How do you release Microservices? - microservices

The question is tied more to CI/CD practices and infrastructure. In the release we follow, we club a set of microservices docker image tags as a single release, and do CI/CD pipeline and promote that version.yaml to staging and production - say a sort of Mono-release pattern. The problem with this is that at one point we need to serialize and other changes have to wait, till a mono-release is tested and tagged as ready for the next stage.A little more description regarding this here.
An alternate would be the micro-release strategy, where each microservice release in parallel through production through the CI/CD pipeline. But then would this mean that there would be as many pipelines as there are microservices? An alternate could have a single pipeline, but parallel test cases and a polling CD - sort of like GitOps way which takes the latest production tagged Docker images.
There seems precious little information regarding the way MS is released. Most talk about interface level or API level versioning and releasing, which is not really what I am after.

Assuming your organization is developing services in microservices architecture and is deploying in a kubernetes cluster, you must use some CD tool (continuous delivery tool) to release new microservices services, or even update a microservice.
Take a look in tools like Jenkins (https://www.jenkins.io), DroneIO (https://drone.io)... Some organizations use Python scripts, or Go and so on... I, personally, do not like this approch, I think the best solution is to pick a tool from CNCF Landscape (https://landscape.cncf.io/zoom=150) in Continuous Integration & Delivery group, these are tools test and used in the market.
An alternate would be the micro-release strategy, where each microservice release in parallel through production through the CI/CD pipeline. But then would this mean that there would be as many pipelines as there are microservices?
It's ok in some tools you have a parameterized pipeline thats build projects based in received parameters, but I think the best solution is to have one pipeline per service, and some parameterized pipelines to deploy, or apply specific tests, archive assets and so on... Like you say micro-release strategy

Agreed, there is little information about this out there. From all I understand the approach to keep one pipeline per service sounds reasonable. With a growing amount of microservices you will run into several problems:
how do you keep track of changes in the configuration
how do you test your services efficiently with regression and integration tests
how do you efficiently setup environments
The key here is most probably that you make better use of parameterized environment variables that you then look to version in an efficient manner. This will allow you to keep track of the changes in an efficient manner. To achieve this make sure to a.) strictly paramterize all variables in the container configs and the code and b.) organize the config variables in a way that allows you to inject them at runtime. This is a piece of content that I found helpful in regard to my point a.);
As for point b.) this is slightly more tricky. As it looks you are using Kubernetes so you might just want to pick something like helm-charts. The question is how you structure your config files and you have two options:
Use something like Kustomize which is a configuration management tool that will allow you to version to a certain degree following a GitOps approach. This comes (in my biased opinion) with a good amount of flaws. Git is ultimately not meant for configuration management, it's hard to follow changes, to build diffs, to identify the relevant history if you handle that amount of services.
You use a Continuous Delivery API (I work for one so make sure you question this sufficiently). CDAPIs connect to all your systems (CI pipelines, clusters, image registries, external resources (DBs, file storage), internal resources (elastic, redis) etc. They dynamically inject environment variables at run-time and create the manifests with each deployment. They cache these as so called "deployment sets". Deployment Sets are the representation of the state of an environment at deployment time. This approach has several advantages: It allows you to share, version, diff and relaunch any state any service and application were in at any given point in time. It provides a very clear and bullet proof audit auf anything in the setup. QA environments or test-feature environments can be spun of through the API or UI allowing for fully featured regression and integration tests.

Related

high-available Infrastructure CI/CD pipeline

I'm interested in IaC's continuous deployment and continuous integration. As we need to ensure the infrastructure is ready to be deployed for production, my initiation thinking was to have separate environments for dev and prod. But the point that I'm a little bit hesitant to consider it as a problem or usual stuff is about the cost efficiency of this idea. Because we are running the infrastructure exactly twice, the infrastructure cost will double.
Is this usual to have two separate and identical infrastructure for dev and prod?
Or is there any working solution that makes the continuous integration for infrastructure considering high availability and high resiliency more cost-efficient?
Yes! having a separate setup for each environment is highly recommended. So you will have a more visible workflow between different environments. But do you need to manage identical setup for dev and prod? Please No. You can keep your dev setup at a minimum. Yes, It will cost some bucks, but it will help you to keep your production bug-free and save more money, and time that you will have to put on troubleshooting.

