#!/usr/bin/python3

import argparse
import asyncio
import os
import socket
import glob
import ssl
import sys
path = os.path.dirname(os.path.realpath(__file__))
path = os.path.realpath(os.path.join(path, '..', 'lib', 'python'))
if path.startswith('/opt'):
    # if installed into system path, do not muck with things
    sys.path.append(path)
import confluent.sshutil as sshutil
import confluent.certutil as certutil
import confluent.client as client
import confluent.config.configmanager as configmanager
import confluent.netutil as netutil
import tempfile
import shutil
import greenlet
import pwd
import signal

def fprint(txt):
    sys.stdout.write(txt)
    sys.stdout.flush()


def tftp_works():
    try:
        subprocess.check_call(['curl', '--connect-timeout', '2', '-sf', 'tftp://localhost/confluent/x86_64/ipxe.efi', '-o', '/dev/null'])
        return True
    except Exception:
        return False

def emprint(txt):
    if sys.stdout.isatty():
        print('\x1b[1m\x1b[4m' + txt + '\x1b[0m')
    else:
        print(txt)

def deployment_configured():
    return os.path.exists('/var/lib/confluent/public/site/confluent_uuid')

def webserver_listening():
    try:
        conn = socket.create_connection(('localhost', 443))
        return conn
    except Exception:
        return False


def certificates_missing_ips(conn):
    # check if the tls can verify by the right CAs, then further
    # check if all ip addresses are in the certificate offered
    ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
    ctx.check_hostname = False
    for cacert in glob.glob('/var/lib/confluent/public/site/tls/*.pem'):
        ctx.load_verify_locations(cacert)
    sock = ctx.wrap_socket(conn)
    crt = sock.getpeercert()
    sans = crt.get('subjectAltName', [])
    ips = certutil.get_ip_addresses()
    missing_ips = []
    for ip in ips:
        for san in sans:
            field, val = san
            if val[-1] == '\n':
                val = val[:-1]
            if ':' in val:
                # must normalize ipv6 to a sane value
                val = socket.getaddrinfo(val, 443, proto=socket.IPPROTO_TCP)[0][-1][0]
            if ip == val:
                break
        else:
            missing_ips.append(ip)
    return missing_ips


def web_download_works():
    try:
        subprocess.check_call(['curl', '-skf', 'https://localhost/confluent-public/site/confluent_uuid', '-o', '/dev/null'])
    except Exception:
        return False
    return True
            
def web_api_works():
    try:
        res = subprocess.check_output(['curl', '-X', 'GET', '-Isk', 'https://localhost/confluent-api/'])
        res = res.split(b'\n')[0]
        if b'401' in res:
            return True
        return False
    except Exception:
        return False
    return True

def nics_missing_ipv6():
    # check for ability to create AF_INET6, for kernel disabled ipv6
    ipaddrs = subprocess.check_output(['ip', '-br', 'a']).split(b'\n')
    missingnics = []
    for line in ipaddrs:
        comps = line.split()
        if not comps:
            continue
        iname, state = comps[:2]
        if iname == b'lo':
            continue
        if iname == b'virbr0':
            continue
        addrs = comps[2:]
        hasv6 = False
        hasv4 = False
        for addr in addrs:
            if b'.' in addr:
                hasv4 = True
            if addr.startswith(b'fe80::'):
                hasv6 = True
        if hasv4 and not hasv6:
            missingnics.append(iname.decode('utf8'))
    return missingnics

def insecure_boot_attempts():
    insecurenodes = set([])
    with open('/var/log/confluent/events') as eventin:
        line = True
        while line:
            line = eventin.readline()
            if 'insecure mode is disabled' in line:
                line = line.split()
                insecurenodes.add(line[7])
    for node in insecurenodes:
        currattr = subprocess.check_output(['nodeattrib', node, 'deployment.useinsecureprotocols'])
        currattr = currattr.split()
        if len(currattr) > 2 and currattr[2] == b'firmware':
            continue
        else:
            return True
    return False


def uuid_matches():
    with open('/var/lib/confluent/public/site/confluent_uuid', 'r') as uuidf:
        fsuuid = uuidf.read().strip()
    dbuuid = configmanager.get_global('confluent_uuid')
    return dbuuid == fsuuid

async def lookup_node(node):
    try:
        cloop = asyncio.get_event_loop()
        return await cloop.getaddrinfo(node, 0)
    except Exception:
        return None

