encled

#!/usr/bin/env python3
"""
encled - SCSI Enclosure indicators (SES LED) control
"""
import argparse
import logging
import subprocess
import re
import os
import numpy

# default settings
defaults = {
    "CLASS":        "/sys/class/enclosure/",
    "SLOT":         None,
    "first_slot":   1
}

# define layouts for enclosures
enclosure_layouts = {"sm20": numpy.array([[0, 8, 14, 20],
                                          [0, 7, 13, 19],
                                          [0, 6, 12, 18],
                                          [0, 5, 11, 17],
                                          [2, 4, 10, 16],
                                          [1, 3, 9, 15]]),
                     "sm24": numpy.array([[6, 12, 18, 24],
                                          [5, 11, 17, 23],
                                          [4, 10, 16, 22],
                                          [3, 9, 15, 21],
                                          [2, 8, 14, 20],
                                          [1, 7, 13, 19]]),
                     "sm44": numpy.array([[6, 12, 18, 24],
                                          [5, 11, 17, 23],
                                          [4, 10, 16, 22],
                                          [3, 9, 15, 21],
                                          [2, 8, 14, 20],
                                          [1, 7, 13, 19],
                                          [0, 32, 38, 44],
                                          [0, 31, 37, 43],
                                          [0, 30, 36, 42],
                                          [0, 29, 35, 41],
                                          [26, 28, 34, 40],
                                          [25, 27, 33, 39]])}


def error(text):
    """
    cancel the operation and exit
    :param text:
    :return:
    """
    logging.error(text)
    exit(-1)


def scan_system():
    """
    use lsscsi, sg_ses to get an overview of the system
    :return:
    """
    # first step: use lsscsi to find all enclosures
    enclosures = {}
    sts, out = subprocess.getstatusoutput("lsscsi -g")
    if sts != 0:
        error("unable to list scsi devices!")
    for line in out.splitlines():
        words = line.split()
        if words[1] == "enclosu":
            enclosures[words[-1]] = {"scsi_tuple": words[0][1:-1]}

    # create a mapping between the /dev/sd* devices and sas addresses
    sas_dev_sd = {}
    dev_sd_scsi = {}
    dev_sd_size = {}
    sts, out = subprocess.getstatusoutput("lsscsi -t -i -s")
    if sts != 0:
        error("unable to list scsi devices!")
    for line in out.splitlines():
        words = line.split()
        if words[1] == "disk" and words[2].startswith("sas:"):
            sas_dev_sd[words[2].replace("sas:", "")] = words[-3]
            dev_sd_scsi[words[-3]] = words[-2]
            dev_sd_size[words[-3]] = words[-1]

