feat: Add /certs/client and docker.sock to volumes for docker in docker (#396)

* Adding /certs/client and docker.sock to volumes for docker in docker

* Make the volumes for docker-in-docker configurable

* Format code and add documentation

* Remove whitespaces in `runners_additional_volumes` if Dind volumes are added

* Add /builds to the volume mount to have everything available inside docker

Co-authored-by: kayma <[email protected]>

Author: kayman-mk

README.md

@@ -397,6 +397,7 @@ terraform destroy
 | <a name="input_runners_additional_volumes"></a> [runners\_additional\_volumes](#input\_runners\_additional\_volumes) | Additional volumes that will be used in the runner config.toml, e.g Docker socket | `list(any)` | `[]` | no |
 | <a name="input_runners_concurrent"></a> [runners\_concurrent](#input\_runners\_concurrent) | Concurrent value for the runners, will be used in the runner config.toml. | `number` | `10` | no |
 | <a name="input_runners_disable_cache"></a> [runners\_disable\_cache](#input\_runners\_disable\_cache) | Runners will not use local cache, will be used in the runner config.toml | `bool` | `false` | no |
+| <a name="input_runners_add_dind_volumes"></a> [runners\_add\_dind\_volumes](#input\_runners\_add\_dind\_volumes) | Add certificates and docker.sock to the volumes to support docker-in-docker (dind) | `bool` | `false` | no |
 | <a name="input_runners_docker_runtime"></a> [runners\_docker\_runtime](#input\_runners\_docker\_runtime) | docker runtime for runners, will be used in the runner config.toml | `string` | `""` | no |
 | <a name="input_runners_ebs_optimized"></a> [runners\_ebs\_optimized](#input\_runners\_ebs\_optimized) | Enable runners to be EBS-optimized. | `bool` | `true` | no |
 | <a name="input_runners_environment_vars"></a> [runners\_environment\_vars](#input\_runners\_environment\_vars) | Environment variables during build execution, e.g. KEY=Value, see runner-public example. Will be used in the runner config.toml | `list(string)` | `[]` | no |

locals.tf

@@ -17,7 +17,7 @@ locals {
   name_sg                    = var.overrides["name_sg"] == "" ? local.tags["Name"] : var.overrides["name_sg"]
   name_iam_objects           = lookup(var.overrides, "name_iam_objects", "") == "" ? local.tags["Name"] : var.overrides["name_iam_objects"]
   runners_additional_volumes = <<-EOT
-  %{~for volume in var.runners_additional_volumes~},"${volume}"%{endfor~}
+  %{~if var.runners_add_dind_volumes~},"/certs/client", "/builds", "/var/run/docker.sock:/var/run/docker.sock"%{endif~}%{~for volume in var.runners_additional_volumes~},"${volume}"%{endfor~}
   EOT
 
   runners_machine_autoscaling = templatefile("${path.module}/template/runners_machine_autoscaling.tpl", {

variables.tf

@@ -183,6 +183,12 @@ variable "runners_disable_cache" {
   default     = false
 }
 
+variable "runners_add_dind_volumes" {
+  description = "Add certificates and docker.sock to the volumes to support docker-in-docker (dind)"
+  type        = bool
+  default     = false
+}
+
 variable "runners_additional_volumes" {
   description = "Additional volumes that will be used in the runner config.toml, e.g Docker socket"
   type        = list(any)