Linux

I made it. Friday was good, but I got here late. TimeAttended?9:00Arduino Meets Raspberry Pi Using O.L.D. Programming Techniques – Cameron Hughes and Tracy Hughes10:00Exploiting the IT Value Stream: Iterative Automation Strategy – Brad Krumme11:00Syslog for Fun (and Profit?) – Warren Myers13:00History of Computing – Ken Elliott14:00NixOS from Basics to Devops – Adam Stephens15:00The Outstanding Advantages of Being a Linux-Based Artist – Thomas Hancock16:00Simulated AI Hardware: a Toy Matrix Multiply – Zak Kohler17:00✔Keynote: Open Source Can’t Win – Joe “Zonker” BrockmeierYouTube Stream ...

Note: I found this article onlineand wanted to save it to my Wallabag instance, but it’s frustratingly split into 2 pages and would require a lot of pointless gymnastics to combine. So, instead, I copy/pasted the article contents here and offer it as geeky entertainment while granting all credit to the original author and publication. All original links are intact. Enjoy The Deep End By Paul Venezia, Senior Contributing Editor, InfoWorld | Feb 14, 2011 6:00 am PST ...

I go out walking every morning. My usual route takes me around my apartment complex and the apartment complex next door. Last Wednesday’s walk was no different. I was up stupid early - before 6:00 AM and out the door shortly thereafter. When rounding the corner next door I saw a pile of hardware garbage near the dumpster on the other side of the garages. There was a tower PC case, opened, that looked pretty gutted (although the hard drive was still in it - sigh). There were a couple what looked to be older stereo components another computer that looked to be in pretty good condition and a nice (if not pretty well-used) desk lamp. ...

How often have you seen something like this? The authenticity of host '111.222.333.444 (111.222.333.444)' can't be established. RSA key fingerprint is f3:cf:58:ae:71:0b:c8:04:6f:34:a3:b2:e4:1e:0c:8b. Are you sure you want to continue connecting (yes/no)? The temptation to quickly type yes and hit the enter key is great. But do you know why you are seeing this message? You should only get this the first time you connect to a new host. After you respond yes the host gets stored in ~/.ssh/known_hosts, and you won’t get prompted the next time you connect. ...

I regularly have directories of files I want to back up in case of disaster. Usually these are files that change often, and I only want to keep recent versions in case I want to revert or recover changes. (Git? Git, who?) I have used this script over and over as a simple way to archive a directory to a location with a date-stamped filename. It also cleans up after itself by deleting files older than X days. I stick it in CRON and let it run on a schedule and I always have an archive of the last X days of the files in my directory. ...

Q: Ubuntu phased updates Recently, during the normal software upgrade process (i.e., apt upgrade or apt dist-upgrade) I started getting messages like this: [...] The following packages have been kept back: [...] 0 upgraded, 0 newly installed, 0 to remove and [...] not upgraded. What are my options? A: Phased Updates are a safety feature Some users get the upgraded packages first, and have the ability to report broken package, instead of everybody getting a broken package at once and millions of users scratching their heads. It’s there for your protection. Don’t try to outsmart it. ...

Summary It’s about time I get a standard sshd_config file that doesn’t rely on sane defaults. Disabling Password-based Authentication You should disable password-based authentication altogether. Make sure to only do this once you have verified that you can log in with an account that can escalate to root - or that you have an alternate way of getting back onto your machine. To lock down your server, edit your /etc/sshd/sshd_config and set the following options: ...

To get UFW to work well with Docker, you have to add some rules to the bottom of /etc/ufw/after.rules # BEGIN UFW AND DOCKER *filter :ufw-user-forward - [0:0] :ufw-docker-logging-deny - [0:0] :DOCKER-USER - [0:0] -A DOCKER-USER -j ufw-user-forward -A DOCKER-USER -j RETURN -s 10.0.0.0/8 -A DOCKER-USER -j RETURN -s 172.16.0.0/12 -A DOCKER-USER -j RETURN -s 192.168.0.0/16 -A DOCKER-USER -p udp -m udp --sport 53 --dport 1024:65535 -j RETURN -A DOCKER-USER -j ufw-docker-logging-deny -p tcp -m tcp --tcp-flags FIN,SYN,RST,ACK SYN -d 192.168.0.0/16 -A DOCKER-USER -j ufw-docker-logging-deny -p tcp -m tcp --tcp-flags FIN,SYN,RST,ACK SYN -d 10.0.0.0/8 -A DOCKER-USER -j ufw-docker-logging-deny -p tcp -m tcp --tcp-flags FIN,SYN,RST,ACK SYN -d 172.16.0.0/12 -A DOCKER-USER -j ufw-docker-logging-deny -p udp -m udp --dport 0:32767 -d 192.168.0.0/16 -A DOCKER-USER -j ufw-docker-logging-deny -p udp -m udp --dport 0:32767 -d 10.0.0.0/8 -A DOCKER-USER -j ufw-docker-logging-deny -p udp -m udp --dport 0:32767 -d 172.16.0.0/12 -A DOCKER-USER -j RETURN -A ufw-docker-logging-deny -m limit --limit 3/min --limit-burst 10 -j LOG --log-prefix "[UFW DOCKER BLOCK] " -A ufw-docker-logging-deny -j DROP COMMIT Adding Rules Then you can add rules. Always add rules with comments. Examples below: ...

Summary Do you work on Linux machines? Do you only have a Windows machine from which to connect? Then you’re probably already using PuTTY. Well, step aside PuTTY, there’s a new terminal client in town. KiTTY is a fork of the original PuTTY software, with loads of new features, including a portable version that saves all of your sessions and settings into an INI file in the same folder. Installation Download KiTTY Portable ??? PROFIT! Just kidding. There are no other steps. The download is an exe that’s ready to go. Just double-click on it and enter your connection parameters (should be familiar if you’ve ever used PuTTY) ...

wget multiple files wget -r -l1 -A.mp3 http://aaa.com/directory In the above example, -r and -l1 options together enable 1-level deep recursive retrieval, and -A option specifies lists of file name suffixes to accept during recursive download (.mp3 in this case). ways to wget entire webpage This one works so well, I’ve created an alias for it: wgetMirror='/usr/bin/wget -o wget.log -mkEpnp –wait=9 –user-agent='\''Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)'\'' –no-check-certificate' Other options: wget --recursive --no-clobber --page-requisites --html-extension --convert-links --restrict-file-names=windows --domains example.com --no-parent <url> Modify User Agent $ wget -U "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)" <url> wget from webdav with authentication wget --http-user=user-id --http-password=password <URL> Reference Download Multiple Files with wget Archiving website with wget Download entire webpage with wget Change the User Agent in wget