I am also a fan of git submodules in the long term, but avoiding them in the short term. We should get things organized as we want them first, and then start thinking about pulling libprocess/stout out into submodules later (while also preserving their history!)
I disagree with moving libprocess and stout up to the same level as src/. If we want to make sure they don't bleed into Mesos proper, we really should treat them the same as any other 3rdparty code that we depend on. This will become more relevant when/if we move them into submodules. Given all that, the only real challenge with flattening our 3rdparty dependencies into a single folder should be the changes we have to make to our configure.ac and Makefile.am scripts to know where to look for their dependencies now. In the end these should be URLs to versioned tarballs that we host somewhere (or git repos that we can have forked and tagged with specific versions). In the short term these can just be relative paths in the mesos tree though. On Tue, Feb 16, 2016 at 1:26 PM, Kapil Arya <ka...@mesosphere.io> wrote: > Thanks for bringing it up Alexander! > > I don't have a strong opinion wrt git submodules since I don't have > much experience with them personally. Having said that, I would like > to go conservative on this one (baby steps :-) ). > > Further, I do understand that moving libprocess and stout directories > will be painful for people who already have several branches and will > have conflicts. But I do think, there are some interim solutions as > well (for example, move libprocess/stout to wherever we want, but keep > a symlink from 3rdparty/libprocess, etc, to those new locations for > some time). I am sure there are better solutions out there, but this > should work too. > > Best, > Kapil > > On Tue, Feb 16, 2016 at 12:38 PM, Erik Weathers > <eweath...@groupon.com.invalid> wrote: >> If we go to git submodules, please ensure there are good docs around how to >> update cloned repos. >> >> e.g., From ansible: https://docs.ansible.com/ansible/intro_installation.html >> >> Note when updating ansible, be sure to not only update the source tree, but >> also the “submodules” in git which point at Ansible’s own modules (not the >> same kind of modules, alas). >> >> $ git pull --rebase >> $ git submodule update --init --recursive >> >> Thanks, >> >> - Erik >> >> On Tue, Feb 16, 2016 at 8:54 AM, Alexander Rojas <alexan...@mesosphere.io> >> wrote: >> >>> +1 >>> I am one who is totally in for that change. It is not only the directories >>> problem, but the structure which has led that the stout tests (which do >>> need to be compiled) are actually managed in the libprocess Makefile, on >>> top of all the things you have already mentioned. >>> >>> >>> > On 09 Feb 2016, at 17:53, Kapil Arya <ka...@mesosphere.io> wrote: >>> > >>> > On Tue, Feb 9, 2016 at 8:23 PM, Jie Yu <yujie....@gmail.com> wrote: >>> >> Kapil, >>> >> >>> >> I guess what I want to understand is why the existing structure makes it >>> >> hard for you to do the things that you want to do (installing >>> >> module-specific 3rdparty dependencies into "${pkglibdir}/3rdparty" as >>> part >>> >> of "make install"). >>> > >>> > Let me see if I can answer that :-). >>> > >>> > This is somewhat related. For example, if we want to install protobuf >>> > in 3rdparty/{include,lib} (for module developers to use them without >>> > doing a proper mesos installation), you need to provide the correct >>> > "--prefix" flag that points to 3rdparty/. However, due to multiple >>> > levels of configure.ac, the "--prefix" can at best be generated by >>> > prepending "../../../" to get to the great-grandparent directory. This >>> > is because we have a separate configure.ac which manages >>> > 3rdparty/libprocess/3rdparty/Makefile.am. There are ways around it, >>> > but they are not clean. >>> > >>> > Similar thing holds for system-wide installation of these 3rdparty >>> > packages. For example, ideally, we would want to use >>> > "${pkglibdir}/3rdparty" as a prefix for those packages. However, since >>> > they are part of libprocess package, we don't get the correct >>> > directory and have to use either hardwired $pkglibdir, or somehow pass >>> > it from the top-level configure all the way down to >>> > 3rdparty/libprocess/3rdparty/Makefile.am :-(. >>> > >>> > >>> >> The only reason you mentioned in the original email is that "in the >>> current >>> >> code base, we don't strictly follow the 3rdparty structure", which IMO >>> is >>> >> not a very convincing reason for such a big change. >>> > >>> > How about a not so big change? :-). What if we just move >>> > 3rdparty/libprocess/3rdparty/* stuff out to 3rdparty/ while leaving >>> > stout as is? That is not a big change since we are not touching >>> > libprocess/stout. Just adjusting Makefiles and I am pretty sure it >>> > will be cleaner and simpler than what we have right now. >>> > >>> > As a later time, we can then consider moving stout out to 3rdparty/ >>> > while leaving libprocess as is. But that's something we can decide >>> > later and leave stout as an exception for now. >>> > >>> > BTW, if we were to install all the 3rdparty packages in 3rdparty/, >>> > that would also cut down a lot on the compiler flags (i.e., fewer "-I" >>> > and "-L" flags) :-). >>> > >>> > Kapil >>> > >>> >> >>> >> - Jie >>> >> >>> >> On Tue, Feb 9, 2016 at 5:04 PM, Kapil Arya <ka...