    # loop over all enclosures to find all connected devices
    for one_enclosure in enclosures.keys():
        # at first count the slots
        enc_path = find_path(enclosures[one_enclosure]["scsi_tuple"], -1)
        slot_dirs = [one_dir for one_dir in os.listdir(enc_path) if defaults["SLOT"] in one_dir]
        enclosures[one_enclosure]["n_slots"] = len(slot_dirs)
        # then go through information provided by sg_ses
        sts, out = subprocess.getstatusoutput("sg_ses -p 0xa %s" % one_enclosure)
        if sts != 0:
            error("unable to find connected devices for enclosure %s" % one_enclosure)
        lines = out.splitlines()
        # the first line is the enclosure name
        enclosures[one_enclosure]["description"] = re.sub("\s+", ", ", lines[0].strip())
        # then find all disks, they start with "Element index:"
        enclosures[one_enclosure]["disks"] = {}
        in_device_slots = False
        for iline, line in enumerate(lines):
            if "Element type: " in line:
                in_device_slots = "Array device slot" in line
            if not in_device_slots:
                continue
            if line.strip().startswith("Element index:"):
                # find slot number and SAS-Address of this device
                current_line = iline+1
                new_dev = {"slot": None, "sas_address": None}
                while current_line < len(lines) and not "Element index:" in lines[current_line]:
                    m = re.search("device slot number: (\d+)", lines[current_line])
                    if m is not None:
                        new_dev["slot"] = int(m.group(1)) + 1
                        new_dev["path"] = find_path(enclosures[one_enclosure]["scsi_tuple"], new_dev["slot"])
                        new_dev["fault"] = int(get_file_content(os.path.join(new_dev["path"], "fault")))
                        new_dev["locate"] = int(get_file_content(os.path.join(new_dev["path"], "locate")))
                        new_dev["status"] = get_file_content(os.path.join(new_dev["path"], "status"))
                        if new_dev["status"] == "not installed":
                            new_dev["status"] = "NI"
                    m = re.search("^SAS address: (\w+)", lines[current_line].strip())
                    if m is not None and m.group(1) != "0x0000000000000000":
                        new_dev["sas_address"] = m.group(1)
                        if new_dev["sas_address"] in sas_dev_sd:
                            new_dev["dev_sd"] = sas_dev_sd[new_dev["sas_address"]]
                        else:
                            new_dev["dev_sd"] = "unknown"
                        if new_dev["dev_sd"] in dev_sd_scsi:
                            new_dev["scsi_id"] = dev_sd_scsi[new_dev["dev_sd"]]
                        else:
                            new_dev["scsi_id"] = "unknown"
                        if new_dev["dev_sd"] in dev_sd_size:
                            new_dev["size"] = dev_sd_size[new_dev["dev_sd"]]
                        else:
                            new_dev["size"] = "unknown"
                    current_line += 1
                # store the disk by slot, /dev/sd* and scsi_id
                enclosures[one_enclosure]["disks"][new_dev["slot"]] = new_dev
                if new_dev["sas_address"] is not None:
                    enclosures[one_enclosure]["disks"][new_dev["dev_sd"]] = new_dev
                    enclosures[one_enclosure]["disks"][new_dev["scsi_id"]] = new_dev
                else:
                    new_dev["dev_sd"] = ""
                    new_dev["scsi_id"] = ""
                    new_dev["size"] = ""
    return enclosures


def find_path(enc, slot):
    """
    find the full path to the slot folder
    :param enc:     scsi_tuple of the enclosure
    :param slot:    number of the slot (starts with 1), use -1 to the the path of the enclosure
    :return:        full path, or None
    """
    if slot == -1:
        result = os.path.join(defaults["CLASS"], enc)
        if os.path.isdir(result):
            return result
        else:
            return None
    if defaults["first_slot"] == 0:
        slot -= 1
    name = str(slot)
    if os.path.isfile(os.path.join(defaults["CLASS"], enc, name, 'type')):
        return os.path.join(defaults["CLASS"], enc, name)
    for z in range(0, 4):
        if os.path.isfile(os.path.join(defaults["CLASS"], enc, defaults["SLOT"] + name, 'type')):  # naming type 'Slot 01'
            return os.path.join(defaults["CLASS"], enc, defaults["SLOT"] + name)
        if os.path.isfile(os.path.join(defaults["CLASS"], enc, name, 'type')):  # naming type '001'
            return os.path.join(defaults["CLASS"], enc, name)
        name = '0' + name  # try same name with more zeroes at front
    return None


def get_file_content(path):
    """
    read the content of a file
    :param path:
    :return:
    """
    try:
        with open(path) as f:
            return f.read().strip()
    except IOError:
        error("unable to read file %s" % path)


def find_disk(enclosures, key):
    """
    find a disk by a slot, a /dev/sd-name, or a scsi_id
    :param enclosures:  enclosure structure created by scan_system
    :param key:         slot, /dev/sd-name, or scsi_id
    :return:
    """
    for enc_dev in sorted(enclosures.keys()):
        one_enc = enclosures[enc_dev]
        if key in one_enc["disks"]:
            result = one_enc["disks"][key]
            result["enclosure"] = enc_dev
            return result
    return None


def cat_text_blocks(blocks, width=20, lines=4):
    """
    take multiline textblocks and concatinate them. Each block is a string with line breaks.
    """
    def splitlines(text):
        result = text.splitlines()
        while len(result) < lines:
            result.append("-")
        return result

