Source code for src.driver.bootstrap

.. module:: bootstrap
   :synopsis: Bootstrap EP2 controller


from src.core.haproxyupdater.haproxyupdate import HaproxyUpdate
from src.core.nodefetchers.awsfetcher.awsfetcher import AwsFetcher
from src.core.nodefetchers.orchestrator import get_orchestrator_handler
from src.core.haproxyupdater.haproxyreloader import HaproxyReloader
from .drivercache import DriverCache
import os


[docs]def bootstrap(**kwargs): """Method to bootstrap EP2 controller This method bootstraps EP2 to creates the neccessary objects and returns it to the driver. Args: **kwargs (object) : kwargs must contains config dictionary, logger object. Returns: bool: Whether bootstrap updater was successfull or not src.core.haproxyupdater.haproxyupdate.HaproxyUPdate: Object for updating haproxy config src.core.nodefetchers.basefetcher: Object for fetching backends """ config = kwargs.get("config") logger = kwargs.get("logger") haproxy_config = config.get("haproxy") logger = kwargs.get("logger") orchestratorHandler = get_orchestrator_handler(config, logger=logger) asg_ips = orchestratorHandler.fetch() if asg_ips == None or len(asg_ips) == 0: ''' This is critical. Bootstrap cannnot work with 0 backends. EP2 must abort run ''' logger.critical("No backends available. Bootstrap cannot proceed with 0 backends. Terminating EP2") exit (2) # Initialise driver cache with the fetched IPs driverCache = DriverCache(set(asg_ips)) #Initialise haproxyupdater haproxyupdater = HaproxyUpdate(**haproxy_config, logger=logger) # Set the fectched nodes in haproxyupdater haproxyupdater.update_node_list(asg_ips) # update and reload haproxy updated = haproxyupdater.update_haproxy_by_config_reload(update_only=True) if updated: ''' Start haproxy if its already not running. If its running then simply reload so that the new config takes affect. ''' running = __start_if_not_running_else_reload(haproxy_config, logger=logger) return running, haproxyupdater, orchestratorHandler, driverCache logger.critical("Haproxy config update at botstrap failed") return updated, haproxyupdater, orchestratorHandler, driverCache
def __is_haproxy_running(config, logger=None): """Method for checking if haproxy is running This method checks whether haproxy is running by sending kill signal 0 to the PID of haproxy. Args: config (dictionary) : haproxy config dictionary logger (object) : logger object Returns: bool : Whether haproxy is running or not str : error string """ pid_file = config.get("pid_file") # return false if PID file path is invalid if not os.path.exists(pid_file): logger.warning("Haproxy pid file not found. Attempt to start haproxy will be made") return False, None error = None try: with open(pid_file) as f: pid = int(f.readline()) except Exception as ex: ''' Log exception ''' logger.warning("Could not access haproxy pid file. Attempt to start haproxy will be made") return False, None try: # Try to send kill signal 0 to haproxy process os.kill(pid, 0) except OSError as ex: ''' Haproxy is not running, log ''' # Since there is an exception, haproxy is not running"Haproxy is not running") return False, None return True, None def __start_if_not_running_else_reload(config, logger=None): """Method to start/reload haproxy if it is not running Args: config (dictionary) : haproxy config dictionary logger (object) : logging object Returns: bool : Whether successfully reloaded or not """ is_haproxy_running, error = __is_haproxy_running(config, logger=logger) ''' If haproxy is not running and ep2 is configured to start haproxy via systemd, then start it by systemd. If systemd is not required then do a not reload via binary. This is taken care by the reloader module. ''' if not is_haproxy_running and config.get("start_by") == "systemd": started = HaproxyReloader.start_by_systemd(config.get("service_name"), logger) return HaproxyReloader.reload_haproxy(**config, logger=logger)