@mesosphere.io> wrote: >>> >> >>> >>> On Tue, Feb 9, 2016 at 7:20 PM, Jie Yu <yujie....@gmail.com> wrote: >>> >>>> >>> >>>>> >>> >>>>> However, in the current code base, we don't strictly follow the >>> >>> 3rdparty >>> >>>>> structure. For example, stout has a dependency on picojson and >>> >>>>> google-protobuf, but we don't put these two packages inside >>> >>>>> 3rdparty/libprocess/3rdparty/stout/3rdparty/. >>> >>>> >>> >>>> >>> >>>> My understanding is that stout is header only. So it does not have to >>> >>>> bundle 3rdparty libraries. The user of stout is responsible for >>> bundling >>> >>>> them if they are used. >>> >>> >>> >>> >>> >>> I don't think being header-only is an excuse to have a broken >>> >>> installation :-). Further, we don't make it easier for the user to get >>> >>> the 3rdparty binaries either. For example, if the user has a different >>> >>> version of protobuf installed on the system, the compilation of any >>> >>> program that uses stout will fail spectacularly! >>> >>> >>> >>> Having said that, the gist here is that we have somewhat deviated from >>> >>> original motivation behind the 3rdparty directory and it would be nice >>> >>> if we can have a flatter structure. >>> >>> >>> >>>> >>> >>>> >>> >>>> - Jie >>> >>>> >>> >>>> On Tue, Feb 9, 2016 at 4:14 PM, Kapil Arya <ka...@mesosphere.io> >>> wrote: >>> >>>> >>> >>>>> Hi All, >>> >>>>> >>> >>>>> TLDR: Move everything from 3rdparty/libprocess/3rdparty/* into >>> >>> 3rdparty/. >>> >>>>> (Optionally) Move libprocess/stout to the top-level directory. >>> >>>>> >>> >>>>> I wanted to start some discussion around reorganizing stuff inside >>> >>>>> "3rdparty". I apologize for the length of the email, please bear with >>> >>> me. >>> >>>>> >>> >>>>> Traditionally, 3rdparty has been used to hold all Mesos dependencies >>> >>>>> (zookeeper, libprocess, protobuf, stout, etc.). Further, >>> >>>>> libprocess/3rdparty was to hold all libprocess dependencies (which >>> may >>> >>> in >>> >>>>> turn be Mesos dependencies as well). >>> >>>>> >>> >>>>> As I understand, the original motivation was to emphasize that >>> >>> libprocess >>> >>>>> is an independent project which depends on "stout", which in turn is >>> >>> also >>> >>>>> an independent project. >>> >>>>> >>> >>>>> However, in the current code base, we don't strictly follow the >>> >>> 3rdparty >>> >>>>> structure. For example, stout has a dependency on picojson and >>> >>>>> google-protobuf, but we don't put these two packages inside >>> >>>>> 3rdparty/libprocess/3rdparty/stout/3rdparty/. >>> >>>>> >>> >>>>> In light of these anomalies, I want to propose that we flatten out >>> the >>> >>>>> 3rdparty directory and put all packages (libprocess, stout, protobuf, >>> >>>>> picojson, zookeeper, etc.) at the same level in 3rdparty. We can >>> still >>> >>> use >>> >>>>> "--with-XYZ=..." to the full extent as needed. >>> >>>>> >>> >>>>> To take it a step further, I want to propose that we bring libprocess >>> >>> and >>> >>>>> stout out of 3rdparty/ and move them at the top level (i.e., make >>> them >>> >>>>> peers of src/). That way, all code in 3rdparty/ is stuff from "third" >>> >>>>> parties and is used only when "--with-bundled" is defined (by >>> default). >>> >>>>> This hierarchy will still allow us to keep libprocess and stout as >>> >>> separate >>> >>>>> independent projects. >>> >>>>> >>> >>>>> The motivation for this proposal came when dealing with 3rdparty >>> >>>>> dependencies for module development. A module developer needs access >>> to >>> >>>>> protobuf, picojson, glog, etc., and for that matter, the exact >>> >>> versions of >>> >>>>> these packages that Mesos was compiled with. >>> >>>>> >>> >>>>> We want to solve this problem by installing module-specific 3rdparty >>> >>>>> dependencies into "${pkglibdir}/3rdparty" as part of "make install" >>> (if >>> >>>>> configured with something like >>> "--enable-install-module-dependencies"). >>> >>>>> (There is a discussion going on in a separate thread). >>> >>>>> >>> >>>>> Further, as of today, when we install Mesos using "make install", we >>> >>>>> install stout headers in "${prefix}/include/stout". However, stout >>> has >>> >>>>> dependencies on picojson[1] and google-protobuf headers which may not >>> >>> be >>> >>>>> present on the machine. This leaves stout, and in turn libprocess and >>> >>> Mesos >>> >>>>> headers, fairly broken. I understand that this issue is somewhat >>> >>> orthogonal >>> >>>>> to the main issue being discussed in this mail, but I wanted to put >>> it >>> >>> out >>> >>>>> since it's related. >>> >>>>> >>> >>>>> Any thoughts, comments, concerns are most welcome! >>> >>>>> >>> >>>>> Best, >>> >>>>> Kapil >>> >>>>> >>> >>>>> >>> >>>>> [1]: Picojson issue was resolved as part of >>> >>>>> https://reviews.apache.org/r/41424/ which installs picojson.h into >>> the >>> >>>>> include-dir. >>> >>>>> >>> >>> >>> >>> -- ~Kevin
