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Diffstat (limited to 'roles/kube_nfs_volumes/library/partitionpool.py')
| -rw-r--r-- | roles/kube_nfs_volumes/library/partitionpool.py | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/roles/kube_nfs_volumes/library/partitionpool.py b/roles/kube_nfs_volumes/library/partitionpool.py new file mode 100644 index 000000000..1ac8eed4d --- /dev/null +++ b/roles/kube_nfs_volumes/library/partitionpool.py @@ -0,0 +1,240 @@ +#!/usr/bin/python +""" +Ansible module for partitioning. +""" + +# There is no pyparted on our Jenkins worker +# pylint: disable=import-error +import parted + +DOCUMENTATION = """ +--- +module: partitionpool +short_description; Partition a disk into parititions. +description: + - Creates partitions on given disk based on partition sizes and their weights. + Unless 'force' option is set to True, it ignores already partitioned disks. + + When the disk is empty or 'force' is set to True, it always creates a new + GPT partition table on the disk. Then it creates number of partitions, based + on their weights. + + This module should be used when a system admin wants to split existing disk(s) + into pools of partitions of specific sizes. It is not intended as generic disk + partitioning module! + + Independent on 'force' parameter value and actual disk state, the task + always fills 'partition_pool' fact with all partitions on given disks, + together with their sizes (in bytes). E.g.: + partition_sizes = [ + { name: sda1, Size: 1048576000 }, + { name: sda2, Size: 1048576000 }, + { name: sdb1, Size: 1048576000 }, + ... + ] + +options: + disk: + description: + - Disk to partition. + size: + description: + - Sizes of partitions to create and their weights. Has form of: + <size1>[:<weigth1>][,<size2>[:<weight2>][,...]] + - Any <size> can end with 'm' or 'M' for megabyte, 'g/G' for gigabyte + and 't/T' for terabyte. Megabyte is used when no unit is specified. + - If <weight> is missing, 1.0 is used. + - From each specified partition <sizeX>, number of these partitions are + created so they occupy spaces represented by <weightX>, proportionally to + other weights. + + - Example 1: size=100G says, that the whole disk is split in number of 100 GiB + partitions. On 1 TiB disk, 10 partitions will be created. + + - Example 2: size=100G:1,10G:1 says that ratio of space occupied by 100 GiB + partitions and 10 GiB partitions is 1:1. Therefore, on 1 TiB disk, 500 GiB + will be split into five 100 GiB partition and 500 GiB will be split into fifty + 10GiB partitions. + - size=100G:1,10G:1 = 5x 100 GiB and 50x 10 GiB partitions (on 1 TiB disk). + + - Example 3: size=200G:1,100G:2 says that the ratio of space occupied by 200 GiB + partitions and 100GiB partition is 1:2. Therefore, on 1 TiB disk, 1/3 + (300 GiB) should be occupied by 200 GiB partitions. Only one fits there, + so only one is created (we always round nr. of partitions *down*). Teh rest + (800 GiB) is split into eight 100 GiB partitions, even though it's more + than 2/3 of total space - free space is always allocated as much as possible. + - size=200G:1,100G:2 = 1x 200 GiB and 8x 100 GiB partitions (on 1 TiB disk). + + - Example: size=200G:1,100G:1,50G:1 says that the ratio of space occupied by + 200 GiB, 100 GiB and 50 GiB partitions is 1:1:1. Therefore 1/3 of 1 TiB disk + is dedicated to 200 GiB partitions. Only one fits there and only one is + created. The rest (800 GiB) is distributed according to remaining weights: + 100 GiB vs 50 GiB is 1:1, we create four 100 GiB partitions (400 GiB in total) + and eight 50 GiB partitions (again, 400 GiB). + - size=200G:1,100G:1,50G:1 = 1x 200 GiB, 4x 100 GiB and 8x 50 GiB partitions + (on 1 TiB disk). + + force: + description: + - If True, it will always overwite partition table on the disk and create new one. + - If False (default), it won't change existing partition tables. + +""" + +# It's not class, it's more a simple struct with almost no functionality. +# pylint: disable=too-few-public-methods +class PartitionSpec(object): + """ Simple class to represent required partitions.""" + def __init__(self, size, weight): + """ Initialize the partition specifications.""" + # Size of the partitions + self.size = size + # Relative weight of this request + self.weight = weight + # Number of partitions to create, will be calculated later + self.count = -1 + + def set_count(self, count): + """ Set count of parititions of this specification. """ + self.count = count + +def assign_space(total_size, specs): + """ + Satisfy all the PartitionSpecs according to their weight. + In other words, calculate spec.count of all the specs. + """ + total_weight = 0.0 + for spec in specs: + total_weight += float(spec.weight) + + for spec in specs: + num_blocks = int((float(spec.weight) / total_weight) * (total_size / float(spec.size))) + spec.set_count(num_blocks) + total_size -= num_blocks * spec.size + total_weight -= spec.weight + +def partition(diskname, specs, force=False, check_mode=False): + """ + Create requested partitions. + Returns nr. of created partitions or 0 when the disk was already partitioned. + """ + count = 0 + + dev = parted.getDevice(diskname) + try: + disk = parted.newDisk(dev) + except parted.DiskException: + # unrecognizable format, treat as empty disk + disk = None + + if disk and len(disk.partitions) > 0 and not force: + print "skipping", diskname + return 0 + + # create new partition table, wiping all existing data + disk = parted.freshDisk(dev, 'gpt') + # calculate nr. of partitions of each size + assign_space(dev.getSize(), specs) + last_megabyte = 1 + for spec in specs: + for _ in range(spec.count): + # create the partition + start = parted.sizeToSectors(last_megabyte, "MiB", dev.sectorSize) + length = parted.sizeToSectors(spec.size, "MiB", dev.sectorSize) + geo = parted.Geometry(device=dev, start=start, length=length) + filesystem = parted.FileSystem(type='ext4', geometry=geo) + part = parted.Partition( + disk=disk, + type=parted.PARTITION_NORMAL, + fs=filesystem, + geometry=geo) + disk.addPartition(partition=part, constraint=dev.optimalAlignedConstraint) + last_megabyte += spec.size + count += 1 + try: + if not check_mode: + disk.commit() + except parted.IOException: + # partitions have been written, but we have been unable to inform the + # kernel of the change, probably because they are in use. + # Ignore it and hope for the best... + pass + return count + +def parse_spec(text): + """ Parse string with partition specification. """ + tokens = text.split(",") + specs = [] + for token in tokens: + if not ":" in token: + token += ":1" + + (sizespec, weight) = token.split(':') + weight = float(weight) # throws exception with reasonable error string + + units = {"m": 1, "g": 1 << 10, "t": 1 << 20, "p": 1 << 30} + unit = units.get(sizespec[-1].lower(), None) + if not unit: + # there is no unit specifier, it must be just the number + size = float(sizespec) + unit = 1 + else: + size = float(sizespec[:-1]) + spec = PartitionSpec(int(size * unit), weight) + specs.append(spec) + return specs + +def get_partitions(diskpath): + """ Return array of partition names for given disk """ + dev = parted.getDevice(diskpath) + disk = parted.newDisk(dev) + partitions = [] + for part in disk.partitions: + (_, _, pname) = part.path.rsplit("/") + partitions.append({"name": pname, "size": part.getLength() * dev.sectorSize}) + + return partitions + + +def main(): + """ Ansible module main method. """ + module = AnsibleModule( + argument_spec=dict( + disks=dict(required=True, type='str'), + force=dict(required=False, default="no", type='bool'), + sizes=dict(required=True, type='str') + ), + supports_check_mode=True, + ) + + disks = module.params['disks'] + force = module.params['force'] + if force is None: + force = False + sizes = module.params['sizes'] + + try: + specs = parse_spec(sizes) + except ValueError, ex: + err = "Error parsing sizes=" + sizes + ": " + str(ex) + module.fail_json(msg=err) + + partitions = [] + changed_count = 0 + for disk in disks.split(","): + try: + changed_count += partition(disk, specs, force, module.check_mode) + except Exception, ex: + err = "Error creating partitions on " + disk + ": " + str(ex) + raise + #module.fail_json(msg=err) + partitions += get_partitions(disk) + + module.exit_json(changed=(changed_count > 0), ansible_facts={"partition_pool": partitions}) + +# ignore pylint errors related to the module_utils import +# pylint: disable=redefined-builtin, unused-wildcard-import, wildcard-import +# import module snippets +from ansible.module_utils.basic import * +main() + |