I have a Node.js web server which, as part of a CD process, I want to deploy to a staging server using Azure Release Pipeline. The problem is, that if I just run a Powershell script:
# Run-Server.ps1
node my-server.js
The Pipeline will hold since the node process blocks the Powershell session.
What I want is to be able to launch the service, and then in the next deployment just kill the node process and run it again with the new code.
So I figured I'll use Start-Process. If I run it locally:
> Start-Process node -ArgumentList ./server.js
I can now exit the Powershell session and the server will continue running. So I thought I can implement it the same way in my Release Pipeline.
But it turns out that once the Release Pipeline ends running, the server is no longer available - the node process is gone.
Can you help me figure out why is that? Is there another way of achieving this? I suppose it's a pretty common use case so there must be best-practices out there regarding to how this should be done.
Another way to achieve this is to use a full-blown web server to host andmanage node process. I.e. on Windows you could use IIS with iisnode module. This is more reliable and gives you a few other benefits:
process management (automatic start, restart on failure, etc.)
security - you can configure the user that node process will run as
scalability on multi-core CPUs
Then the process of app deployment would be just copying files to the right directory - the web server should pick up the change automatically.
By default, A pipeline job cleans up all of the child processes it spins up when it exits. This is killing your node server.
Set Process.Clean variable to false to override the default behavior.
Related
I am currently configuring a virtual machine to work as an agent within Azure (with Ubuntu as image). In which the additional configuration is running through a cloud init file.
In which, among others, I have the below 'fix' within bootcmd and multiple steps within runcmd.
However the machine already gives the state running within the azure portal, while still running the cloud configuration phase (cloud_config_modules). This has as a result pipelines see the machine as ready for usage while not everything is installed/configured yet and breaks.
I tried a couple of things which did not result in the desired effect. After which I stumbled on the following article/bug;
The proposed solution worked, however I switched to a rhel image and it stopped working.
I noticed this image is not using walinuxagent as the solution states but waagent, so I tried to replacing that like the example below without any success.
bootcmd:
- mkdir -p /etc/systemd/system/waagent.service.d
- echo "[Unit]\nAfter=cloud-final.service" > /etc/systemd/system/waagent.service.d/override.conf
- sed "s/After=multi-user.target//g" /lib/systemd/system/cloud-final.service > /etc/systemd/system/cloud-final.service
- systemctl daemon-reload
After this, also tried to set the runcmd steps to the bootcmd steps. This resulted in a boot which took ages and eventually froze.
Since I am not that familiar with rhel and Linux overall, I wanted to ask help if anyone might have some suggestions which I can additionally try.
(Apply some other configuration to ensure await on the cloud-final.service within a waagent?)
However the machine already had the state running, while still running the cloud configuration phase (cloud_config_modules).
Could you please be more specific? Where did you read the machine state?
The reason I ask is that cloud-init status will report status: running until cloud-init is done running, at which point it will report status: done
I what is the purpose of waiting until cloud-init is done? I'm not sure exactly what you are expecting to happen, but here are a couple of things that might help.
If you want to execute a script "at the end" of cloud-init initialization, you could put the script directly in runcmd, and if you want to wait for cloud-init in an external script you could do cloud-init status --wait, which will print a visual indicator and eventually return once cloud-init is complete.
On not too old Azure Linux VM images, cloud-init rather than WALinuxAgent acts as the VM provisioner. The VM is marked provisioned by the Azure cloud-init datasource module very early during cloud-init processing (source), before any cloud-init modules configurable with user data. WALinuxAgent is only responsible for provisioning Azure VM extensions. It does not appear to be possible to delay sending the 'VM ready' signal to Azure without modifying the VM image and patching the source code of cloud-init Azure datasource.
We have a cloud full of self-hosted Azure Agents running on custom AMIs. In some cases, I have some cleanup operations which I'd really like to do either before or after a job runs on the machine, but I don't want the developer waiting for the job to wait either at the beginning or the end of the job (which holds up other stages).
What I'd really like is to have the Azure Agent itself say "after this job finishes, I will run a set of custom scripts that will prepare for the next job, and I won't accept more work until that set of scripts is done".
In a pinch, maybe just a "cooldown" setting would work -- wait 30 seconds before accepting another job. (Then at least a job could trigger some background work before finishing.)
Has anyone had experience with this, or knows of a workable solution?
I suggest three solutions
Create another pipeline to run the clean up tasks on agents - you can also add demand for specific agents (See here https://learn.microsoft.com/en-us/azure/devops/pipelines/process/demands?view=azure-devops&tabs=yaml) by Agent.Name -equals [Your Agent Name]. You can set frequency to minutes, hours, as you like using cron pattern. As while this pipeline will be running and taking up the agent, the agent being cleaned will not be available for other jobs. Do note that you can trigger this pipeline from another pipeline, but if both are using the same agents - they can just get deadlocked.
Create a template containing scripts tasks having all clean up logic and use it at the end of every job (which you have discounted).
Rather than using static VM's for agent hosting, use Azure scaleset for Self hosted agents - everytime agents are scaled down they are gone and when scaled up they start fresh. This saves a lot of money in terms of sitting agents not doing anything when no one is working. We use this option and went away from static agents. We have also used packer to create the VM image/vhd overnight to update it with patches, softwares required, and docker images cached.
ref: https://learn.microsoft.com/en-us/azure/devops/pipelines/agents/scale-set-agents?view=azure-devops
For those discovering this question, there's a much better way: run your self-hosted agent with the --once flag, documented here.
