How do I build RPMS under Red Hat?
I need to package a newer version of some software than is available from the repositories.
(I can build it locally already, its just the packaging that I need to do, so that I can use it on other machines)
I could just take the .spec file from the older version's SRPM and start from there, right? - But i'm brand new to packaging, any pointers?
Starting with the existing SRPM is a fantastic first step -- trying to build one from scratch is an exercise in frustration, especially if your users expect it to work with previously packaged versions of the same tool.
You'll need to keep the documentation at rpm.org handy at all times. The Maximum RPM book is probably a little too dated now, but at one time it was always loaded in one of my browser tabs.
One thing to be very careful of is builds that work on your machine but aren't repeatable anywhere else. You really should get a dedicated building environment of some sort set up so you can have repeatable builds.
Related
I'm building a c++ repo that depends on external company repos that exist to support this repo. I have to build these to target certain versions of boost and other libraries specific to my system. At the end of the (long) build process, I have several static libraries and my finished executable. I use Docker for these builds.
I'm trying to decide what the cleanest approach is for managing these dependencies.
git submodules and build binaries from source each time (longest build)
build libraries individually and store them as artifacts/releases for each repo (most work, across several repos)
make a README on how to rebuild and commit the binaries to the main repo (feels dirty for some reason)
What is the common practice in c++ for dealing with these intermediate binaries?
It's probably impossible to give a generally valid answer. You have to think about who the users of your code (I mean those who compile it) are and what their workflow is.
I personally more and more tend to favor option three in your list - yes, the README file. The reason is that in many cases the users don't need to (and should not) bother with dependencies at all. Very often there is the higher-level build process in place, that makes sure all dependencies are properly prepared (downloaded, optionally patched, compiled and installed) as your application expects. With Docker, I have the feeling this is becoming the norm now. I always provide a Dockerfile (or sometimes even a complete Docker image) where all dependencies are in place and the user can compile without even thinking of those.
If it's not Docker, there may be an other higher-level build process that handles dependencies. As I'm in the embedded industry, we use mostly Yocto, but there are others also. The users don't even need to use Yocto themselves, as I provide them with an SDK that contains all dependencies.
And for the very few who refuse to use all these options and insist on compiling natively on their main machine, I write a list of dependencies in the README file, with a few lines on each, describing how to fetch, compile and install them.
As for the other two options you mentioned:
Option one (git submodules) - I must say that I never really got comfortable with that. IMO they are a bit poorly implemented in git (e.g. it's really cumbersome to find out exactly at which version each submodule is currently checked out). Also, with a higher-level build process in place, it might mean double-fetching each dependency, which is inefficient. Then it's hard to apply patches to the dependency, if you must. You would have to write some extra script and include it in your build process. Lastly, your dependencies may have dependencies by themselves, and then it gets really ugly.
Option two (storing binary artifacts in the repo) is an absolute emergency solution that I would always try to avoid.
And because somebody mentioned git subtrees - we tried that in our team for about half a year. It was an absolute disaster. Nobody really understood it, and about once a week someone messed up the entire repository. Never would I use that again.
For past 4 years, I have been programming with Eclipse (for Java), and Visual Studio Express (for C#). The IDEs mentioned always seemed to provide every facility a programmer might ask for (related to programming, of course).
Lately I have been hearing about something called "build tools". I heard they're used almost in all kind of real world development. What are they exactly? What problems are they designed to solve? How come I never needed them in past four years? Are they kind of command-line stripped down IDEs?
What are build tools?
Build tools are programs that automate the creation of executable
applications from source code (e.g., .apk for an Android app). Building
incorporates compiling,linking and packaging the code into a usable or
executable form.
Basically build automation is the act of scripting or automating a
wide variety of tasks that software developers do in their day-to-day
activities like:
Downloading dependencies.
Compiling source code into binary code.
Packaging that binary code.
Running tests.
Deployment to production systems.
Why do we use build tools or build automation?
In small projects, developers will often manually invoke the build
process. This is not practical for larger projects, where it is very
hard to keep track of what needs to be built, in what sequence and
what dependencies there are in the building process. Using an
automation tool allows the build process to be more consistent.
