controller.py

import libvirt
import sys
from xml.dom import minidom

CONNSTRING = "qemu:///system"


def _get_ro_conn():
    """Returns a read-only connection to the local qemu hypervisor"""
    conn = libvirt.openReadOnly(CONNSTRING)
    if conn == None:
        print("Failed to open connection to qemu:///system", file=sys.stderr)
        exit(1)
    else:
        return conn


def _get_conn():
    """Returns a read/write connection to the local qemu hypervisor"""
    conn = libvirt.open(CONNSTRING)
    if conn == None:
        print("Failed to open connection to qemu:///system", file=sys.stderr)
        exit(1)
    else:
        return conn


def list_all_domains():
    """Returns a list of all domains on a hypervisor, active or not"""
    conn = _get_ro_conn()
    domain_names = conn.listDefinedDomains()

    domain_ids = conn.listDomainsID()
    if domain_ids == None:
        print("Failed to get a list of domain IDs", file=sys.stderr)
        conn.close()
        exit(1)

    if len(domain_ids) != 0:
        for domain_id in domain_ids:
            domain = conn.lookupByID(domain_id)
            domain_names.append(domain.name())
    elif len(domain_ids) == 0:
        conn.close()
        return "No domains"

    conn.close()
    return domain_names


def list_active_domains():
    """Returns a list of active domains on this hypervisor"""
    conn = _get_ro_conn()
    domain_names = {}

    domain_ids = conn.listDomainsID()
    if domain_ids == None:
        print("Failed to get a list of domain IDs", file=sys.stderr)
        conn.close()
        exit(1)

    if len(domain_ids) == 0:
        conn.close()
        return "No active domains"
    else:
        for domain_id in domain_ids:
            domain = conn.lookupByID(domain_id)
            domain_names[domain_id] = domain.name()
        conn.close()
        return domain_names


def domain_state(domain_name):
    """Takes in the name of a domain; returns the state of the domain and the reason it is in that state"""
    conn = _get_ro_conn()
    domain = conn.lookupByName(domain_name)

    if domain == None:
        print("Failed to find the domain " + domain_name, file=sys.stderr)
        conn.close()
        exit(1)

    state_code, reason_code = domain.state()

    domain_states = {
        0: "VIR_DOMAIN_NOSTATE",
        1: "VIR_DOMAIN_RUNNING",
        2: "VIR_DOMAIN_BLOCKED",
        3: "VIR_DOMAIN_PAUSED",
        4: "VIR_DOMAIN_SHUTDOWN",
        5: "VIR_DOMAIN_SHUTOFF",
        6: "VIR_DOMAIN_CRASHED",
        7: "VIR_DOMAIN_PMSUSPENDED",
    }

    domain_reasons = {
        "VIR_DOMAIN_NOSTATE": {0: "VIR_DOMAIN_NOSTATE_UNKNOWN"},
        "VIR_DOMAIN_RUNNING": {
            0: "VIR_DOMAIN_RUNNING_UNKNOWN",
            1: "VIR_DOMAIN_RUNNING_BOOTED",
            2: "VIR_DOMAIN_RUNNING_MIGRATED",
            3: "VIR_DOMAIN_RUNNING_RESTORED",
            4: "VIR_DOMAIN_RUNNING_FROM_SNAPSHOT",
            5: "VIR_DOMAIN_RUNNING_UNPAUSED",
            6: "VIR_DOMAIN_RUNNING_MIGRATION_CANCELED",
            7: "VIR_DOMAIN_RUNNING_SAVE_CANCELED",
            8: "VIR_DOMAIN_RUNNING_WAKEUP",
            9: "VIR_DOMAIN_RUNNING_CRASHED",
            10: "VIR_DOMAIN_RUNNING_POSTCOPY",
        },
        "VIR_DOMAIN_BLOCKED": {0: "VIR_DOMAIN_BLOCKED_UNKNOWN"},
        "VIR_DOMAIN_PAUSED": {
            0: "VIR_DOMAIN_PAUSED_UNKNOWN",
            1: "VIR_DOMAIN_PAUSED_USER",
            2: "VIR_DOMAIN_PAUSED_MIGRATION",
            3: "VIR_DOMAIN_PAUSED_SAVE",
            4: "VIR_DOMAIN_PAUSED_DUMP",
            5: "VIR_DOMAIN_PAUSED_IOERROR",
            6: "VIR_DOMAIN_PAUSED_WATCHDOG",
            7: "VIR_DOMAIN_PAUSED_FROM_SNAPSHOT",
            8: "VIR_DOMAIN_PAUSED_SHUTTING_DOWN",
            9: "VIR_DOMAIN_PAUSED_SNAPSHOT",
            10: "VIR_DOMAIN_PAUSED_CRASHED",
            11: "VIR_DOMAIN_PAUSED_STARTING_UP",
            12: "VIR_DOMAIN_PAUSED_POSTCOPY",
            13: "VIR_DOMAIN_PAUSED_POSTCOPY_FAILED",
        },
        "VIR_DOMAIN_SHUTDOWN": {
            0: "VIR_DOMAIN_SHUTDOWN_UNKNOWN",
            1: "VIR_DOMAIN_SHUTDOWN_USER",
        },
        "VIR_DOMAIN_SHUTOFF": {
            0: "VIR_DOMAIN_SHUTOFF_UNKNOWN",
            1: "VIR_DOMAIN_SHUTOFF_SHUTDOWN",
            2: "VIR_DOMAIN_SHUTOFF_DESTROYED",
            3: "VIR_DOMAIN_SHUTOFF_CRASHED",
            4: "VIR_DOMAIN_SHUTOFF_MIGRATED",
            5: "VIR_DOMAIN_SHUTOFF_SAVED",
            6: "VIR_DOMAIN_SHUTOFF_FAILED",
            7: "VIR_DOMAIN_SHUTOFF_FROM_SNAPSHOT",
            8: "VIR_DOMAIN_SHUTOFF_DAEMON",
        },
        "VIR_DOMAIN_CRASHED": {
            0: "VIR_DOMAIN_CRASHED_UNKNOWN",
            1: "VIR_DOMAIN_CRASHED_PANICKED",
        },
        "VIR_DOMAIN_PMSUSPENDED": {
            0: "VIR_DOMAIN_PMSUSPENDED_DISK_UNKNOWN",
        },
    }

    state = domain_states[state_code]
    reason = domain_reasons[state][reason_code]

    conn.close()
    return state, reason