Category Archives for "Docker Blog"

Docker Hub Incident Reviews – April 3rd and 15th 2021

In line with our promise last year to continue publishing incident reviews for Docker Hub, we have two to discuss from April. While many users were unaffected, it is important for us to be transparent with our community, and we hope it is both informative and instructive.

April 3rd 2021

Starting at about 07:30 UTC, a small proportion of registry requests (under 3%) against Docker Hub began failing. Initial investigation pointed towards several causes, including overloaded internal DNS services and significant and unusual load from several users and IPs. Changes were made to address all of these (scaling, blocking, etc), and while the issue seemed to resolve for several hours at a time, it continued coming back.

The issue re-occurred intermittently into the next day, at which point the actual root cause was determined to be under-scaled load balancers doing service discovery and routing for our applications. 

In the past, the bottleneck for the load balancing system was network bandwidth on the nodes, and auto scaling rules were thus tied to bandwidth metrics. Over time and across some significant changes to this system, the load balancing application had become more CPU intensive, and thus the current auto scaling setup Continue reading

DockerCon LIVE 2021 Keynotes

Join us for DockerCon LIVE 2021 on Thursday, May 27. DockerCon LIVE is a free, one day virtual event that is a unique experience for developers and development teams who are building the next generation of modern applications. If you want to learn about how to go from code to cloud fast and how to solve your development challenges, DockerCon LIVE 2021 offers engaging live content to help you build, share and run your applications. Register today at

With DockerCon just around the corner, we’re pleased to announce our outstanding keynote speaker line-up.

Among the Docker luminaries taking the virtual stage May 27 will be CEO Scott Johnston, CTO Justin Cormack and VP of Products Donnie Berkholz. Look for keynotes, too, from special guests Dana Lawson, GitHub VP of Engineering, and Matt Falk, VP of Engineering, Data Science and Computer Vision at Orbital Insight.

Picking up hosting duties will be Docker’s Peter McKee and William Quiviger, along with DevOps consultant and Docker Captain Bret Fisher.

They’re just part of the one-day event packed with demonstrations, product announcements, company updates and more — all of it focused on modern application delivery in a cloud-native world.

Last year 78,000 registrants Continue reading

Video: How to Dockerize a Python App with FastAPI

Join host Peter McKee and Python wizard Michael Kennedy for a warts-and-all demo of how to Dockerize a Python app using FastAPI, a popular Python framework. Kennedy is a developer and entrepreneur, and the founder and host of two successful Python podcasts — Talk Python To Me and Python Bytes. He’s also a Python Software Foundation Fellow.

With some skillful back-seat driving by McKee, Kennedy shows how to build a bare-bones web API — in this case one that allows you to ask questions and get answers about movies (director, release date, etc.) — by mashing together a movie service and FastAPI. Next, he shows how to put it into a Docker container, create an app and run it, finally sharing the image on GitHub.

If you’re looking for a scripted, flawless, pre-recorded demo, this is not the one for you! McKee and Kennedy iterate and troubleshoot their way through the process — which makes this a great place to start if you’re new to Dockerizing Python apps. Install scripts, libraries, automation, security, best practices, and a pinch of Python zen — it’s all here. (Duration 1 hour, 10 mins.)

Join Us for DockerCon LIVE 2021  

Join us Continue reading

Community Rooms at DockerCon LIVE 2021

The Docker community spans the four corners of the world. To celebrate the global nature of our community at DockerCon this year, we’ve created something new: Community Rooms.

Building on the learnings of our “regional rooms experiment” during our last Community All-Hands, Community Rooms are virtual spaces that DockerCon attendees will be able to join to discuss, share and learn about Docker in their own language and/or around a specific topic area. 

100% LIVE

The main focus of these Community Rooms is to bring people together and encourage interaction so we have set them up to be 100% live. Yep, that’s right, all the content you’ll find in these rooms, whether they’re talks, demos, workshops, panel discussions etc. will be in real-time, all broadcast over a live Zoom link. 

