Retrieve all installed packages and their versions from nodes - puppet

I use puppet to manage package installations on a number of nodes. These nodes are used as software testing environments. It happens that packages are uninstalled during software tests or their version might change, depending on the test scenario.
Is it possible to retrieve a list of all currently installed packages on each of my nodes? A "snapshot" of the whole testing environment, so to say.
Thanks!

With Facter 2, you can create a custom fact that hands a hash structure to the master, e.g. package-name => package-version.
With PuppetDB, you can store all those fact values and retrieve them via the API.

Related

How to be able to "move" all necessary libraries that a script requires when moving to a new machine

We work on scientific computing and regularly submit calculations to different computing clusters. For that we connect using linux shell and submitting jobs through SGE, Slurm, etc (it depends on the cluster). Our codes are composed of python and bash scripts and several binaries. Some of them depend on external libraries such as matplotlib. When we start to use a new cluster, it is a nightmare since we need to tell the admins all the libraries we need, and sometimes they can not install all of them, or they only have old versions that can not be upgraded. So we wonder what could we do here. I was wondering if we could somehow "pack" all libraries we need along with our codes. Do you think it is possible? Otherwise, how could we move to new clusters without the need for admins to install anything?
The key is to compile all the code you need by yourself, using the compiler/library/MPI toolchains installed by the admins of the clusters, so that
your software is compiled properly for the cluster hardware, and
you do not depend on the admin to install the software.
The following are very useful in this case:
Ansible, to upload/manage configuration files, rc files, set permissions, compile your binaries, etc. and deploy a new environment easily on new clusters
Easybuild to install your version of Python with all the needed dependencies, and install other scientific software thanks to the community supported build procedures
CDE to build a package with all dependencies for your binaries on your laptop and use it as-is on the clusters.
More specifically for Python, you can use
virtual envs to setup a consistent set of Python modules across all clusters, independently from the modules already installed; or
Anaconda or Canopy to use a Python scientific distribution
to have a consistent Python install across all clusters.
Don't get me wrong, but I think what you have to do so: stop behaving like amateurs.
Meaning: the integrity of your "system configuration" is one of the core assets of your "business". And you just told us that you are basically unable of easily re-producing your system configuration.
So, the real answer here can't be a recommendation to use this or that technology. The real answer is: you, and the other teams involved in running your operations need to come together and define a serious strategy how to fix this.
Maybe you then decide that the way to go is that your development team provides Docker buildfiles, so that your operations team can easily create images on new machines. Or you decide that you need to use something like ansible to enable centralized control over your complete environment.
That's what venv is for, it allows you to create a portable customized environment easily, with exactly what you need and nothing more.
I completely agree with https://stackoverflow.com/users/1531124/ghostcat
but here is the really bad answer that will cause you a lot of problems in near future!!!:
if you need some dynamic library and you are not planning to upgrade them in future, you can try copying all needed libs to a folder in your app and use an script to launch the app:
#!/bin/sh
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/path/to/your/lib/folder
./myAPP
but keep in mind that this is bad practice.
Create a chroot image, like here - click. Install everything you need and then you can just chroot into it on any machine.
I work on scientific clusters as well, and you are going to find that wherever you go.
I would only rely on the admins on installing the most basic stuff. That is:
- Software necessary to build your software or run the most basic stuff: compilers and most basic utilities (python, perl, binutils, autotools, cmake, etc.).
Software libraries that make use of I/O devices: MPI, file I/O libraries...
A queue system (they already have it most of the time).
Environment modules. This is not a must, but it really helps you get the job done, specially if you mess with different library versions or implementations (that's my case, for example).
From that point on, you can build and install on your own directories all the software you use most of the time.
This does not mean that you cannot ask an admin to install some libraries. If you feel that many people is going to benefit from that, then you should request its installation. In addition, you may need some specific version or some special features which are not used most of the time, but you really need them. A very good example is with BLAS libraries (basic lineal algebra subroutines):
You have lots of BLAS implementations available: the original BLAS, Intel MKL, OpenBLAS, ATLAS, cuBLAS
If that is not enough, the open source versions usually offer multiple configuration options: serial version, parallel version with PThreads, parallel version with OpenMP, parallel version with MPI...
In my particular case, most of the software that I felt was necessary for many users in the cluster ended up being installed by the admins without any problem (either me or other users requested it), but you also have to keep in mind that in a cluster there can be many users and a single person/team is not able to attend the specific requirements you need, specially if you are able to do so.
I think you want to containerize your application in some way. Two main options (because docker/rkt and similar things are way too heavyweight for your task if I understand it correctly) in my opinion are runc and snappy.
Runc relies on OCI runtime specification, you need to create an environment (that is very similar to chroot environment in that you need to copy everything you software uses in one directory) and then you'll be able to run your application with runc tool. Runc itself is just one binary, at the moment it requires root privileges to run (hello, cluster admins), but there are patches at least partly solving that, so if you build your own runc and there are no blocking things wrt root privilege requirements you may be able to run your application with no administration overhead at all.
Snappy is similar in that you need to prepare a snap package for your application, this time using snapcraft as an assistant tool. Snappy is probably a bit easier in creating an application image and IMO is certainly better for long-term support because it clearly separates your application from the data (kinda W^X, application image is a read-only squashfs file and application can only write to a limited set of directories). But at the moment it will require your cluster admins to install snapd and to perform some operations like snap installation that require root privileges. Still, it should be better than your current situation, because that's just one non-intrusive package to install.
If these tools don't fit for some reason, there is always an option to make something of your own. That won't be easy and there are many subtle details that can bite you when doing that, but it can be done, compile all of your dependencies and applications into some path, create wrapper scripts to set up PATH and LD_LIBRARY_PATH environment for your components and then bring that directory into the new cluster, run wrapper scripts instead of target binaries and that's it. It's similar to what XAMPP does, they have quite a number of integrated things packaged into one directory that works across many distributions.
update
Let's also add AppImage into the mix, theoretically it can be a savior for your case, as it specifically does not require root privileges. It's kinda inbetween Snappy and rolling your own, as you need to prepare your application directory yourself (snappy can manage some of dependencies with snapcraft when you just specify "I need this Ubuntu package"), add appropriate metadata and then it can be packaged into single executable.

