I'm trying to use RPMs to install public and private software into disk images that are eventually written to the boot flash of Linux based embedded systems.
My current methodology is to mount the image (/mnt/foo) read/write on a CentOS 6.5 box and use the rpm --installroot=/mnt/foo option. There are two problems:
--installroot=/mnt/foo appears to chroot into /mnt/foo, meaning that when the post install scripts run /bin/sh (etc.) they're actually using /mnt/foo/bin/sh (etc.) That's sort of workable if the target architecture is the same as the installation box but gets very messy if its not. I'm interested to hear if someone has solved this before.
At a higher level it would be nice to use yum or apt-get or ??? to handle package dependencies and repositories. yum is the obvious choice on CentOS but it has a weak grasp of non-native architectures and would likely require some hacking. apt-get looks more promising in that department but in truth I've never used it and my attempts to install it on CentOS 6.5 have left me in dependency hell.
This seems like a problem someone would have hit before but unfortunately everything I can find about RPMs and embedded systems assumes identical processor architectures.
Bottom line, I need to use RPMs to install software to a Linux image that will be the boot disk for a embedded system. Other than doing the rpm install as part of the image installation on the embedded system (our installation time is already a big problem) I'm open to just about anything.
Any suggestions will be gratefully received.
Have you tried using some continuous build system like Jenkins? You can use that to easily set up build hosts on any architecture/platform you like, so long as that platform has some basic tools (like ssh).
You could use a combination of the --installroot flag mentioned by other commenters, alongside of some VMs setup as build hosts in Jenkins in order to install your RPMs in a specific directory while avoiding any platform/architecture issues.
I'm not sure what your specific requirements are, but, depending on how far you are willing to go... RPMs are just compressed CPIO archives with a header, so you could use rpm2cpio piped to cpio to extract the files in the RPM. You can then extract the postinstall scripts using rpm -qp --scripts filename.rpm and run them yourself. The downside to this, is of course, that you lose a lot of the benefit of using RPM/yum in the first place like the automatic installation of dependencies, and so on.
Related
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
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 am trying my hands new on Linux.
The following command is very useful:
sudo apt-get install <application>;
As it adds the application into the linux programs list and automatically upgrades it while running the update manager.
But I would like to get more knowledge on installing the programs from the .tar.gz archives as well.
So I do:
Extract the archive
./configure;
make;
make install;
I have two questions in this process:
1) I read in the forum that "make install" is not good if we are updating the binaries.
So should I just do "make" and the "install" ?
2) Second question is that is there a way to add the program installed in such manner to the Linux Software Update list so that I do not have to use the terminal for every new version that is released
Installing programs from tarballs:
You really do not want to install packages from .tar.gz when they are in the repositories. It is much harder to update or remove it manually than you could do with apt-get.
If you really have to compile the program yourself use checkinstall instead of make install. This creates a package you can install it via the package management and later remove using apt-get. This is much cleaner.
Also you may want to type
./configure && make && sudo checkinstall
instead of the commands you wrote. This way the program is only compiled if the configuration succeeded. The package is only built if the compilation succeeded. With ; instead of && all processes would be attempted no matter if its prerequisites are matched.
Graphical package managers
You can install your packages from GUI programs. Kubuntu uses for example uses muon for this, but the programs vary between distributions.
make install is "not good" if you want to be able to easily remove the files associated with a package as there is no log of the work it does and often no easy way to reverse the process. That has little to nothing to do with updating the software though (though updates can certainly run into related issues).
No, you can't add the manually compiled and installed software to your distributions list of packaged software (other than through something like checkinstall or creating a package yourself) since that's exactly what you were avoiding in the first place.
That all being said if the package exists for your distribution and you want to build it from source yourself you can often just build a more-or-less official version of the package from the distributions source package.
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.
It seems that the RPM logic is quite different from what I know already and I am having some issues understanding the "RPM logic". For my work, I have to create a documentation on "How-to create a RPM package on Red Hat 5".
I'm used to Debian and it's derivatives (Ubuntu, and so on) and thus to Debian packages (aka. .deb files).
From what I read, it seems that ones need to be root to create a RPM package. While I understand why root could be required to install a package, I still don't understand why elevated privileges should be needed just to create one.
If I try to create a RPM package as a user, changing the buildroot it fails on the %installstep because I don't have permission to write files into /usr/bin. Fair enough but... why does it want to copy my files into /usr/bin at this step?! I just want to create the package, not install it!
I'm sure I'm missing something here. Is there anyone who could give me at least a basic understanding of how rpmbuild works and why?
Will this do?
You don't need to be root to build RPM packages. I recommend you to read this two part article to get you started.
The official Maximum RPM book also has a chapter on Having RPM Use a Different Build Area, which allows non-root users to build RPMs.