added support for specifying user data for the worker launch config that runs before anything else

Author: jimbeck

data.tf

@@ -73,6 +73,7 @@ data template_file userdata {
     endpoint            = "${aws_eks_cluster.this.endpoint}"
     cluster_auth_base64 = "${aws_eks_cluster.this.certificate_authority.0.data}"
     max_pod_count       = "${lookup(local.max_pod_per_node, lookup(var.worker_groups[count.index], "instance_type", lookup(var.workers_group_defaults, "instance_type")))}"
+    pre_userdata        = "${lookup(var.worker_groups[count.index], "pre_userdata",lookup(var.workers_group_defaults, "pre_userdata"))}"
     additional_userdata = "${lookup(var.worker_groups[count.index], "additional_userdata",lookup(var.workers_group_defaults, "additional_userdata"))}"
   }
 }

templates/userdata.sh.tpl

@@ -1,5 +1,8 @@
 #!/bin/bash -xe
 
+# Allow user supplied pre userdata code
+${pre_userdata}
+
 # Certificate Authority config
 CA_CERTIFICATE_DIRECTORY=/etc/kubernetes/pki
 CA_CERTIFICATE_FILE_PATH=$CA_CERTIFICATE_DIRECTORY/ca.crt

variables.tf

@@ -57,6 +57,7 @@ variable "workers_group_defaults" {
     asg_min_size         = "1"           # Minimum worker capacity in the autoscaling group.
     instance_type        = "m4.large"    # Size of the workers instances.
     key_name             = ""            # The key name that should be used for the instances in the autoscaling group
+    pre_userdata         = ""            # userdata to pre-append to the default userdata.
     additional_userdata  = ""            # userdata to append to the default userdata.
     ebs_optimized        = true          # sets whether to use ebs optimization on supported types.
     public_ip            = false         # Associate a public ip address with a worker