support regexes

app.py

@@ -3,6 +3,7 @@
 
 import io
 import os
+import re
 import sys
 import utils
 import random
@@ -21,7 +22,7 @@ with open(sys.argv[1] if len(sys.argv) > 1 else 'config.toml') as f:
 for host in config['hosts'].values():
 	if not host.get('replace', True): continue
 	host['pattern_decoded'] = host['pattern']
-	host['pattern'] = host['pattern'].encode()
+	host['pattern'] = re.compile(host['pattern'].encode())
 	host['repl_decoded'] = host['repl']
 	host['repl'] = host['repl'].encode()
 
@@ -51,7 +52,7 @@ async def handler(request):
 			# iter_lines when
 			print('replacing', repr(hconfig['pattern_decoded']), 'with', repr(hconfig['repl_decoded']))
 			while (line := await upstream_resp.content.readline()):
-				await resp.write(line.replace(hconfig['pattern'], hconfig['repl']))
+				await resp.write(hconfig['pattern'].sub(hconfig['repl'], line))
 		else:
 			print('not replacing')
 			async for chunk in upstream_resp.content.iter_chunked(io.DEFAULT_BUFFER_SIZE):

config.example.toml

@@ -10,6 +10,7 @@ debug = True
 # replace foo with bar for site1.example
 [hosts."site1.example"]
 upstream = 'http://localhost:3001'
+# these can be regexes
 pattern = 'foo'
 repl = 'bar'