout, bool):
+        return [(None, [0, 0])]
+
+    partition_specs = []
+    for partition in layout:
+        if isinstance(partition, list):
+            if len(partition) != 2:
+                raise Exception(
+                    "Partition was incorrectly defined: %s" % partition)
+            percent, partition_type = partition
+        else:
+            percent = partition
+            partition_type = None
+
+        part_size = int(float(size) * (float(percent) / 100))
+        partition_specs.append((partition_type, [0, '+{}'.format(part_size)]))
+
+    # The last partition should use up all remaining space
+    partition_specs[-1][-1][-1] = 0
+    return partition_specs
+
+
 def purge_disk_ptable(device):
     # wipe the first and last megabyte of a disk (or file)
     # gpt stores partition table both at front and at end.
@@ -556,6 +606,22 @@ def exec_mkpart_mbr(device, layout):
     read_parttbl(device)
 
 
+def exec_mkpart_gpt(device, layout):
+    try:
+        util.subp([SGDISK_CMD, '-Z', device])
+        for index, (partition_type, (start, end)) in enumerate(layout):
+            index += 1
+            util.subp([SGDISK_CMD,
+                       '-n', '{}:{}:{}'.format(index, start, end), device])
+            if partition_type is not None:
+                util.subp(
+                    [SGDISK_CMD,
+                     '-t', '{}:{}'.format(index, partition_type), device])
+    except Exception:
+        print "Failed to partition device %s" % (device,)
+        raise
+
+
 def exec_mkpart(table_type, device, layout):
     """
     Fetches the function for creating the table type.
@@ -618,7 +684,7 @@ def mkpart(device, definition):
         return
 
     LOG.debug("Checking for device size")
-    device_size = get_hdd_size(device)
+    device_size = get_hdd_size(table_type, device)
 
     LOG.debug("Calculating partition layout")
     part_definition = get_partition_layout(table_type, device_size, layout)
diff --git a/cloudinit/sources/DataSourceAzure.py b/cloudinit/sources/DataSourceAzure.py
index c599d50f..444070bb 100644
--- a/cloudinit/sources/DataSourceAzure.py
+++ b/cloudinit/sources/DataSourceAzure.py
@@ -53,9 +53,9 @@ BUILTIN_DS_CONFIG = {
 
 BUILTIN_CLOUD_CONFIG = {
     'disk_setup': {
-        'ephemeral0': {'table_type': 'mbr',
-                       'layout': True,
-                       'overwrite': False},
+        'ephemeral0': {'table_type': 'gpt',
+                       'layout': [100],
+                       'overwrite': True},
         },
     'fs_setup': [{'filesystem': 'ext4',
                   'device': 'ephemeral0.1',