In my network configuration, some of my Docker containers, for example DNS, need to achieve high availability with Anycast. In my previous post , I created a Busybox container and run tail -f /dev/null , in order to let it persist infinitely, but without using any CPU cycles, to maintain a network namespace used by both the server application and BIRD. In short: I invented a Pod in Kubernetes on my own. I don't use K8S, since my nodes run individually rather than in a cluster, I don't need the cluster functionality of K8S at all. In addition, K8S is difficult to set up. But on another thought, a Busybox container seems like an overkill for this purpose, and I have to set the entrypoint manually. It would be great if I have a tiny Docker image that only sleeps indefinitely. Plan A:...

What's stored in Docker images can be seen as numerous tiny Linux systems. Most of them are based on Debian, Ubuntu, or Alpine, with extra software installed on top. Using a complete Linux distribution as the basis gives the benefit of having commonly used commands available, such as ls and cat . They are often used in the image-building process. In addition, they have comprehensive libraries of software packages, allowing users to create images that "just work" with apt-get . However, as soon as the image is built, these utilities become unnecessary burdens for disk space. In addition, a full Linux contains a service managing daemon, like SystemD or OpenRC, useless for Docker containers running only one program at a time. Although Docker images are "overlaid",...

History of x86 & x86_64, and x32 ABI Most of the personal computers and servers we use nowadays use the x86_64 architecture, whose specification was released by AMD in 2000 and the first processor released in 2003. Since x86_64 is a 64-bit architecture, in x86_64, each register in the CPU can hold 64 bits of data (or 8 bytes). Before x86_64 went popular, most computers used Intel processors, and the corresponding x86 architecture / ISA, a 32-bit architecture whose registers hold 32 bit of data (or 4 bytes). One significant improvement of the 64-bit architecture is the improved memory addressing ability. Computers usually follow such a routine while accessing the memory: write the memory address to be accessed into a register,...

At exactly one year ago, I set up an Anycast service with Docker in the DN42 network (Chinese only atm) . Back then, I customized the container's image and added a Bird installation to it, then put in a config file to broadcast Anycast routes via OSPF. However, as time went by, a few problems were exposed: The process of installing Bird takes time. Instead of installing Bird with apt-get , since my Dockerfiles need to support multiple architectures (Chinese only atm) , and Bird isn't available in some architecture's repos for Debian. And since my building server is AMD64, and is running images of other architectures with qemu-user-static (Chinese only atm) , a lot of instruction translation is needed in the image building and software compilation progress, which is extremely inefficient....