• All programmers MUST learn C and Assembly

    These are the slides from Joe Damato’s talk at Deconstruct 2017, titled “All programmers must learn C and Assembly.” This talk covers: C, assembly, system calls, operating systems, kernels, and more! Video Once Deconstruct posts videos, we’ll update this blog post! Slides

  • HOWTO: Private Maven Repositories

    This post will detail how to setup a private Maven repository in order to easily share Java, Scala, Clojure, and Android libraries with internal teams. Our example will use Jenkins CI to push an example library that will be used by an internal using Maven and an external team using Gradle. Overview As microservice...

  • HOWTO: Create debian repositories with reprepro

    This blog post will explain the steps needed for creating a Debian APT repository using command line tools. Quick start The fastest, easiest, and most secure way to create a Debian repository is to sign up at packagecloud.io. You will take advantage of numerous features like SSL and consistent APT repositories without needing to...

  • Extract python egg and python wheel

    This post covers how to extract and list the contents of python eggs and python wheels on the command line. Extract python egg A python egg is a simple Zip file, so you can extract it using any program that reads Zip files: $ unzip /path/to/file.egg NOTE: You may need to rename the file...

  • Inspecting and extracting JAR files from the command line

    This post covers how to extract and list the contents of JAR files using the command line. Extract JAR file $ jar xvf /path/to/file.jar Easy to use Maven repositories, free. Sign up! Extract JAR file without jar command line tool JAR files are Zip files but with a different name. You can use any...

  • Using strace to understand a 10x Java performance improvement

    In this blog post, we’ll examine the UseLinuxPosixThreadCPUClocks command line flag to the JVM. Starting in a patch update of the Sun JVM 1.6, the default value of this switch was changed to true, yielding a nice performance boost, roughly 10x in our test. Users of more recent JVMs get this behavior by default,...

  • How does a maven repository work?

    Similar to our APT Repository Internals and YUM Repository Internals posts, this post aims to illustrate the inner workings of a Maven repository. Read on if you have ever been curious as to how mvn compile figures out which dependencies to download and how to retrieve them in order to build your project.

  • Two frequently used system calls are ~77% slower on AWS EC2

    This blog post dives into an interesting finding: two frequently used system calls (gettimeofday, clock_gettime) are much slower on AWS EC2. Linux provides a mechanism for speeding up those two frequently used system calls by implementing the system call code in userland and avoiding the switch to the kernel entirely. This is done via...

  • Micro-optimizations matter: preventing 20 million system calls

    This blog post is a followup on our previous post How setting the TZ environment variable avoids thousands of system calls. In this post, we’ll explore a particularly prominent case where a micro-optimization (like removing a system call in a hot path) had a drastic effect on software performance.

  • Announcing Android AAR Support

    You can now upload your Android projects (AAR files) to packagecloud.io! Easily share them publicly or privately. Read on to find out the different ways to upload, download, and depend on AAR files. How to upload AAR files There are various ways to upload your Android project files to packagecloud.io. You can use Gradle/Maven...

  • How setting the TZ environment variable avoids thousands of system calls

    This blog post explains how setting an environment variable can save thousands (or in some cases, tens of thousands) of unnecessary system calls that can be generated by glibc over small periods of time. This has been tested on Ubuntu Precise (12.04) and Ubuntu Xenial (16.04). It likely applies to other flavors of Linux,...

  • Monitoring and Tuning the Linux Networking Stack: Sending Data

    This blog post explains how computers running the Linux kernel send packets, as well as how to monitor and tune each component of the networking stack as packets flow from user programs to network hardware.

  • Continuous Delivery of Python Applications using Travis CI and packagecloud

    This post will go through the steps needed to implement an automated software pipeline for Python packages. On every tagged commit pushed to Github, Travis CI will automatically build this project and push it to packagecloud.

  • HOWTO: Build debian packages for simple shell scripts

    This post goes over the creation of a debian package containing shell scripts using dh_make and debuild. Starting from structuring the packaging directory to building the final debian package, this tutorial covers the process of creating a debian package with just a few simple steps.

  • Announcing package promotion: easily move packages between repositories

    We’re excited to announce that we’ve added support for package promotion, which allows repository owners and collaborators to easily move packages between repositories! This feature can be used via the package promote API or via the package_cloud command line tool.

  • Debugging SSL in Java using mitmproxy

    In this post we’ll go over setting up the popular mitmproxy tool on an external host and configuring your Java programs to proxy traffic through it, allowing you to debug misbehaving HTTP clients and libraries.

  • Announcing official support for zypper

    Summary We’re excited to announce that we’ve added official support for zypper, the package manager that is widely used on openSUSE and SUSE Enterprise Linux Server (SLES)! Create a package repository in less than 10 seconds, free. Sign up! Uploading packages To upload a package for openSUSE or SLES you can either upload via our...

