bug: mocking plugin panic when response_example contain $

[yangxikun]

Current Behavior

lua entry thread aborted, cause http 500 response.

Expected Behavior

Should not abort.

Error Logs

2023/02/06 16:20:21 [error] 52#52: *75286 lua entry thread aborted: runtime error: /usr/local/apisix-2.13.2/apisix/core/utils.lua:298: attempt to index upvalue '_ctx' (a nil value)
stack traceback:
coroutine 0:
	/usr/local/apisix-2.13.2/apisix/core/utils.lua: in function 'replace'
	/usr/local/openresty/lualib/resty/core/regex.lua:1003: in function 're_gsub'
	/usr/local/apisix-2.13.2/apisix/core/utils.lua:319: in function 'resolve_var'
	/usr/local/apisix-2.13.2/apisix/plugins/mocking.lua:221: in function 'phase_func'
	/usr/local/apisix-2.13.2/apisix/plugin.lua:748: in function 'run_plugin'
	/usr/local/apisix-2.13.2/apisix/init.lua:481: in function 'http_access_phase'
	access_by_lua(nginx.conf:300):2: in main chunk

Steps to Reproduce

config mocking like:

routes:
  -
    uri: /hello
    upstream:
      nodes:
        "127.0.0.1:1980": 1
      type: roundrobin
    plugins:
      mocking:
        response_example: '{"$a":1}'

Environment

• APISIX version (run apisix version): master branch
• Operating system (run uname -a):
• OpenResty / Nginx version (run openresty -V or nginx -V):
• etcd version, if relevant (run curl http://127.0.0.1:9090/v1/server_info):
• APISIX Dashboard version, if relevant:
• Plugin runner version, for issues related to plugin runners:
• LuaRocks version, for installation issues (run luarocks --version):

[yangxikun]

The bug code line:

apisix/apisix/plugins/mocking.lua

Line 221 in 5984321

return conf.response_status, core.utils.resolve_var(response_content)

Should call core.utils.resolve_var(response_content, ctx.var).

[monkeyDluffy6017]

I think you are right, would you like to fix this and add some test cases ?

[yangxikun]

Ok, Let me try.

[github-actions]

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[github-actions]

This issue has been closed due to lack of activity. If you think that is incorrect, or the issue requires additional review, you can revive the issue at any time.