url-mapper/src/handler.py

97 lines
2.2 KiB
Python

#!/usr/bin/env python
import os
import sys
import time
import urllib.request
import yaml
def eprint(*args, **kwargs):
print(*args, file=sys.stderr, **kwargs)
# The key is the url
# The value holds the content and the timestamp
file_cache = {}
file_cache_ttl = 60
mapper_file = ''
with open('/var/openfaas/secrets/url-mapper-file', 'r') as f:
mapper_file = f.read().strip()
def get_url_content(url):
if url in file_cache:
cache_entry = file_cache[url]
if cache_entry['timestamp'] + file_cache_ttl > time.time():
return cache_entry['content']
try:
response = urllib.request.urlopen(url)
targets = yaml.safe_load(response.read())
except Exception as e:
eprint("Failed to load URL mapper file: %s" % e)
return None
file_cache[url] = {
'content': targets,
'timestamp': time.time()
}
return targets
def get_dict_entry_fallback(d, key, fallback):
if key and key in d:
return d[key]
if key.isnumeric() and int(key) in d:
return d[int(key)]
if fallback in d:
return d[fallback]
return d.get('_default', None)
def get_entry(args, targets):
while args:
arg = args.pop(0)
if not arg:
continue
# Fallback to _404 if the key is not found
targets = get_dict_entry_fallback(targets, arg, '_404')
if isinstance(targets, dict):
continue
return targets, args
# Try to match an index entry
return get_dict_entry_fallback(targets, '', '_index'), args
def get_entry_for_url(url, args):
targets = get_url_content(url)
if not targets:
return None
entry, args = get_entry(args, targets)
if not entry:
return None
if entry.startswith('include:'):
entry = entry.split(':', 1)[1]
return get_entry_for_url(entry, args)
return entry
def handle(event, context):
args = event.path.split('/')
url = get_entry_for_url(mapper_file, args)
if not url:
return {
"statusCode": 404,
"body": "URL not found"
}
return {
"statusCode": 302,
"body": url,
"headers": {
"Location": url
}
}