Hosted by the Community for the Community

Each Community Room will be overseen by Docker Captains and Community Leaders. They will be responsible for every aspect of the room, from the curation of content, to the management of the schedule, to the recruitment of the speakers, to the moderation of their room’s live chat. 

There will be seven community rooms to choose from, each with one or Continue reading

10 Reasons to Attend DockerCon LIVE 2021

DockerCon Live 2021 is almost here and it’s going to be one to remember. Our one-day, all-digital event on May 27 will be jam-packed with the application development technology, skills, tools and people you need to help solve the problems you face day to day — all for free.

Designed for developers by developers, this year’s event is all about modern application delivery in a cloud-native world. At DockerCon, you’ll learn how Docker helps you grow your development capacity and community connections so you can accelerate how you build, share and run your applications, and spend more of your time actually coding the next great application.

Ten Reasons to Attend

  1. Get the scoop. Be the first to see the latest Docker innovations, features and technology updates.
  2. Hear from industry leaders. In addition to Docker’s executive team, the speaker lineup includes AWS, Cockroach Labs, Instana, Mirantis, Accurics, Snyk and other companies that will share how Docker is an integral part of their software supply chain.
  3. Get up close. See live, on-demand technical demos.
  4. Connect. Network with peers and a vibrant community of developers, and connect with Docker Captains and Community Leaders.
  5. Learn. Attend tutorials on how to get started with containers Continue reading

DockerCon LIVE 2021: One Month Before Lift Off

WIth exactly one month before lift off, here’s a quick update on all the goodness that awaits you at this year’s DockerCon LIVE 2021. Like last year, we’ll have one full day of keynotes, breakout sessions across several tracks and live panels and interviews. The current agenda and full list of speakers is available on our website.  

Engaging in real-time

A big focus is live content and interaction between speakers and attendees. Our partners at The Cube have worked hard on improving their conference platform and expanding on functionality, so get ready for more real-time content and awesome new features to help speakers and attendees connect, meet, greet, share and learn from each other. 


To help set the stage, that day kick’s with must-see keynotes from Docker leadership and compelling guest speakers. We’ll have a special post about our keynote line-up on our blog soon.

Breakout sessions

We’re still building out the schedule (yes, that’s what happens when you have so much awesome content to work with!) but we anticipate that we’ll have at least 40 breakout sessions with an absolutely stellar line-up of speakers. You can find the current list of speakers here and the Continue reading

LinuxKit as a Commodity for Building Linux Distributions

Guest post by Docker Captain Gianluca Arbezzano

Recently Corey Quinn from LastWeekInAWS wrote an article that made me think “Nobody Cares About the Operating System Anymore”. Please have a look at it! I like the idea that nobody cares about where their application runs. Developers only want them running.

A bit of context about Tinkerbell

I am one of the maintainers for the Tinkerbell project. A bare metal workflows engine that heavily relies on containers and Docker to get its work done. It tries to find an answer for a reasonable question: how do we manage rooms of pieces of hardware? More in practice, how can we bring an API on top of everybody’s data centers?

Containers are the abstraction we decided to use when running reusable code (that we call actions) in somebody else’s hardware. Mainly because distribution, packaging, and runtime are solved issues. Everyone knows how to build, push and run a container.

I think this scenario compares well with the story Corey highlighted. Operating systems are an established, well-known abstraction for the majority of the use cases.

The special operating system for bare metal provisioning

The lifecycle of a bare metal server can be summarised as follows:

  1. Continue reading

The Stars Are Aligning: Announcing our first round of speakers at DockerCon LIVE 2021

With just over a month to go before DockerCon LIVE 2021, we’re thrilled to announce our first round of speakers. We have returning favorites and compelling new first time speakers to round out your DockerCon experience. 

We received hundreds of amazing speaker proposals which made it difficult to select just a few. We set up a small team this year composed of seven Docker staff members and three Docker Captains to diligently review each proposal and deliberate once a week. We have more speakers and sessions to announce so stay tuned. 

Remember, if you haven’t registered for DockerCon, please make sure to do so now to get an early peak at the conference website.