Multiple microservices in one repository

I have question about microservices and repositories. We are a small team (5 people) and we creating new project in microservices. Expected microservice applications in our project is between 10-15.
We are thinking about one repository for all microservices in structure like that:
-/
--/app1
--/app2
--/app3
-./script.sh
-./script.bat
What do you think about this design? Can you recommend something better? We think if we will have repository per app it will be overkill for that small project in one team. As our applications you can imagine spring boot or spa applications in angular. Thank you in advice.
In general you can have all your micro-services in one repository but I think while the code grows for each of them it can be difficult to manage that.
Here are some things that you might want to consider before deciding to put all your micro-services in one repository:
Developer discipline:
Be careful with coupling of code. Since the code for all your micro-services is in one repository you don't have a real physical boundary between them, so developers can just use some code from other micro-services like adding a reference or similar. Having all micro-services in one repository will require some discipline and rules for developers not to cross boundaries and misuse them.
Come into temptation to create and misuse shared code.
This is not a bad thing if you do it in a proper and structured way. Again this leaves a lot of space for doing it the wrong way. If people just start using the same shared jar or similar that could lead to a lot of problems. In order to have something shared it should be isolated and packaged and ideally should have some versioning with support for backwards compatibility. This way each micro-service when this library is updated would still have a working code with the previous version. Still it is doable in the same repository but as with the 1. point above it requires planing and managing.
Git considerations:
Managing a lot of pull requests and branches in one repository can be challenging and can lead to the situation: "I am blocked by someone else". Also as possibly more people are going to work on the project and will commit to your source branch you will have to do rebase and/or merge source branch to your development or feature branch much more often(even if you do not need the changes from other services). Email notifications configured for the repository can be very annoying as you will receive Emails for things which are not in your micro-service code. In this case you need to create some Filters/Rules in your Email clients to avoid the Emails that you are not interested in.
Number of micro-services grow even further then your initial 10-15. The number can grow? If not, all fine. But if it does, at some point you could maybe consider to split each micro-service in a dedicated repository. Doing this at the point where you are in later stage of project can be challenging and could require some work and in worst case you will find out that there are some couplings that people made over time which you will have to resolve at this stage.
CI pipelines considerations:
If you use something like Jenkins to build, test and/or deploy your code
you could encounter some small configuration difficulties like the integration between Jenkins and GitHub. You would need to configure a pipeline which would only build/test a specific part of the code (or one micro-service) if someone creates a merge/pull request against that micro-service. I never tried to do such a thing but I guess you will have to figure out how to do it (script and automate this). It is doable I guess but will required some work to achieve it.
Conclusion
Still all or most of these points can be resolved with some extra management and configuration but it is still worth knowing what additional effort you could encounter. I guess there are some other points to be taken into considerations as well but my general advice would be to use separate repositories for each micro-service if you can (Private Repository pricing and similar reasons). This is a decision which is made project by project.

MicroService with DCOS

I decided to move to MicroService architecture, divide a project into multiple services and run those services on DCOS.It really gives a good story to project deployment and maintenance. But it makes development process complex.
For the developer, it was easy to run the application locally while implementation is in progress.Now the project is divided into multiple services and runs on DCOS which require good configuration. so to test application for the developer in the middle of implementation becomes a nightmare.
Guys, anyone is using DCOS with Microservice, can you please suggest what process you are following for internal development.
DCOS is just a tool for your deployment, so in order to give a better answer you'd have to share more about your technology stack in your question. But here some general thoughts: There are different types/levels of testing and there are different considerations for each.
On unit level - This depends on what technology you use for implementing your services and is the reason why languages like go become more and more popular for server development. If you use go for example, you can easily run any service you are currently developing locally (not containerized) on the dev machine. And you can easily run attached unit tests. You would either run dependent services locally or mock them up (probably depending on effort). You may also prefer asking each service team to provide mock services as part of their regular deliveries.
And you will require special environment settings and service configuration for the local environment.So summarized this approach will require you to have means in place to run services locally and depending on the implementation technologies you use it will be easier or harder.
On deployment/integration level - Setting up a minimal cluster on the dev's local machine and/or using dedicated testing- and staging clusters. This allows you to test the services including containerization and in a more final deployment environment with dependencies. You would probably write special test clients for this type of test. And this approach will also require you to have separate environment settings, configuration files, etc. for the different environments. Tools like Jaeger become more popular for helping with debugging errors through multiple services here.
Canary testing. Like the name suggests - You deploy your latest service version to a small portion of your production cluster in order to test it on a limited number of users first before rolling it out to the masses. In this stage you can run user level tests and in fact your users become the testers, so it is to be used carefully. Some organizations prefer to have special beta-type-users that will only get access to those environments.

