Mongodb REST API returns no results - mongodb

Question

I'm using the builtin MongoDB "simple REST interface" to try to tie together my MongoDB collection with a simple javascript frontend without writing an API myself. I have the REST server up and running, as proven by running the following inside my production server:
$> http get "http://localhost:28017/mydb/mycoll/?limit=1"
HTTP/1.0 200 OK
Connection: close
Content-Length: 437
Content-Type: text/plain;charset=utf-8
x-action:
x-ns: mydb.mycoll
{
"offset" : 0,
"rows": [
{ <redacted data> }
],
"total_rows" : 1 ,
"query" : {} ,
"millis" : 0
}
The Mongodb REST server does not by, by default, bind to an interface which is publicly accessible, so I'm proxying localhost:28017 to the outside world using Nginx, with the following configuration:
server {
listen 80;
server_name api.myapp.com;
rewrite ^ https://$server_name$request_uri? permanent;
}
server {
listen 443 default_server;
server_name api.myapp.com;
ssl on;
ssl_certificate /etc/ssl/myapp.crt;
ssl_certificate_key /etc/ssl/myapp.key;
access_log /logs/nginx_access.log;
error_log /logs/nginx_error.log;
location /mongo {
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto https;
proxy_set_header Host $http_host;
proxy_redirect off;
if (!-f $request_filename) {
proxy_pass http://127.0.0.1:28017;
break;
}
}
}
I reload nginx and try the same query I ran inside the machine hosting Mongo from a machine outside that network instead, and get:
$> http get "https://api.myapp.com/mongo/mydb/mycoll/?limit=1"
HTTP/1.1 200 OK
Connection: keep-alive
Content-Encoding: gzip
Content-Type: text/plain;charset=utf-8
Date: Fri, 27 Feb 2015 17:06:40 GMT
Server: nginx/1.4.6 (Ubuntu)
Transfer-Encoding: chunked
Vary: Accept-Encoding
x-action:
x-ns: mongo.mydb.mycoll
{
"offset" : 0,
"rows": [
],
"total_rows" : 0 ,
"query" : {} ,
"millis" : 0
}
Essentially, it is hitting the Mongo REST server (making it through the nginx proxy), but it is not returning any results for the same query that I ran on localhost.
The only lead I have so far is that the x-ns header on the two responses is different - like the Mongo REST server is not picking up the fact that Nginx is instructing it to lie behind the https://api.myapp.com/mongo route and is instead thinking I'm trying to access the database mongo.
Thanks for your help.

Answer 1

Solved my own issue. The problem was as I guessed at the end of my question: the Nginx config was proxying requests to the Mongo API server with the /mongo/ path intact, resulting in queries being run on the (nonexistent) database mongo.
I fixed the problem by adding the following line to the /mongo/ location in the Nginx configuration file:
rewrite /mongo/(.+) /$1 break;
so that it reads, in full:
location /mongo/ {
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto https;
proxy_set_header Host $http_host;
proxy_redirect off;
if (!-f $request_filename) {
rewrite /mongo/(.+) /$1 break;
proxy_pass http://127.0.0.1:28017;
break;
}
}
Thanks to anyone who gave this question a look.