  • APT 1.2.10 backport for Ubuntu Trusty (14.04) and Ubuntu Precise (12.04)

    Summary We’re excited to announce that we’ve backported APT 1.2.10 to Ubuntu Trusty (14.04) and Ubuntu Precise (12.04)! This version of APT includes a new feature called Acquire-by-hash which completely eliminates the “Hash sum mismatch” errors. You can read more about this APT feature on our blog. Create an APT repository in less than 10...

  • Illustrated Guide to Monitoring and Tuning the Linux Networking Stack: Receiving Data

    This blog post expands on our previous blog post Monitoring and Tuning the Linux Networking Stack: Receiving Data with a series of diagrams aimed to help readers form a more clear picture of how the Linux network stack works. Create a package repository in less than 10 seconds, free. Sign up! There are no...

  • Infrastructure as code might be literally impossible part 2

    These are the the slides from Joe Damato’s keynote at Automacon 2016, titled “Infrastructure as code might be literally impossible part 2”. This talk covers: package managers, ssl, linux, scary stories, and more! Slides

  • Fixing APT Hash Sum Mismatch: Consistent APT Repositories

    The APT repository metadata format is inherently racy. This bug makes it impossible to guarantee that: Frequently updated APT repositories will remain consistent for users Mirrors of APT repositories will be consistent A new feature has been added to APT 1.2.0 and newer to prevent this race condition. Support for this feature has been...

  • SBT SNAPSHOT Deploys and fatjar Support

    You can now deploy your Scala packages directly from SBT to your packagecloud repositories (including SNAPSHOT versions)! Also, we’ve released support for deployment JARs, also known as “fatjars” or “uberjars” to the packagecloud CLI! Read on to find out how to take advantage of these new features.

  • IPv6 access for all APT, YUM, Maven, PyPI, and RubyGem repositories

    IPv6 APT, YUM, PyPI, RubyGem and Maven package repositories We are pleased to announce that IPv6 support for packagecloud has now entered public beta! The changes have been rolled out site-wide. The website, all package repositories, and all API endpoints are now accessible with both IPv4 and IPv6. No changes are necessary for our users;...

  • Announcing Maven repository support

    packagecloud now fully supports public and private maven2 repositories! Deploy releases and SNAPSHOTs right from your favorite build tool: Maven, Gradle, or Leiningen!

  • Monitorama 2016: All of Your Networking Monitoring is (probably) wrong

    These are the slides from Joe Damato’s talk at Monitorama 2016 titled “All Your Networking Monitoring is (probably) Wrong”. This talk covers: parts of the Linux kernel, networking, and some tips and tricks for understanding and gathering network monitoring statistics.

  • Monitoring and Tuning the Linux Networking Stack: Receiving Data

    This blog post explains how computers running the Linux kernel receive packets, as well as how to monitor and tune each component of the networking stack as packets flow from the network toward userland programs. UPDATE We’ve released the counterpart to this post: Monitoring and Tuning the Linux Networking Stack: Sending Data. UPDATE Take...

  • Announcing README support for packagecloud repositories

    You can now add a README to all your packagecloud repositories! Use the embedded markdown editor on your repository homepage (or settings page) to share important information about your packages with users.

  • Free Fastly CDN support for all package repositories and more

    All repositories on packagecloud are now backed by the Fastly CDN for super fast download speeds! In addition, we’ve completely redesigned search to make it faster and easier to use, added an indexing badge to repository pages, and dramatically improved the performance of our RPM indexers.

  • Philly ETE 2016: Infrastructure as code might be literally impossible

    This is the video and the slides from Joe Damato’s talk at Philly ETE 2016, titled “Infrastructure as code might be literally impossible”. This talk covers: package managers, puppet, chef, scary stories, and more!

  • The Definitive Guide to Linux System Calls

    This blog post explains how Linux programs call functions in the Linux kernel. It will outline several different methods of making systems calls, how to handcraft your own assembly to make system calls (examples included), kernel entry points into system calls, kernel exit points from system calls, glibc wrappers, bugs, and much, much more....

  • Pushing packages to packagecloud

    This blog post details all ways you can push packages to packagecloud using different languages and platforms.

  • APT Hash sum mismatch

    NOTE we recently blogged about another more serious cause for APT’s Hash sum mismatch bug and we’ve backported APT 1.2.10 to Ubuntu 12.04 (Precise) and Ubuntu 14.04 (Trusty) which includes bug fixes for the bug mentioned in this post and many exciting new features. APT repository can be provided uncompressed or compressed in a...

  • March Outages post-mortem

    We had a few brief outages in the past couple of weeks, this post-mortem aims to detail what happened, how we responded, and what was done to prevent similar incidents in the future.

  • How does ltrace work?

    This blog post explains how ltrace works, internally. This is a great companion post to our previous blog post which describes strace internals.