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Apache Mesos on Debian

I decided to try packaging Mesos for Debian/Stretch. I had a spare system with a i7-930 CPU, 48G of RAM, and SSDs to use for building. The i7-930 isn’t really fast by today’s standards, but 48G of RAM and SSD storage mean that overall it’s a decent build system – faster than most systems I run (for myself and for clients) and probably faster than most systems used by Debian Developers for build purposes.

There’s a github issue about the lack of an upstream package for Debian/Stretch [1]. That upstream issue could probably be worked around by adding Jessie sources to the APT sources.list file, but a package for Stretch is what is needed anyway.

Here is the documentation on building for Debian [2]. The list of packages it gives as build dependencies is incomplete, it also needs zlib1g-dev libapr1-dev libcurl4-nss-dev openjdk-8-jdk maven libsasl2-dev libsvn-dev. So BUILDING this software requires Java + Maven, Ruby, and Python along with autoconf, libtool, and all the usual Unix build tools. It also requires the FPM (Fucking Package Management) tool, I take the choice of name as an indication of the professionalism of the author.

Building the software on my i7 system took 79 minutes which includes 76 minutes of CPU time (I didn’t use the -j option to make). At the end of the build it turned out that I had mistakenly failed to install the Fucking Package Management “gem” and it aborted. At this stage I gave up on Mesos, the pain involved exceeds my interest in trying it out.

How to do it Better

One of the aims of Free Software is that bugs are more likely to get solved if many people look at them. There aren’t many people who will devote 76 minutes of CPU time on a moderately fast system to investigate a single bug. To deal with this software should be prepared as components. An example of this is the SE Linux project which has 13 source modules in the latest release [3]. Of those 13 only 5 are really required. So anyone who wants to start on SE Linux from source (without considering a distribution like Debian or Fedora that has it packaged) can build the 5 most important ones. Also anyone who has an issue with SE Linux on their system can find the one source package that is relevant and study it with a short compile time. As an aside I’ve been working on SE Linux since long before it was split into so many separate source packages and know the code well, but I still find the separation convenient – I rarely need to work on more than a small subset of the code at one time.

The requirement of Java, Ruby, and Python to build Mesos could be partly due to language interfaces to call Mesos interfaces from Ruby and Python. Ohe solution to that is to have the C libraries and header files to call Mesos and have separate packages that depend on those libraries and headers to provide the bindings for other languages. Another solution is to have autoconf detect that some languages aren’t installed and just not try to compile bindings for them (this is one of the purposes of autoconf).

The use of a tool like Fucking Package Management means that you don’t get help from experts in the various distributions in making better packages. When there is a FOSS project with a debian subdirectory that makes barely functional packages then you will be likely to have an experienced Debian Developer offer a patch to improve it (I’ve offered patches for such things on many occasions). When there is a FOSS project that uses a tool that is never used by Debian developers (or developers of Fedora and other distributions) then the only patches you will get will be from inexperienced people.

A software build process should not download anything from the Internet. The source archive should contain everything that is needed and there should be dependencies for external software. Any downloads from the Internet need to be protected from MITM attacks which means that a responsible software developer has to read through the build system and make sure that appropriate PGP signature checks etc are performed. It could be that the files that the Mesos build downloaded from the Apache site had appropriate PGP checks performed – but it would take me extra time and effort to verify this and I can’t distribute software without being sure of this. Also reproducible builds are one of the latest things we aim for in the Debian project, this means we can’t just download files from web sites because the next build might get a different version.

Finally the fpm (Fucking Package Management) tool is a Ruby Gem that has to be installed with the “gem install” command. Any time you specify a gem install command you should include the -v option to ensure that everyone is using the same version of that gem, otherwise there is no guarantee that people who follow your documentation will get the same results. Also a quick Google search didn’t indicate whether gem install checks PGP keys or verifies data integrity in other ways. If I’m going to compile software for other people to use I’m concerned about getting unexpected results with such things. A Google search indicates that Ruby people were worried about such things in 2013 but doesn’t indicate whether they solved the problem properly.

1 comment to Apache Mesos on Debian

  • Andrew Cater

    Passed on to colleagues who are producing FLOSS software to advise about what might be useful considerations. I’ve been lucky enough to avoid having to rely on gems (or NodeJS or PyPi) thus far in my life – it’s symptomatic of the fact that the ecosystems for these don’t care too much for packaging or maintenance – they’ve not been through the pain of long term understanding and support for real users.

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