I want to write a n-tier application, where the server part can be hosted on the customer site or our company can host the server part (for each customer) on our machine (over the internet).
When our company is hosting the customers server part. We then have to run the same server application multiple times (for each customer). I don't want to change and maintain the port numbers for every server instance.
So my question is: Is it possible to run the same server app with the same port mapping on the same machine? Just specifying a unique uri/url in the server app? like:
http://10.0.0.127:8090/customer_1/
http://10.0.0.127:8090/customer_2/
I am using Indy components for client/server communication.
The only way multiple servers can listen on the same port on the same machine is if they are bound to different IP addresses. Otherwise, you have to use different ports.
The alternative is to host just one HTTP server and utilize HTTP 1.1's virtual host feature (via the Host header, which is a required header in all HTTP 1.1 requests) to differentiate between different customer sites on the same server, eg:
http://customer1.myserver.com:8090/ generates:
GET / HTTP/1.1
Host: customer1.myserver.com:8090
http://customer2.myserver.com:8090/ generates:
GET / HTTP/1.1
Host: customer1.myserver.com:8090
Your server can look at the Host header to know which customer site to access.
Read RFC 2616 Section 19.6.1.1 for more information:
Changes to Simplify Multi-homed Web Servers and Conserve IP Addresses
Related
I have made an account on Linode website and have a "linode" running. I have a server running using ruby on rails. The command I used is the following:
rails server --binding=<ip_adress>
The server starts up without issue. The question I have is why can't I visit the the side I created using my browser, just by putting the ip_address in the browser? The server logs display the following
Environment: development Listening on tcp:<ip_address>:3000
I can visit this ip_address on my browser but I need to add the ":3000" in the browser so I can view the site.
Shouldn't I be able to just visit the stand alone ip_address without entering ":3000"? I also wanted to say I am just learning ruby on rails as well.
I haven't tried anything more than described above
An IP address is a way to identify a machine on the internet.A port is a number assigned to uniquely identify a connection endpoint and to direct data to a specific service.
Therefore, your rails service is a combination of an IP address and a Port number. Since you can have different services running on the same machine at the same IP address.
HTTP has a default port of 80 which is what your browser will try to access when you don't provide a port.
Most likely, you will want a Reverse Proxy hosted at port 80 that forwards traffic to your rails app.
This post provides a better answer of how this works. https://superuser.com/questions/394078/how-can-i-map-a-domain-name-to-an-ip-address-and-port
Not Recommended
If you don't want to use a reverse proxy, you can host the rails server at port 80 itself.
rails server -p 80
Note that this requires you to have root permissions on the machine.
I have a server and I am using Ubuntu 20.04, nginx , mosquitto and node-red and docker , let's call the website http://mywebsite.com. The problem that I am facing that I have created a client lets call it client1 in docker so the URL will be http://mywebsite.com/client1
and I want to establish an MQTT connection via mosquitto and I'm sending the data on topic test
The problem that on node red node of MQTT when I write the IP address of my mosquitto container it works
But if I change the IP address 192.144.0.5 with mywebsite.com/client1 I can't connect to mosquitto and I can't send or receive any form of data
any idea on how to solve this problem
OK, you are going to have several problems here.
You can not do path based proxying with MQTT. If you want to have multiple MQTT brokers (1 per client) bound to a single public facing domain/IP address then they are all going to have to run on separate ports (other than the default 1883).
Nginx can do MQTT protocol proxying (e.g. like this), so you can use this to expose the different ports and forward them to the separate instances of mosquitto, but even if you had a different hostname (all pointing at the same IP address) nginx has no way to know which host name was used because there is no equivalent to the HOST HTTP header to direct it. If you were to use MQTT with TLS then you may be able to get it to work with SNI, but I've never seen anybody do that yet (possible docs for SNI based routing here) It works, explanation about how to do it here.
If you use MQTT over Websockets then you should be able to use hostname based routing.
Path based proxying for Node-RED currently doesn't work properly if you enable admin authentication, because the admin auth tokens are currently stored in browser local storage and only scoped to the hostname, not the hostname + path. This will mean that a client will only ever be able to log into one instance at a time.
