At this point probably everybody has heard about Docker and most developers are familiar with it, use it, and therefore know the basics such as how to build a Docker image. It is as easy as running docker built -t name:tag ., yet there is much more to it, especially when it comes to optimizing both the build process and the final image that is created.

The article goes on to cover caching, slimming, and securing your images so they’ll run faster and be less prone to abuse.

Container security is often overlooked topic, as people assume that containers are secure by default - which is not true. One of the ways to secure container workloads in Docker and Kubernetes is to leverage seccomp profiles and this advanced feature of container runtimes is explained and shown in this article.

Vladimir Dementyev:

I only installed Git, Docker, and Dip on my new computer to see how productive I can be with a barebones system setup.

I hadn’t heard of Dip prior to reading this. It definitely looks like it’ll clean up your setup. 👌

Alex Ellis:

This post by a community member from India shows how to use GitHub actions to build, push and deploy to OpenFaaS anywhere - whether in the cloud or on an RPi at home. The best part is that this is a fully multi-arch setup, and uses the new Docker buildx with GitHub Actions.

Avoid the hassle of following security best practices each time you need a web server or reverse proxy. Bunkerized-nginx provides generic security configs, settings and tools so you don’t need to do it yourself.

What’s not to love?

8 common security issues when using Docker and how to avoid them. Here’s a sampler:

Avoid curl bashing

Pulling stuff from internet and piping it into a shell is as bad as it could be. Unfortunately it’s a widespread solution to streamline installations of software.

The risk is the same framed for supply chain attacks and it boils down to trust. If you really have to curl bash, do it right…

The incomparable Jessica Kerr drops by with a grab-bag of amazing topics. Understanding software systems, transferring knowledge between devs, building relationships, using VS Code & Docker to code together, observability as a logical extension of TDD, and a whole lot more.

Build your own using these as a reference or simply pull them as-is from Docker Hub and docker run

This Dockerfile automates the setup of OSX-KVM. All your host system needs is hardware virtualization enabled in BIOS and QEMU installed.

Itamar Turner-Trauring:

If you’re using Docker, the next natural step seems to be Kubernetes, aka K8s. Or is it? If you’re part of a small team, Kubernetes probably isn’t for you: it’s a lot of pain with very little benefits.

If you’ve been following along in the open source news cycle lately, you’ve probably heard that Red Hat has dropped the docker container runtime engine from both its Red Hat Enterprise Linux (RHEL) and CentOS Linux distributions.

I must not be following along, because that’s news to me.

That being the case, what do you do when you need to deploy containers? Fortunately, they’ve created a near drop-in replacement for docker, called Podman.

Podman is a rename from kpod, sorta. The new thing is actually called libpod, and Podman exists as the CLI for that library. It’s all a bit confusing, but what’s cool is none of this requires a daemon like the Docker Engine.

If you’d like to give it a go, this walk-through by The New Stack will get you started.

localdots combines Caddy and smallstep/certificates with automated configuration and hot reload.

• Generates SSL/TLS certificates automatically
• Reloads Caddy automatically with every change

Gives you access to a virtualised ARM based Raspberry Pi machine running the Raspian operating system. This is not just a Raspian Docker image, it’s a full ARM based Raspberry Pi virtual machine environment.

How it does its thing:

A full ARM environment is created by using Docker to bootstrap a QEMU virtual machine. The Docker QEMU process virtualises a machine with a single core ARM11 CPU and 256MB RAM, just like the Raspberry Pi. The official Raspbian image is mounted and booted along with a modified QEMU compatible kernel.

DockerSlim promises a lot:

docker-slim will optimize and secure your containers by understanding your application and what it needs using various analysis techniques. It will throw away what you don’t need reducing the attack surface for your container. What if you need some of those extra things to debug your container? You can use dedicated debugging side-car containers for that.

Their minification examples are impressive…

Jack Wallen:

A new cryptojacking worm, named Graboid, has been spread into more than 2,000 Docker hosts, according to the Unit 42 researchers from Palo Alto Networks. This is the first time such a piece of malware has spread via containers within the Docker Engine (specifically docker-ce).