async def main():
    ap = argparse.ArgumentParser(description='Run configuration checks for a system running confluent service')
    ap.add_argument('-n', '--node', help='A node name to run node specific checks against')
    ap.add_argument('-a', '--automation', help='Do checks against a deployed node for automation and syncfiles function', action='store_true')
    args, extra = ap.parse_known_args(sys.argv)
    if len(extra) > 1:
        ap.print_help()
        sys.exit(1)
    sys.stdout.write('OS Deployment: ')
    sys.stdout.flush()
    if deployment_configured():
        print("Initialized")
        sys.stdout.write('Confluent UUID: ')
        sys.stdout.flush()
        if uuid_matches():
            print('Consistent')
        else:
            emprint('Inconsistent between confluent database and /var/lib/confluent (Example resolution: confetty set /uuid resync=1)')
        fprint('Web Server: ')
        conn = webserver_listening()
        if conn:
            print('Running')
            fprint('Web Certificate: ')
            cert = certificates_missing_ips(conn)
            if cert:
                cert = ', '.join(cert)
                emprint('Addresses missing from certificate: {0} (Example resolution: osdeploy initialize -t)'.format(cert))
            else:
                print('OK')
                fprint('Checking web download: ')
                if web_download_works():
                    print('OK')
                else:
                    emprint('Failed to download /confluent-public/site/confluent_uuid')
                fprint('Checking web API access: ')
                if web_api_works():
                    print('OK')
                else:
                    emprint('Failed access, if selinux is enabled, `setsebool -P httpd_can_network_connect=1`, otherwise check web proxy configuration')
        else:
            emprint('Not Running (Example resolution: systemctl enable httpd --now)')
        fprint('TFTP Status: ')
        if tftp_works():
            print('OK')
        else:
            emprint('TFTP failure, PXE will not work, though media and HTTP boot can still work. (Example resolution: osdeploy initialize -p)')
        fprint('SSH root user public key: ')
        if glob.glob('/var/lib/confluent/public/site/ssh/*.rootpubkey'):
            print('OK')
        else:
            emprint('No trusted ssh keys for root user, passwordless SSH from managers to nodes may not work (Example resolution: osdeploy initialize -u)')
        if sshutil.sshver() > 7.6:
            fprint('Checking SSH Certificate authority: ')
            try:
                sshutil.prep_ssh_key('/etc/confluent/ssh/ca')
                print('OK')
            except Exception:
                emprint('Failed to load SSH authority key, deployed servers will not have host certificates for known_hosts and users may be unable to ssh between nodes without a password (Example resolution: osdeploy initialize -s)')            
            fprint('Checking confluent SSH automation key: ')
            try:
                sshutil.prep_ssh_key('/etc/confluent/ssh/automation')
                print('OK')
            except subprocess.CalledProcessError:
                emprint('Failed to load confluent automation key, syncfiles and profile ansible plays will not work (Example resolution: osdeploy initialize -a)')
            os.kill(int(sshutil.agent_pid), signal.SIGTERM)
        fprint('Checking for blocked insecure boot: ')
        if insecure_boot_attempts():
            emprint('Some nodes are attempting network boot using PXE or HTTP boot, but the node is not configured to allow this (Example resolution: nodegroupattrib everything deployment.useinsecureprotocols=firmware)')
        else:
            print('OK')
        fprint('Checking IPv6 enablement: ')
        nics = nics_missing_ipv6()
        if nics:
            snics = ','.join(nics)
            emprint('Some interfaces ({0}) have ipv6 disabled, and may be unable to fully perform discovery or deployment (Example resolution: nmcli c m {1} ipv6.method link-local )'.format(snics, nics[0]))
        else:
            print('OK')
    else:
        print("Uninitialized, further OS deployment checks skipped, see `osdeploy initialize` to set up OS deployment feature")
    if args.node:
        print("Performing node checks for '{}'".format(args.node))
        print("Checking node attributes in confluent...")
        sess = client.Command()
        allok = True
        uuidok = False
        macok = False
        valid_nodes = [node['item']['href'][:-1] async for node in sess.read('/nodes/')] #get all valid nodes
        async for rsp in sess.read(f'/nodes/{args.node}/attributes/all'):
            if rsp.get('errorcode', None) == 404:
                emprint(f'There is no node named "{args.node}"')
                allok = False
                uuidok = True  # not really, but suppress the spurious error
            dnsdomain = rsp.get('dns.domain', {}).get('value', '')
            if dnsdomain and (',' in dnsdomain or ' ' in dnsdomain):
                allok = False
                emprint(f'{args.node} has a dns.domain that appears to be a search instead of singular domain')
                uuidok = True  # not really, but suppress the spurious error
            uuid = rsp.get('id.uuid', {}).get('value', None)
            if uuid:
                uuidok = True
            if 'deployment.useinsecureprotocols' in rsp:
                insec = rsp.get('deployment.useinsecureprotocols', {}).get('value', None)
                if insec != 'firmware':
