bug: nacos discovery config valid error when using special character password symbol in config.yaml

[jthann]

Issue description

When using special characters in nacos password in config.yaml following the document from https://apisix.apache.org/docs/apisix/discovery/nacos.
At starting time the json schema validator report error and apisix start failure

Environment

• apisix version (cmd: apisix version): 2.11.0
• OS (cmd: uname -a): macOS Big Sur 11.3.1

Steps to reproduce

1、Config following yaml fragment in config.yaml

discovery:
  nacos:
    host:
      - "http://nacos:NOK1&(&*!#3@127.0.0.1:8848"

2、Start apisix

Actual result

apisix start failure and report error

Error log

2022/01/26 11:02:52 [error] 15735#7581333: init_worker_by_lua error: [string "jsonschema:anonymous"]:43: invalid option '%]' to 'format'
stack traceback:
	[C]: in function 'string_format'
	[string "jsonschema:anonymous"]:43: in function 'var_0_4'
	[string "jsonschema:anonymous"]:60: in function 'var_0_3'
	[string "jsonschema:anonymous"]:211: in function 'check'
	.../apisix-2.11.0/apisix/discovery/nacos.lua:382: in function 'init_worker'
	.../apisix-2.11.0/apisix/discovery/init.lua:35: in function 'init_worker'
	.../gts-apigw/apisix-2.11.0/apisix/init.lua:109: in function 'http_init_worker'
	init_worker_by_lua:2: in main chunk

Expected result

No response

[tzssangglass]

NOK1&(&*!#3@127.0.0.1:8848

can you change NOK1&(&*!#3@127.0.0.1:8848 to normal String to verify if this error is special characters caused by.

[leslie-tsang]

Hello there, The host match pattern for the APISIX v2.11 nacos plugin is ^http(s)?:\/\/[a-zA-Z0-9-_.:\@%]+$
Refer to nacos.lua, the error may caused by jsonschema.

jsonschema will generate a dynamic code

retrun false, string.format([[failed to match pattern "^http(s)?:\\/\\/[a-zA-Z0-9-_.:\\@%]+$" with %q]], "http://nacos:NOK1&(&*!#3@127.0.0.1:8848")

I don't know if I'm wrong. also cc @spacewander

[spacewander]

Yes. We should fix host match pattern.