X-Git-Url: https://git.tld-linux.org/?p=TLD.git;a=blobdiff_plain;f=pld-builder.new%2Fdoc%2FARCHITECTURE;fp=pld-builder.new%2Fdoc%2FARCHITECTURE;h=7bcbcefd75ed610ed6c53c6db168b3ea03132ec9;hp=0000000000000000000000000000000000000000;hb=90809c8fec988489786ce00247d9a4150070748b;hpb=ab3934fab858112cd552359b18cb980ea07c310b diff --git a/pld-builder.new/doc/ARCHITECTURE b/pld-builder.new/doc/ARCHITECTURE new file mode 100644 index 0000000..7bcbcef --- /dev/null +++ b/pld-builder.new/doc/ARCHITECTURE @@ -0,0 +1,165 @@ +0. ABSTRACT + +Below is a description of the way the builder infrastructure works. You should +read it in order to be able to understand what's exactly going on when you try +to build a package. + +(It assumes you have a basic understanding of how RPM packages are created.) + +1. OVERVIEW + +The builder infrastructure is divided into three parts: +- the client +- the source builder +- the binary builders + +The basic idea is to allow developers (requesters) to easily specify which +package they want built, and have the rest of the system take care of building +and upgrading packages, uploading them where appropriate and reporting back to +the developers on the results (were there errors, how long it took to build, +etc.). + +What follows is a more detailed description of what each part is supposed to +do. + +1.1 NOTES ON UPLOADING + +When talking of uploading packages and logs it is meant as placing them +somewhere on the original system (via a simple 'cp'; this also includes copying +to /dev/null), or placing them on a remote system via the scp or rsync +protocols. + +1.2 TOOLS USED + +99% of the system is written in python, with remaining parts using shell +scripts (POSIX shell is assumed, bashisms are to be shot at sight and their +authors beheaded in a public display). The presence of various helper tools is +assumed. They are: gpg, rsync and scp command line utilities. + +2. SHORT DIAGRAM + +Below are complete basics of how data is tossed around. Only the most relevant +transfers are presented. + + status info status info + +--------------+<--+------------------+ + | build | | | + V request | V src.rpm | +requester ---------> src.builder ---------> bin.builders + | | + | arch.rpms | + FTP server <---+------------------+ + +3. CLIENT + +Main task: sending build requests to source builders. + +This is the simplest part. It consists of a shell script (make-request.sh), +which, based on the way it's configured and on the cmdline parameters given to +it, generates an xml-formated build request, which it then signs with the +requester's PGP key (using the gpg utility) and then sends it to the source +builder via a sendmail compatible command line application (by default invoking +"sendmail -t"). + +Two modes of operation are: +- sending requests to build chosen package(s) on a specified group of builders +- sending a chosen command to be executed on a specified group of builders + +See HOWTO-CLIENT for a hands-on approach to setting yourself up for being able +to send out build requests. + +4. SOURCE BUILDER (AKA SRC.BUILDER) + +Main task: building src.rpm packages and serving them to binary builders. +Additional tasks: reporting back to the requester about the status of the build +and uploading generated src.rpm packages where appropriate. Also -- tagging, +access control, uploading buildlogs and keeping the 'queue.html' file in sync. + +The source builder is the central place for managing access rights for +requesters. Upon receiving a request (via email), it first checks the pgp +signature with which the request was signed, against the pgp key currently +assigned to the requester (all done with the 'gpg' command). After verifying +that the requester name/requester pgp signature pair match, it then checks if +the requester is actually allowed to perform the actions she wants to perform. +That is: does she have access to a specified binary builder, is she allowed to +specify the 'upgrade' flag or not, is she allowed to use the priority she set +for the request and even if she is allowed to request building of a given +package. + +Once a request passes all verifications, the src.builder uses its own chroot +equipped with a basic build environment to fetch the sources of a given +package, tag them if configured to do so and create a src.rpm out of them (all +done by invoking the 'builder' script as found in the SPECS module of the PLD +cvs repository (see http://www.pld-linux.org/Repositories for details)). + +After finishing the build procedure the src.builder reports (via email) to the +requester on the status of the build (OK/FAIL), updates the 'queue.html' file +with that information (urls for PLD2.0 and 3.0 queues: +http://ep09.pld-linux.org/~buildsrc/queue.html and +http://src.th.pld-linux.org/queue.html) and, if configured to do so, +uploads the complete log of the whole procedure (called the buildlog) +somewhere, most likely to our PLD buildlogs system +(http://buildlogs.pld-linux.org). + +If the build procedure was successful, the resulting src.rpm file is most +likely uploaded somewhere (if configured to do so; in our case it's our FTP +server) and, what is most important, it's being served via a http server for +the binary builders to download. An xml-formated (and pgp signed) 'queue.gz' +and a small 'max_req_no' files are also updated with relevant information, in +order for the bin.builders to be able to notice new requests and figure out +which are addressed to which builders. + +The last matter taken care of by the src.builder is receiving (gpg signed) +emails from bin.builders with status information regarding what happened to +various builds (whether they succeeded or failed) and updating the 'queue.html' +file accordingly. + +See the HOWTO-BUILDERS file for a hands-on approach on setting up builders. All +of the technical details are there. + +5. BINARY BUILDERS (AKA BIN.BUILDERS) + +Main task: building arch.rpm packages and uploading them where appropriate. +Additional tasks: reporting back to the requester and the source builder on the +status of the build. Also -- uploading buildlogs. + +Upon noticing that a new request has been published by the src.builder and +verifying the appropriate gpg signatures, binary builders download the relevant +src.rpm files and use their build-environment-equipped chroots to start +building them (by invoking the 'rpmbuild' command). Once a build is completed +(meaning arch.rpm files are produced, or the whole procedure is interrupted for +whatever reason), the status of the build (OK/FAIL) is sent via email both to +the requester and to the src.builder. + +Procedure for uploading the produced arch.rpms and buildlogs is the same as +with the src.builder. + +Bin.builders however need to deal with one thing src.builders are mostly not +affected by -- managing the build environments inside their chroots. That means +installing new packages if required by a given build (using the 'poldek' +package manager; http://poldek.pld-linux.org/), upgrading older packages for +much the same reasons, downgrading from time to time and locally caching newly +built files for short periods of times. + +All of this, along with lots of quirks and obscure details is explained in the +HOWTO-BUILDERS file. + +6. Q/A + +Q: What's this 'tagging' all about with the src.builder? +A: When a src.rpm is created and arch.rpms built based on it, it is sometimes +useful to be able to check which sources were used to build them. Casual users +might be satisfied with just extracting everything from the src.rpm (that is +what they are uploaded to the ftp server for), but the old ones aren't always +available and even if they are, developers require source control in order to +work efficiently. Hence all sources used to build a given src.rpm for a given +line are tagged appropriately in the PLD CVS repository, for example trying to +build cthulu.spec on the 2.0 (codename Ac) line of our distro might result in a +tag looking something like this being set -- 'auto-ac-cthulu-6.6-6'. +(Technically the previous sentence is not 100% correct due to (a) the way our +DISTFILES infrastructure impacts which sources are and aren't in the CVS repo +and hence are subject to tagging and (b) specific policies regarding tagging +for each distro line; for the latter refer to appropriate policies.) + + +# vi: formatoptions=aw expandtab