Best practices for continuous deployment with Concourse and Cloud Foundry

So I've been investigating ci/cd pipelines using concourse and cloud foundry lately, and I've been confused about what the best way to do this is. So I've been thinking about how the overall flow would go from development to release. There are a lot of talks and videos that discuss this at a very high level, but often they abstract away too much of the actual implementation details for it to be useful. Like how do people actually roll this out in actual companies? I have a lot of questions, so I will try to list a few of them here in the hope that someone could enlighten me a little.
What does the overall process and pipeline look like conceptually from development to prod? So far I have something along the lines of :
During development each product team is under their own org, with each developer possibly having their own development "space" that they could manually cf push to and just develop against. There will be development spaces that devs can just directly push to as well as spaces that can only be used by the automated pipeline to deploy artifacts for functional tests.
Once devs finish a feature they would make a pull request, which would trigger a smaller pipeline with some tests using something like the git-multibranch-resource or the git-pullrequest-resource, which would hook into the github required status check hooks and report back if any particular PRs are able to be merged into master or not
Once all checks pass and the pull request is merged into master the below pipeline is kicked off, which validates the master branch before releasing the artifact to prod.
code repo [master] -> build -> snapshot artifact repo -> deploy to test space -> run functional tests -> deploy to staging space -> run smoke tests and maybe other regression tests -> deploy artifact to prod -> monitoring/rollbacks (?)
What other things could/should be added to this pipeline or any part of this process?
Once you automate deployment how do you do also automate things like canary releases or rollbacks once something happens? Should this be part of the pipeline or something completely separate?
I've been playing with the idea of creating spaces temporarily and then tearing them down for the functional testing phase, would there be any benefit to doing that? The idea is that the apps being deployed would have their own clean environments to use, but this could also potentially be slow, and it is difficult to know what services are required inside of each space. You would have to read the manifest, which only specifies service-names, which seems to necessitate some sort of canonical way of naming service instances within the same space? The alternative is managing a pool of spaces which also seems complicated...
Should the pipeline generate the manifest files? Or should that be completely up to the developers? Only the developers know which services the app needs, but also it seems like things like instance count, memory etc should be something that the performances tests/pipeline should be able to determine/automate. You could generate a manifest inside the pipeline, but then you would not know which services the app needs without reading a manifest....chicken and egg problem?
I have many more burning questions, but I will cut it off here for now. I know the subjects have kind of bounced back and forth between Concourse and Cloud Foundry, but it seems when discussing CI/CD concepts the nitty gritty implementation details are often the actual tricky bits which tangle the two rather tightly together. I am also aware that the specific implementation details are often very specific to each company, but it would be great if people could talk about how they have implemented these pipelines / automated pipelines using Concourse and Cloud Foundry at their companies (if you can spare the details of course). Thanks everyone!
During development each product team is under their own org, with each developer possibly having their own development "space" that they could manually cf push to and just develop against. There will be development spaces that devs can just directly push to as well as spaces that can only be used by the automated pipeline to deploy artifacts for functional tests.
Honestly it doesn't matter if you create multiple orgs in your CloudFoundry. If your CI/CD system runs on the same director that is (ab)used by other developers you going to have a hard time probably (i was there).
Once devs finish a feature they would make a pull request, which would trigger a smaller pipeline with some tests using something like the git-multibranch-resource or the git-pullrequest-resource, which would hook into the github required status check hooks and report back if any particular PRs are able to be merged into master or not
We are doing almost the exact thing. For PR's checkout jtarchie's PR resource here https://github.com/jtarchie/github-pullrequest-resource.
The only difference is that we are not using Github checks. The problem with them is, that you have to select a set of checks fixed for a branch.
But in case i just changed manifest xyz in the PR, i don't want to run all tests. You can overcome that problem by using the Github Status API only with the pending and successful status.
Once all checks pass and the pull request is merged into master the below pipeline is kicked off, which validates the master branch before releasing the artifact to prod.
We make PR's into the develop branch and following the Git Flow system. Our releases are merged into master manually.
You want to check first which updates you want to carry out before you merge every PR into master and trigger an update of the production system. Your test cases might be good, but you can always miss something.
What other things could/should be added to this pipeline or any part of this process?
You can have a pipeline which updates releases/stemcells in your manifests automatically.
Once you automate deployment how do you do also automate things like canary releases or rollbacks once something happens? Should this be part of the pipeline or something completely separate?
Test your stuff on a staging system before you go to production. Otherwise you a) won't know if the update is happening at zero downtime and b) to prevent a potential problem in production is always better than doing rollbacks.
Ofc you can also create a rollback pipeline, but if you come to that point something else might be wrong with your setup.
Should the pipeline generate the manifest files? Or should that be completely up to the developers? Only the developers know which services the app needs, but also it seems like things like instance count, memory etc should be something that the performances tests/pipeline should be able to determine/automate. You could generate a manifest inside the pipeline, but then you would not know which services the app needs without reading a manifest....chicken and egg problem?
We write our manifests by ourselves and use the CI/CD system to update/deploy/test them.
But if you find a valid case and a concept which lets you apply your manifest generating pipeline for many cases, i would just try it out.
At the very end you have to decide if a certain atomisation holds a business value for your company.
cheers, Dennis