                    emprint(f'{args.node} does not have deployment.useinsecureprotocols set to firmware. This is fine for USB boot. HTTP boot can work, but requires the deployment server CA certificates be provisioned to the UEFI first.  PXE and HTTP boot without preprovisioned certificates will fail.')
            for key in rsp:
                if key.endswith('.hwaddr'):
                    mac = rsp[key].get('value', None)
                    if mac:
                        macok = True
            #adding new code to check if the response is something like net.<something>switch
            for key in rsp:
                if ((key.startswith('net.') and key.endswith('switch')) 
                        or (key.startswith('power.') and key.endswith('pdu'))
                        or (key.startswith('enclosure.') and key.endswith('manager'))
                        ):
                    switch_value = rsp[key].get('value',None)
                    if switch_value and switch_value not in valid_nodes:
                        emprint(f'{switch_value} is not a valid node name (as referenced by attribute "{key}" of node {args.node}).')
        print(f"Checking network configuration for {args.node}")
        cfg = configmanager.ConfigManager(None)
        bootablev4nics = []
        bootablev6nics = []
        targsships = []
        for nic in glob.glob("/sys/class/net/*/ifindex"):
            idx = int(open(nic, "r").read())
            nicname = nic.split('/')[-2]
            ncfg = netutil.get_nic_config(cfg, args.node, ifidx=idx)
            if ncfg['ipv4_address']:
                targsships.append(ncfg['ipv4_address'])
            if ncfg['ipv4_address'] or ncfg['ipv4_method'] == 'dhcp':
                bootablev4nics.append(nicname)
            if ncfg['ipv6_address']:
                targsships.append(ncfg['ipv6_address'])
                bootablev6nics.append(nicname)
        if bootablev4nics:
            print("{} appears to have network configuration suitable for IPv4 deployment via: {}".format(args.node, ",".join(bootablev4nics)))
        elif bootablev6nics:
            print('{} appears to have networking configuration suitable for IPv6 deployment via: {}'.format(args.node, ",".join(bootablev6nics)))
        else:
            emprint(f"{args.node} may not have any viable IP network configuration (check name resolution (DNS or hosts file) "
                    "and/or net.*ipv4_address, and verify that the deployment serer addresses and subnet mask/prefix length are accurate)")
        if not uuidok and not macok:
            allok = False
            emprint(f'{args.node} does not have a uuid or mac address defined in id.uuid or net.*hwaddr, deployment will not work (Example resolution: nodeinventory {args.node} -s)')
        if allok:
            print(f'No issues detected with attributes of {args.node}')
        fprint("Checking name resolution: ")
        deaddns = False
        try:
            result = await asyncio.wait_for(lookup_node(args.node), timeout=5)
        except asyncio.exceptions.TimeoutError:
            emprint('Name resolution takes too long, check state of /etc/resolv.conf and indicated nameservers, this can produce failure to netboot or failure to commence installation')
            deaddns = True
        if not result and not deaddns:
            emprint('Name resolution failed for node, it is normally a good idea for the node name to resolve to an IP')
        if result:
            print("OK")
        if args.automation:
            print(f'Checking confluent automation access to {args.node}...')
            child = os.fork()
            if child > 0:
                pid, extcode = os.waitpid(child, 0)
            else:
                sshutil.ready_keys = {}
                sshutil.agent_pid = None
                cuser = pwd.getpwnam('confluent')
                os.setgid(cuser.pw_gid)
                os.setuid(cuser.pw_uid)
                sshutil.prep_ssh_key('/etc/confluent/ssh/automation')
                for targ in targsships:
                    srun = subprocess.run(
                        ['ssh', '-Tn', '-o', 'BatchMode=yes', '-l', 'root',
                        '-o', 'StrictHostKeyChecking=yes', targ, 'true'],
                        stdin=subprocess.DEVNULL, stderr=subprocess.PIPE)
                    if srun.returncode == 0:
                        print(f'Confluent automation access to {targ} seems OK')
                    else:
                        if b'Host key verification failed' in srun.stderr:
                            emprint(f'Confluent ssh unable to verify host key for {targ}, check /etc/ssh/ssh_known_hosts. (Example resolution: osdeploy initialize -k)')
                        elif b'ermission denied' in srun.stderr:
                            emprint(f'Confluent user unable to ssh in to {targ}, check /root/.ssh/authorized_keys on the target system versus /etc/confluent/ssh/automation.pub (Example resolution: osdeploy initialize -a)')
                        else:
                            emprint('Unknown error attempting confluent automation ssh:')
                            sys.stderr.buffer.write(srun.stderr)
                os.kill(int(sshutil.agent_pid), signal.SIGTERM)
    else:
        print("Skipping node checks, no node specified (Example: confluent_selfcheck -n n1)")
# possible checks:
# arping on the node, check for dupes/against nodeinventory?
# arping -D for mgt own ip addresses? check for dupes, also check for bleed through from one nic to another
# iterate through profiles, use mtools to extract site initramfs, check if outdated
if __name__ == '__main__':
    asyncio.get_event_loop().run_until_complete(main())