It is interesting that we must have used Jenkins predefined build environment variables like $WORKSPACE, $BUILD_NUMBER etc in a lot of our Jenkins job.
I find it boggling to understand that, how does Jenkins set rules such that when we print $WORKSPACE, it prints the current workspace of various jobs. How does it map the variable $WORKSPACE to the corresponding Jenkins Job.
Jenkins needs to know certain things about your build environment and jobs in order to do its job properly. For instance it needs to know the current build number, the location where your project should be checked out, who started the current build, etc. These things are typically exposed to you through the web interface.
Jenkins also exposes this information to your build scripts through environment variables that are injected into your scripts by Jenkins when your it is first launched. These environment variables can then be picked up by your script to do whatever is necessary with them.
In the example you gave ($WORKSPACE) Jenkins needs to know the absolute path to this location on your build slave because if it didn't, it wouldn't be able to check out your source and build it. Since it knows this information it exposes it to you as well to make writing your scripts easier.
There's a complete list of generally available environment variables provided by Jenkins available here.
Related
I am building a CI/CD pipeline for a product and am confused about a few things.
I have so far worked in a system where I used to do "code promotion" for environment progression ie each branch pointed towards a certain env and PRs between the branches but very recently I read about "artifact promotion" and I feel like it is a sensible thing to do and want to give it a try.
Now for my microservices, I am able to manage it by keeping a Docker image for each env, free from any env specific variables, and supplying env variables to my pod directly. It all works. But for my frontend, I am hosting it using S3 & CloudFront and I am using Next JS f/w and the way env variables work in Next JS is that we need to supply them at build time and they get embedded in the export/dist.
How do I do "artifact promotion" in such cases, specially when the env variables are different for each environment.
PS: I know this question is very specific to my use case. Apologies if I am asking it at a wrong place!
I'm adapting an existing program to use Autotools for its build, but the resulting process depends on an environment variable. Is there a way to permanently set this environment variable during the build or installation process?
The program is intended to be used by Unix users and I could try to concatenate an export command directly to the .bashrc file and warn the user in case it fails because most of them will actually just use Ubuntu to run it (it's a relatively simple program that targets students), but I'd like to know if there's a more portable way to do this.
That's what I wouldn't like to do:
export VAR=/my/totally/not/hardcoded/path >> $HOME/.bashrc
Sorry to come to this late, but all of the answers to date are shockingly ... incomplete.
Building and installing software are both core use cases for the Autotools, and the installation part can absolutely involve adding or modifying files that affect user environments. If the software is installed by a user with sufficient privilege, then such effects can absolutely be applied to all system users, though the details may vary a bit from system to system (and the Autotools can help with that, too!).
For example, on RedHat-family Linuxes such as RedHat Enterprise, Fedora, Oracle Linux, and various others, you can drop an appropriately named file in /etc/profile.d, and the commands in it will automatically be read and executed by every login shell. Setting environment variables for all users is one of the common uses of this feature. I'm uncertain about Debian-family Linuxes such as Ubuntu, but it is always possible to modify file /etc/profile instead to have the same effect, and you absolutely can write an Automake install hook to do that.
Or for an altogether different approach, you can always provide a wrapper script around your program that sets the needed environment variables (supposing that the point is other than to add a directory to the PATH so as to find the program in the first place). In that case, you can even install the main program in a location that is not ordinarily in the path, so that users don't accidentally run it directly. This mechanism has the advantage that the environment variables are scoped to a run of the program, not a whole login session, but the disadvantage that users cannot override them.
I guess, no.
Autotools are about building your program, not about environment setup for the program to run. That's what users/admins are supposed to do. (Well I can imagine doing this, but I really don't want to try to figure it out, because the idea itself seems broken to me)
If your program REALLY needs some environment variable during run-time, then you should patch your sources for your application to test if the variable exists, and set one to default desired value, if it doesn't. Another idea is to enforce usage of an obligatory command line switch to pass the value in.
It's not clear what this has to do with autotools (or any other build system). No build system, by itself, can arrange for an env var to be present when the program it builds is run at a later tiem.
One solution is for your program to have a hardcoded default value for the var which is used if the environment var isn't present when the program starts running. Another frequently used solution is to name your binary something like myprog.bin and install a shell script named myprog which sets up the environment before doing exec myprog.bin.
I'm adapting an existing program to use Autotools for its build, but the resulting process depends on an environment variable. Is there a way to permanently set this environment variable during the build or installation process?
You've not been very concrete about what the program is (e.g. is the program a daemon? A user program?) or the nature of the environment variable dependency (e.g. is it another program? A mount point? A URL? A DB connection string?). Being more specific might give a better answer for you.
