feat: Allow workspace resources to attach multiple agents (#942)

This enables a "kubernetes_pod" to attach multiple agents that
could be for multiple services. Each agent is required to have
a unique name, so SSH syntax is:

`coder ssh <workspace>.<agent>`

A resource can have zero agents too, they aren't required.

examples/aws-linux/main.tf

@@ -2,7 +2,7 @@ terraform {
   required_providers {
     coder = {
       source  = "coder/coder"
-      version = "0.2.1"
+      version = "~> 0.3.1"
     }
   }
 }
@@ -55,12 +55,6 @@ provider "aws" {
 data "coder_workspace" "me" {
 }
 
-data "coder_agent_script" "dev" {
-  arch = "amd64"
-  auth = "aws-instance-identity"
-  os   = "linux"
-}
-
 data "aws_ami" "ubuntu" {
   most_recent = true
   filter {
@@ -75,8 +69,9 @@ data "aws_ami" "ubuntu" {
 }
 
 resource "coder_agent" "dev" {
-  count       = data.coder_workspace.me.transition == "start" ? 1 : 0
-  instance_id = aws_instance.dev[0].id
+  arch = "amd64"
+  auth = "aws-instance-identity"
+  os   = "linux"
 }
 
 locals {
@@ -105,7 +100,7 @@ Content-Transfer-Encoding: 7bit
 Content-Disposition: attachment; filename="userdata.txt"
 
 #!/bin/bash
-sudo -E -u ubuntu sh -c '${data.coder_agent_script.dev.value}'
+sudo -E -u ubuntu sh -c '${coder_agent.dev.init_script}'
 --//--
 EOT
 
@@ -139,11 +134,9 @@ resource "aws_instance" "dev" {
   ami               = data.aws_ami.ubuntu.id
   availability_zone = "${var.region}a"
   instance_type     = "t3.micro"
-  count             = 1
 
   user_data = data.coder_workspace.me.transition == "start" ? local.user_data_start : local.user_data_end
   tags = {
     Name = "coder-${data.coder_workspace.me.owner}-${data.coder_workspace.me.name}"
   }
-
 }

examples/aws-windows/main.tf

@@ -2,7 +2,7 @@ terraform {
   required_providers {
     coder = {
       source  = "coder/coder"
-      version = "0.2.1"
+      version = "~> 0.3.1"
     }
   }
 }
@@ -42,12 +42,6 @@ provider "aws" {
 data "coder_workspace" "me" {
 }
 
-data "coder_agent_script" "dev" {
-  arch = "amd64"
-  auth = "aws-instance-identity"
-  os   = "windows"
-}
-
 data "aws_ami" "windows" {
   most_recent = true
   owners      = ["amazon"]
@@ -59,8 +53,9 @@ data "aws_ami" "windows" {
 }
 
 resource "coder_agent" "dev" {
-  count       = data.coder_workspace.me.transition == "start" ? 1 : 0
-  instance_id = aws_instance.dev[0].id
+  arch = "amd64"
+  auth = "aws-instance-identity"
+  os   = "windows"
 }
 
 locals {
@@ -71,7 +66,7 @@ locals {
   user_data_start = <<EOT
 <powershell>
 [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
-${data.coder_agent_script.dev.value}
+${coder_agent.dev.init_script}
 </powershell>
 <persist>true</persist>
 EOT

examples/gcp-linux/main.tf

@@ -2,7 +2,7 @@ terraform {
   required_providers {
     coder = {
       source  = "coder/coder"
-      version = "~> 0.2"
+      version = "~> 0.3.1"
     }
     google = {
       source  = "hashicorp/google"
@@ -42,25 +42,14 @@ provider "google" {
   project     = jsondecode(var.service_account).project_id
 }
 
-data "coder_workspace" "me" {
-}
-
-data "coder_agent_script" "dev" {
-  auth = "google-instance-identity"
-  arch = "amd64"
-  os   = "linux"
-}
-
 data "google_compute_default_service_account" "default" {
 }
 
-resource "random_string" "random" {
-  length  = 8
-  special = false
+data "coder_workspace" "me" {
 }
 
 resource "google_compute_disk" "root" {
-  name  = "coder-${lower(random_string.random.result)}"
+  name  = "coder-${data.coder_workspace.me.owner}-${data.coder_workspace.me.name}-root"
   type  = "pd-ssd"
   zone  = var.zone
   image = "debian-cloud/debian-9"
@@ -69,10 +58,16 @@ resource "google_compute_disk" "root" {
   }
 }
 
+resource "coder_agent" "dev" {
+  auth = "google-instance-identity"
+  arch = "amd64"
+  os   = "linux"
+}
+
 resource "google_compute_instance" "dev" {
   zone         = var.zone
-  count        = data.coder_workspace.me.transition == "start" ? 1 : 0
-  name         = "coder-${lower(random_string.random.result)}"
+  count        = data.coder_workspace.me.start_count
+  name         = "coder-${data.coder_workspace.me.owner}-${data.coder_workspace.me.name}"
   machine_type = "e2-medium"
   network_interface {
     network = "default"
@@ -88,10 +83,5 @@ resource "google_compute_instance" "dev" {
     email  = data.google_compute_default_service_account.default.email
     scopes = ["cloud-platform"]
   }
-  metadata_startup_script = data.coder_agent_script.dev.value
-}
-
-resource "coder_agent" "dev" {
-  count       = length(google_compute_instance.dev)
-  instance_id = google_compute_instance.dev[0].instance_id
+  metadata_startup_script = coder_agent.dev.init_script
 }

examples/gcp-windows/main.tf

@@ -2,7 +2,7 @@ terraform {
   required_providers {
     coder = {
       source  = "coder/coder"
-      version = "~> 0.2"
+      version = "~> 0.3.1"
     }
     google = {
       source  = "hashicorp/google"
@@ -45,22 +45,11 @@ provider "google" {
 data "coder_workspace" "me" {
 }
 
-data "coder_agent_script" "dev" {
-  auth = "google-instance-identity"
-  arch = "amd64"
-  os   = "windows"
-}
-
 data "google_compute_default_service_account" "default" {
 }
 
-resource "random_string" "random" {
-  length  = 8
-  special = false
-}
-
 resource "google_compute_disk" "root" {
-  name  = "coder-${lower(random_string.random.result)}"
+  name  = "coder-${data.coder_workspace.me.owner}-${data.coder_workspace.me.name}-root"
   type  = "pd-ssd"
   zone  = var.zone
   image = "projects/windows-cloud/global/images/windows-server-2022-dc-core-v20220215"
@@ -69,9 +58,15 @@ resource "google_compute_disk" "root" {
   }
 }
 
+resource "coder_agent" "dev" {
+  auth = "google-instance-identity"
+  arch = "amd64"
+  os   = "windows"
+}
+
 resource "google_compute_instance" "dev" {
   zone         = var.zone
-  count        = data.coder_workspace.me.transition == "start" ? 1 : 0
+  count        = data.coder_workspace.me.start_count
   name         = "coder-${data.coder_workspace.me.owner}-${data.coder_workspace.me.name}"
   machine_type = "e2-medium"
   network_interface {
@@ -89,12 +84,7 @@ resource "google_compute_instance" "dev" {
     scopes = ["cloud-platform"]
   }
   metadata = {
-    windows-startup-script-ps1 = data.coder_agent_script.dev.value
+    windows-startup-script-ps1 = coder_agent.dev.init_script
     serial-port-enable         = "TRUE"
   }
 }
-
-resource "coder_agent" "dev" {
-  count       = length(google_compute_instance.dev)
-  instance_id = google_compute_instance.dev[0].instance_id
-}