Various build tools available(Naming only few):
For java - Ant,Maven,Gradle.
For .NET framework - NAnt
c# - MsBuild.
For further reading you can refer following links:
1.Build automation
2.List of build automation software
Thanks.
Build tools are tools to manage and organize your builds, and are very important in environments where there are many projects, especially if they are inter-connected. They serve to make sure that where various people are working on various projects, they don't break anything. And to make sure that when you make your changes, they don't break anything either.
The reason you have not heard of them before is that you have not been working in a commercial environment before. There is a whole lot of stuff that you have probably not encountered that you will within a commercial environments, especially if you work in software houses.
As others have said, you have been using them, however, you have not had to consider them, because you have probably been working in a different way to the usual commercial way of working.
Build tools are usually run on the command line, either inside an IDE or completely separate from it.
The idea is to separate the work of compiling and packaging your code from creation, debugging, etc.
A build tool can be run on the command or inside an IDE, both triggered by you. They can also be used by continuous integration tools after checking your code out of a repository and onto a clean build machine.
make was an early command tool used in *nix environments for building C/C++.
As a Java developer, the most popular build tools are Ant and Maven. Both can be run in IDEs like IntelliJ or Eclipse or NetBeans. They can also be used by continuous integration tools like Cruise Control or Hudson.
Build tools are generally to transform source code into binaries - it organize source code, set compile flags, manage dependencies... some of them also integrate with running unit test, doing static analysis, a generating documentation.
Eclipse or Visual Studio are also build systems (but more of an IDE), and for visual studio it is the underlying msbuild to parse visual studio project files under the hood.
The origin of all build systems seems like the famous 'make'.
There are build systems for different languages:
C++: make, cmake, premake
Java: ant+ivy, maven, gradle
C#: msbuild
Usually, build systems either using a propriety domain specific language (make, cmake), or xml (ant, maven, msbuild) to specify a build. The current trend is using a real scripting language to write build script, like lua for premake, and groovy for gradle, the advantage of using a scripting is it is much more flexible, and also allows you the to come up with a set of standard APIs(as build DSL).
These are different types of processes by which you can get your builds done.
1. Continuous Integration build: In this mainly developers check-in their code and right after their check-in a build initiates for building of the recent changes so we should know whether the changes done by the developer has worked or not right after the check-in is done. This is preferred for smaller projects or components of the projects. In case where multiple teams are associated with the project or there are a large no. of developers working on the same project this scenario becomes difficult to handle as if there are 'n' no. of check-in’s and the build fails at certain points it becomes highly difficult to trace whether all the breakage has occurred because of one issue or with multiple issues so if the older issues are not addressed properly than it becomes very difficult to trace down the later defects that occurred after that change. The main benefit of these builds is that we get to know whether a particular check-in is successful or not.
2. Gated check-in builds: In this type of check in a build is initiated right after the check in is done keeping the changes in a shelve sets. In this case if the build succeeds than the shelve-set check-in gets committed otherwise it will not be committed to the Team Foundation Server. This gives a slightly better picture from the continuous integration build as only the successful check-in's are allowed to get committed.
3. Nightly builds: This is also referred as Scheduled builds. In this case we schedule the builds to run for a specific time in order to build the changes. All the previous uncommitted changes from the last build are built during this build process. This is practiced when we want to check in multiple times but do not want a build every time we check in our code so we can have a fixed time or period in which we can initiate the build for building of the checked-in code.
The more details about these builds can be found at the below location.
Gated-check in Builds
Continuous Integration Builds
Nightly Builds
Build Process is a Process of compiling your source code for any errors using some build tools and creating builds(which are executable versions of the project). We(mainly developers) do some modifications in the source code and check-in that code for the build process to happen. After the build process it gives two results :
1. Either build PASSES and you get an executable version of your project(Build is ready).
2. It fails and you get certain errors and build is not created.
There are different types of build process like :
1. Nightly Build
2. gated Build
3. Continuous integration build etc.
Build tools help and automates the process of creating builds.
