Can I stick with server_name directive from nginx or do I still need to set DNS in linux? - linux

I am learning nginx and I have this doubt. Do I need to setup a dns in linux (/etc/resolv.conf) or can I just stay with what nginx uses inside its directive server_name?

You can set nginx to listen to ANY domain pointed to that web server with:
listen 80 default_server;
or you can be specific via server_name. Check Nginx docs
Setting DNS on the webserver itself does not help much..
Adding the entry in your visitor's PC hosts file can override a domain name's A record pointer to the one specified by you.

Related

Nginx is refusing to connect on AWS EC2

I'm trying to use nginx to setup a simple node.js server, I'm running the server in background on port 4000, my nginx config file is
server {
listen 80;
listen [::]:80;
server_name 52.53.196.173;
location / {
include /etc/nginx/proxy_params;
proxy_pass http://127.0.0.1:4000;
}
}
I saved it in /etc/nginx/sites-available and also symlinked it to sites-enabled, the nginx.conf file has the include line already to load files from sites-enabled, then i restarted the service using
sudo service nginx restart
I tried going to 52.53.196.173 and it refuses to connect, however going to 52.53.196.173:4000 with port 4000 it is working, but I'm trying to make it listen on port 80 with nginx, i tried putting my .ml domain as server_name and no luck, and i have the IP 52.53.196.173 as the A record in the domain dns settings, and I'm doing this on an AWS EC2 Instance Ubuntu Server 16.04, i even tried the full ec2 public dns url no luck, any ideas?
Edit: I solved it by moving the file directly in sites-enabled instead of a symlink
There is few possible things. First of all you need to verify that nginx server is running & listening on port 80. you can check the listening ports using the following command.
netstat -tunlp
Then you need to check your server firewall & also the selinux policies. ( OR disable selinux for test )
Then you need to verify that AWS security group configured to access the http/https connections on port 80.
PS : Outputs from the following command & configurations will be helpful for troubleshooting.
netstat -tunlp
sestatus
iptables -L
* AWS Security Group Rules
* Nginx configurations ( including main configuration if changed )
P.S : OP fixed the problem by moving the config file directly into site-enabled directory. maybe, reefer the comments for more info if you are having the same issue.
Most probably port 80 might not be open in your security group or nginx is not running to accept the connections. Please post the nginx status and check the security group
check belows:
in security group, add Http (80) and Https (443) in inbound section with 0.0.0.0 ip as follow:
for 80 :
for 443 :
in Network ACL, allow inbound on http and https. outbound set custom TCP role as follow:
inbound roles:
outbound roles:
assign a elastic ip on ec2 instance, listen to this ip for public.

Use Reverse Proxy from Https client to Http server running locally on my machine

I have a published site that uses HTTPS. The site needs to communicates with a HTTP node Express API. The API is run on my local machine. Everything worked fine until I switched the client application to use HTTPS. Now I receive mixed content warnings. I have been reading about reverse proxys and wonder if this could be the solution to my problem. Is it possible to proxy a request to my localhost? Or will localhost point to the server the proxy is on?
I have been looking at using nginx as the reverse proxy server but I have zero experience with proxys and not positive how to go about it.
I am mainly wondering if it is possible or not before I dig any deeper.
Yes, this is a pretty standard use case for using nginx (or any other reverse proxy). You would configure the location prefixes, etc that need to go to your backend application and proxy (via proxy_pass directive) to them. Any static content can be served directly from nginx. All of this can then behind nginx.
Assuming that your application is never issuing absolute urls which make use of "http://" this should resolve your mixed content warnings.
You will probably want to read some tutorials but the basics of your configuration would be:
server {
listen 443 ssl; # you can also add http2
server_name hostnames that you listen for;
ssl_certificate_key /path/to/cert.key;
ssl_certificate /path/to/cert.pem;
root /var/www/sites/foo.com;
location /path/handled/by/application {
proxy_pass http://localhost:8000; # or whatever port is
}
}

Where do I put my Node JS app so it is accessible via the main website?

I've recently installed a nodejs app (keystone) app in my home/myusername/myappname directory.
When I visit www.mydomain.com, nothing displays - even after turning on my nodejs app.
Where should these files be?
I am running ubuntu 16.04.
In the past I have worked with a var/www folder, but I am not using apache - do I need to manually create this folder?
Thanks!
For your app to be visible it has to be running (obviously) and accessible on port 80 (if you want it to be available without adding a port number to the URL).
It doesn't matter where it is on the disk as long as it's running.
You don't need Apache or nginx or any other server. Your Node app may listen on port 80. But alternatively it can listen on some other port and your other server (Apache, nginx, etc.) can proxy the requests to that port.
But if your app is listening on, e.g. port 3000 then you should be able to access it as http://www.example.com:3000/.
Also, make sure that your domain is configured correctly. It's A record for IPv4 (or AAAA for IPv6) of the www subdomain should be equal to the publicly accessible IP address of your server.
And make sure that the port you use is not blocked by the firewall.
Update
To see how you can set the port with Keystone, see:
http://keystonejs.com/docs/configuration/#options-server
It can be either changed in the config or you can run your app with:
PORT=80 node yourApp.js
instead of:
node yourApp.js
but keep in mind that to use the port number below 1024 you will usually need the program to run as root (or add a special privilege which is more complicated).
It will also mean that this will be the only application that you can run on this server, even if you have more domain names.
If you don't want to run as root or you want to host more application, it is easiest to install nginx and proxy the requests. Such a configuration is called a "reverse proxy" - it's good to search for info and tutorials using that phrase.
The simplest nginx config would be something like this:
server {
listen 80;
server_name www.example.com;
location / {
proxy_pass http://localhost:3000;
}
}
You can set it in:
/etc/nginx/sites-available/default
or in a different file as e.g.:
/etc/nginx/sites-available/example
and then symlinked as /etc/nginx/sites-enabled/example
You need to restart nginx after changing the config.
You can find more options on configuring reverse proxies here:
https://www.nginx.com/resources/admin-guide/reverse-proxy/
You need to make a proxy between Apache and your Node.js application because Node.js has a built-in server. Supose your Node.js app is served on 9000 port. Then you need to make a proxy to redirect all trafic in 80 port to 9000 port where the Node.js app is running.
1. Enable mod_proxy
You can do this through a2enmond.
sudo a2enmod proxy
sudo a2enmod proxy_http
2. Set the proxy
Edit the /etc/apache2/sites-available/example.com.conf file and add the following lines:
ProxyRequests Off
Order deny, allow from All
ProxyPass / http://0.0.0.0:9000 ProxyPassReverse / http://0.0.0.0:9000
This basically say: "Redirect all traffic from root / to http://0.0.0.0:9000. The host 0.0.0.0:9000 is where your app is running.
Finally restart apache to enable changes.

