feat(packer): Allow passing in an instance_profile to packer (github-aws-runners#4278)

We ran into needing to pass a custom instance profile to packer in order
to get AWS IAM credentials for pre-pulling some ECR images.

I noticed what I think was a missing `instance_type` override variable
in the windows-core-2022 file. I'm not sure if that was an oversight, or
if it was omitted for a reason. It's been a long time since I've been
proficient in Windows, so I wasn't able to test that part of this very
well.

Thanks so much for this project, this has been immensely beneficial for
us.

---------

Co-authored-by: Niek Palm <npalm@users.noreply.github.com>

Author: bshelton229

images/linux-al2023/github_agent.linux.pkr.hcl

@@ -42,6 +42,12 @@ variable "instance_type" {
   default     = "m3.medium"
 }
 
+variable "iam_instance_profile" {
+  description = "IAM instance profile Packer will use for the builder. An empty string (default) means no profile will be assigned."
+  type        = string
+  default     = ""
+}
+
 variable "root_volume_size_gb" {
   type    = number
   default = 8
@@ -98,6 +104,7 @@ locals {
 source "amazon-ebs" "githubrunner" {
   ami_name                                  = "github-runner-al2023-x86_64-${formatdate("YYYYMMDDhhmm", timestamp())}"
   instance_type                             = var.instance_type
+  iam_instance_profile                      = var.iam_instance_profile
   region                                    = var.region
   security_group_id                         = var.security_group_id
   subnet_id                                 = var.subnet_id

images/ubuntu-focal/github_agent.ubuntu.pkr.hcl

@@ -42,6 +42,12 @@ variable "instance_type" {
   default     = "t3.medium"
 }
 
+variable "iam_instance_profile" {
+  description = "IAM instance profile Packer will use for the builder. An empty string (default) means no profile will be assigned."
+  type        = string
+  default     = ""
+}
+
 variable "root_volume_size_gb" {
   type    = number
   default = 8
@@ -98,6 +104,7 @@ locals {
 source "amazon-ebs" "githubrunner" {
   ami_name                                  = "github-runner-ubuntu-focal-amd64-${formatdate("YYYYMMDDhhmm", timestamp())}"
   instance_type                             = var.instance_type
+  iam_instance_profile                      = var.iam_instance_profile
   region                                    = var.region
   security_group_id                         = var.security_group_id
   subnet_id                                 = var.subnet_id
@@ -200,6 +207,7 @@ build {
       "sudo chmod +x /var/lib/cloud/scripts/per-boot/start-runner.sh",
     ]
   }
+
   post-processor "manifest" {
     output     = "manifest.json"
     strip_path = true

images/ubuntu-jammy-arm64/github_agent.ubuntu.pkr.hcl

@@ -42,6 +42,12 @@ variable "instance_type" {
   default     = "t4g.small"
 }
 
+variable "iam_instance_profile" {
+  description = "IAM instance profile Packer will use for the builder. An empty string (default) means no profile will be assigned."
+  type        = string
+  default     = ""
+}
+
 variable "root_volume_size_gb" {
   type    = number
   default = 8
@@ -98,6 +104,7 @@ locals {
 source "amazon-ebs" "githubrunner" {
   ami_name                                  = "github-runner-ubuntu-jammy-arm64-${formatdate("YYYYMMDDhhmm", timestamp())}"
   instance_type                             = var.instance_type
+  iam_instance_profile                      = var.iam_instance_profile
   region                                    = var.region
   security_group_id                         = var.security_group_id
   subnet_id                                 = var.subnet_id
@@ -200,6 +207,7 @@ build {
       "sudo chmod +x /var/lib/cloud/scripts/per-boot/start-runner.sh",
     ]
   }
+
   post-processor "manifest" {
     output     = "manifest.json"
     strip_path = true

images/ubuntu-jammy/github_agent.ubuntu.pkr.hcl

@@ -42,6 +42,12 @@ variable "instance_type" {
   default     = "t3.medium"
 }
 
+variable "iam_instance_profile" {
+  description = "IAM instance profile Packer will use for the builder. An empty string (default) means no profile will be assigned."
+  type        = string
+  default     = ""
+}
+
 variable "root_volume_size_gb" {
   type    = number
   default = 8
@@ -98,6 +104,7 @@ locals {
 source "amazon-ebs" "githubrunner" {
   ami_name                                  = "github-runner-ubuntu-jammy-amd64-${formatdate("YYYYMMDDhhmm", timestamp())}"
   instance_type                             = var.instance_type
+  iam_instance_profile                      = var.iam_instance_profile
   region                                    = var.region
   security_group_id                         = var.security_group_id
   subnet_id                                 = var.subnet_id
@@ -200,6 +207,7 @@ build {
       "sudo chmod +x /var/lib/cloud/scripts/per-boot/start-runner.sh",
     ]
   }
+
   post-processor "manifest" {
     output     = "manifest.json"
     strip_path = true

images/windows-core-2019/github_agent.windows.pkr.hcl

@@ -24,6 +24,12 @@ variable "instance_type" {
   default     = "t3a.medium"
 }
 
+variable "iam_instance_profile" {
+  description = "IAM instance profile Packer will use for the builder. An empty string (default) means no profile will be assigned."
+  type        = string
+  default     = ""
+}
+
 variable "ebs_delete_on_termination" {
   description = "Indicates whether the EBS volume is deleted on instance termination."
   type        = bool
@@ -64,6 +70,7 @@ source "amazon-ebs" "githubrunner" {
   ami_name                                  = "github-runner-windows-core-2019-${formatdate("YYYYMMDDhhmm", timestamp())}"
   communicator                              = "winrm"
   instance_type                             = var.instance_type
+  iam_instance_profile                      = var.iam_instance_profile
   region                                    = var.region
   associate_public_ip_address               = var.associate_public_ip_address
   temporary_security_group_source_public_ip = var.temporary_security_group_source_public_ip
@@ -114,6 +121,7 @@ build {
       })
     ], var.custom_shell_commands)
   }
+
   post-processor "manifest" {
     output     = "manifest.json"
     strip_path = true

images/windows-core-2022/github_agent.windows.pkr.hcl

@@ -18,6 +18,18 @@ variable "region" {
   default     = "eu-west-1"
 }
 
+variable "instance_type" {
+  description = "The instance type Packer will use for the builder"
+  type        = string
+  default     = "m4.xlarge"
+}
+
+variable "iam_instance_profile" {
+  description = "IAM instance profile Packer will use for the builder. An empty string (default) means no profile will be assigned."
+  type        = string
+  default     = ""
+}
+
 variable "security_group_id" {
   description = "The ID of the security group Packer will associate with the builder to enable access"
   type        = string
@@ -74,7 +86,8 @@ locals {
 source "amazon-ebs" "githubrunner" {
   ami_name                                  = "github-runner-windows-core-2022-${formatdate("YYYYMMDDhhmm", timestamp())}"
   communicator                              = "winrm"
-  instance_type                             = "m4.xlarge"
+  instance_type                             = var.instance_type
+  iam_instance_profile                      = var.iam_instance_profile
   region                                    = var.region
   security_group_id                         = var.security_group_id
   subnet_id                                 = var.subnet_id