*So in Short Build is a Version of Software in pre-release format used by the Developer or Development team to gain confidence for the final result of their Product by continuously monitoring their Product and solving any issues early during the development process.*
You have been using them - IDE is a build tool. For the command line you can use things like make.
People use command line tools for things like a nightly build - so in the morning with a hangover the programmer has realised that the code that he has been fiddling with with the latest builds of the libraries does not work!
"...it is very hard to keep track of what needs to be built" - Build tools does not help with that all. You need to know what you want to build. (Quoted from Ritesh Gun's answer)
"I heard they're used almost in all kind of real-world development" - For some reason, software developers like to work in large companies. They seem to have more unclear work directives for every individual working there.
"How come I never needed them in past four years". Probably because you are a skilled programmer.
Pseudo, meta. I think build tools do not provide any really real benefit at all. It is just there to add a sense of security arising from bad company practices, lack of direction - bad software architectural leadership leading to bad actual knowledge of the project. You should never have to use build tools(for testing) in your project. To do random testing with a lack of knowledge of the software project does not give any sort of help at all.
You should never ever add something to a project without knowing it's purpose, and how it will work with the other components. Components can be functional separate, but not work together. (This is the responsibility of the software architect I assume).
What if 4-5 components are added into the project. You add a 6th component. Together with the first added component, it might screw up everything. No automatic would help to detect that.
There is no shortcut other than to think think think.
Then there is the auto download from repositories. Why would you ever want to do that? You need to know what you download, what you add to the project. How do you detect changes in versions of the repositories? You need to know. You can't "auto" anything.
What if we were to test bicycles and baby transports blindfolded with a stick and just randomly hit around with it. That seems to be the idea of build tool testing.
I'm sorry there are no shortcut
https://en.wikipedia.org/wiki/Scientific_method
and
https://en.wikipedia.org/wiki/Analysis
A little background, we have a fairly large code base, which builds in to a set of libraries - which are then distributed for internal use in various binaries. At the moment, the build process for this is haphazard and everything is built off the trunk.
We would like to explore whether there is a build system which will allow us to manage releases and automatically pull in dependencies. Such a tool exists for java, Maven. I like it's package, repository and dependency mechanism, and I know that with either the maven-native or maven-nar plugin we could get this. However the problem is that we cannot fix the source trees to the "maven way" - and unfortunately (at least the maven-nar) plugins don't seem to like code that is not structured this way...
So my question is, is there a tool which satisfies the following for C++
build
package (for example libraries with all headers, something like the .nar)
upload package to a "repository"
automatically pull in the required dependencies from said repository, extract headers and include in build, extract libraries and link. The depedencies would be described in the "release" for that binary - so if we were to use CI server to build that "release", the build script has the necessary dependencies listed (like the pom.xml files).
I could roll my own by modifying either make+shell scripts or waf/scons with extra python modules for the packaging and dependency management - however I would have thought that this is a common problem and someone somewhere has a tool for this? Or does everyone roll their own? Or have I missed a significant feature of waf/scons or CMake?
EDIT: I should add, OS is preferred, and non-MS...
Most of the linux distributions, for example, contain dependency tracking for their packages. Of all the things that I've tried to cobble together myself to take on your problem, in the end they all are "not quite perfect". The best thing to do, IMHO, is to create a local yum/deb repository or something (continuing my linux example) and then pull stuff from there as needed.
Many of the source-packages also quickly tell you the minimum components that must be installed to do a self-build (as opposed to installing a binary pre-compiled package).
Unfortunately, these methods are that much easier, though it's better than trying to do it yourself. In the end, to be cross-platform supporting, you need one of these systems per OS as well. Fun!
I am not sure if I understand correctly what you want to du, but I will tell you what we use and hope it helps.
We use cmake for our build. It hat to be noted that cmake is quite powerful. Among other things, you can "make install" in custom directories to collect headers and binaries there to build your release. We combine this with some python scripting to build our releases. YMMV, but some things might just be too specific for a generic tool and a custom script may be the simpler solution.
Our build tool builds releases directly from a svn reposity (checkout, build, ...) which I can really recommend to avoid some local state polluting the release in some unforseen way. It also enforces reproducability.
It depends a lot on the platforms you're targeting. I can only really speak for Linux, but there it also depends on the distributions you're targeting, packages being a distribution-level concept. To make things a bit simpler, there are families of distributions using similar packaging mechanisms and package names, meaning that the same recipe for making a Debian package will probably make an Ubuntu package too.
I'd definitely say that if you're willing to target a subset of all known Linux distros using a manageable set of packaging mechanisms, you will benefit in the long run from not rolling your own and building packages the way the distribution creators intended. These systems allow you to specify run- and build-time dependencies, and automatic CI environments also exist (like OBS for rpm-based distros).
We recently moved to an automatic build system (something internal, not Hudson or Teamcity, yet).
Our version is stored in a header file and is included by some cpp and resource files. It is also used by the installer.
Its format is A.B.C.D where:
A didn't change in years.
B changes rarely (major version).
C changes with minor versions.
D changes when a new minor version (bug fix) is delivered to QA.
Up until now, the one incharge of building a new version, incremented C/D by hand (D being the more common) before starting the build, checked in the change and then started the build. The version stayed the same until that person built the app successfully.
Naturally with the move to an automatic build system I'd like to get rid of the manual step of changing the version number.
How should this be approached?
Do I increment D whenever a new build is made, whether it's a QA build or an internal-test build (i.e. I'm working on some feature and I'd like to test I haven't broke anything)?
Is the increment step a task in the automatic build system?
After incrementing, should I commit the version file?
How do I avoid having a lot of noise in my version control? I don't want tons of "version incremented" commits.
What do I do if the build failed? Still increment the version and commit?
Do I increment D whenever a new build is made, whether it's a QA build or an internal-test build (i.e. I'm working on some feature and I'd like to test I haven't broke anything)?
The Eclipse Foundation adds an E element, the date and time of the build. I think that's a good idea for the internal-test builds. It's up to you if you want to use E for the QA builds.
Is the increment step a task in the automatic build system?
Seems logical, but you have to have some way of telling that task what kind of build you're doing.
How do I avoid having a lot of noise in my version control? I don't want tons of "version incremented" commits.
Commit the version control file with the source code.
Basically, your development build process should proceed in the following order.
Build the product from the development source code.
If the build succeeds, increment the version number.
Commit the source code and the version control file.
Build the product again from your version control system.
If the build fails, back out the source code and version control file commit.
This tests your build and your build process. The second build should never fail, but if it does, there's a problem in the process.
Your production build process would start at the 2nd step, skipping the 3rd step.
What do I do if the build failed? Still increment the version and commit?
My E is auto-incrementing. :-) I'd say no for the other elements A, B, C, or D.
Do I increment D whenever a new build is made, whether it's a QA build or an internal-test build (i.e. I'm working on some feature and I'd like to test I haven't broke anything)?
Yes, change your process so that D increments with every build (successful or not) rather than with every delivery to QA.
It can be quite frustrating having several builds, some working some not and not being able to tell them apart because the failed build is the same id as the good one, well eventually.
Then you don't even have to consider if it was on the same day or in the same hour.
Is the increment step a task in the automatic build system?
I'd have the build system auto increment the build number (D) only.
After incrementing, should I commit the version file?
How do I avoid having a lot of noise in my version control? I don't want tons of "version incremented" commits.
The version control storage is all about recording the detailed noise.
I'd have the version update checked in, this can make a reasonable tag visible in SVN of what build the previous changes where included in, have the build system ignore checkins by the build system, or those identified as the version update checkin.
Then to view the version history you should have an appropriate tool that allows you to filter the history to show you the view you need, in some cases excluding the version commit tags.
If you choose not to commit the version number for each build, then it might be a good idea to maintain the version number in a separate file to avoid accidental updates.
What do I do if the build failed? Still increment the version and commit?
