AWS EKS from scratch - terraform or eksctl? - terraform

Are there any benefits to spawn a new AWKS EKS cluster by using terraform or eksctl?
Are there some long-term maintenance benefits of one vs another?

Well, although I haven't actually tried this out with Terraform, I can definitely say that the eksctl way is not recommended. At least not if you're interested in manageing your infrastructure as code.
With eksctl, most changes to an existing cluster need to be made with specific eksctl commands. Just changing the (declarative) cluster.yaml (or whatever you name) does not apply anything relevant. You want to scale a nodeGroup? Well, please use eksctl scale nodegroup, as changing the size in the YAML file is not applying anything. I think you get the pattern.
It's really sad that, of all companies, Weaveworks, the "inventors" of GitOps, provide a tool that does not even support basic IaC :(

I would highly recommend using terraform. It is declarative and provides an interface that can be used to support all of your infrastructure and not just your EKS cluster(s).
The time and effort you put into learning terraform and implementing it in your pipeline can be easily re-used for other infrastructure needs unlike eksctl.

Related

Terraform azure_rm multi-region best practice

I'm using Terraform to deploy Azure resources and now want to deploy across multiple regions.
I'm finding even with Modules I'm repeating code, once for each region.
How should I be writing code for multi region? I can't find any best practices
You could create a list variable and put your regions inside.
Then you could create a for loop and create the resource for each region. This approach works only when you really want to have each resource in each region.
It really depends on your resources. Some resources are reasonably maintained as multi-region within a single module, but this is rare. This would be a case where a module specifically addresses resources in multiple regions, with some kind of unifying logic for those resources. Since regions are typically very independent by design, this is typically an anti-pattern.
Often, it is more sane to use an infrastructure module (or root module, which means the same thing) per region. Some methodologies would have you use a different directory for each region, and again per environment. Yes, you're repeating yourself, but not that much. Your root modules should usually be pretty small and opinionated, serving as a hub for modules and top-level resources to be called.
Yes, you should keep your code DRY, but don't get carried away with it. Some duplication for the sake of organizing resources is totally acceptable.
In the cases where this is truly a problem (large root modules, and/or many regions across many environments), there are tools that can handle this effectively for you. Terragrunt is a fairly effective one, and can template your root modules (including their backend configuration) via a single code location, which is then callable via fairly small files. This can help to deduplicate a codebase like the one I just described.
You may also design your infrastructure modules to be re-usable by defining variables for regional and environmental variances between deployments. Backend configuration is also configurable during Terraform runtime via CLI or environment variable settings. Between these two, you can create infrastructure modules that are capable of being applied in arbitrary environments and regions. I like this better than Terragrunt's approach, because it's much simpler.
How you call these re-usable modules is up to your orchestration implementation, be that a CI/CD system, Kubernetes, Terraform Enterprise/Cloud, whatever.
Hopefully that helps you to make a decision.

Terraform Cloud workspace structure

I am pretty new to Terraform and Terraform Cloud and I'm looking at the best way to structure my Terraform Cloud Workspaces.
Use Case: Relatively simple webapp, RDS, ECS/Fargate etc
I am currently evaluating with the following workspaces:
ECR
Database
AppCore (ECS Cluster, ALB, etc etc)
ECS Service/Tasks
Benefits: Small blast radius, logical chunks, can use Terraform when updating to new ECS task definitions.
I thought I found a doc on Terraforms site that suggested breaking workspaces similar to this was their recommended approach but I can't seem to find it again at the moment.
Is this good? bad? I've heard putting all your infrastructure in a single workspace can make things painful later.
Any ideas, thoughts or suggestions greatly appreciated!

Should I choose Terraform cdktf over aws cdk

I am having difficulty in understanding whether to use aws cdk or terraform cdktf. From my work so far, it appears to me that aws cdk has more robust patterns and constructs which will comply with the well architected framework, all available out of the box. Terraform cdktf will require hand crafting many of such constructs and patterns.
An example in point is the construct ecs_patterns.ApplicationLoadBalancedEc2Service which does a lot of heavy lifting in spinning up a industrial strength infrastructure for EC2 based ECS service. I can't find the equivalent of that in Terraform cdktf and it appears I will have to manually assemble and connect all the infra elements.
However, Terraform apparently has the advantage of working with several different cloud vendors, and therefore I want to do due diligence before choosing one of the other.
Therefore, I would like to know if my understanding is correct and if I am not missing something really important. Any other advice / considerations in this matter are highly appreciated
Thanks
The AWS CDK is limited to only AWS as a cloud, whereas you can use CDKTF with any / most of the clouds since terraform providers exist for most of them. The AWS CDK has a diverse ecosystem of constructs that can be used, which is a plus. CDKTF will eventually support these via the CDKTF AWS Adapter.