Deploying multiple nodeJS on Digitalocean with Dokku

I've tried to deploy two nodeJS apps on Digitalocean using a dokku droplet. I am using the "virtualhost naming" scheme but there is a problem.
My DNS configuration looks like this:
I have the main app and the admin app. I would expect to view the admin app when i visit app.example.com (I actually have a proper domain name) but I can see the same app when hitting example.com and app.example.com.
There is something wrong with nginx probably, but I don't know exactly what is going bad?
One thing I have noticed is that whichever app is installed first will be the one that example.com forwards to.
You are correct to attribute this behaviour to Nginx. I think it's due to it falling back to this config somehow when it doesn't detect a config for example.com
This dokku plugin (https://github.com/progrium/dokku/tree/master/plugins/nginx-vhosts) is responsible for rewriting the nginx.conf for each app every time it is deployed.
Nowadays it uses a template nginx.conf (https://github.com/progrium/dokku/blob/master/plugins/nginx-vhosts/templates/nginx.conf) although this is a fairly recent change so be sure your on a recent version.
You will end up with a Nginx config that looks like the following:
server {
listen [::]:80;
listen 80;
server_name app.example.com;
return 301 https://$host$request_uri;
}
I'm not currently sure why the above snippet results in the described behaviour. A work around is to setup your own nginx conf in /etc/nginx/sites-enabled/ with
server_name example.com;
but pointing to a holding page or whatever works for you.

Nginx and multiple domains

I bought some domains at godaddy.com (i.e mydomain.com) for my droplet at digitalocean.com (i.e 199.216.110.210). I run a nodejs application on port 80 on the droplet. From godaddy.com, I forward with masking mydomain.com to 199.216.110.210 and I could see may app.
Now I want to run on 199.216.110.210 several node applications on different ports, using ngnix as reverse proxy. I followed the instructions here (www.digitalocean.com/community/articles/how-to-host-multiple-node-js-applications-on-a-single-vps-with-nginx-forever-and-crontab).
My nginx .conf file is
server {
listen 80;
server_name mydomain.com;
location / {
proxy_pass http://localhost:3000;
# same as in the link above
}
}
(and I am sure it is read: when ngnix start if I put an error there, ngnix reports it).
I start the nodejs application on port 3000:
I try mydomain.com, but ngnix shows always the welcome page.
Also doing mydomain.com: 3000 does not work,
it works only with 199.216.110.210:3000.
From godaddy.com, if I forward with masking the mydomain.com to 199.216.110.210:3000 I can see may app.
But I do not like this solution. I would like domains pointing to my droplet, without specifing the port and admin them with nginx.
How can I get a domain name to use with ngnix as reverse proxy to select my apps, mapped on different domains on different ports? I suppose that forwarding from godaddy.com is somehow limited.
In your server go to /var/log/nginx and do a tail -F *log. Now in another shell restart nginx.
I suspect that your domain name is too long and nginx will complain about its hash_bucket_size is too small. If this is the case open /etc/nginx/nginx.conf and make sure that the line
server_names_hash_bucket_size 64;
exists, has a value of 64 and is uncommented. Then do sudo service nginx reload, and check if all works as expected.
I am going to detail step by step how I am able to do it in my aws ec2 instance;
I set up a DNS record to my instance, so i can set mydomain.com to 192.168.123.123 (my specific IP).
Inside my instance I have forever running my node.js app in port 3000 (I test it work by issuing curl localhost:3000 from the command line)
I then download this .sh file in order to properly intantiate nginx; curl -o nginxStarter.sh https://gist.githubusercontent.com/renatoargh/dda1fbc854f7957ec7b3/raw/c0bc1a1ec76e50cdb4336182c53a0b222edb6c0e/start.sh
I configure nginx with this configuration file. Put this file in; /etc/nginx/nginx.conf
Start nginx with this command; sudo sh nginxStarter.sh start
PS.: For multiple apps just replicate the lines that routes the requests to specific ports, very easy...! If not needed you can eliminate lines regarding out SSL.

Resources