Scary stuff, and (at the moment) difficult to detect & prevent:

We’ve reached a point with containers where security must be constantly on the front burner. Antivirus and anti-malware applications currently have no means of analyzing and cleaning containers and container images. That’s the heart of the issue.

Graboid may be the first malware to target containers, but it certainly won’t be the last.

Memorising docker commands is hard. Memorising aliases is slightly less hard. Keeping track of your containers across multiple terminal windows is near impossible. What if you had all the information you needed in one terminal window with every common command living one keypress away (and the ability to add custom commands as well). Lazydocker’s goal is to make that dream a reality.

If you’d like to follow along with someone who “has no idea what they’re doing” to learn how to take a base Docker image made with a single line Dockerfile FROM debian:latest and convert it to something launch-able, then read on…

…messing about with things like this is the only way to gain extra knowledge of any system internals. We are going to speak Docker and Linux here. What if we want to take a base Docker image, I mean really base, just an image made with a single line Dockerfile like FROM debian:latest, and convert it to something launchable on a real or virtual machine? In other words, can we create a disk image having exactly the same Linux userland a running container has and then boot from it?

Docker builds can be slow, so you want to use Docker’s layer caching, reusing previous builds to speed up the current one. But there’s a down-side: caching can lead to insecure images. Read on to learn why, and what you can do about it.

Run a secure DoT (DNS-over-TLS) and DoH (DNS-over-HTTPS) DNS server that can do ad blocking and hide your DNS query from your ISP.

Liran Tal:

Developers, often lacking insights into the intricacies of Docker, may set out to build their Node.js-based docker images by following naive tutorials which lack good security approaches in how an image is built. One of these nuances is the use of proper permissions when building Docker images.

To minimize exposure, opt-in to create a dedicated user and a dedicated group in the Docker image for the application; use the USER directive in the Dockerfile to ensure the container runs the application with the least privileged access possible.

We’re talking with Gerhard Lazu, our resident ops and infrastructure expert, about the setup we’ve rolled out for 2019. Late 2016 we relaunched Changelog.com as a new Phoenix/Elixir application and that included a brand new infrastructure and deployment process. 2019’s infrastructure update includes Linode, CoreOS, Docker, CircleCI, Rollbar, Fastly, Netdata, and more — and we talk through all the details on this show.

This show is also an open invite to you and the rest of the community to join us in Slack and learn and contribute to Changelog.com. Head to changelog.com/community to get started.

Attention Docker Hub users — Docker Hub has been hacked, so check your email to read the report from Kent Lamb, Director of Docker Support and take appropriate action. Here are the details…

During a brief period of unauthorized access to a Docker Hub database, sensitive data from approximately 190,000 accounts may have been exposed (less than 5% of Hub users). Data includes usernames and hashed passwords for a small percentage of these users, as well as Github and Bitbucket tokens for Docker autobuilds.

From lugg on Hacker News:

If you got an email you should:

• Change your password on https://hub.docker.com

• Check https://github.com/settings/security

• Reconnect oAuth for automated builds

• Rollover effected passwords and API keys stored in private repos / containers

Containerization technologies are one of the trendiest topics in the cloud economy and the IT ecosystem. The container ecosystem can be confusing at times, this post may help you understand some confusing concepts about Docker and containers. We are also going to see how the containerization ecosystem evolved and the state of containerization in 2019.

Put on your swimming suit, because this is a deep dive. 🏊‍♀️🏊

Instantbox spins up a temporary Linux system with instant webshell access from any browser. Great for presentations, demos at schools and user groups, testing out random ideas, and more.

Distros supported include Ubuntu, CentOS, Arch Linux, Debian, Fedora, and Alpine.

The new changelog.com setup for 2019 is packed with exciting features that are too good to keep to ourselves. Since the infrastructure code is already public and has been running changelog.com for a few months now, the value that we are sharing is proven to us.