It depends.

At first, AWS -> GCP resources mapping:

At first, you'll want to know the mapping between AWS and GCP resources. There are several articles:

• Cloud Services Mapping For AWS, Azure, GCP ,OCI, IBM and Alibaba provider – Technology Geek
• Cloud Terminology Glossary for AWS, Azure, and GCP | Lucidchart:
• Cloud Services Terminology Guide: Comparing AWS vs Azure vs Google | CloudHealth by VMware

Migrate AWS EKS to GCP GKE: the hard way

If your cluster is deployed with managed kubernetes service:

• from Elastic Kubernetes Service (EKS)
• to Google Kubernetes Engine (GKE)

Then it would be hard to migrate. Just due to complexity of kubernetes architecture and differences in the approaches of manage cluster in AWS vsGCP`

Migrate VMs and cluster deployed using your own k8s manifest.

If your kubernetes cluster is deployed on cloud virtual machines with k8s or helm manifests, then it would be easier.

And there are two ways:

• Either migrate VMs using GCP Migrate Connector (as @vicente-ayala said in his answer)
• Or import your infrastructure to the terraform manifest, change resources definitions step-by-step, and then apply this updated manifest to GCP

Migrating with Migrate Connector

You can found the latest migration manual on migrating VM's here:

Prerequisites

As per GCP manual,

Before you can migrate a source VM to Google Cloud, you must configure the migration environment on your on-premises data center and on Google Cloud. See:

• Enabling Migrate for Compute Engine services
• Installing the Migrate Connector

Migrating

How-to Guides  |  Migrate for Compute Engine  |  Google Cloud

• Migrating individual VMs
• Migrating VM groups

Migrating using Terraform and Terraformer

There is a great tool for reverse Terraform GoogleCloudPlatform/terraformer. Infrastructure to Code

A CLI tool that generates tf/json and tfstate files based on existing infrastructure (reverse Terraform).

And you can import your infrastructure into terraform manifest:

 terraformer import aws --resources=vpc,subnet --connect=true --regions=eu-west-1 --profile=prod

You'll get the terraform manifest declared with aws provider

And you may try to replace every AWS resource to the appropriate GCP resource. There is official terraform GCP provider: hashicorp/google. Unfortunately, there isn't mapping for terraform resources of both cloud providers. But, again, you may some of these mapping lists:

• Cloud Services Mapping For AWS, Azure, GCP ,OCI, IBM and Alibaba provider – Technology Geek
• Cloud Terminology Glossary for AWS, Azure, and GCP | Lucidchart:
• Cloud Services Terminology Guide: Comparing AWS vs Azure vs Google | CloudHealth by VMware

And then apply the new GCP manifest:

terraform init
terraform plan
terraform apply

Additional resources on AWS <-> GCP

• GCP to AWS Migration: Why and How to Make the Move
• GCP | Google Cloud Migrate for Compute Engine | AWS to GCP Migration using Velostrata - YouTube
• Managing a Large and Complex GCP Migration (Cloud Next '19) - YouTube
• Lessons Learned Migrating from GCP to AWS | Leverege
• How to approach a GCP-to-AWS migration
• How Rapyder helped ride-sharing app migrate from GCP to AWS | Rapyder
• Cloud Migration Use Case: Moving From AWS to GCP (PDF)

Here is a detailed guide of steps you need to perform to migrate you k8s cluster from AWS to GCP.

https://cloud.google.com/migrate/compute-engine/docs/4.8/how-to/migrate-aws-to-gcp/overview

https://cloud.google.com/migrate/compute-engine/docs/4.8/how-to/migrate-aws-to-gcp/aws-prerequisites

https://cloud.google.com/migrate/compute-engine/docs/4.8/how-to/migrate-aws-to-gcp/configure-aws-as-a-source