    blocks_in_lines = map(lambda x: splitlines(x), blocks)
    result = []
    for one_block in blocks_in_lines:
        for i, line in enumerate(one_block):
            if i >= len(result):
                result.append("")
            if "\033" in line:
                result[i] += ("%%-%ds" % (width + 13)) % line
            else:
                result[i] += ("%%-%ds" % width) % line
    return "\n".join(result)


def get_status_block_for_disk(one_disk):
    """
    returns a formatted text block for one disk
    :param disk:    disk-dictionary created by scan_system
    :return:
    """
    # highlight block by red colored text
    if one_disk["locate"] != 0 or one_disk["fault"] != 0:
        prefix = "\033[1;31m"
        suffix = "\033[0;0m"
    else:
        prefix = ""
        suffix = ""
    block = "%sSlot %d: %s%s\n" % (prefix, one_disk["slot"], one_disk["dev_sd"], suffix)
    block += "%s%s%s\n" % (prefix, one_disk["scsi_id"], suffix)
    if one_disk["status"] != "NI":
        block += "%sSize=%s%s\n" % (prefix, one_disk["size"], suffix)
    else:
        block += "\n"
    block += "%sStatus=%s L=%d F=%d%s" % (prefix, one_disk["status"], one_disk["locate"], one_disk["fault"], suffix)
    return block


def set_single_disk_led(disk, status):
    """
    turn leds for disks on and off
    :param disk:    the disk-dictionary from scan_system
    :param status:  "locate", "fault", or "off"
    :return:
    """
    if status == 'fault':
        with open(os.path.join(disk["path"], 'locate'), 'w') as f:
            f.write('0')
        with open(os.path.join(disk["path"], 'fault'), 'w') as f:
            f.write('1')
    elif status == 'locate':
        with open(os.path.join(disk["path"], 'fault'), 'w') as f:
            f.write('0')
        with open(os.path.join(disk["path"], 'locate'), 'w') as f:
            f.write('1')
    elif status == 'off':
        with open(os.path.join(disk["path"], 'locate'), 'w') as f:
            f.write('0')
        with open(os.path.join(disk["path"], 'fault'), 'w') as f:
            f.write('0')
    else:
        error("Wrong status (%s)" % status)


def check_zpool_status():
    """
    :return:    a dictionary with all disks used within any connected zpool. The key is the device identifier used by
                the zpool, the value is the zfs status of the disk.
    """
    sts, out = subprocess.getstatusoutput("zpool status")
    if sts != 0:
        error("unable to check the zfs pool status:\n %s" % out)
    # parse the output to get the disk state
    result = {}
    for line in out.splitlines():
        if line.startswith("\t    "):
            words = line.split()
            if len(words) < 5:
                continue
            result[words[0]] = words[1]
    return result


def set_leds(enclosures, arg_disk, status):
    """
    set for one or multiple disk the leds
    :param enclosures:  enclosure structure created by scan_system
    :param arg_disk:    disk-dictionary
    :param status:      "locate", "fault", or "off"
    :return:
    """
    # is the requested operation auto-zpool? check the disk-status with the zpool command
    if status == "auto-zpool":
        pool_disks_status = check_zpool_status()
        for dev_key, dev_status in pool_disks_status.items():
            one_disk = find_disk(enclosures, dev_key)
            if dev_status != "ONLINE":
                set_single_disk_led(one_disk, "fault")
            else:
                set_single_disk_led(one_disk, "off")
        return

    # one disk, or everything?
    if arg_disk is not None:
        set_single_disk_led(arg_disk, status)
        return

    # loop over all enclosures
    for enc_dev in sorted(enclosures.keys()):
        one_enc = enclosures[enc_dev]
        # loop over all disks
        for one_disk_key in one_enc["disks"].keys():
            if type(one_disk_key) != int:
                continue
            set_single_disk_led(one_enc["disks"][one_disk_key], status)


def show_status(enclosures, arg_disk):
    """
    create a formatted overview of the status
    :param enclosures:  enclosure structure created by scan_system
    :param arg_disk:    disk-dictionary
    :return:
    """
    # one disk, or everything?
    if arg_disk is not None:
        print("Enclosure: %s (%s)" % (enclosures[arg_disk["enclosure"]]["description"], arg_disk["enclosure"]))
        print(get_status_block_for_disk(arg_disk))
        return

