AWS: add a IPAM Pool for kOps CI

Related to:
  - kubernetes#5127

Add a VPC IPAM pool used to manage the IP addresses used by the VPC

Signed-off-by: Arnaud Meukam <ameukam@gmail.com>

infra/aws/terraform/kops-infra-ci/locals.tf

@@ -19,4 +19,6 @@ locals {
   kops-infra-ci-name       = "kops-infra-ci"
   kops-infra-ci-index      = index(data.aws_organizations_organization.current.accounts.*.name, local.kops-infra-ci-name)
   kops-infra-ci-account-id = data.aws_organizations_organization.current.accounts[local.kops-infra-ci-index].id
+
+  prefix = "k8s-infra-kops"
 }

infra/aws/terraform/kops-infra-ci/variables.tf

@@ -0,0 +1,29 @@
+/*
+Copyright 2023 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+variable "tags" {
+  type = map(string)
+  default = {
+    "managed-by"    = "Terraform",
+    "group" = "sig-cluster-lifecycle",
+    "subproject" = "kops"
+  }
+}
+
+variable "region" {
+  type = string
+  default = "us-east-2"
+}

infra/aws/terraform/kops-infra-ci/vpc.tf

@@ -0,0 +1,47 @@
+/*
+Copyright 2023 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+resource "aws_vpc_ipam" "main" {
+  provider    = aws.kops-infra-ci
+  description = "${local.prefix}-${data.aws_region.current.name}-ipam"
+  operating_regions {
+    region_name = data.aws_region.current.name
+  }
+
+  tags = merge(var.tags, {
+    "region" = "${data.aws_region.current.name}"
+  })
+}
+
+resource "aws_vpc_ipam_scope" "main" {
+  provider    = aws.kops-infra-ci
+  ipam_id     = aws_vpc_ipam.main.id
+  description = "${local.prefix}-${data.aws_region.current.name}-ipam-scope"
+  tags = merge(var.tags, {
+    "region" = "${data.aws_region.current.name}"
+  })
+}
+
+# IPv4
+resource "aws_vpc_ipam_pool" "main" {
+  provider       = aws.kops-infra-ci
+  address_family = "ipv4"
+  ipam_scope_id  = aws_vpc_ipam.main.private_default_scope_id
+  locale         = data.aws_region.current.name
+  tags = merge(var.tags, {
+    "region" = "${data.aws_region.current.name}"
+  })
+}