You can work round this by using host based proxying, e.g. http://client1.mywebsite.com
A fix for this is on the backlog for Node-RED, probably (no promises) to be looked at after version 1.2.0 ships
I have a docker container which exposes a RESTful API on a specific port (e.g. 4567) on a host machine. According to security requirements, I need to block all requests coming to this port (i.e. 4567) except the one coming from a specific application (say a scheduler like oozie). I'm not very familiar with firewalls, but I'm guessing the first part (blocking on access to the port) can be done in the firewall, but how can I open access to only one application?
Can someone explain why using a port is necessary when running things locally?
I assume the reason is because the same software could be run remotely and in that case specifying a port would be necessary.
When a database or server is running locally, do requests from a locally running web browser really "go through the port" specified?
Good question. In fact, there are local-only communication protocols, such as pipes and UNIX domain sockets that do not actually require port numbers to operate. This is because they refer to files or other identifiers that are only valid on the computer itself.
However, most servers are designed for TCP/IP connections. TCP/IP itself specifies a port number in the protocol. It is normally intended for remote use, but when a server that is used to TCP/IP runs "on local host", it must supply a port number to satisfy the TCP protocol.
Port numbers also enable multiple servers to coexist on a single computer, all running on different ports. For a protocol without port numbers, this is achieved by using different identifiers (e.g. a filesystem file) for each server.
Some servers can operate on both TCP/IP and local sockets. For example, MySQL can accept connections both through the usual TCP port, and also through a local socket (mysql.sock). Connecting through the local socket is reserved for local users only, and may be faster on some systems.
Sometimes You may have some other software installed in your computer that may use the same port. For instance Apache and IIS: imagine you set port 8080 to IIS as default, what about if you had previously installed Apache set port 8080 ?
Another example will be if you installed Mysql Workbench and days later install XAMPP you may have trouble with the ports if you don't change one instance's port different from 3306
This is why it is necessary to specify ports even though is locally.
Using WEBrick you could navigate to an app you were serving from another device/virtual machine by navigating to your.ip.address.here:port
Is it possible to do something similar with pow.cx?
The latest version of Pow (0.4.0) now includes xip.io support. You can read about the release here.
Here's a quick explanation of how this helps Pow serve your Rails apps across your entire local network, from their post:
Say your development computer’s LAN IP address is 10.0.0.1. With the
new version of Pow, you can now access your app at
http://myapp.10.0.0.1.xip.io/. And xip.io supports wildcard DNS, so
any and all subdomains of 10.0.0.1.xip.io resolve too.
Here's a description of xip.io, from their site:
xip.io runs a custom DNS server on the public Internet. When your
computer looks up a xip.io domain, the xip.io DNS server extracts the
IP address from the domain and sends it back in the response.
There are basically two options:
Don't use pow: run your applications on localhost as usual and access them as usual
Edit the hosts file (or local DNS) to point your server machine ip
Example accessing from a virtual windows machine:
Suppose you are running two rails applications in pow: store.dev and auth.dev, and you want to access them from a windows xp virtual machine to test them with IE, you only need to edit your hosts file to add the lines:
C:\WINDOWS\system32\drivers\etc\hosts
# Allow to access applications in pow.
# The ip address points to the host machine localhost, that usually is the default gateway
10.0.2.2 store.dev
10.0.2.2 auth.dev
And then open the IE browser to access your applications in http://store.dev and http://auth.dev respectivelly.
Specifically, no, because Pow uses the Host header of the request to determine which app you need to access. To get that working remotely, you would have to have the remote machine map the required domain name to your IP address - either with a local DNS server or by editing the HOSTS file. Both of which are possible but annoying.
The simplest thing to do in that case is to start up a standalone Rails server as you mentioned (using ./script/server or rails s depending on the version), and then you can address http://[ip address]:3000 as before.
In other words, Pow works because it intercepts your local domain resolution, something that isn't affected by (or available to) remote machines.