Posts
Raspberry PI: install ClusterHAT software
Jan 29, 2024 (updated)
I’ve had these nice Raspberry Pi Zero (vanilla, not ‘W’) lying around for quite some time and I wanted to give them a purpose in life.
By chance (meaning, during my endless browsing of the Twitter-verse and the Reddit-verse) I have discovered the ClusterHAT (Hardware Attached on Top) which “interfaces a (Controller) Raspberry Pi A+/B+/2/3 with 4 Raspberry Pi Zeros configured to use USB Gadget mode”.
Buildx: building multi-arch images
Jan 29, 2024 (updated)
docker
x86_64
x64
amd64
armv6
armv7
arm64
aarch64
containers
In this post I’ll explore how to build images that can run on multiple architectures. My scenario is composed of the two following hosts:
on x86_64: $ docker info | grep Architecture Architecture: x86_64 $ cat /proc/cpuinfo | grep "model name" | uniq model name: Intel(R) Core(TM) i5-3317U CPU @ 1.
Docker in depth: namespaces, cgroups, images from scratch
Jun 13, 2023 (updated)
docker
arm64
aarch64
containers
Images and containers Let’s take a closer look at what’s in an image.
NOTE: I’m filtering out lots of info by using Docker’s –format command.
user@laptop $ docker inspect --format="{{json .
AArch64 assembly - part 5
May 29, 2023 (updated)
assembly
arm64
aarch64
coding
AArch64 Index Home Let’s break the ice Under the surface Under the microscope Cross-compilation Resources AArch64 Exploring AArch64 assembler
A Guide to ARM64/AArch64 Assembly on Linux with Shellcodes and Cryptography
AArch64 assembly - part 4
May 29, 2023 (updated)
assembly
arm64
aarch64
coding
AArch64 Index Home Let’s break the ice Under the surface Under the microscope Cross-compilation Resources Cross-compilation Interestingly, one does not need to own an ARM64 processor. With the help of QEMU user mode emulation (qemu-user) and the GNU C compiler for AArch64 (gcc-aarch64-linux-gnu), assembling and linking native code is a breeze.
AArch64 assembly - part 3
May 29, 2023 (updated)
assembly
arm64
aarch64
coding
AArch64 Index Home Let’s break the ice Under the surface Under the microscope Cross-compilation Resources Under the microscope We could be happy with the overall result but, since we’re dealing with a very low-level language, this little intro wouldn’t be complete if GDB wasn’t mentioned here.
AArch64 assembly - part 2
May 29, 2023 (updated)
assembly
arm64
aarch64
coding
AArch64 Index Home Let’s break the ice Under the surface Under the microscope Cross-compilation Resources Under the surface In the process we’ve followed not only we’ve generated file answer.s but answer.
AArch64 assembly - part 1
May 29, 2023 (updated)
assembly
arm64
aarch64
coding
AArch64 Index Home Let’s break the ice Under the surface Under the microscope Cross-compilation Resources Let’s break the ice … or, let’s quickly generate some assembly code and run it.
AArch64 assembly - part 0
May 29, 2023 (updated)
assembly
arm64
aarch64
coding
AArch64 Index Home Let’s break the ice Under the surface Under the microscope Cross-compilation Resources Background I’m not exactly a programmer. I can write some (mostly bad) code, understand a few tiny bits here and there, but I can’t claim to be an expert here.
CIBot: CounterIntelligence Bot
May 26, 2023 (updated)
linux
brute force
security
A cheap (but useful, IMHO) approach at keeping your home network under control I know shouldn’t have been but I was genuinely surprised when, upon login onto my tiny home server, I was greeted by:
Breaking the ice with Shodan
Apr 1, 2020
Shodan.io Shodan defines itself as the search engine for Internet-connected devices. Replace Internet-connected devices with webcams, refrigerators, power plants… Raspberry Pis… you-name-it.
I’d always been curious about Shodan but not that curious to break into someone else’s webcam, not my cup of tea.
Running a REPL on-premise
Mar 29, 2020
Nodebook Nodebook is a multi-language REPL offering both a web UI and a CLI interface. Github: https://github.com/netgusto/nodebook
NOTE: REPL: Read-Eval-Print Loop
Set up OS (e.g. CentOS 7) sudo sed -i "s/^#PermitRootLogin yes/PermitRootLogin prohibit-password/" /etc/ssh/sshd_config sudo sed -i "s/^#UseDNS yes/UseDNS no/" /etc/ssh/sshd_config sudo systemctl restart sshd sudo firewall-cmd --permanent --add-port=9001/tcp && sudo firewall-cmd --reload IMPORTANT: be aware of any security implcations when running such an application.
Docker Swarm on KVM (CentOS)
Mar 13, 2020
Docker Swarm on KVM (CentOS) Fast re-run of the previous post, this time streamlined to match VM’s on KVM.
One thing I like about KVM is the ability to have templates and quickly install VM’s through Kickstart.
Docker Swarm on ClusterHAT
Mar 10, 2020
INDEX
The basics: hardware architecture Our app, an HTTP server Docker Swarm, finally! NOTE: during this tutorial I’ll be using ARM32v6 images since the Controller and the Nodes do not share a common hardware architecture.