Melissa McKay – Developer Advocate @ JFrog
The Docker and Container Ecosystem 101

Lukonde Mwila – Senior Software Engineer @ Entelect
Docker Swarm: A Journey to the AWS Cloud

Peter Mckee – Head of Developer Relations @ Docker
Event Emcee and Panel Moderator

Bret Fisher – DevOps Consultant and Docker Captain
Panel Moderator

Julie Lerman – Software Coach and Docker Captain
Panel Member

Nick Janetakis – Full-Stack Developer and Docker Captain
Best Practices around Creating a Production Ready Web App with Docker Continue reading

Released: Docker Desktop for Mac [Apple Silicon]

Today we are excited to announce the general availability of Docker Desktop for Mac [Apple Silicon], continuing to support developers in our community with their choice of local development environments.  

First, we want to say a big thank you to our community. The excitement you have shown about being able to run Docker Desktop on the new M1 chip has been tremendous and hugely motivating to us. Your engagement on testing builds and reporting problems has been invaluable. As soon as Apple announced the new M1 chip, you let us know on our public roadmap that this was a high priority for you, and it quickly became by far our most upvoted roadmap item ever. You also responded very positively to our previous blog posts.

After the M1 machines were publicly available, those of you on our developer preview program tested some very early builds. And then as we moved into public tech previews and release candidates, many more of you joined in with testing your enormous variety of use cases, and reporting bugs. In total we have had 45,000 downloads of the various preview builds, and 140 tickets raised on our public bug tracker, not to Continue reading

Captain Take 5 – Nuno do Carmo

Docker Captains are select members of the community that are both experts in their field and are passionate about sharing their Docker knowledge with others. “Docker Captains Take 5” is a regular blog series where we get a closer look at our Captains and ask them the same broad set of questions ranging from what their best Docker tip is to whether they prefer cats or dogs (personally, we like whales and turtles over here). Today, we’re interviewing Nuno do Carmo who has been a Docker Captain since 2019. He is a Sr System Analyst for a pharmaceutical company based in Switzerland and he is based in Montreux.

How/when did you first discover Docker?

Back in 2015, I was hanging with friends and we would meet once a week to check on technologies and we found out a training on Pluralsight, given by a certain Nigel Poulton, and we decided to “temporarily” download it, **cough**.

Both the training method from Nigel and the technology of Docker were an instant hit for us. We started to learn as hobbyists and fast forward, I guess I took it more at heart than my friends, haha.

What is your favorite Docker command?

`docker Continue reading

Changing How Updates Work with Docker Desktop 3.3

Today we are pleased to announce the release of Docker Desktop 3.3.

We’ve been listening to your feedback on our Public Roadmap and we are consistently asked for three things: smaller downloads, more flexible installation options, and more frequent feature releases, bug fixes, and security updates.

We also heard from our community that the smaller updates are appreciated, requiring immediate installation is not convenient, and automatic background downloads are problematic for developers on constrained or metered bandwidth.

We’ve heard you and are changing how updates to Docker Desktop work, while still maintaining the ability to provide you with smaller, faster updates. We are also providing additional flexibility to developers with Pro or Team subscriptions.

Flexibility for Updates 

With Docker Desktop 3.3, when a new update to Docker Desktop is available, it will no longer be automatically downloaded and installed on your next restart. You can now choose when to start the download and installation process.

To encourage developers to stay up to date, we have built in increasingly persistent reminders after an update has become available.

If you use Docker Desktop at work you may need to skip a specific update. For this reason, Pro or Team subscription Continue reading

Get Involved with Docker

Every day, hundreds of passionate Docker users around the world contribute to Docker. Whether you are just getting started or are an expert in your field, there are many ways to get involved and start contributing to Docker. If you’re into technical writing, you can easily publish and/or edit articles in If you’re more into code contribution, there are dozens of open source Docker projects you can dive into. Or if you’re just interested in sharing knowledge and spreading Docker goodness, you can organize a local meetup or a virtual workshop on our community events page. 

