Content_by_lua not reading/printing header values

Server NGINX
1

My nginx.conf

upstream testdb {
    postgres_server 10.0.9.43:9000 dbname=testdb user=postgres

password=postgres;
postgres_keepalive max=100 mode=multi overflow=ignore;
}

    location / {
        set $x "";

        content_by_lua '
            local a = ngx.var.http_cookie
            local b = ngx.var.http_my_custom_auth

            print(a)
            print(b)

            if ngx.var.http_my_custom_auth ~= nil then
                local res = ngx.location.capture("/postgresquery",
                                                { args = {x = b } }
                                                )
                print(res.status)
                print(res.header)
                print(res.body)
                -- I would like to do more actions based on the

result.
However, for now, we simply move ahead
return ngx.exec(“@final”)
elseif ngx.var.http_cookie ~= nil then
return ngx.exec(“@final”)
else
ngx.status = 444
return
end
';
}

    location @final {
        #
        # This is an internal location. Cannot be accessed from the

outside
#

        internal;
        proxy_pass http://10.0.1.42;
    }

    location /postgresquery {
        internal;

        postgres_pass testdb;
        postgres_output text;
        postgres_escape $http_my_custom_auth;
        postgres_query "select id, name from testtable where key =

$x";
}

My error Log:

2014/06/24 13:01:36 [debug] 6073#0: epoll add event: fd:7 op:1
ev:00002001
2014/06/24 13:01:38 [debug] 6073#0: post event 099D1620
2014/06/24 13:01:38 [debug] 6073#0: delete posted event 099D1620
2014/06/24 13:01:38 [debug] 6073#0: accept on 0.0.0.0:80, ready: 0
2014/06/24 13:01:38 [debug] 6073#0: posix_memalign: 099A8D40:256 @16
2014/06/24 13:01:38 [debug] 6073#0: *1 accept: 127.0.0.1:57731 fd:11
2014/06/24 13:01:38 [debug] 6073#0: *1 event timer add: 11:
60000:3435819925
2014/06/24 13:01:38 [debug] 6073#0: *1 reusable connection: 1
2014/06/24 13:01:38 [debug] 6073#0: *1 epoll add event: fd:11 op:1
ev:80002001
2014/06/24 13:01:38 [debug] 6073#0: *1 post event 099D1688
2014/06/24 13:01:38 [debug] 6073#0: *1 delete posted event 099D1688
2014/06/24 13:01:38 [debug] 6073#0: *1 http wait request handler
2014/06/24 13:01:38 [debug] 6073#0: *1 malloc: 0999FA50:1024
2014/06/24 13:01:38 [debug] 6073#0: *1 recv: fd:11 98 of 1024
2014/06/24 13:01:38 [debug] 6073#0: *1 reusable connection: 0
2014/06/24 13:01:38 [debug] 6073#0: *1 posix_memalign: 099A56D0:4096 @16
2014/06/24 13:01:38 [debug] 6073#0: *1 http process request line
2014/06/24 13:01:38 [debug] 6073#0: *1 http request line: “HEAD /
HTTP/1.1”
2014/06/24 13:01:38 [debug] 6073#0: *1 http uri: “/”
2014/06/24 13:01:38 [debug] 6073#0: *1 http args: “”
2014/06/24 13:01:38 [debug] 6073#0: *1 http exten: “”
2014/06/24 13:01:38 [debug] 6073#0: *1 http process request header line
2014/06/24 13:01:38 [debug] 6073#0: *1 http header: “User-Agent:
curl/7.32.0”
2014/06/24 13:01:38 [debug] 6073#0: *1 http header: “Host: 127.0.0.1”
2014/06/24 13:01:38 [debug] 6073#0: *1 http header: “Accept: /”
2014/06/24 13:01:38 [debug] 6073#0: *1 http header: “my-custom-auth:
Vamshi”
2014/06/24 13:01:38 [debug] 6073#0: *1 http header done
2014/06/24 13:01:38 [debug] 6073#0: *1 event timer del: 11: 3435819925
2014/06/24 13:01:38 [debug] 6073#0: *1 rewrite phase: 0
2014/06/24 13:01:38 [debug] 6073#0: *1 test location: “/”
2014/06/24 13:01:38 [debug] 6073#0: *1 using configuration “/”
2014/06/24 13:01:38 [debug] 6073#0: *1 http cl:-1 max:1048576
2014/06/24 13:01:38 [debug] 6073#0: *1 rewrite phase: 2
2014/06/24 13:01:38 [debug] 6073#0: *1 http script value: “”
2014/06/24 13:01:38 [debug] 6073#0: *1 http script set $x
2014/06/24 13:01:38 [debug] 6073#0: *1 post rewrite phase: 3
2014/06/24 13:01:38 [debug] 6073#0: *1 generic phase: 4
2014/06/24 13:01:38 [debug] 6073#0: *1 generic phase: 5
2014/06/24 13:01:38 [debug] 6073#0: *1 access phase: 6
2014/06/24 13:01:38 [debug] 6073#0: *1 access phase: 7
2014/06/24 13:01:38 [debug] 6073#0: *1 post access phase: 8
2014/06/24 13:01:38 [debug] 6073#0: *1 lua content handler, uri:“/” c:1
2014/06/24 13:01:38 [debug] 6073#0: *1 lua reset ctx
2014/06/24 13:01:38 [debug] 6073#0: *1 lua creating new thread
2014/06/24 13:01:38 [debug] 6073#0: *1 http cleanup add: 099A5FAC
2014/06/24 13:01:38 [debug] 6073#0: *1 lua run thread, top:0 c:1
2014/06/24 13:01:38 [debug] 6074#0: epoll add event: fd:7 op:1
ev:00002001

Curl output:

[vamshi@localhost ~]$ curl -I -H “my-custom-auth: Vamshi”
http://127.0.0.1
curl: (52) Empty reply from server

Postgres Table (on a different machine):
1 Row
ID : 1
Name : Vamshi Krishna Ramaka
Key: Vamshi

I know that code 444 is being returned, because lua seems to find the
cookie
and my header as empty. Can you tell me why Lus thinks they are empty ?
The
current config is not production quality since this is my first attempt
at
nginx as well as Lua. I have almost removed everything else is trying to
catch this bug, and this is where I have landed. So do excuse me if
there
are any glaringly obvious errors.

-Vamshi

Posted at Nginx Forum:

2

I found the issue(s). I am not sure why the error log did not have any
logs
after the lua thread got launched.

Here is the updated /etc/nginx/nginx.conf

    location / {
        set $dbKey "";

        content_by_lua '
            local a = ngx.var.http_cookie
            local b = ngx.var.http_my_custom_auth

            print(a)
            print(b)

            if ngx.var.http_my_custom_auth ~= nil then
                local res = ngx.location.capture("/postgresquery",
                                                { args = {dbKey = b

} }
)
print(res.status)
print(QueryResult)
if res.status == 200 then
return ngx.exec(“@final”)
else
ngx.status = 403
return
end
elseif ngx.var.http_cookie ~= nil then
return ngx.exec(“@final”)
else
ngx.status = 444
return
end
';
}

    location /postgresquery {
        internal;

        postgres_pass testdb;
        postgres_escape $escaped_dbKey $arg_dbKey;
        postgres_query "select id from testtable where key =

$escaped_dbKey;";
postgres_output value;
}

However, as you can see, I had to delete print(res.headers) and
print(res.body), since lua was complaining that it expects a single
value,
but it got a table

-Vamshi

Posted at Nginx Forum: