My knowledge on Linux administration is limited and hence wanted to check here about the pros and cons of installing any RHEL/CentOS Linux software using rpm packages over installing through tar/zip files.
Thanks
a non-exhaustive list of pros and contras:
rpm
intelligent dependency managment
conflict checking
allow easy and clean uninstall
allow for upgrades / downgrades
list all files owned by a package
a central database with all packages installed, which files they own, their interdependencies
from source
you choose yourself all compiler flags
you can choose a custom installation path
I have tried to explain the diff, pros and cons,
Tar
Basically tar is old way of dealing with in Linux. We can say its existence when the Linux was created.
Usually the tar consists of Source Code and needs to be compiled in binary format for us to use.
Pros:
Using tar packages you gain more control over the programs that you install.
If you want certain portions that avoided, you could do that on the go. Which give you the upper hand.
Cons:
The main issue comes in the maintainability of the packages installed.
They are hard to manage. Once you install, there was no way to manage the software unless and until its well documented. It also hard to version them and you are left blank on the software version you have. The possible reason for this because of the non-indexing nature of files. The files could be spread across your file system, which makes it difficult to remove or upgrade it.
Hard to automate.
It is also hard to automate because of the complexities in maintaining the packages.
Below I tried explaining how tar file are compiled to get better understanding,
Prepare(setup) environment for building
./configure
This script has lots of options that you should change. Like --prefix or --with-dir=/foo. That means every system has a different configuration. Also ./configure checks for missing libraries that should be installed. Anything wrong here causes not to build your application. That's why distros have packages that are installed on different places, because every distro thinks it's better to install certain libraries and files to certain directories. It is said to run ./configure, but in fact you should change it always.
Building the system
make
This is actually make all by default. And every make has different actions to do. Some do building, some do tests after building, some do checkout from external SCM repositories. Usually you don't have to give any parameters, but again some packages execute them differently.
Install to the system
make install
This installs the package in the place specified with configure. If you want you can specify ./configure to point to your home directory. However, lots of configure options are pointing to /usr or /usr/local. That means then you have to use actually sudo make install because only root can copy files to /usr and /usr/local.
Please go through the below link for more information on the above commands
Why always ./configure; make; make install; as 3 separate steps?
RPM
The RPM Package Manager (RPM) is an open packaging system,
RPM packages pre-compiled binary packages (as well as source packages) for an easy one-click installation experience. RPM by itself does not manage dependency and resolve conflicts. When combined with Yum or PackageKit it will resolve all the dependency for the package.
RPM makes system updates easy. Installing, uninstalling and upgrading RPM packages can be accomplished with short commands. RPM maintains a database of installed packages and their files, so you can invoke powerful queries and verification on your system. During upgrades, RPM handles configuration files carefully, so that you never lose your customisation, that you cannot accomplish with regular .tar files.
RPM feature has the ability to verify packages. If you deleted an important file for some package, you can verify the package. You will notified of changes, if any—at which point you can reinstall the package, if necessary. Any configuration files that you modified are preserved during re installation.
Pros:
Install, reinstall, remove, upgrade and verify packages
Use a database of installed packages to query and verify packages
Use metadata to describe packages, their installation instructions, and so on
Package pristine software sources into source and binary packages
Add packages to Yum repositories
Digitally sign your packages
Querying a package (if the package is on your local file system or after the package is installed)
Validating a package (checking a package has not been tampered with, before or after installation).
Cons
Not as customisable as tar.
eg on usability: We will see how to install package using Tar or rpm:
in Tar:
$ tar xvf package.tar
$ cd package
$ ./configure --prefix=PREFIX
$ make
$ make install
in RPM:
rpm -U package-2.4.x-1.i686.rpm
That simple!!.
It basically depends on the usability and the purpose of your use.
Each of them has its on pros and cons depends on how and for what we use it.
I know it a long explanation,how this will give you clear picture. I know there are more untouched such as architecture and execution. I am not pretty confident to explain those here.
In simple words you can say that rpm are prepackaged binaries. They're just ready to go, it does everything for you. But to install rpm and deb you need to be root to have some write permissions. That leaves some serious security hole in the system. You may be unknowingly installing a Torjan horse. Also if the packages are screwed up they may cause the installation to fail altogether.
I personally recommend using tar as you are in more control. It is old school, I know, that's why a bit difficult but, in my opinion best way to go.
You can further refer to the link:
https://tldp.org/HOWTO/Software-Building-HOWTO-4.html
Related
Good afternoon,
I am currently building an RPM that has some requirements I have not found answers to on the web. I have narrowed this down to a single question.
Normally when I run an install from command line, one of the steps has me run the following command yum groupinstall "Compatibility libraries" which installs 32-bit compatibility libraries on my 64-bit desktop. I am wondering if there is a way to accomplish this in the Requires: field of my RPM-spec file, as I have only found a way to require very specific RPM's for dependencies?
I could always add in the 10-15 individual packages that get installed with yum groupinstall "Compatibility Libraries", but I was hoping there was a better option.
Description of RPM:
My RPM is very basic in nature. It will untar multiple tar files into various locations, overwrite files throughout the main install directory, install compatibility libraries, and then proceed to startup a service.
If anyone needs more information to what I am trying to accomplish please let me know. Thank you.
You can only require specific packages, not groups, in your Requires: lines. You should absolutely not run yum in your %post script, because then (a) you are then hiding your dependencies, and nobody likes to see things get installed that they didn't expect, and (b) you will probably end up getting stuck because yum in %post would need to wait for the existing yum process to exit.
For library Requires:, the rpm build process will generally figure things out for you. You still need to manually specify the appropriate BuildRequires: dependencies, which are things that are required to build the package.
If you want to update your question with more details (e.g., a link to the spec file and a description of what you're trying to do, if it's not obvious from the spec), maybe we can come up with better solutions.
I need to install a YUM package(OpenNMS) on a server that doesn't have internet access. Is there a clean way to download all dependencies on a server with internet, package it , export it and install it on the server?
Yes/no: there are some limited tools available, and a few problems.
On your server, you can use yumdownloader (or a Downloadonly plugin for yum of yum) to create a local repository of packages. With either approach, you would download the package along with its dependencies.
This process is mentioned in
Download all dependencies with yumdownloader, even if already installed?.
yumdownloader vs repotrack
There is a caveat: my experience is that the tools can be confused by the presence of existing packages on your server (i.e., installed) and will often overlook those in the actual download. One way to work around this is to reprocess the list of downloaded files (asking for their dependencies) to check if no further files will be downloaded.
Of course, if successful, you will end up with a large number of packages (including glibc). However the alternative would be to use the dependencies known to rpm -qpR, which require a lot of work to be useful.
Alright so after trying to chase down the dependencies for various pieces of software for the n-th time and replicating work that various people do for all the different linux distributions I would like to know if there is a better way of bundling various pieces of software into one .rpm or .deb file for easier distribution.
My current set up for doing this is a frankenstein monster of various tools but mainly Vagrant and libguestfs (built from source running in Fedora because none of the distributions actually ship it with virt-diff). Here are the steps I currently follow:
Spin up a base OS using either a Vagrant box or by create one from live CDs.
Export the .vmdk and call it base-image.
Spin up an exact replica of the previous image and go to town: use the package manager,
or some other means, to download, compile, and install all the pieces that I need. Once again, export the .vmdk and call it non-base-image.
Make both base images available to the Fedora guest OS that has libguestfs.
Use virt-diff to diff the two images and dump that data to file called diff.
Run several ruby scripts to massage diff into another format that contains the information I need and none of the stuff I don't like things in /var.
Run another script to generate a command script for guestfish with a bunch of copy-out commands.
Run the guestfish script.
Run another script to regenerate the symlinks from diff because guestfish can't do it.
Turn the resulting folder structure into a .deb or .rpm file and ship it.
I would like to know if there is a better way to do this. You'd think there would be but I haven't figured it out.
I would definitely consider something along the lines of:
A)
yum list (select your packages/dependencies whatever)
use yumdownloader on the previous list (or use th pkgs you have already downloaded)
createrepo
ship on media with install script that adds the cd repo to repolist, etc.
or B)
first two steps as above, then pack the rpms into an archive build a package that contains all of the above and kicks off the actual install of the rpms (along the lines of rpm -Uvh /tmp/repo/*) as a late script (in the cleanup phase, maybe). Dunno if this can be done avoiding locks on the rpm database.
I think you reached the point of complexity - indeed a frankenstein monster - where you should stop fearing of making proper packages with dependencies. We did this in my previous work - we had a set of fabricated rpm packages - and it was very easy and straightforward, including:
pre/post install scripts
uninstall scripts
dependencies
We never had to do anything you just described. And for the customer, installing even a set of packages was very easy!
You can follow a reference manual of how to build RPM package for more info.
EDIT: If you need a single installation package, then create this master packge, that would contain all the other packages (with dependencies set properly) and installed them in the post-install script (and uninstalled them in the uninstall script).
There are mainly 3 steps to make a package with all dependencies (let it be A, B & C).
A. Gather required files.
There are many way to gather files of the main software and its dependencies. In order to get all the dependices and for error free run you need to use a base OS (i.e live system)
1. Using AppDirAssistant
This app is used by www.portablelinuxapps.org to create portable app directory. They scan and watch for the files accessed by the app to find required.
2. Using chroot & overlayfs
In this method you don't need to boot into live cd instead chroot into it.
a. mount the .iso # /cdrom and
b. mount the filesystem(filesystem.squashfs) # another place, say # /tmp/union/root
c. Bind mount /proc # /tmp/union/root/proc
d. Overlay on it
mount -t overlayfs overlayfs /tmp/union/root -o lowerdir=/tmp/union/root,upperdir=/tmp/union/rw
e. Chroot
chroot /tmp/union/root
Now you can install packages using apt-get or another method (only from the chrooted terminal). All the changed files are stored # /tmp/union/rw. Take files from there.
3. Using manually collected packages
Use package manager to collect dependencies. For example
apt-get install package --print-uris will print download uris for dep packages. Using this uris download packages and extract all (dpkg -x 1.deb ./extracted).
B. Clean garbage files
After gathering files remove unwanted files
C. Pack files
1. Using appImageAssistance
If you manually gathered files then you need to copy appname.desktop file from ./usr/share/applications to root of directory tree. Also copy file named AppRun from another app or extract it from AppDirAssistance.
2. Make a .deb or .rpm using gathered files.
Is the problem primarily that of ensuring that your customers have installed all the standard upstream distro packages necessary for your package to run?
If that's the case, then I believe the most straightforward solution would be to leverage the yum and apt infrastructure to have those tools track down and install the necessary prerequisite packages.
If you supply a native yum/apt repository with complete pre-req specs (the hard work you've apparently already completed). Then the standard system install tool takes care of the rest. See link below for more on creating a personal repository for yum/apt.
For off-line customers, you can supply media with your software, and a mirror - or mirror subset - of the upstream distro, and instructions for adding them to yum config/apt config.
Yum
Creating a Yum Repository in the Fedora Deployment Guide
Apt
How To Setup A Debian Repository on the Debian Wiki
So your customers aren't ever going to install any other software that might specify a different version of those dependencies that you are walking all over, right?
Why not just create your own distro if you're going to go that far?
Or you can just give them a bunch of packages and a single script that does rpm -i dep1 dep2 yourpackage
I have a libfoo-devel rpm that I can create, using the trick to override _topdir. Now I want to build a package "bar" which has a BuildRequires 'libfoo-devel". I can't seem to find the Right Way to get access to the contents of libfoo-devel without having to install it on the build host. How should I be doing it?
EDIT:
My build and target distros are both SuSE.
I prefer solutions that don't require mock, since I believe SuSE does not include it in its stock repo.
Subsequent EDIT:
I believe that the answer I seek is in the build package. Perhaps it's SuSE's answer to mock? Or it's the distributed version of the oBS service?
DESCRIPTION
build is a tool to build SuSE Linux
RPMs in a safe and clean way. build
will install a minimal SuSE Linux as
build system into some directory and
will chroot to this system to compile
the package. This way you don't risk
to corrupt your working system (due to
a broken spec file for example), even
if the package does not use BuildRoot.
build searches the spec file for a
BuildRequires: line; if such a line is
found, all the specified rpms are
installed. Otherwise a selection of
default packages are used. Note that
build doesn't automatically resolve
missing dependencies, so the specified
rpms have to be sufficient for the
build.
Note that if you really don't need libfoo-devel installed to build package bar the most sensible alternative would be to remove libfoo-devel from the BuildRequires directive (and maybe put the requirement where it belongs).
However, if you cannot do that for some reason, create a "development" rpm database. Basically it involves using rpm --initdb --root /path/to/fake/root. Then populate it with all of the "target packages" of your standard distro installation.
That's a lot of rpm --install --root /path/to/fake/root --justdb package-name.rpm commands, but maybe you can figure out a way to copy over your /var/lib/rpm/* database files and use those as a starting point. Once you have the alternative rpm database, you can fake the installation of the libfoo-devel package with a --justdb option. Then you'll be home free on the actual rpm build.
If neither mock nor the openSUSE Build Service are a viable choice then you will have to buckle down and install the package, either directly or in a chroot; the package provides files that the SRPM packager has decided are required to build, and hence is in the BuildRequires tag.
I'm looking into trying to find an easy way to manage packages compiled from source so that when it comes time to upgrade, I'm not in a huge mess trying to uninstall/install the new package.
I found a utility called CheckInstall, but it seems to be quite old, and I was wondering if this a reliable solution before I begin using it?
http://www.asic-linux.com.mx/~izto/checkinstall/
Also would simply likely to know any other methods/utilities that you use to handle these installations from source?