There are literally countless ways one can contribute to Docker. This makes it sometimes a bit difficult to find the right project or activity that maps to your interests and level of Docker expertise. That’s why we’ve been working to make it easier for anyone to learn more about ways to contribute and find the right project or activity. To this end, we created a community-driven website that aims to make it easier than ever to navigate the many different contribution opportunities that exist at Docker, and ultimately, to find the right contribution pathway to get started. 

The website Continue reading

Compiling Containers – Dockerfiles, LLVM and BuildKit

Today we’re featuring a blog from Adam Gordon Bell at Earthly who writes about how BuildKit, a technology developed by Docker and the community, works and how to write a simple frontend. Earthly uses BuildKit in their product.


How are containers made? Usually, from a series of statements like `RUN`, `FROM`, and `COPY`, which are put into a Dockerfile and built.  But how are those commands turned into a container image and then a running container?  We can build up an intuition for how this works by understanding the phases involved and creating a container image ourselves. We will create an image programmatically and then develop a trivial syntactic frontend and use it to build an image.

On `docker build`

We can create container images in several ways. We can use Buildpacks, we can use build tools like Bazel or sbt, but by far, the most common way images are built is using `docker build` with a Dockerfile.  The familiar base images Alpine, Ubuntu, and Debian are all created this way.     

Here is an example Dockerfile:

FROM alpine
RUN echo "standard docker build" > /built.txt"

We will be using Continue reading

A Birthday Challenge as Docker Turns 8

Time flies. Eight years ago Docker was introduced to the world and forever changed the way applications are developed. We have enjoyed watching developers from all walks of life and from every corner of the globe bring their ideas to life using our technology. 

As is our tradition in the Docker community, and as announced during our last Community All-Hands, we are celebrating Docker’s big day with a birthday challenge where Docker users are encouraged to learn some of our Docker Captain’s favorite tips + tricks by completing 8 hands-on interactive exercises. Unlike last year’s challenge, this year as you complete an exercise you not only earn badges but you also earn points based on speed and accuracy which will be displayed on a leaderboard organised by individual score, country score and Captain score.

The challenge is on for the next month and we will announce the winners and award special prizes to the top three individual scores. 

So let’s celebrate 8 years of Docker and let the challenge begin!

The post A Birthday Challenge as Docker Turns 8 appeared first on Docker Blog.

DockerCon LIVE 2021 Registration is Now Open

We’re excited to announce that registration for DockerCon LIVE 2021 is now officially open!

Taking place on Thursday, May 27th, the one day virtual event brings together all of the application development technology, skills, tools and people to help you build, share and run applications faster. And the best part? It’s FREE.  

Attendees will:

  • Learn about the latest Docker features and technology updates
  • See live, on-demand technical demos
  • Talk to a panel of experts and industry leaders who can help you build better apps 
  • Connect with peers and network with a thriving, vibrant community of developers
  • Share experiences with other developers about creating leading edge cloud native applications for any cloud environment
  • Attend tutorials on how to get started with containers and how to use multiple languages
  • Get best practices tips and insights from innovative organizations that are building next generation applications with Docker
  • Hear about what’s new with tools and partner integration
  • Participate in live sessions with Docker Captains

Be in on the Action

Our Call For Presentations is open until April 1st so there’s still time for you to submit a talk. If you have any questions about our CFP or the the conference in general, Continue reading

Advanced Image Management in Docker Hub

We are excited to announce the latest feature for Docker Pro and Team users, our new Advanced Image Management Dashboard available on Docker Hub. The new dashboard provides developers with a new level of access to all of the content you have stored in Docker Hub providing you with more fine grained control over removing old content and exploring old versions of pushed images. 

Historically in Docker Hub we have had visibility into the latest version of a tag that a user has pushed, but what has been very hard to see or even understand is what happened to all of those old things that you pushed. When you push an image to Docker Hub you are pushing a manifest, a list of all of the layers of your image, and the layers themselves.

When you are updating an existing tag, only the new layers will be pushed along with the new manifest which references these layers. This new manifest will be given the tag you specify when you push, such as bengotch/simplewhale:latest. But this does mean that all of those old manifests which point at the previous layers that made up your image are removed from Hub. These Continue reading

Docker Community All Hands Recap

We are sharing a recap of last week’s second quarterly Community All-Hands and the feedback we got from the community.