yum/ zypper for non-root installation in independent rpm database

My company is developing a Linux based software product which is shipped to different customers.
The product it self consits out of small software components which interact with each other.
What we usually ship as an update/ new release to the customer are the the current versions of the different software components e.g. compA-2.0.1, compB-3.2.3 and compC-4.1.2
Currently we employ a rather simple shell script for the installation/ upgarding process. However, we'd like to move forwarard to state of the art packaging, mainly to have an easy way of swapping different versions of components, keeping track of files and the packages they belong to and also to provide the customers with an easier interface for the update/ installation.
The software components are installed in different directories, depending on the customers demands. So it could be in /opt, /usr/local or something completely different.
Since the vast majority of our customers runs on rpm-based Linux distributions we decided for rpm-packages instead of dpkg.
In rpm terms our problem is a non-root installation. This is realativly straight forward using the following features:
own rpm database using the --dbpath option
installing in different locations using the Prefix mechanism
optional: disabling auto library dependancies using AutoReqProv: no in the rpm spec file
Using those features/ options allows us to create rpm packages which can be installed using the rpm command line tool as non-root user.
However, what we really would like to see is to install those packages via a http repository with either yum or zypper. The latter one is the tool of choice in SUSE based distributions.
The problem we see is, that non of the tools is providing the required alternative rpm database option (--dbath in rpm) and prefix support required for a non-root installation.
Does anybody have a suggestion/ idea how to deal with this issue? Is there maybe a third package-tool with we're not aware of?
Or should we maybe go a totally different route? I had a play with GNU stow and wrote some very simplistic yum-like logic around it - but then I would basically start my own package installation tool which I tried to circumvent.

