Possible to use the module from content_by_lua_file

[nbhatti]

I am using currently using content_by_lua_file, so I was thinking if I can use the module from the lua script itself?

[agentzh]

@nbhatti Sure. You can use the ngx.location.capture to initiate nginx subrequest to a (internal) location configured by ngx_postgres. AFAIK, qunar.com has been using this approach in production for years already :)

[nbhatti]

@agentzh Do you have an example? I want to manage db connection and everything inside the Lua script and not in nginx directives. Currently I am just passing everything to content_by_lua_file and initiate the db connection and complete the script. Is that aso doable with ngx.location.capture?

[agentzh]

@nbhatti Then you should not use ngx_postgres in the first place. There're some 3rd-party pure Lua PostgreSQL client libraries based on ngx_lua's nonblocking cosocket API, for example,

1. https://github.com/azurewang/lua-resty-postgres
2. https://github.com/leafo/pgmoon

They're much more flexible than doing subrequests + ngx_postgres.