Asynchronous HTMLRewriter for Cloudflare Workers
Last year, we launched HTMLRewriter for Cloudflare Workers, which enables developers to make streaming changes to HTML on the edge. Unlike a traditional DOM parser that loads the entire HTML document into memory, we developed a streaming parser written in Rust. Today, we’re announcing support for asynchronous handlers in HTMLRewriter. Now you can perform asynchronous tasks based on the content of the HTML document: from prefetching fonts and image assets to fetching user-specific content from a CMS.
How can I use HTMLRewriter?
We designed HTMLRewriter to have a jQuery-like experience. First, you define a handler, then you assign it to a CSS selector; Workers does the rest for you. You can look at our new and improved documentation to see our supported list of selectors, which now include nth-child selectors. The example below changes the alternative text for every second image in a document.
async function editHtml(request) {
return new HTMLRewriter()
.on("img:nth-child(2)", new ElementHandler())
.transform(await fetch(request))
}
class ElementHandler {
element(e) {
e.setAttribute("alt", "A very interesting image")
}
}
Since these changes are applied using streams, we maintain a low TTFB (time to first byte) and users never know the HTML was transformed. If you’re interested in how we’re Continue reading
Video: Networks Are Not Homogenous
The last Fallacy of Distributed Computing I addressed in the introductory part of How Networks Really Work webinar was The Network Is Homogenous. No, it’s not and it never was… for more details watch this video.
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Navigating the open network operating systems space
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Some of your favorites are back together on this episode of the Kernel of Truth podcast— specifically Roopa Prabhu, Brian O’Sullivan and Pete Lumbis. Things have changed a little around here since the last time the three of them were chatting together on the podcast but one thing hasn’t, how much they love to talk all things open networking. In this episode the group talks about how to navigate the open networking operating systems space. From figuring out how to choose an open network operating system, to understanding what works best for deployments, and even what resources and communities are out there for you to tap into. We have it all here for you to help you get started. All you have to do is sit back and enjoy the episode and don’t forget to also check out the links below with resources referenced in the podcast.
Guest Bios
Roopa Prabhu: Roopa is a Linux Architect at NVIDIA, formally Cumulus Networks. She and her team work on all things kernel networking and Linux system infrastructure areas. Her primary Continue reading
Leveraging OpenStack to Orchestrate Distributed Cloud Deployments
The industry is seeing an increasing distribution of data centers, driven by a desire to improve the end user experiences,...Announcing VMware Container Networking with Antrea for Kubernetes
By Cody McCain, Senior Product Manager and Susan Wu, Senior Product Marketing Manager, Networking and Security Business Unit
Enterprises benefit from collaborative engineering and receive the latest innovations from open source projects. However, it’s a challenge for enterprise to rely solely on community support to run their operations. This is because community support is best-effort and cannot provide a pre-defined SLA.
While Kubernetes itself is open source, and part of Cloud Native Computing Foundation (CNCF), it takes an ecosystem of surrounding technologies as curated by CNCF—from the container registry and storage engine to the container network plugin to run Kubernetes.
Announcing VMware Container Networking with Antrea
With the new release of VMware Container Networking with Antrea, enterprises get the best of both worlds – access to the latest innovation from Project Antrea and world-class support from VMware. Container Networking with Antrea is the commercial offering consisting of and 24/7 support for Project Antrea.
Container Networking with Antrea will package the latest release of Project Antrea version 0.9.1. Antrea is a purpose-built Kubernetes networking solution for public and private clouds building upon Open vSwitch, the open source technology optimized for distributed multi-layer switching performance. Antrea is designed to run anywhere Kubernetes Continue reading
How Argo Tunnel engineering uses Argo Tunnel
Whether you are managing a fleet of machines or sharing a private site from your localhost, Argo Tunnel is here to help. On the Argo Tunnel team we help make origins accessible from the Internet in a secure and seamless manner. We also care deeply about productivity and developer experience for the team, so naturally we want to make sure we have a development environment that is reliable, easy to set up and fast to iterate on.
A brief history of our development environment (dev-stack)
Docker compose
When our development team was still small, we used a docker-compose file to orchestrate the services needed to develop Argo Tunnel. There was no native support for hot reload, so every time an engineer made a change, they had to restart their dev-stack.
We could hack around it to hot reload with docker-compose, but when that failed, we had to waste time debugging the internals of Docker. As the team grew, we realized we needed to invest in improving our dev stack.
At the same time Cloudflare was in the process of migrating from Marathon to kubernetes (k8s). We set out to find a tool that could detect changes in source code and Continue reading
Review Questions: Switching, Bridging and Routing
One of the most annoying part in every training content development project was the ubiquitous question somewhere at the end of the process: “and now we’d need a few review questions”. I’m positive anyone ever involved in a similar project can feel the pain that question causes…
Writing good review questions requires a particularly devious state of mind, sometimes combined with “I would really like to get the answer to this one” (obviously you’d mark such questions as “needs further research”, and if you’re Donald Knuth the question would be “prove that P != NP").
Security Policy Self-Service for Developers and DevOps Teams
In today’s economy, digital assets (applications, data, and processes) determine business success. Cloud-native applications are designed to iterate rapidly, creating rapid time-to-value for businesses. Organizations that are able to rapidly build and deploy their applications have significant competitive advantage. To this end, more and more developers are creating and leading DevOps teams that not only drive application development, but also take on operational responsibilities formerly owned by platform and security teams.
What’s the Value of a Self-Service Approach?
Cloud-native applications are often designed and deployed as microservices. The development team that owns the microservice understands the behavior of the service, and is in the best position to define and manage the network security of their microservice. A self-service model enables developers to follow a simple workflow and generate network policies with minimal effort. When problems occur with. application connectivity, developers should be able to diagnose connectivity issues and resolve them quickly without having to depend on resources outside of the team.
Developers and DevOps teams can also take a leading role in managing security, which is an integral part of cloud-native applications. There are two aspects to security in the context of Kubernetes.
- Cluster security – is a uniform set Continue reading
Reflecting on Three Years of Board Service and a Commitment to Quality Improvement
Departing Trustee Glenn McKnight looks back at his three years of service as a member of the Internet Society Board of Trustees.
During the past three years we have seen a tremendous amount of productive work by a functional and focused Internet Society Board of Trustees. This included not only the normal board and committee work, but also the extra efforts associated with the selection of a new CEO, creation of the Internet Society Foundation, and meeting the challenges of the proposed PIR/Ethos transaction.
It’s important to learn from these experiences, but it’s also important to focus on achievements and to reassert the core values of the Internet Society as a force of good in the Internet ecosystem. We see the Internet Society focusing its efforts with purposeful strategic direction lead by CEO Andrew Sullivan and his team. As a departing Trustee, I would like to see the Internet Society explore more opportunities for members to learn from one other, including “Meet the Board” to foster improved communication and a means to help teach the community about the role of the Board of Trustees.
During these three years, my work beyond the normal board work has also involved committee Continue reading
Day Two Cloud 063: The How And Why Of Migrating Databases To The Cloud
Planning a database migration to the cloud? If you're going to do it right, prepare to dig in because you have many options and trade offs to consider, including whether to go with IaaS or PaaS, security and monitoring issues, and much, much more. Day Two Cloud dives into the inner workings of database migration with expert Joey D’Antoni, Principal Consultant at Denny Cherry & Associates.
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