Cloud based CI server that can handle concurrency blocking based on external resources

I've been researching cloud based CI systems for a while now and cannot seem to find any systems that can address a major need of mine.
I'm building CI processes for development on Salesforce, but this question is more generally about builds which rely on an external resource. In our builds, we deploy code into a cloud hosted Salesforce instance and then run the tests in that instance. During a build, the external resource is effectively locked and build failures will occur if two builds target the same external resource at the same time. This means that the normal concurrency model of cloud based CI systems would start tripping over the Salesforce instance (external resource) with a concurrency greater than 1.
To complicate things a bit more, we actually have 5 different external resources for each project (feature, master, packaging, beta, and release) and need to control the concurrency of any builds relying on an external resource to 1. For example, all our feature branches build against the feature external resource. We can identify these builds by the branch name which uses the pattern feature/* and need to ensure that only one feature build runs at a time. However, the feature build doesn't tie up the other 4 external resources so ideally any builds that would need those resources should still be able to run concurrently.
I currently accomplish this in Jenkins using the Throttle Concurrent Builds plugin and assign a throttle group to each build identifying the external resource it relies on. This has been successful at preventing concurrent builds from tripping over external resources.
A few clarifications:
I'm not asking how to reduce concurrency to 1 at the repo level. I know every cloud CI system can do that. I should be able to set repo concurrency to N external resources (in my case, 5).
Ideally, I'd like to be able to use a regex pattern on branch name as the "group" with which to block concurrence. So, a setting like: If branch name matches 'feature/.*' then limit concurrency to 1. I want to avoid having to manually configure new feature branches in the build system and instead match on pattern.
I have to say, it's been nearly impossible to find a restrictive Google search term that would help me answer this question. Hopefully someone out there has faced this problem before and can shed some light for me :)
With Jenkins Pipeline plugin you can set the stage concurrency to 1 - and only 1 thing will pass through that stage at a time. The stage was designed to be able to represent things like this.
https://www.cloudbees.com/blog/parallelism-and-distributed-builds-jenkins
stage "build"
node {
sh './test-the-awesome'
}
stage name: "environment test", concurrency: 1
node {
sh 'tests that lock the environment'
}
You can put the build pipeline in a Jenkinsfile in a repo too: https://documentation.cloudbees.com/docs/cookbook/pipeline-as-code.html (so any branches that build, also obey that lock).
As pointed out by #Jesse Glick in the comments below, perhaps a more general solution (not yet compatible with pipeline) is to use the Lockable Resources Plugin - which will then work across jobs, of any type.
I accomplish this with a Drone.io setup.
Essentially, I use a grunt plugin to access a Redis db hosted externally. It provides semaphore locking on any param you'd like.
Determine if the lock is free for that Env.
If so that Env's Key with a reasonable timeouts
Run the tests
Clear the lock
If the lock is held, get it's expiration time, and sleep until then.
I am not aware of any cloud based CI tools that can manage external resources the way you want to, unless you include the logic as part of the build script, which you've already said you'd prefer not to do. If you decide you want to do that you could do it with Snap CI or Drone or any of the other cloud tools I imagine.
In this sort of situation, I would usually recommend an agent-based system such as Go.cd

Resources