156 lines
3.9 KiB
Python
156 lines
3.9 KiB
Python
import json
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import random
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from time import sleep
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import uuid
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import atexit
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import os
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import socket, struct
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import requests
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from flask import Flask
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import consul
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from logging.config import dictConfig
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dictConfig({
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'version': 1,
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'formatters': {'default': {
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'format': '[%(asctime)s] %(levelname)s in %(module)s: %(message)s',
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}},
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'handlers': {'wsgi': {
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'class': 'logging.StreamHandler',
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'stream': 'ext://sys.stdout',
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'formatter': 'default'
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}},
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'root': {
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'level': 'INFO',
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'handlers': ['wsgi']
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}
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})
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def get_ip():
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s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
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s.settimeout(0)
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try:
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# doesn't even have to be reachable
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s.connect(('10.254.254.254', 1))
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IP = s.getsockname()[0]
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except Exception:
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IP = '127.0.0.1'
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finally:
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s.close()
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return IP
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def get_default_gateway_linux():
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with open("/proc/net/route") as fh:
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for line in fh:
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fields = line.strip().split()
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if fields[1] != '00000000' or not int(fields[3], 16) & 2:
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continue
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return socket.inet_ntoa(struct.pack("<L", int(fields[2], 16)))
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if os.getenv('CONSUL') != None:
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CONSUL = os.getenv('CONSUL')
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else:
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CONSUL=get_default_gateway_linux()
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BASE_CONSUL_URL = 'http://' + CONSUL + ':8500'
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HOSTNAME = os.getenv('HOSTNAME')
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config = {'default':'config'}
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prev_config = {'default':'config'}
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changed = 0
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SERVICE_ADDRESS = get_ip()
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PORT = 8080
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UUID=str(uuid.uuid5(uuid.NAMESPACE_DNS, str(SERVICE_ADDRESS) + ":" + str(PORT) + ":" + HOSTNAME))
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c = consul.Consul(host=CONSUL)
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app = Flask(__name__)
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@app.route('/')
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def home():
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global config
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global prev_config
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global changed
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if changed == 1:
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ad = f'<br>configuration changed. new configuration: {config} | prev config: {prev_config}'
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if config != {}:
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prev_config = config
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changed = 0
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else:
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ad = f'configuration NOT changed: {config}'
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return f"Hello World, <br> I`m {HOSTNAME} from {SERVICE_ADDRESS} {PORT} {UUID} <br> my config: {config} | {ad}"
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@app.route('/health')
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def hello_world():
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data = {
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'status': 'healthy'
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}
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global config
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global prev_config
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global changed
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try:
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_, resp = c.kv.get('PythonApp/config', wait='2s')
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resp_config = resp['Value']
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if resp_config != prev_config:
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changed = 1
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config = resp_config
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except Exception as e:
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# config = {}
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app.logger.debug(f'Get config from consul failed: {e}')
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return json.dumps(data)
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@app.route('/register')
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def register():
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url = BASE_CONSUL_URL + '/v1/agent/service/register'
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data = {
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'Name': 'PythonApp',
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'ID': UUID,
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'Tags': ['flask'],
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'Address': SERVICE_ADDRESS,
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'Port': PORT,
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'Check': {
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'http': 'http://{address}:{port}/health'.format(address=SERVICE_ADDRESS, port=PORT),
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'interval': '10s'
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}
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}
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res = requests.put(
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url,
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data=json.dumps(data)
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)
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return res
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def cleanup():
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try:
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sleep(int(random.randrange(1,5)))
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url = BASE_CONSUL_URL + '/v1/agent/service/deregister/' + UUID
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data = {
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'service_id': UUID,
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}
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res = requests.put(
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url,
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data=json.dumps(data)
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)
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app.logger.debug(f'Service registration parameters: {data} | {res.status_code} : {res.text}')
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return f'Response: {res.text} | status_code: {res.status_code}'
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except Exception as e:
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app.logger.debug(f'{e}')
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atexit.register(cleanup)
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if __name__ == '__main__':
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sleep(1)
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status = ""
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while status != 200:
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try:
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app.logger.debug(f'Registering on consul')
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status = register().status_code
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sleep(int(random.randrange(1,5)))
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except Exception as e:
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app.logger.debug(f'ERROR::::: {e}')
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app.run(debug=True, host="0.0.0.0", port=PORT) |