You'll need to wrap it in your own bash script, but something like this works:
while :
do
echo "Performing pre-job setup..."
echo "Waiting for job..."
./run.sh --once
echo "Cleaning up..."
sleep 2
done
Another option would be to use a ScaleSet VM setup which preps a new agent for each run and discards the VM when the run is done. It can prepare new VMs in the background while the job is running.
And I suspect you could implement your own IMaintenanceProvirer..
https://github.com/microsoft/azure-pipelines-agent/blob/master/src/Agent.Worker/Maintenance/MaintenanceJobExtension.cs#L53
Im working on a simple deployment pipeline with azure devops. I created a deployment pipeline running on a self hosted ubuntu deployment group.
The pipeline looks like this:
Download artifacts from CI pipeline (created with dotnet publish)
Stop running deployment
Unzip the ASP.NET Core Web API to the deployment directory
Run new deployment with dotnet MyApp.dll
The first two steps work as expected. However, when the dotnet My App.dll command is run, the process runs for 10 seconds with following "error" message being printed at the end:
The STDIO streams did not close within 10 seconds of the exit event from process '/usr/bin/bash'. This may indicate a child process inherited the STDIO streams and has not yet exited.
The deployment task is successful despite the message and the app not running. I tried to work around this feature by using nohup & and relocating the command output. After some research I found that all processes started by a pipeline agent are stopped after the agent's work is done - meaning this behaviour is intended and my understanding of azure deployments/agents is wrong.
How do I deploy and run my app in an automated way on my own ubuntu machine using azure devops pipelines?
How do I deploy and run my app in an automated way on my own ubuntu machine using azure devops pipelines?
You are already on the right way.
All the process launched in the pipeline will be finished/clean up in “Finalize Job” step when the pipeline is over.
If you don't want the process to be closed, please try set variable Process.clean= false to stops the "finalize job" step from killing all processes.
But when you create a new pipeline next time, you need to close the app before starting it.
I'd like to enhance the release definition so that I don't need to have a separate environment that only starts an Azure VM.
If we take a scenario where we have a Test, Beta, Production environments. The client wants the application to be installed in Beta and Production on their local network. We internally want a Test environment to run E2E tests against, allow for non-technical folks to exercise the app without needing VPN access to the customer beta environment, etc.
So here we have Environment followed by where the Agent is running:
Test - Azure VM
Beta - Client machine
Production - Client machine
How we've solved this is to install the VSTS Agent on a machine at the client, which allows us to target that agent queue in the Beta and Production environments defined for that release. Then we typically build an Azure VM and target that agent queue for the Test environment.
We don't want to run that Azure VM 24/7/365. However if it's not running, then it can't respond to requests from Release Management.
What I've done is to create a environment named Start Test VM and Stop Test VM that use the Azure Resource Group Deployment to start and stop the VM. Those 2 additional environments can have their agent queue set to Hosted.
I'd like to figure out how to combine the first 3 environments into a logical Test instead of having to create 3 release management environments.
Start Test VM - Hosted
Test - Azure VM
Stop Test VM - Hosted
Beta - Client machine
Production - Client machine
The problem is that can be rather ugly and confusing when handing this over to one of our PM's or even myself when I circle back around 3 months later and think, "What the hell is this environment? Oh it's just there to start/stop the VM."
Options:
Stay with status quo - keep it like it is, it can't be fixed
We could open up a port on the Azure VM and use Powershell remoting. Then run on the Hosted agent or on an on-premise agent to start the VM, then deploy the application, then stop the VM. - we really dislike this because the deployment would not be the same as the client on-premise deploy. We'd like each environments' tasks to be the same, just with different variables.
You can use "Azure PowerShell" and "Azure SQL Database Deployment" tasks to configure your Azure VM and SQL or call other script to run on the Azure VM.
There isn't any way to set the agent for tasks. You can submit a feature request on VSTS User Voice for this.
And another way to reduce the environment is that: if you deploy every build linked to the release, then you can add "Start Test VM" task into your build definition to start the VM when build is successful and add "Stop Test VM" task into "Beta" environment.
What we've currently settled on is to continue with having an environment that isn't really what I would consider an environment, but more of a stage in the release pipeline that starts and/or shuts down a VM. We run that on a hosted agent so it can start the VM and make sure to check Skip artifacts download on the environment.
For a continuous integration build, we set a chain so the VM gets started, CI environment gets kicked off and then VM gets stopped. The remaining environments are then manually deployed up the chain as desired.
So here's an example:
Start CI VM
CI
Stop CI VM
Beta
Production
And here's an image of how it looks in Release Management as of 2016.06.27:
I put single quotes around environment because I think I agree with this user voice request in that, it's really more of a stage in the release pipeline. Much like database development, the logical and the physical don't necessarily map 1 to 1.
Is there any way to do the following:
I have 2 jobs. One job on offline node has to trigger the second one. Are there any plugins in Jenkins that can do this. I know that TeamCity has a way of achieving this, but I think that Jenkins is more constrictive
When you configure your node, you can set Availability to Take this slave on-line when in demand and off-line when idle.
Set Usage as Leave this machine for tied jobs only
Finally, configure the job to be executed only on that node.
This way, when the job goes to queue and cannot execute (because the node is offline), Jenkins will try to bring this node online. After the job is finished, the node will go back to offline.
This of course relies on the fact that Jenkins is configured to be able to start this node.
One instance will always be turn on, on which the main job can be run. And have created the job which will look in DB and if in the DB no running instances, it will prepare one node. And the third job after running tests will clean up my environment.