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Cloud · head to head

K3s vs Terragrunt

K3s logo

K3s

Cloud

Lightweight certified Kubernetes distribution in a single binary

From
Free
Rated
-
Full reviewWebsite
Terragrunt logo

Terragrunt

Cloud

The Open Source IaC Orchestrator Platform Teams Trust

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: K3s the SQLite default is single-server only; highly available control planes need etcd or an external datastore, which removes much of the simplicity; Terragrunt additional complexity layer on top of Terraform
  • They diverge on capability: K3s covers Single binary, Terragrunt covers Infrastructure orchestration.

Where they differ

Only the attributes on which K3s and Terragrunt actually diverge.

Attributes where K3s and Terragrunt differ
AttributeK3sTerragrunt
Pricing modelOpen source, no licence feeUnknown
PlatformsLinux, ARM, Self-hostedAWS, Azure, GCP

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (Cloud).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in K3s

  • Single binary
  • SQLite by default
  • Certified conformant
  • Batteries included
  • Low resource footprint
  • Simple install

Only in Terragrunt

  • Infrastructure orchestration
  • Run Queue
  • DRY configuration
  • Automated hooks
  • Infrastructure catalog
  • Least-privilege access

What people use each for

The jobs each tool is most often brought in to do.

K3s

  • Kubernetes on edge sites and IoT hardware where full clusters will not fitnot Terragrunt
  • Development and CI clusters that must start fast and cost nothingnot Terragrunt
  • Small production clusters where full Kubernetes is more operations than the workload justifiesnot Terragrunt
  • Teaching and learning Kubernetes without cloud spendnot Terragrunt

Terragrunt

  • Organizing Terraform code across multiple environmentsnot K3s
  • Automating infrastructure deployment workflowsnot K3s
  • Implementing infrastructure as code templates for developer self-servicenot K3s

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

K3s

  • The SQLite default is single-server only; highly available control planes need etcd or an external datastore, which removes much of the simplicity
  • Bundled components such as Traefik are opinionated defaults that larger teams often strip out and replace
  • Removed in-tree cloud provider integrations mean cloud-specific features need external controllers
  • Aimed at small and edge clusters, so very large deployments are better served by a standard distribution

Terragrunt

  • Additional complexity layer on top of Terraform
  • Requires understanding of Terraform concepts
  • Paid tier pricing not clearly published

Pricing, plan by plan

K3s

Free
  • K3sFree
    • Full functionality
    • No usage limits
    • Community support

Terragrunt

Free
  • Open SourceFree
    • Terragrunt CLI - completely free
    • Community support
  • Terragrunt Scale FreeFree
    • Free CI/CD pipeline
    • Unlimited runs and resources
    • For up to 25 infrastructure units
  • Terragrunt Scale Paid$undefined/custom
    • Volume pricing for more than 25 infrastructure units
    • Enterprise support

Which should you pick?

Choose K3s if

  • You need single binary.
  • You want to start without paying.
  • You work on Linux, ARM, Self-hosted.
  • You also want sqlite by default.
K3s review

Choose Terragrunt if

  • You need infrastructure orchestration.
  • You want to start without paying.
  • You work on AWS, Azure, GCP.
  • You also want run queue.
Terragrunt review

Questions people ask

Is K3s or Terragrunt better?
Neither clearly leads. K3s starts at Free and Terragrunt at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, K3s or Terragrunt?
K3s starts at Free and Terragrunt at Free.
Does K3s or Terragrunt run on more platforms?
K3s runs on Linux, ARM, Self-hosted. Terragrunt runs on AWS, Azure, GCP.
Can I use K3s for free?
Both have a free tier, so you can try either at no cost before committing.
What is K3s best used for?
K3s is most often used for kubernetes on edge sites and iot hardware where full clusters will not fit, development and ci clusters that must start fast and cost nothing, small production clusters where full kubernetes is more operations than the workload justifies, teaching and learning kubernetes without cloud spend. Of those, kubernetes on edge sites and iot hardware where full clusters will not fit and development and ci clusters that must start fast and cost nothing are not what Terragrunt is typically brought in for.
What can K3s do that Terragrunt cannot?
K3s covers Single binary, SQLite by default, Certified conformant, Batteries included. Terragrunt covers Infrastructure orchestration, Run Queue, DRY configuration, Automated hooks.

Answered from the vendors’ own pages

K3s: Is K3s free?

Yes. K3s is open source with no licence fee. SUSE sells commercial support around Rancher separately.

Terragrunt: Is Terragrunt free?

Yes, the Terragrunt CLI is completely free and open source. Terragrunt Scale offers a free tier for up to 25 infrastructure units.

Source
K3s: Is K3s real Kubernetes?

Yes. It is CNCF-certified conformant, so standard manifests, kubectl and Helm charts work without modification.

Terragrunt: What is the difference between Terragrunt and Terraform?

Terragrunt is an orchestration layer on top of Terraform that handles state management, DRY principles, and deployment automation without replacing Terraform itself.

Source
K3s: Why is K3s smaller than Kubernetes?

It strips legacy, alpha and in-tree cloud provider code, packages everything as one binary, and defaults to SQLite instead of etcd.

K3s: Can K3s run in production?

Yes, and it does, particularly at the edge and for small clusters. For a highly available control plane you need to move off the SQLite default to etcd or an external datastore.

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