FluentBit setup - terraform

Question

I'm trying to set up FluentBit for my EKS cluster in Terraform, via this module, and I have couple of questions:
cluster_identity_oidc_issuer - what is this? Frankly, I was just told to set this up, so I have very little knowledge about FluentBit, but I assume this "issuer" provides an identity with needed permissions. For example, Okta? We use Okta, so what would I use as a value in here?
cluster_identity_oidc_issuer_arn - no idea what this value is supposed to be.
worker_iam_role_name - as in the role with autoscaling capabilities (oidc)?
This is what eks.tf looks like:
module "eks" {
source = "terraform-aws-modules/eks/aws"
cluster_name = "DevOpsLabs"
cluster_version = "1.19"
cluster_endpoint_private_access = true
cluster_endpoint_public_access = true
cluster_addons = {
coredns = {
resolve_conflicts = "OVERWRITE"
}
kube-proxy = {}
vpc-cni = {
resolve_conflicts = "OVERWRITE"
}
}
vpc_id = "xxx"
subnet_ids = ["xxx","xxx", "xxx", "xxx" ]
self_managed_node_groups = {
bottlerocket = {
name = "bottlerocket-self-mng"
platform = "bottlerocket"
ami_id = "xxx"
instance_type = "t2.small"
desired_size = 2
iam_role_additional_policies = ["arn:aws:iam::aws:policy/AmazonSSMManagedInstanceCore"]
pre_bootstrap_user_data = <<-EOT
echo "foo"
export FOO=bar
EOT
bootstrap_extra_args = "--kubelet-extra-args '--node-labels=node.kubernetes.io/lifecycle=spot'"
post_bootstrap_user_data = <<-EOT
cd /tmp
sudo yum install -y https://s3.amazonaws.com/ec2-downloads-windows/SSMAgent/latest/linux_amd64/amazon-ssm-agent.rpm
sudo systemctl enable amazon-ssm-agent
sudo systemctl start amazon-ssm-agent
EOT
}
}
}
And for the role.tf:
data "aws_iam_policy_document" "cluster_autoscaler" {
statement {
effect = "Allow"
actions = [
"autoscaling:DescribeAutoScalingGroups",
"autoscaling:DescribeAutoScalingInstances",
"autoscaling:DescribeLaunchConfigurations",
"autoscaling:DescribeTags",
"autoscaling:SetDesiredCapacity",
"autoscaling:TerminateInstanceInAutoScalingGroup",
"ec2:DescribeLaunchTemplateVersions",
]
resources = ["*"]
}
}
module "config" {
source = "github.com/ahmad-hamade/terraform-eks-config/modules/eks-iam-role-with-oidc"
cluster_name = module.eks.cluster_id
role_name = "cluster-autoscaler"
service_accounts = ["kube-system/cluster-autoscaler"]
policies = [data.aws_iam_policy_document.cluster_autoscaler.json]
tags = {
Terraform = "true"
Environment = "dev-test"
}
}

Answer 1

Since you are using a Terraform EKS module, you can access attributes of the created resources by looking at the Outputs tab [1]. There you can find the following outputs:
cluster_id
cluster_oidc_issuer_url
oidc_provider_arn
They are accessible by using the following syntax:
module.<module_name>.<output_id>
In your case, you would get the values you need using the following syntax:
cluster_id -> module.eks.cluster_id
cluster_oidc_issuer_url -> module.eks.cluster_oidc_issuer_url
oidc_provider_arn -> module.eks.oidc_provider_arn
and assign them to the inputs from the FluentBit module:
cluster_name = module.eks.cluster_id
cluster_identity_oidc_issuer = module.eks.cluster_oidc_issuer_url
cluster_identity_oidc_issuer_arn = module.eks.oidc_provider_arn
For the worker role I didn't see an output from the eks module, so I think that could be an output of the config module [2]:
worker_iam_role_name = module.config.iam_role_name
The OIDC parts of configuration are coming from the EKS cluster [3]. Another blog post going in details can be found here [4].
[1] https://registry.terraform.io/modules/terraform-aws-modules/eks/aws/latest?tab=outputs
[2] https://github.com/ahmad-hamade/terraform-eks-config/blob/master/modules/eks-iam-role-with-oidc/outputs.tf
[3] https://docs.aws.amazon.com/eks/latest/userguide/iam-roles-for-service-accounts.html
[4] https://aws.amazon.com/blogs/containers/introducing-oidc-identity-provider-authentication-amazon-eks/