consul-template-check.py

#! /usr/bin/python
# Sanity check that consul-template is writing the services in Consul to the
# nginx config file.
import requests

HOST = '10.1.1.13'
CONSUL_PORT = 8500
NGINX_CONFIG_PATH = '/etc/nginx/sites-enabled/consul_template.conf'


def read_file_lines(path):
    with open(path) as f:
        return f.read().split('\n')


def find_in_file_lines(lines, keyword):
    for line in lines:
        if keyword in line:
            return line
    return None


def is_consular_service(tags):
    return any([tag.startswith('consular-') for tag in tags])


def get_consul_services(host, port):
    response = requests.get('http://%s:%s/v1/catalog/services' % (host, port))
    services = response.json()
    return [name for name, tags in services.items()
            if is_consular_service(tags)]


lines = read_file_lines(NGINX_CONFIG_PATH)
print('Read nginx config file with %d lines' % len(lines))
print('Fetching Consul services...')
consul = get_consul_services(HOST, CONSUL_PORT)
print('Found %d Consul services started by Consular' % len(consul))
missing = 0
skipped = 0
for service in consul:
    line = find_in_file_lines(lines, service)
    if line is None:
        missing += 1
        print('Service "%s" was not found in the nginx config' % service)
    elif line.startswith('# Skipped'):
        skipped += 1
        print('Service "%s" was skipped in the nginx config' % service)

print('%d services in Consul not found in the nginx config' % missing)
print('%d services in Consul skipped in the nginx config' % skipped)