    # sort enclosures by their /dev/sg-number
    enc_devs = enclosures.keys()
    enc_devs_sortable = {}
    for one_key in enc_devs:
        enc_devs_sortable[int(one_key.replace("/dev/sg", ""))] = one_key

    # loop over all enclosures
    for enc_dev in sorted(enc_devs_sortable.keys()):
        enc_dev = enc_devs_sortable[enc_dev]
        one_enc = enclosures[enc_dev]
        print("\nEnclosure: %s (%s)" % (one_enc["description"], enc_dev))
        print("-" * 80)

        # create blocks of text for each slot
        n_slot = one_enc["n_slots"]
        # guess the enclosure type from the number of disks
        if n_slot == 20:
            enc_type = "sm20"
        elif n_slot == 24:
            enc_type = "sm24"
        else:
            enc_type = "sm44"
        slot_blocks = numpy.empty(enclosure_layouts[enc_type].shape, dtype="U200")
        for slot in range(1,n_slot+1):
            if slot in one_enc["disks"]:
                slot_blocks[enclosure_layouts[enc_type] == slot] = get_status_block_for_disk(one_enc["disks"][slot])

        # arrange the blocks, six per row
        rows = slot_blocks.shape[0]
        for row in range(0, rows):
            print(cat_text_blocks(slot_blocks[row, :]))
            print()


def create_device_list(enclosures, args):
    """
    create a list of devices usable in other commands
    :param enclosures:  enclosure structure created by scan_system
    :param args:        the command line arguments
    """

    result = []
    vdevs = [[args.vdev_type]]
    disk_size = None
    disk_number = 0
    total_disk_number = 0

    def add_one_disk():
        # include this disk?
        nonlocal disk_number, disk_size, total_disk_number
        disk_number += 1
        if args.first_disk is not None and disk_number < args.first_disk:
            return
        if args.last_disk is not None and disk_number > args.last_disk:
            return

        # has this disk the correct size?
        if args.type == "zpool-create":
            if args.disk_size is not None and one_enc["disks"][slot]["size"] != args.disk_size:
                return
            if disk_size is None:
                disk_size = one_enc["disks"][slot]["size"]
            elif disk_size != one_enc["disks"][slot]["size"]:
                error("Disks of different size within the same pool: %s and %s!" % (
                disk_size, one_enc["disks"][slot]["size"]))

        # create list of devices in proper format
        if args.type == "fence-mpath":
            result.append("/dev/mapper/%s" % one_enc["disks"][slot]["scsi_id"])
        if args.type == "zpool-create":
            if len(vdevs[-1]) < args.vdev_size + 1:
                vdevs[-1].append(one_enc["disks"][slot]["scsi_id"])
            else:
                vdevs.append([args.vdev_type, one_enc["disks"][slot]["scsi_id"]])
        total_disk_number += 1

    # loop over all enclosures
    if args.loop_order == "enc":
        for enc_dev in sorted(enclosures.keys()):
            one_enc = enclosures[enc_dev]
            # get the number of slots in this enclosure
            n_slot = one_enc["n_slots"]
            # loop over all devices
            for slot in range(1,n_slot+1):
                if slot in one_enc["disks"] and one_enc["disks"][slot]["status"] != "NI":
                    add_one_disk()

    # loop over all slots
    elif args.loop_order == "slot":
        # find at first the larges number of slots
        n_slot_max = 0
        for enc_dev in sorted(enclosures.keys()):
            n_slot = enclosures[enc_dev]["n_slots"]
            if n_slot > n_slot_max:
                n_slot_max = n_slot
        # now loop over all slots
        for slot in range(1, n_slot_max + 1):
            # and look into this slot for all enclosures
            for enc_dev in sorted(enclosures.keys()):
                one_enc = enclosures[enc_dev]
                if slot in one_enc["disks"] and one_enc["disks"][slot]["status"] != "NI":
                    add_one_disk()

