feat: Added custom AMI support for managed node groups (#1473)

modules/node_groups/README.md

@@ -20,6 +20,7 @@ The role ARN specified in `var.default_iam_role_arn` will be used by default. In
 | additional\_tags | Additional tags to apply to node group | map(string) | Only `var.tags` applied |
 | ami\_release\_version | AMI version of workers | string | Provider default behavior |
 | ami\_type | AMI Type. See Terraform or AWS docs | string | Provider default behavior |
+| ami\_id | ID of custom AMI. If you use a custom AMI, you need to supply bootstrap script via user-data or as AMI built-in. | string | Provider default behavior |
 | capacity\_type | Type of instance capacity to provision. Options are `ON_DEMAND` and `SPOT` | string | Provider default behavior |
 | create_launch_template | Create and use a default launch template | bool |  `false` |
 | desired\_capacity | Desired number of workers | number | `var.workers_group_defaults[asg_desired_capacity]` |

modules/node_groups/launch_template.tf

@@ -9,8 +9,10 @@ data "cloudinit_config" "workers_userdata" {
     content_type = "text/x-shellscript"
     content = templatefile("${path.module}/templates/userdata.sh.tpl",
       {
-        pre_userdata       = each.value["pre_userdata"]
-        kubelet_extra_args = each.value["kubelet_extra_args"]
+        pre_userdata         = each.value["pre_userdata"]
+        kubelet_extra_args   = each.value["kubelet_extra_args"]
+        cluster_name         = var.cluster_name
+        run_bootstrap_script = lookup(each.value, "ami_id", null) != null
       }
     )
   }
@@ -64,7 +66,7 @@ resource "aws_launch_template" "workers" {
   }
 
   # if you want to use a custom AMI
-  # image_id      = var.ami_id
+  image_id = lookup(each.value, "ami_id", null)
 
   # If you use a custom AMI, you need to supply via user-data, the bootstrap script as EKS DOESNT merge its managed user-data then
   # you can add more than the minimum code you see in the template, e.g. install SSM agent, see https://github.com/aws/containers-roadmap/issues/593#issuecomment-577181345

modules/node_groups/templates/userdata.sh.tpl

@@ -4,3 +4,6 @@
 ${pre_userdata}
 
 sed -i '/^KUBELET_EXTRA_ARGS=/a KUBELET_EXTRA_ARGS+=" ${kubelet_extra_args}"' /etc/eks/bootstrap.sh
+%{ if run_bootstrap_script }
+    /etc/eks/bootstrap.sh ${cluster_name}
+%{ endif }