NodeJS Production Deployment Best Practice

I'm looking for ways in which to deploy some web services into production in a consistent and timely manner.
I'm currently implementing a deployment pipeline that will end with a manual deployment action of a specific version of the software to a number of virtual machines provisioned by Ansible. The idea is to provision x number of instances using version A whilst already having y number of instances running version B. Then image and flick the traffic over. The same mechanism should allow me to scale new vms in a set using the image I already made.
I have considered the following options but was wondering if theres something I'm overlooking:
TGZ
The CI environment would build a tarball from a project that has passed unit tests and integration tests. Optionally depednencies would be bundled (removing the need to run npm install on the production machine and relying on network connectivity to public or private npm repository).
My main issue here is that any dependencies that depend on system libraries would be build on a different machine (albeit the same image). I don't like this.
NPM
The CI environment would publish to a private NPM repository and the Ansible deployment script would check out a specific version after provisioning. Again this suffers from a reliance on external services being available when you want to deploy. I dont like this.
Git
Any system dependent modules become globally installed as part of provisioning and all other dependencies are checked into the repository. This gives me the flexibility of being able to do differential deployments whereby just the deltas are pushed and the application daemon can be restarted automatically by the process manager almost instantly. Dependencies are then absolutely locked down.
This would mean that theres no need to spinning up new VM unless to scale. Deployments can be pushed straight to all active instances.
First and foremost, regardless of the deployment method, you need to make sure you don't drop requests while deploying new code. One simple approach is removing the node from a load balancer prior to switchover. Before doing so, you may also want to try and evaluate if there are pending requests, open connections, or anything else negatively impacted by premature termination. Or perhaps something like the up module.
Most people would not recommend source controlling your modules. It seems that a .tgz with your node_modules already filled in from an npm install while utilizing a bundledDependencies declaration in your package.json might cover all your concerns. With this approach, an npm install on your nodes will not download and install everything again. Though, it will rebuild node-gyp implementations which may cover your system library concern.
You can also make use of git tags to more easily keep track of versions with specific dependencies and payloads. Manually deploying the code may get tedious, you may want to consider automating the routine while iterating over x amount of known server entries in a database from an interface. docker.io may be of interest.

Using Vagrant, why is puppet provisioning better than a custom packaged box?

I'm creating a virtual machine to mimic our production web server so that I can share it with new developers to get them up to speed as quickly as possible. I've been through the Vagrant docs however I do not understand the advantage of using a generic base box and provisioning everything with Puppet versus packaging a custom box with everything already installed and configured. All I can think of is;
Advantages of using Puppet vs custom packaged box
Easy to keep everyone up to date - Ability to put manifests under
version control and share the repo so that other developers can
simply pull new updates and re-run puppet i.e. 'vagrant provision'.
Environment is documented in the manifests.
Ability to use puppet modules defined in production environment to
ensure identical environments.
Disadvantages of using Puppet vs custom packaged box
Takes longer to write the manifests than to simply install and
configure a custom packaged box.
Building the virtual machine the first time would take longer using
puppet than simply downloading a custom packaged box.
I feel like I must be missing some important details, can you think of any more?
Advantages:
As dependencies may change over time, building a new box from scratch will involve either manually removing packages, or throwing the box away and repeating the installation process by hand all over again. You could obviously automate the installation with a bash or some other type of script, but you'd be making calls to the native OS package manager, meaning it will only run on the operating system of your choice. In other words, you're boxed in ;)
As far as I know, Puppet (like Chef) contains a generic and operating system agnostic way to install packages, meaning manifests can be run on different operating systems without modification.
Additionally, those same scripts can be used to provision the production machine, meaning that the development machine and production will be practically identical.
Disadvantages:
Having to learn another DSL, when you may not be planning on ever switching your OS or production environment. You'll have to decide if the advantages are worth the time you'll spend setting it up. Personally, I think that having an abstract and repeatable package management/configuration strategy will save me lots of time in the future, but YMMV.
One great advantages not explicitly mentioned above is the fact that you'd be documenting your setup (properly), and your documentation will be the actual setup - not a (one-time) description of how things were/may have been intended to be.

Maintaining software as a user (on a cluster)

Every cluster of computers I've encountered suffers from the same problem: its software is outdated. Naturally, one has the ability as a user to install everything from source in the home directory. I was wondering if there are any tools that would allow one to install and update software within home directory the same way package managers do in Linux distributions, i.e. with minimal pain and effort.
I have found toast, which is good, but not always reliable and up-to-date. Are there alternatives?
My particular needs at the moment are a recent version of GCC, boost, python, cmake.
I recommended using a sensible distribution for your cluster nodes. Then keeping the nodes up-to-date can be as simple as running the package manager, which you can even do via a distributed shell on all nodes at once. And for what it is worth, my choice would be Debian or Ubuntu.
You could try nix (http://nixos.org/). I haven't used it, so I don't know if it's more up-to-date than toast.
Either use a package manager that installs/updates on all cluster nodes transparently or create a directory that is shared (i.e. network file system) from all nodes

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