vm.py

from fabric.api import env, execute, hide, hosts, parallel, run, sudo, task
from fabric.utils import error
import re

import nagios


@task
def uptime():
    """Show uptime and load"""
    run('uptime')


@task
def free():
    """Show memory stats"""
    run('free')


@task
def top_mem_proc():
    """Show top processes by memory usage"""
    run('ps aux |sort -rk4 |head')


@task
def disk():
    """Show disk usage"""
    run('df -kh')


@task
def os_version():
    """Show operating system"""
    run('facter lsbdistcodename lsbdistdescription operatingsystem operatingsystemrelease')


@task
def deprecated_library(name):
    """
    Find processes that are using a deprecated library and need restarting

    For example:
      - Processes using a non-upgraded version of libssl:
        vm.deprecated_library:libssl

      - Processes that are using any deleted/upgraded library:
        vm.deprecated_library:/lib
    """
    sudo("lsof -d DEL | awk '$8 ~ /{0}/'".format(re.escape(name)))


@task
def stopped_jobs():
    """Find stopped govuk application jobs"""
    with hide('running'):
        run('grep -l govuk_spinup /etc/init/*.conf | xargs -n1 basename | while read line; do sudo status "${line%%.conf}"; done | grep stop || :')


@task
def bodge_unicorn(name):
    """
    Manually kill off (and restart) unicorn processes by name

    e.g. vm.bodge_unicorn:content-tagger

    Yes. This is a bodge. Sorry.
    """
    pid = run("ps auxwww | grep '/%s/' | grep -F 'unicorn master' | grep -v grep | awk '{ print $2 }' | xargs" % name)
    if pid:
        sudo("kill -9 %s" % pid)
    sudo("start '{0}' || restart '{0}'".format(name))


@task
def reload_unicorn(name):
    error("task deprecated by 'app.reload'")


def reboot_required():
    """
    Check whether a reboot is required

    """
    result = run("/usr/local/bin/check_reboot_required 30 0", warn_only=True)
    return (not result.succeeded)


@task
def reboot():
    """Schedule a host for downtime in nagios and reboot (if required)

    Usage:
    fab production -H frontend-1.frontend.production vm.reboot
    """
    if reboot_required():
        # we need to ensure we only execute this task on the current
        # host we're operating on, not every host in env.hosts
        execute(force_reboot, hosts=[env['host_string']])


@task
def force_reboot():
    """Schedule a host for downtime in nagios and force reboot (even if not required)"""
    execute(nagios.schedule_downtime, env['host_string'])
    run("sudo shutdown -r now")


@task
def poweroff():
    """Schedule a host for downtime in nagios and shutdown the VM

    Usage:
    fab production -H frontend-1.frontend.production vm.poweroff
    """
    execute(nagios.schedule_downtime, env['host_string'])
    run("sudo poweroff")


@task
@hosts('puppetmaster-1.management')
def host_key(hostname):
    """
    Check the SSH host key of a machine. This task runs on the Puppetmaster because
    it's the only machine that knows about all host keys.

    Usage:
    fab production vm.host_key:backend-1.backend
    """
    with hide('running', 'stdout'):
        ssh_key = run("grep {0} /etc/ssh/ssh_known_hosts | head -1".format(hostname))

    if ssh_key == '':
        print 'Machine {0} not found in ssh_known_hosts file'.format(hostname)
    else:
        with hide('running'):
            run("ssh-keygen -l -f /dev/stdin <<< '{0}'".format(ssh_key))


@task
@parallel(pool_size=5)
def connected_users():
    """
    Output a list of users who are logged in to a machine
    """

    with hide('running', 'stdout'):
        username = run('whoami')
        users = run('who | grep -v {0} || true'.format(username))

    if users:
        print 'There are users connected to {0}:'.format(env.host_string)
        for user in users.split("\n"):
            print '  - {0}'.format(user.split(' ')[0])
        print "\n"