Whatever you do, make sure that you eventually go through your distribution's package management system (e.g. rpm for Fedora/Mandriva/RH/SuSE, dpkg for Debian/Ubuntu etc). Otherwise your package manager will not know anything about the packages you installed by hand and you will have unsatisfied dependencies at best, or the mother of all messes at worst.
If you don't have a package manager, then get one and stick with it!
I would suggest that you learn to make your own packages. You can start by having a look at the source packages of your distribution. In fact, if all you want to do is upgrade to version 1.2.3 of MyPackage, your distribution's source package for 1.2.2 can usually be adapted with a simple version change (unless there are patches, but that's another story...).
Unless you want distribution-quality packages (e.g. split library/application/debugging packages, multiple-architecture support etc) it is usually easy to convert your typical configure & make & make install scenario into a proper source package. If you can convince your package to install into a directory rather than /, you are usually done.
As for checkinstall, I have used it in the past, and it worked for a couple of simple packages, but I did not like the fact that it actually let the package install itself onto my system before creating the rpm/deb package. It just tracked which files got installed so that it would package them, which did not protect against unwelcome changes. Oh, and it needed root prilileges to work, which is another main sticking point for me. And lets not go into what happens with statically linked core utilities...
Most tools of the kind seem to work that way, so I simply learnt to build my own packages The Right Way (TM) and let checkinstall and friends mess around elsewhere. If you are still interested, however, there is a list of similar programs here:
http://www.dwheeler.com/essays/automating-destdir.html
PS: BTW checkinstall was updated at the end of 2009, which probably means that it's still adequately current.
EDIT:
In my opinion, the easiest way to perform an upgrade to the latest version of a package if it is not readily available in a repository is to alter the source package of the latest version in your distribution. E.g. for Centos the source packages for the latest version are here:
http://mirror.centos.org/centos/5.5/os/SRPMS/
http://mirror.centos.org/centos/5.5/updates/SRPMS/
...
If you want to upgrade e.g. php, you get the latest SRPM for your distrbution e.g. php-5.1.6-27.el5.src.rpm. Then you do:
rpm -hiv php-5.1.6-27.el5.src.rpm
which installs the source package (just the sources - it does not compile anything). Then you go to the rpm build directory (on my mandriva system its /usr/src/rpm), you copy the latest php source tarball to the SOURCES subdirectory and you make sure it's compressed in the same way as the tarball that just got installed there. Afterwards you edit the php.spec file in the SPECS directory to change the package version and build the binary package with something like:
rpmbuild -ba php.spec
In many cases that's all it will take for a new package. In others things might get a bit more complicated - if there are patches or if there are some major changes in the package you might have to do more.
I suggest you read up on the rpm and rpmbuild commands (their manpages are quite good, in a bit extensive) and check up the documentation on writing spec files. Even if you decide to rely on official backport repositories, it is useful to know how to build your own packages. See also:
http://www.rpm.org/wiki/Docs
EDIT 2:
If you are already installing packages from source, using rpm will actually simplify the building process in the long term, apart from maintaining the integrity of your system. The reason for this is that you won't have to remember the quirks of each package on your own ("oooh, right, now I remember, foo needs me to add -lbar to its CFLAGS"), as the build process will be in the .spec file, which you could imagine as a somewhat structured build script.
As far as upgrading goes, if you already have a .spec file for a previous version of the package, there are two main issues that you may encounter, but both exist whether you use rpm to build your package or not:
A patch that was applied to the previous version by the distribution does not apply any more. In many cases the patch has already been applied to the upstream package, so you can simply drop it. In others you may have to edit it - or I suppose if you deem it unimportant you can drop it too.
The package changed in some major way which affected e.g. the layout of the files it installs. You do read the release notes notes for each new version, don't you?
Other than these two issues, upgrading often boils down to just changing a version number in the spec file and running rpmbuild - even easier than installing from a tarball.
I would suggest that you have a look at the tutorials or at the source package for some simple piece of software such as:
http://mirror.centos.org/centos/5.5/os/SRPMS/ipv6calc-0.61-1.src.rpm
http://mirror.centos.org/centos/5.5/os/SRPMS/libevent-1.4.13-1.src.rpm
If you have experience in buildling packages from a tarball, using rpm to build software is not much of a leap really. It will never be as simple as installing a premade binary package, however.
I use checkinstall on Debian. It should not be so different on CentOS. I use it like that:
./configure
make
sudo checkinstall make install # fakeroot in place of sudo works usally for more security
# install the package generated