3.7 KiB
LocalStack
It's a fair tool to test terraform code without actually deploying anything on aws. However, there are a few limitations on LocalStack.
Setup
Sign up for localstack and obtain the auth token. Then fire up a container:
docker run -e LOCALSTACK_AUTH_TOKEN=ls-xxx-yyy-zzz-aaa-bbb -it \
--name localstack --network macvlan localstack/localstack-pro localstack
or use community edition while it is still available
docker run \
-e AWS_ACCESS_KEY_ID=test \
-e AWS_SECRET_ACCESS_KEY=test \
-e SERVICES="s3,iam,lambda,dynamodb,cloudwatch,rds,ec2,secretsmanager,stepfunctions" \
-e DEBUG=0 \
-d --rm --name localstack --network macvlan localstack/localstack localstack
In terraform, configure aws endpoints to go to localstack and add localstack required configurations:
provider "aws" {
region = var.aws-region
# localstack config
access_key = "test"
secret_key = "test"
skip_credentials_validation = true
skip_metadata_api_check = true
skip_requesting_account_id = true
# localstack endpoints https://docs.localstack.cloud/aws/integrations/infrastructure-as-code/terraform/#:~:text=tflocal%20is%20a%20small%20wrapper,unmodified%20Terraform%20scripts%20against%20LocalStack.
endpoints {
apigateway = "http://192.168.86.96:4566"
apigatewayv2 = "http://192.168.86.96:4566"
cloudformation = "http://192.168.86.96:4566"
cloudwatch = "http://192.168.86.96:4566"
dynamodb = "http://192.168.86.96:4566"
ec2 = "http://192.168.86.96:4566"
es = "http://192.168.86.96:4566"
elasticache = "http://192.168.86.96:4566"
firehose = "http://192.168.86.96:4566"
iam = "http://192.168.86.96:4566"
kinesis = "http://192.168.86.96:4566"
lambda = "http://192.168.86.96:4566"
rds = "http://192.168.86.96:4566"
redshift = "http://192.168.86.96:4566"
route53 = "http://192.168.86.96:4566"
s3 = "http://192.168.86.96:4566"
secretsmanager = "http://192.168.86.96:4566"
ses = "http://192.168.86.96:4566"
sns = "http://192.168.86.96:4566"
sqs = "http://192.168.86.96:4566"
ssm = "http://192.168.86.96:4566"
stepfunctions = "http://192.168.86.96:4566"
sts = "http://192.168.86.96:4566"
}
}
Limitations
At time of writing, localstack seems very limited. Many basic layers would not run. For example, vpc with ipv6 could not be created. It failed with the following error
│ Error: waiting for EC2 Subnet (subnet-c113e8c02abd344e0) EnableDns64 update: timeout while waiting for state to become 'true' (last state: 'false', timeout: 5m0s)
│
│ with module.vpc.aws_subnet.private[1],
│ on .terraform/modules/vpc/main.tf line 293, in resource "aws_subnet" "private":
│ 293: resource "aws_subnet" "private" {
Also, ec2 instance's associate_public_ip_address attribute is always set to true, despite
it is set to false in my code. This caused the instance to be redeployed everytime terraform
apply is ran.
If I tried to deploy a lambda function, LocalStack actually tried to create an executable container via docker. That cannot be disabled and without docker, I got this error when trying to deploy a function. Subsequently, I cannot destroy the function since provisioning failed.
Error: waiting for Lambda Function (HelloWorldFunction) create: unexpected state 'Failed', wanted target
'Active, ActiveNonInvocable'. last error: InternalError: Error while creating lambda: Docker not available
Both the free and community editions of LocalStack do not support rds, among other services described in https://docs.localstack.cloud/aws/licensing/