Andrew, do you might putting this on our wiki? Such a great and well-put explanation! I am sure it will help a lot of new contributors to get up to speed much quicker!
Thanks! Cos On Tue, Apr 28, 2015 at 04:01PM, Andrew Purtell wrote: > Inline > > On Tue, Apr 28, 2015 at 8:51 AM, Andre Kelpe <[email protected]> > wrote: > > > Hi, > > > > I am currently learning the ins and outs of bigtop to work on the Cascading > > integration (https://issues.apache.org/jira/browse/BIGTOP-1766). I have a > > few questions around packaging in bigtop: > > > > 1) most linux distros have packaging guidelines that should be followed. > > Does bigtop follow any set of rules in particular? Is there a linting tool > > for spec files etc? > > > > This is distro specific. RedHat family distributions (RHEL, Fedora, Centos, > Amazon Linux) offer 'rpmlint'. You can install it and run it by hand. From > personal experience if you build deb packages on Ubuntu the package build > will run the lintian tool automatically. > > > > 2) Related to 1): Does bigtop require to follow a certain directory layout? > > Our tools are currently meant to be untarred and used as is, if bigtop > > requires them to be split over the file-system, we will have to work on > > that upstream before they can be included. > > > > Yes, broadly speaking we follow the Linux standard base (LSB). A typical > package build happens in four steps. We move files around in the third step > to make packages look more like LSB. Let me take you through one package as > an example: > > Step 1. Download source tarball from the software release site and expand > it. > > Step 2. do-package-build > > Here, for example, see what we do for ZooKeeper: > https://github.com/apache/bigtop/blob/master/bigtop-packages/src/common/zookeeper/do-component-build > . We kick off a build of the component's binary artifacts while first > normalizing dependency versions according to the release BOM. > > Step 3. install_<component>.sh > > Again let's look at the ZK package: > https://github.com/apache/bigtop/blob/master/bigtop-packages/src/common/zookeeper/install_zookeeper.sh > . Here we take the resulting tarball from the component build, expand it, > and move the locations of various types of files around to be more > LSB-like. > > Step 4. Native packager > > Finally we hand off the expanded and munged result from step 3 to the > native packager. For ZK, the RPM specfile used is here: > https://github.com/apache/bigtop/blob/master/bigtop-packages/src/rpm/zookeeper/SPECS/zookeeper.spec > . The Debian package control files are here: > https://github.com/apache/bigtop/tree/master/bigtop-packages/src/deb/zookeeper > > > > > > 3) I noticed that the packages are build from source instead of re-using > > binary releases. Is that a strict requirement or does it just happen to be > > that way? For the Cascading integration I was planning on downloading our > > binary releases so that bigtop ship with the same bits as our SDK. > > > > We typically build packages from source so we can normalize dependencies. > For example, if a given Bigtop release ships with Hadoop 2.6.0 but the > Cascading SDK includes 2.5.1 artifacts, this would be ugly at best and > broken at worst. > > > > 4) What is your take on packaging standalone libraries? I noticed that most > > parts of bigtop are tools in the broader sense. Something one can invoke on > > the command line, but there is also a package for apache crunch, which is a > > library. What is the reasoning here? Would it make sense to build packages > > for libraries in the Cascading eco-system? > > > > > I'm not sure we have anything that amounts to a policy here. Crunch isn't > the only case. We package the DataFu library of UDFs for Pig. We package > the Phoenix SQL skin add-on for HBase. We also package Tez, which is a YARN > application requiring Hadoop, and although it could be useful on its own > it's meant to be picked up and used by the Hive and Pig packages. > > If a champion for a component shows up we will give it a look. We could > absolutely build a core Cascading package and then a number of library or > add-on packages, if that's how you would like to set things up as champion > or maintainer of same. > > > > > Thanks for your answers! > > > > - André > > > > -- > > André Kelpe > > [email protected] > > http://concurrentinc.com > > > > > > -- > Best regards, > > - Andy > > Problems worthy of attack prove their worth by hitting back. - Piet Hein > (via Tom White)