    # print the final list
    if args.type == "fence-mpath":
        print(",".join(result))
    if args.type == "zpool-create":
        # check length of vdevs
        for i in range(0, len(vdevs)):
            if len(vdevs[i]) != args.vdev_size +1:
                error("wrong number of disks in vdev. Use --vdev-size!\nTotal number of disks: %d" % total_disk_number)
        vdevs = map(lambda x: " ".join(x), vdevs)
        print(" ".join(vdevs))


def check_defaults():
    """
    check the default path of slots and enclosures
    """
    enclosures = os.listdir(defaults["CLASS"])
    entries = os.listdir(os.path.join(defaults["CLASS"], enclosures[0]))
    # slots are counted from 0 or from 1?
    if "Slot00" in entries or "Slot 00" in entries or "Slot000" in entries or "Slot 000" in entries:
        defaults["first_slot"] = 0
    # Slot names include space or not
    if "Slot01" in entries or "Slot001" in entries:
        defaults["SLOT"] = "Slot"
    if "Slot 01" in entries or "Slot 001" in entries:
        defaults["SLOT"] = "Slot "


def add_enc_disk_args(sp, add_enc=True, add_disk=True):
    if add_enc:
        sp.add_argument("-e", "--enc", nargs='+', help="the enclosure of interest.")
    if add_disk:
        sp.add_argument("-d", "--disk", help="the disk of interest.")
        sp.add_argument("-s", "--slot", type=int, help="the slot of interest.")


if __name__ == "__main__":
    # set default log level
    logging.basicConfig(level=logging.INFO, format="%(levelname)s: %(message)s")

    # parse command line arguments
    parser = argparse.ArgumentParser(description=__doc__)
    subparsers = parser.add_subparsers(dest='action', title='available operations')
    sp_status = subparsers.add_parser("status", help="show the status of enclosures or disks")
    sp_led = subparsers.add_parser("led", help="turn on/off the leds of a disk")
    sp_led.add_argument("status", choices=["locate", "fault", "off", "auto-zpool"], help="select the led to turn on/off.")
    sp_list = subparsers.add_parser("list", help="list devices in different formats")
    sp_list.add_argument("--type", choices=["zpool-create", "fence-mpath"], required=True, help="select the type of device list to create.")
    sp_list.add_argument("--vdev-size", type=int, default=6, help="number of devices within one vdev.")
    sp_list.add_argument("--vdev-type", default="raidz2", help="type to use in device list for zpool-create.")
    sp_list.add_argument("--first-disk", type=int, help="Number between 1 and the total number of disks. Empty slots don't count as disk.")
    sp_list.add_argument("--last-disk", type=int, help="Number between 1 and the total number of disks. Empty slots don't count as disk.")
    sp_list.add_argument("--disk-size", help="Size of disk to be included (same format as in status).")
    sp_list.add_argument("--loop-order", default="enc", choices=["enc", "slot"], help="the list is created in a loop over all enclosures with a nested loop over all slots (=enc), or in a loop over all slots with a nested loop over all enclosures (=slot).")
    add_enc_disk_args(sp_status)
    add_enc_disk_args(sp_led)
    add_enc_disk_args(sp_list, add_disk=False)
    args = parser.parse_args()

    # is an operation selected?
    if args.action is None:
        error("no operation selected!")

    # check the default settings
    check_defaults()

    # scan the system and create a mapping between device names and slots
    encs = scan_system()

    # check arguments
    if args.enc is not None:
        encs_filtered = {}
        for one_enc in args.enc:
            if one_enc not in encs:
                error("Enclosure '%s' not found!" % args.enc)
            else:
                # add this enclosure to filtered list
                encs_filtered[one_enc] = encs[one_enc]
        encs = encs_filtered
    if "disk" in args and args.disk is not None:
        disk_dev = find_disk(encs, args.disk)
        if disk_dev is None:
            error("Disk '%s' not found!" % args.disk)
        args.disk = disk_dev
    if "slot" in args and args.slot is not None:
        disk_dev = find_disk(encs, args.slot)
        if disk_dev is None:
            error("Slot '%s' not found!" % args.slot)
        args.disk = disk_dev

    # perform requested operation
    if args.action == "status":
        show_status(encs, args.disk)
    if args.action == "led":
        set_leds(encs, args.disk, args.status)
    if args.action == "list":
        create_device_list(encs, args)