Anyway, autotools is not likely to offer any feature to help: It's a build system. Depending on the nature of your environment variable dependency, you're likely going to need package management (if you package it) or system administration level setup.
Since you think your primary user base is on Ubuntu this help page might give you some ideas.
Symfony introduced a new Dotenv component since Symfony 3 which allows us to handle environment variables as application parameters. This looks really nice and it's the best practice to follow according to 12factor app manifesto.
Now, regarding Symfony 4 they went further by pushing forward this practice and that's why I started using environment variables via the .env file.
And then I wanted to deploy and I realized that the .env file must not be persisted on the server as it would be the same as having a parameters.yml file.
So I've been digging into the documentation a bit and I found this article which explains that we can directly create environment variables via some webserver directives. That's great for code being executed via FPM but it does not tell us how to handle environment variables when running a command via the CLI for instance.
How can I achieve this ?
Should there be an equivalent of a .env file stored somewhere? But then parameters would be duplicated ?
I'm welcoming any help ;)
Finally had the time to check the link Neodan posted and everything is in there!
So for those of you wondering what to do, simply edit the /etc/environment file and add your variables. Then reboot your server and all your processes will have access to these variables.
I guess that's the simplest solution. The only drawback of this method is that these variables are available by any process / users but that's ok as far as I'm concerned.
If you want a more secure solution I suppose that you could, as I stated before, configure your webserver to add environment variables and export them via your .bash_profile or .bashrc file but be careful about how you start your shell (when deploying your application for instance). It's more complicated to maintain and prone to errors I'd say.
N.B.: You also might want to be careful about how you name your variables to prevent collisions.
I'm new to DevOps, so forgive me if this is trivial, but given the following workflow, what is the purpose of the integration server?
I've been given the following steps as an example of an approach to DevOps at my organisation :
Developers check in changes to source control (TFS).
Build server checks for changes.
Artefacts of the build are deployed to an "integration server" which has a copy of our ERP on it.
A release management application takes the output from this ERP environment and moves it to test, pre-production, and production environment as and when.
Is this approach correct, and if so, is the purpose of an integration server merely to provide a working implementation of code, that isn't accessed for any means other than moving code onto other servers?
My answer is making some assumptions on what it sounds like is going on in your environment.
When you check in changes to source control with AX, it's adding *.xpo text files of the code/objects that are your changes only.
It sounds like your "integration server" is a build/staging server. Imagine these two scenarios:
You have a customization with 3 objects, and you add 2 of the objects to source control and forget one. When you build on the integration server, it could have compile errors because that missing dependent object.
In your development environment, you create test forms and jobs that are basically junk you are experimenting with. You do not add these objects to source control. You wouldn't want this code to be deployed to your other environments, so the integration environment ensures the code is strictly from the repo.
Doing full compiles/syncs against the integration will also help identify issues. Then you can deploy the environment in its entirety to your other environments.
The big thing to realize is that your repo is really only your changes to the base (sys/syp) code. So part of the integration/build process is your code & base code combining.
I have 3 stages (dev / staging / production). I've successfully set up publishing for each, so that the code will be deployed, using msbuild, to the correct location, with the correct web configs transformed - all within Jenkins.
The problem I'm having is that I don't know to deploy the code to staging from what was built on dev (and staging to production). I'm currently using SVN as the source control, so I think I would need to somehow save the latest revision number dev has built and somehow tell Jenkins to build/deploy staging based on that number?
Is there a way to do this, or a better alternative?
Any help would be appreciated.
Edit: Decided to use the save the revision number method, which parses a file containing the revision number to the next job -- to do this, I followed this answer:
How to promote a specific build number from another job in Jenkins?
It explains how to copy an artifact from one job to another using the promotion plugin. For the artifact itself, I added a "Execute Windows batch command" build step after the main build with:
echo DEV_ENVIRONMENT_CORE_REVISION:%SVN_REVISION%>env.properties
Then in the staging job, using that above guide, copied that file, and then using a plugin EnvInject, to read from that file and set an environment variable, which can then be used as a parameter to the SVN Repository URL.
You should be able to identify the changeset number that was built in DEV and manually pass that changeset to the Jenkins build to pull that same changeset from SVN. Obviously that makes your deployment more manual. Maybe you can setup Jenkins to publish the changeset number to a file and then have the later env build to read that file for the changeset number.
We used to use this model as well and it was always complex. Eventually we moved to a build once and deploy many times model using WebDeploy. This has made the process much more simple. Check it out - http://www.dotnetcatch.com/2016/04/16/msbuild-once-msdeploy-many-times/