k8s: document current limitations (#458)

Co-authored-by: Quetzalli <hola@quetzalliwrites.com>

Author: simonrw

src/content/docs/aws/enterprise/kubernetes/limitations.md

@@ -0,0 +1,53 @@
+---
+title: Limitations
+description: Known limitations when running LocalStack on Kubernetes
+template: doc
+sidebar:
+    order: 7
+tags: ["Enterprise"]
+---
+
+Some LocalStack services have limited or no support when running on Kubernetes.
+
+:::note
+We are continually working on improving parity between Docker and Kubernetes so there will be fewer limitations in the future.
+:::
+
+## Unsupported services
+
+The following services require the use of Docker, and are not supported when running LocalStack on Kubernetes:
+
+- Sagemaker
+- Bedrock
+- EKS
+- CodeBuild
+
+## Limitations of partially supported services
+
+### SSM
+
+- Exec into EC2 instances is not supported.
+
+### ECS
+
+- Firelens is not supported.
+- Volumes are not supported.
+- Exposing ports from tasks is not supported.
+- [`RepositoryCredentials`](https://docs.aws.amazon.com/AmazonECS/latest/APIReference/API_RepositoryCredentials.html) is not supported.
+
+### EC2
+
+- Userdata does not have full parity with AWS.
+
+### ElastiCache/MemoryDB
+
+- Requires using `REDIS_CONTAINER_MODE=1`.
+
+### RDS
+
+- MySQL 5.7 is not supported on Kubernetes.
+- Persistence is not supported.
+
+### Neptune
+
+- Persistence is not supported.