Is it possible to run the Mosquitto Broker on any shared server? The closest solution I got to is this here, it only tells how to configure it, but I can't figure out how to install it on my server without ssh.
Another possible solution for my problem will be to use hosted brokers like CloudMQTT. I don't like it's plans and pricing, are there any other alternatives to this?
If you don't have console (SSH) access to the machine to install and run software it is going to be very difficult to add a broker without help from the administrator.
If you do mean a virtual host on a shared web server, then this is unlikely to happen as there is no concept of virtual hosts for MQTT so each user would have to be given their own port number (may be 2 if you want MQTT over websockets)
Related
I have an Ubuntu VM installed on a client's VMware system. Recently, the client's IT informed us that his firewall has been detecting consistent potential port scans to our VM's internal IP address (coming from 87.238.57.227). He asked if this was part of a known package update process on our VM.
He sent us a firewall output where we can see several instances of the port scan, but there are also instances of our Ubuntu VM trying to communicate back to the external server on port 37258 (this is dropped by the firewall).
Based on a google lookup, the hostname of the external IP address is "feris.postgresql.org", with the ASN pointing to a European company called Redpill-Linpro. As far as I can tell, they offer IT consulting services, specializing in open source software (like PostgreSQL, which is installed on our VM). I have never heard of them before though and have no idea why our VM would be communicating with them or vice-versa. I'm also not sure if I'm interpreting the IP lookup information correctly: https://ipinfo.io/87.238.57.227
I'm looking for a way to confirm or disprove that this is just our VM pinging for a standard postgres update. If that's the case I'd like to restrict this behaviour. We would prefer to do these types of updates manually and limit the communication outside of the VM to what is strictly necessary for the functionality of our application.
Update
I sent an email to Redpill's abuse account. They responded quickly saying that the server should not be port scanning anyone and if it appears that way, something is wrong.
The server is part of a cluster of machines that serves apt.postgresql.org among other postgres download sites. I don't think we have anything like ansible or puppet installed that would automatically check for updates but I will look into that to make sure. I'm wondering if Ubuntu reaching out to update the MOTD with the number of available packages would explain why our VM is trying to reach out to the external postgres server?
The abuse rep said in any case there should only be outgoing connections from the VM, not incoming. He asked for some additional info so I will keep communicating with him and try to update this post accordingly
My communication with the client's IT dropped off so I did not get a definitive answer on this, but I'll provide some new details:
I reached out to the abuse email for Redpill-Linpro. He got back to me and confirmed the server corresponding to the detected IP address is part of a cluster that hosts postgres download sites, including apt.postgresql.org. He was surprised to learn we had detected a port scan from their server and seems eager to figure out why that is happening.
He asked if the client IT could pass along some necessary info for them to set up tracking on that server. But the client IT never got back to me. I think he was satisfied that it wasn't malicious and stopped pursuing it.
Here's one of the messages the abuse rep sent me that may be relevant:
That does look a lot like the tcp to the apt download server yes. It's
strange that your firewall reports that many incoming connections, but
they could be fallout from some connection tracking that's not
operating as intended. The timing appears to be matching up more or
less perfectly. And there should definitely not be any ping-back
connections from it.
Since you appear to be using the http version of the server (and not https) bringing the data in cleartext, they should be able to just
dump the TCP connection contents and verify exactly what it does. But
I bet they are going to see a number of http requests initiated by the
apt client that is checking for updates.
How do I remotely pull configuration information from a running bind name server without logging in as root on the server where it is running?
I searched a lot and read many materials about BIND9 but still no answers.
I know there are some commands to conduct zone transfer or update zone resource data, but I didn't find any way to pull configuration info from a name server.
In short: you cannot. There is no provision in the DNS protocol to send server configuration. So whatever technology you use, it will NOT be DNS. And since Bind9 is designed to serve DNS requests and send DNS replies only, Bind9 cannot be coerced to send its configuration the way you'd expect.
You have to install and configure some other piece of software to be able to access the configuration. SSH is one of the most widespread such technology used for managing server configurations.
You could use "rndc -s dns-server dumpdb".
In named's configuration you point dump-file to a shared folder which is accessible from the system that ran rndc.
I want to offer IRC service to other users on my local network.
I'd like to have persistent logs of all (or at least certain) channels and private messages that can be replayed by the client. The log capacity could be limited. I know this is usually handled by a bouncer.
I want this setup to work locally, even if the server uplink goes down, so I probably want to run my own IRC server.
Are there any IRC servers already support this?
Having a common chat and pastebin on the local network is very useful.
I've been attempting this today. And after some tribulations I have success.
I've been running ircd-hybrid without any problems for a while, but conversation histories, as you know, are not saved.
You could use any bouncer but I'll demonstrate ZNC:
If you're running linux, run...
sudo apt-get install znc
once it's installed, run...
znc --makeconf
This generates a config file. When asked for a port number specify a free port. This is the one you will connect to from your client and should NOT be the same as you IRC daemons port.
Later on you will be asked to specify the server you want to connect to, this should be 127.0.0.1:.
Make sure you firewall allows the new port, and restart ircd:
sudo service <your irc daemon> restart
That's it. Unless you've set it's modes to +i, your bouncer should now be visible on the channels you've asked it to join.
For more info on ZNC:
http://wiki.znc.in/FAQ
Might help to talk to the IRC crew at #ircd-coders on irc.ircd-hybrid.org
and for ZNC people... #znc on chat.freenode.net
I have a certain number of hosts running different servers. All of them have nagios plugin installed. I wanted to write a script that would tell me daily if all the instances are up and running.
I tried opsview, but due to certain restrictions, I couldn't go ahead with it. It was then that I decided to use the nagios plugin directly. I thought about NRPE but it would be used to run a plugin remotely (provided you must know the address of the host), but in my case, I want to know if someone added a new server overnight, or some server failed or what all servers are running.
Nagios doesn't do discovery. You configure it with a list of machines and services to check.
Assuming we're talking about cloud servers, AWS can send you a message when a new server is added. See the doc The message can be SNS or SQS. These notifications could be read to rebuild your nagios configuration to match the auto-scale group.
I would like to do my study practice.
To install the multiservers seperating on multiple vm -web server in first vm ,app server in second and db server in the last vm .then,I will create my own webpage to test about accessing data in db .Each of vm is based on VMware in my computer and just do it on localhost environment.not need to connect internet.
How can I do this or Where can I find any Tutorial .Plese give me some suggestion to finish my project ^^"
Thank u very muchh
Just like what you do in physical machines. And IMHO, your question is too general and has nothing to do with virtual machines. I think what you are looking for is how to setup a web server and how to use a database. Why not check the sites such as nginx or apache and mysql or postgresql ?
First of all you need to run all the machines and connected with each other.
By doing this you'll get IP addresses of those machines..
Now simply replace your IP addresses with localhost according to server
Note that every machine must have an appropriate server