Category: centos

dovecot – out of the box setup

Matthew Heick Leave a comment

Trying to learn a new programming language is a daunting task. My process is to take programs that I’ve written before and rewrite them in the target language of choice.

I’ve got a PHP program that interacts with my IMAP server (smart-imap), reads all the messages in the Inbox, takes the localpart of the email address, creates a folder and moves that email into that folder. If the localpart is part of a pre-determined list of email addresses that have been sold off for Spam it’ll move it to the SPAM folder. If there are no localparts that match the domain name of the server then it drops it into an UNSORTED folder.

Today’s language of choice is Python, specifically 3.9.21. To do this entire feat without breaking things I need an IMAP server, and dovecot 2.3.16 is going to be the death of me.

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Server Problems, 2025…

Matthew Heick Leave a comment

After Gettin’ hacked and rebuilding with a cheaper server I started encountering random slowness and problems. I always seemed to have random CPU spikes here and there but the console at digitalocean didn’t really give me much to work with.

Today I tried to install git so I can get some repos cloned down to demo and the process kept getting Killed. After some simple googling and basic cross referencing of the system I’m leasing I learned the stupidest thing in the world.

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Today I Learned: Storage expensive, Data priceless

Matthew Heick Leave a comment

We have a combination Plex Media/Minecraft/Archive server that we’ve had since we purchased our first 6TB Hard Drive on December 30, 2019 ($99.99 at the time). After some time we upgraded to our massive 14TB Hard Drive ($293.00 at the time) on October 16, 2021. It took a bit over a couple years to fill things up, and now we recently invested into a 16TB Hard Drive ($279.00 at purchase) to continue our storage needs.

$ df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda3       457G  288G  169G  64% /
/dev/sda1      1014M  202M  813M  20% /boot
/dev/sdd1        13T   12T   52G 100% /mnt/usb14
/dev/sdc1       5.5T  4.3T  962G  82% /mnt/usb03

Now it’s time to get this new drive ready for usage.

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ssh port forwarding / ssh tunneling

Matthew Heick Leave a comment

I’ve always been curious on ssh port forwarding enough to experiment and learn it to be deadly enough. I currently have two machines that I’d like to test this with, both -L (local) and -R (remote).

I have a C7 host behind a router and a C8 host on the internet that I’ll be testing with.

Our set up is the following:

192.168.2.222:22 (c7 Host) <-> 192.168.2.1:* (router) <-> 159.203.99.198:22 (c8 host)

Local Forwarding

What I’m going to do is forward port 4444 on my c7 machine to connect to the c8 host on port 22 by launching the following on 192.168.2.222:

$ ssh -L 192.168.2.222:4444:159.203.99.198:22 localhost

At this point I can start a SSH session to 192.168.2.222 at port 4444. I’m prompted to log in at 159.203.99.198, and i’m good to go. As long as the command is running I maintain a connection.

To remove the login necessity I added ~/.ssh/id_rsa.pub to ~/.ssh/authorized_keys for passwordless local log in.

Remote Forwarding

Remote forwarding allows world-accessible hosts to provide access to internal hosts. In our previous scenario we forwarded from an intranetwork host to a world host. Now we’re gonna use that intranetwork host and make it so that if we SSH to the world host at port 4444 that we will be ssh-ing to our intranetwork host, bypassing the router.

On 192.168.2.222 I execute the following:

$ ssh -R 4444:localhost:22 159.203.99.198 -ldiffuser

On my world-accessible host I log in with “diffuser”, and the forwarding is set up.

On 159.203.99.198 I can ssh to localhost:4444 and connect as internaluser with ease:

$ ssh localhost -p 4444 -linternaluser

Due to how /etc/ssh/sshd_config has GatewayPorts set up by default I cannot connect with my home computer to my world-accessible host. I would have to restart sshd service after setting GatewayPorts=yes (by default it’s no)

Learning Docker: Take 1

Matthew Heick Leave a comment

It was time. I’ve been waiting for enough time to learn Docker and begin to get familiar with it. I’ve heard of it, seen it in action, and thought it was the coolest thing in the world and I had to learn it. I decided to take the dive off the actual Docker ship and descend into the depths.

So, I found a YouTube video from the Docker YouTube video channel (link: https://youtu.be/iqqDU2crIEQ). Albeit it provided me some terminology and knowledge, it didn’t really tell me everything I wanted to know, like some under-the-core or how docker did the docker thing. I learned how to build, ps, port forward, docker hub, and a Dockerfile, but then they went to docker-compose and I got lost.

So, after sitting on that video and registering all the information I decided to set a goal: Load minecraft in a docker container. This shouldn’t be difficult, as it requires java, some source files, and that should be simple.

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