Still increment the version number, I wouldn't commit the version number unless it was a successful build. You can have a variety of failures outside of source change in version control that don't need to be recorded - build server out of disk, server crash, compiler got all wobbly in the knees building 32 and 64 bit, debug and release aix, linux and windows builds at the same time...
You could consider to use the convention for .NET assemblies, as described in the documentation for class System.Version. Quote:
Build [your C]: A difference in build number represents a recompilation of the same source. Different build numbers might be used when the processor, platform, or compiler changes.
Revision [your D]: Assemblies with the same name, major, and minor version numbers but different revisions are intended to be fully interchangeable. A higher revision number might be used in a build that fixes a security hole in a previously released assembly.
How are you going to automate this? I mean, what system would know that "this build is the release build!". It would seem to me that all your digits in a version is relevant. If the next release (D + 1) requires two builds, then would A.B.C.D+2 be the next version? Sounds fishy to me. I would rather add the build number on top of the version instead, if it's really necessary to have this information on your DLLs and EXEs.
I don't think the build number is a relevant piece of information to have attached to the binary, unless you distribute files of version A.B.C.D from different builds (which you shouldn't do anyway!)
I would setup the build server to store the artifacts (DLLs, EXEs, MSIs, PDBs, etc) in a directory, whose name includes the build number and version, and then burn DVD/whatever from there. If you ever need to back track from a version to a specific build, you can use this information, provided that you keep an archive of your releases (recommended!).
I would recommend the use of autorevision.
You could still keep the A.B.C.D format for your tags and use the script to create header files that are generated at build time that have the needed info in them.
What we need in our firm is a sort of release management tool for Linux/C++. Our products consist of multiple libraries and config files. Here I will list the basic features we want such system to have:
Ability to track dependencies, easily increase major versions of libraries whose dependencies got their major version increased. It should build some sort of dependency graph internally so it can know who is affected by an update.
Know how to build the products it handle. Either a specific build file or even better - ability to read and understand makefiles.
Work with SVN so it can check for new releases from there and does the build.
Generate some installers - in rpm or tar.gz format. For that purpose it should be able to understand the rpm spec file format.
Currently we are working on such tool which is already pretty usable. However I believe that our task is not unique and there should be some tool out there which does the job.
You should look into using a mix between Hudson, Maven (for build management), Ivy (for dependencies management) and Archiva (for artifacts archival).
Also, if you are looking into cross.compilation, take a look at Make Project Creator (MPC) and Bakefile.
Have fun!!
In the project I'm currently working on we use cmake and other Kitware tools to handle most of this issues for native code (C++). Answering point by point:
The cmake scripts handle the dependencies for our different projects. We have a dependency graph but I don't know if is a home-made script or it is a functionality that cmake provides.
Well cmake generates the makefiles regarding the platform. I generates projects for eclipse cdt and visual studio if it is asked to do so in case of developing.
Cmake has a couple of tools, ctest and cdash that we use to do the daily build and see how the test are doing.
In order to create the installer cmake has cpack. From just one script it can generate tar.gz, deb or rpm files in Linux or an automatically generated NSIS script to generate installers in windows.
For Java code we use maven and hudson that have been already mentioned here.
Take a look at this article from DDJ, in which a more robust build system concept (than make) is presented and implemented. Not sure it will fit well to your requirements, but it's the closest I've ever seen. I was looking for the same thing months ago, and then I discovered the article.
http://www.drdobbs.com/architect/218400678
Maven has a native code plugin. I don't think it'll do everything you want, but it's good at tracking version numbers of dependencies, will build artefacts and it'll work with your VCS.
No idea
cmake/scons: I have used cmake but I don't exactly love it, but I have heard really good things about scons. But scons is python-based, so you need to have python installed on the build/dev machines.
I use Hudson, which has a plugin to fetch from svn. It performs intelligently in general, and in particular builds only if some file has changed in an svn update. Hudson is easy to get started with. Hudson is java-based and is pretty popular with the Java community. This means it is quite cross-platform, but you need to have JRE installed on the build machine.
Probably can call some rpm tool within hudson.