Is Pulumi that magical when compared to using Azure .NET SDK?

I'm with a dilema here about which SE site to ask this question so please help me out if it should be somewhere else.
I've been looking into Infrastructure as Code solutions.
Didn't like Terraform too much. The lack of intellisense makes discoberability harder than programmers have been used to.
I've been considering ARM templates. I like it that the templates are made available as we create resources in the portal but it seems way less readable and harder to maintain afterwards.
Then I found out Pulumi and love their idea compared to Terraform. The way I see it, they're approach is also declarative like the above options but we can use decent programming languages to get the job done.
The for loops is a must.
Cool, I like that! But since we like using C# (or other alternatives), then why don't we SDKs to manage our infrastructure as code?
Pulumi has compared themselves with cloud SKDs by positioning their solution as much safer advocating that, if we just use a cloud SDK ourselves, then our solution wouldn't be that reliable.
To what extent is this really true, I wonder?
Last year, I wrote some libraries that used Azure service bus queues/topics. There were several integration tests that would run in parallel and I needed to isolate them by creating new queues/topics and used Microsoft.Azure.ServiceBus.Management.ManagementClient to do this.
It really didn't seem like I had to learn anything at all.
Going to the point now. Not discarding Pulumi's innovation which I think is great:
Will Pulumi's really add that much benefit compared to using Azure SDKs?
What's been your experience with it?
A Pulumi developer here, so I'm definitely biased. I suspect the SO community may find your question violating some of the guidance, but I hope my answer survives :)
One upside of using Pulumi is that you get access to multiple providers with consistent developer experience. You may be using exclusively Azure, but you might at some point start combining it with things like building and publishing Docker images, deploying Kubernetes applications, or Datadog dashboards. All can be done from the same program or solution.
Now, the biggest difference with imperative SDKs is the notion of desired-state configuration. A Pulumi program describes the graph of resources and dependencies between them (what), not the steps to provision them (how). When you have an environment that lives for months and years, there's a big difference between evolving a single definition with baby steps and applying incremental changes (Pulumi) and writing a bunch of update scripts/programs to bring each environment to the new state (SDK).
How do you maintain multiple environments that may be similar but still different? (production vs staging vs test vs dev) How do you make sure that your short-lived infra that you created for nightly tests reflects the reality of production? What happens when an SDK program fails in the middle - can you retry running it again or will it create duplicate resources/fail with another error? How do you get a simple overview of changes over time in git? Concurrency control? Change history?
All the things above are baked into Pulumi and require manual consideration with a cloud SDK.

Using Terraform as an API

I would like to use Terraform programmatically like an API/function calls to create and teardown infrastructure in multiple specific steps. e.g reserve a couple of eips, add an instance to a region and assign one of the IPs all in separate steps. Terraform will currently run locally and not on a server.
I would like to know if there is a recommended way/best practices for creating the configuration to support this? So far it seems that my options are:
Properly define input/output, heavily rely on resource separation, modules, the count parameter and interpolation.
Generate the configuration files as JSON which appears to be less common
Thanks!
Instead of using Terraform directly, I would recommend a 3rd party build/deploy tool such as Jenkins, Bamboo, Travis CI, etc. to manage the release of your infrastructure managed by Terraform. Reason being is that you should treat your Terraform code in the exact same manner as you would application code (i.e. have a proper build/release pipeline). As an added bonus, these tools come integrated with a standard api that can be used to execute your build and deploy processes.
If you choose not to create a build/deploy pipeline, your other options are to use a tool such as RunDeck which allows you to execute arbitrary commands on a server. It also has the added bonus of having a excellent privilege control system to only allow specified users to execute commands. Your other option could be to upgrade from the Open Source version of Terraform to the Pro/Premium version. This version includes an integrated GUI and extensive API.
As for best practices for using an API to automate creation/teardown of your infrastructure with Terraform, the best practices are the same regardless of what tools you are using. You mentioned some good practices such as clearly defining input/output and creating a separation of concerns which are excellent practices! Some others I can recommend are:
Create all of your infrastructure code with idempotency in mind.
Use modules to separate the common shared portions of your code. This reduces the number of places that you will have to update code and therefore the number of points of error when pushing an update.
Write your code with scalability in mind from the beginning. It is much simpler to start with this than to adjust later on when it is too late.

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