Add ami input to provider

Author: DavidGOrtega

README.md

@@ -11,7 +11,7 @@ terraform {
   required_providers {
     iterative = {
       source = "iterative/iterative"
-      version = "0.5.0"
+      version = "0.5.1"
     }
   }
 }
@@ -32,6 +32,7 @@ resource "iterative_machine" "machine" {
 | Variable | Values | Default | |
 | ------- | ------ | -------- | ------------- |
 | ```region``` | ```us-west``` ```us-east``` ```eu-west``` ```eu-north``` | ```us-west``` | Sets the collocation region |
+| ```ami``` | | ```iterative-cml``` | Sets the ami to be used. For that the provider does a search in the cloud provider by image name not by id, taking the lastest version in case there are many with the same name. Defaults to [iterative-cml image](#iterative-cml-image) |
 | ```instance_name``` |  | cml_{UID} | Sets the instance name and related resources like AWS key pair. |
 | ```instance_hdd_size``` | | 10 | Sets the instance hard disk size in gb |
 | ```instance_type``` | ```m```, ```l```, ```xl``` | ```m``` | Sets thee instance computing size. You can also specify vendor specific machines in AWS i.e. ```t2.micro``` |
@@ -65,3 +66,11 @@ The instance type in AWS is calculated joining the ```instance_type``` and ```in
 | us-east | us-east-1 |
 | eu-north | us-north-1 |
 | eu-west | us-west-1 |
+
+# Iterative CML image
+
+It's a GPU ready image based on Ubuntu 18.04. It has the following stack already installed:
+
+ - nvidia drivers
+ - docker
+ - nvidia-docker

iterative/resource_machine.go

@@ -27,6 +27,12 @@ func resourceMachine() *schema.Resource {
 				ForceNew: true,
 				Default:  "us-west",
 			},
+			"ami": &schema.Schema{
+				Type:     schema.TypeString,
+				Optional: true,
+				ForceNew: true,
+				Default:  "iterative-cml",
+			},
 			"instance_name": &schema.Schema{
 				Type:     schema.TypeString,
 				Optional: true,
@@ -112,11 +118,13 @@ func resourceMachineCreate(ctx context.Context, d *schema.ResourceData, m interf
 		return diag.FromErr(errClient)
 	}
 
+	ami := d.Get("ami").(string)
+
 	imagesRes, imagesErr := svc.DescribeImages(&ec2.DescribeImagesInput{
 		Filters: []*ec2.Filter{
 			{
 				Name:   aws.String("name"),
-				Values: []*string{aws.String("iterative-cml")},
+				Values: []*string{aws.String(ami)},
 			},
 			{
 				Name:   aws.String("architecture"),
@@ -130,7 +138,7 @@ func resourceMachineCreate(ctx context.Context, d *schema.ResourceData, m interf
 	if len(imagesRes.Images) == 0 {
 		diags = append(diags, diag.Diagnostic{
 			Severity: diag.Error,
-			Summary:  "iterative-cml ami not found in region",
+			Summary:  ami + " ami not found in region",
 		})
 
 		return diags