Can't connect to postgresql from mod_lua

Question

I've downloaded and installed Apache 2.4.4 (which now comes with mod_lua module). Enabled it like so:

--httpd.conf--

LoadModule lua_module modules/mod_lua.so
AddHandler lua-script .lua

and ran a simple script and it works.

--htdocs/hello.lua--

function handle(r)
    r.content_type = "text/html"
    r:puts("Hello Lua World!\n")
end

I'd now like to connect to a local pg database but can't get it work.

function handle(r)
    r.content_type = "text/html"
    r:puts("Hello Lua World!\n")
    local db, err = r:dbacquire("postgres", "postgres://user:secret@localhost/db0")
    if not err then
     r:puts("connected!")
    else
     r:puts("couldn't connect!")
    end
end

No error messages whatsoever. Am I missing further configuration?

Thanks for any input!

Sure but I was hoping to use the new db access API's within mod_lua/Apache. http://httpd.apache.org/docs/2.4/mod/mod_lua.html#databases — Sunder, Mar 04 '13 at 21:48
Yes, but to check, if the connection is active or not. Also, include a `db:close()` after your `puts()` call. — hjpotter92, Mar 04 '13 at 21:52

score 1 · Answer 1 · answered Mar 22 '13 at 12:09

1

Apache httpd is based on APR which provides the database connectivity; so make sure that your APR installation supports the database layer you want to use.

answered Mar 22 '13 at 12:09

ApMonkey

31
1

Yes, I configured my build to include dbd and postgres. Thanks. – Sunder Mar 22 '13 at 14:00

score 0 · Accepted Answer · answered Mar 22 '13 at 14:05

Turns out I got the driver name and connection string wrong. Replacing the dbacquire line in the question with this should make it work.

db = r:dbacquire("pgsql", "hostname=localhost dbname=foo user=bar password=baz")

Better yet, by embedding these in the httpd.conf like so

DBDriver pgsql
DBDParams "hostname=localhost dbname=foo user=bar password=baz"

You can get away by simply doing this in your lua scripts

db = r:dbacquire()
--start using your db here

Can't connect to postgresql from mod_lua

2 Answers2