The Community All-Hands deepen our engagement with the Docker community and bring users, contributors and staff together on a quarterly basis. It is an opportunity for the community to get updates on what we’re working on and align on priorities for the year. It also provides a live forum for the community to engage and ask questions directly to Docker’s executive and community leadership. 

In December, we wrote that we wanted to build on the feedback we got after our first Community All-Hands and that we are committed to providing more content, a longer format and make it more interactive for attendees. To this end, we chose to extend the event by 2 hours and include parallel tracks with more speakers and a mix of live keynotes, workshops, lightning talks and regional content. We also picked the video platform to host the event, leveraging their awesome innovative features (eg. integrated chat, multi-casting, WebRTC).

These improvements paid off in an impressive way: we had close to 3,000 unique attendees (including Youtube-live stream viewers), almost tripling the number of Continue reading

Docker and CNCF Join Forces for “Container Garage” Event Series

At Docker, we’re constantly trying to engage and connect with developer communities around the world to explore ways we can cross pollinate ideas, share, and learn from each other. Today, we’re thrilled to announce that Docker and the CNCF are joining forces to run a community-led event series called “Container Garage”, covering all things containers and focusing on a particular theme each time (eg. “runtime”, “images”, “security” etc…). The aim of the event is to engage our respective communities and foster closer collaboration.

To this end Docker Captains and CNCF Ambassadors are taking the lead with the planning and execution of the event, working in lock-step to curate excellent content and recruit amazing speakers for engaging talks, demos, and live panels.

The kick-off event will be on Thursday April 1st around the theme of container runtimes. The agenda is structured as follows: 

2pm – 4pm CET : Talks & Demos

4pm – 4:15 CET : Break

4:15pm – 5pm CET : Live panel discussion

5pm – 5:15 : Break

5pm – 7pm CET : Talks & Demos 

Again, the first event will be held on April 1st on the topic of container runtimes.

You can register for free Continue reading

Docker Series B: More Fuel To Help Dev Teams Get Ship Done

Today we’re excited and humbled to announce Docker’s Series B raise of $23 million to accelerate our mission of delivering tools development teams love to quickly take their ideas from code to cloud. The round was led by Tribe Capital with participation from our existing investors, Benchmark and Insight Partners. Arjun Sethi, Tribe co-founder and partner, will join the Docker board. 

This would not have been possible without the Docker team: Thank you for giving each other your best, every day, despite the disruptions of the refocusing, the pandemic, the overnight switch to work-from-home, and so much more. We also thank our developer community of users, contributors, customers, partners, and Docker Captains – your enthusiastic engagement throughout this past year was invaluable.

Hit Refresh

Tribe sees in Docker what we saw in November 2019 when we refocused the company: the opportunity to build on the bottoms-up developer love of the Docker experience and provide a collaborative app development platform for development teams to accelerate getting their ideas from code to cloud. And that’s just what we did.

Key inputs to Tribe’s investment decision were our results this last year, which included attracting 80,000 developer participants to DockerCon 2020, adding Continue reading

Docker Compose: From Local to Amazon ECS

By using cloud platforms, we can take advantage of different resource configurations and compute capacities. However, deploying containerized applications on cloud platforms is proving to be quite challenging, especially for new users who have no expertise on how to use that platform. As each platform may provide specific APIs, orchestrating the deployment of a containerized application can become a hassle.

Docker Compose is a very popular tool used to manage containerized applications deployed on Docker hosts. Its popularity is maybe due to the simplicity on how to define an application and its components in a Compose file and the compact commands to manage its deployment.

Since cloud platforms for containers have emerged, being able to deploy a Compose application on them is a most-wanted feature by many developers that use Docker Compose for their local development.

In this blog post, we discuss how to use Docker Compose to deploy containerized applications to Amazon ECS. We aim to show how the transition from deploying to a local Docker environment to deploying to Amazon ECS is effortless, the application being managed in the same way for both environments.


In order to exercise the examples in this blogpost, the following tools need Continue reading

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