Debian - default ip per user? - sockets

I got a server that has 64 public IPv4 adresses. Is there any way to set default IP per user on Debian? I don't mean virtual server setup. Or if not, is there any console application to bind other application (that doesn't support IP binding nativly) to selected IP?
Best regards,
FlashT

you could use a crafty firewall that marks packages originating from processes owned by a given user and then rewrites packages accordingly, as described here.

Related

Automatically update a domain with an IP address

Over the years, I used No-IP to link a domain to my IP address, and then used No-IP's DUC (Dynamic Update Client) to update my IP, so that the domain will always point to my IP.
That's very handy for running dedicated game servers.
Is there a DUC-equivalent for Google Cloud DNS?
In essence - No - there isn't :(
Unless yo're using Google Domains for your domain hosting then yes - they support just the thing.
Cloud DNS doesn't have that functionality. There are several workarounds like reserving a public IP for your VM which in my opinion would be the best way to do it. Unless your VM get's deployed using Deployment Manager then it may require some more scripting.
Similar questions have been raised on Stackoverflow here and here which you might find helpful.
If you're running Linux here you'll find a complete script how to update DNS records after a machine startup.

Hosting a website using server software

How can i host a website through my computer using server softwares?
I tried to host a website through my own computer using apache tomcat server but it didnt work ( please briefly explain every point )
The main issue that you need to deal with is getting the clients to your computer.
Yes, it is possible and yes I have done it, albeit a while ago.
You need to see if you can browse to your computers website from another device on your network, this will ensure that apache is working. Try another computer/laptop/tablet/whatever to see if this site reachable by other computers using the IP Address and possibly port number. If you cannot get to the site, there are settings in apache to deny certain ip's, google it to get the exact steps for your version. If it works, move on to step 2.
You will need a static IP Address to ensure that all further steps stay working, google this if you are not sure how to do it
You need to have the external IP address of your router(whatsmyip.org) or use Dynamic DNS to route traffic from an address to your ip and there are services that allow this. I can recommend no-ip.com - This is all assuming that you have access to the router.
You would be required to set up port forwarding on your router. This will direct the internet traffic to your computer. You will need to get the exact instructions for your specific model of router.
Please be aware that you need to have proper firewalls and systems in place to prevent attacks. I am sure that you are just testing at this point though...
All the best!

Can I force Eureka registrations to use an ip address instead of a hostname?

I have a standalone, embedded Eureka server powered by Spring Boot 1.2.0.RELEASE and Spring Cloud 1.0.0.RC1. I see services properly registering themselves in the dashboard, which is great. The status links are using the host name of the box they are running on. Unfortunately, we are using virtual machines and they don't register themselves in DNS, which means that the links are unresolvable. I started looking through the code but was unable to find a way to force the links to use the host's ip address instead. Having a broken dashboard is not the end of the world but I am afraid that once we start using Ribbon or Feign to contact services, those URLs will also use the host name and be unresolvable. Maybe what I am really asking is there a way to force the clients to register with an ip address instead of a host name? Any help is appreciated.
set eureka.instance.preferIpAddress=true as documented here

How to make a Google Cloud SQL Instance accessible for any IP address?

I have just created a Google Cloud SQL instance. When I was looking on the access control of my instance, I found that if I want to access my database, I should authorize my IP address to get the right to access the database, but the problem is that my application will be deployed anywhere where the clients need, and even if I know where they will run the application and also I authorized their IP address, it (the IP) will be changed at least one time every 24 hours because it is not static IP, and then I have to re-authorize the IP again and again!
Is there any way to make the instance accessible from any IP?
Thanks
You can whitelist any subnet. You just need to enter it using CIDR notation: http://en.wikipedia.org/wiki/Cidr
In particular, you can whitelist 0.0.0.0/0 which includes all possible IP Address.
Please note that this is not recommended for security reasons. You want your access to be as restricted as possible.
This is an older post, but I noticed it on the sidebar so I figured I would add my 2c.
If you're able to use Cloud SQL Second Gen (currently in Beta) there is a new feature which allows access to the database without having to whitelist any firewalls: https://cloud.google.com/sql/docs/sql-proxy
Today, I was looking for a way to set-up an MS-SQL server for development purpose and found the similiar problem (how to allow my laptop to access).
This guide, helps.
In short, you need to allow firewall to enable EXTERNAL access to your VM instance at port 1433.

Get Azure public IP address from deployed app

I'm implementing the PASV mode in a FTP server, and I send to the client the IP address and port of the data end point. This is stupid because the IP is actually where the client is already connecting, so there ire two options:
How could I get the public IP
address from a given instance? Not
the VIP, but the public one.
How could I get the original target
IP address that the user used from
a Socket object? Considering routers and load balancers in the middle :P
An answer to any of this questions would do, although there is another way that could work... may I get the public IP address doing a DNS look up of myapp.cloudapp.net?
A fourth option would be use the Azure Management API library... but, too much trouble :P.
Cheers.
Not sure if you ever figured this out, but here's my take on it. The individual role instances are all behind the Windows Azure load balancer and have no idea what the original, outward-facing IP address is. Also, there's no Management API call that returns IP address - Get Deployment returns the URL but not the IP address. I think the only option is going to be a dns lookup.
Having said that: I don't think you can host a passive ftp server in your role instance (at least not elegantly). You may open up to 25 input endpoints on your role (up from 5 - see my recent blog post about this update), but there's manual work involved in the configuration. I don't know if your ftp application lets you limit your port range to such a small number of ports. Also:
You'd have to define each port as its own input endpoint (this is the manual labor part I mentioned) - input endpoints don't allow a port range to be specified, unlike the internal endpoints.
You'd have to specify the port number that's used internally, and the port numbers would need to be sequential
One last thing on ftp: you should be able to host an sftp server with no trouble, since all traffic comes through one port.
The hack that I'm contemplating right now is to retrieve http://www.icanhazip.com/. It isn't elegant and is subject to the availability of that service, but it gets the job done. A better solution would be appreciated!