Automatically create snapshots when destroying volumes

README.md

@@ -50,6 +50,7 @@ This will use the default settings which are:
 |-a|ami_id|ID of a specific image (e.g.: ami-dca37ea5). If left unset, will default to ubuntu. Note that some amis are only available in specific regions, which will need to be specified with `-r`. Note that these images will incur an additional cost.|
 |-p|playbook|playbooks/databox.yml. Path to ansible playbook used for custom deployment tasks.|
 |-s|snapshot_id|The id of a snapshot to be loaded onto the EBS volume. If not provided, an empty volume will be provisioned. The snapshot must be in the same region as specified in `aws_region`, and it must be the same size or smaller than the size of the volume specified in `volume_size`. Note that a snapshot is not saved before the resources are destroyed with `./databox.sh down`: you will need to make a new snapshot at the AWS console to persist the data.|
+|-c|create_snapshot|Can only be passed when calling `./databox.sh down`. Setting this to `1` creates a snapshot of the mounted volume prior to destroying it. The snapshot information will be output to the console in a json.|
 
 *NOTE: Ansible will require you to enter your local sudo password before continuing.*
 
@@ -213,6 +214,14 @@ Note that if you create a databox by specifying region this way, you must also p
 
 *NOTE: Failing to pass the correct region argument to the `./databox.sh down` command will result in your resources not being found, and consequently, not destroyed.*
 
+You can create a snapshot of the default volume by passing `-c 1` like so:
+
+```
+./databox.sh -r eu-west-1 -c 1 down
+```
+
+Information about the snapshot will be passed to the console as a json.
+
 ### Using terraform and ansible directly
 
 If you need additional customisations, the following commands can be run without the `./databox.sh` wrapper:

databox.sh

@@ -29,6 +29,11 @@ case $key in
     SNAPSHOT_ID="$2"
     shift # past argument
     ;;
+    -c|--create_snapshot)
+    CREATE_SNAPSHOT="1"
+    shift # past argument
+    ;;
+	  # unknown option
     -p|--playbook)
     PLAYBOOK="$2"
     shift # past argument
@@ -87,20 +92,27 @@ case "$1" in
     ansible-playbook -i "$DATABOX_IP," -K "$PLAYBOOK" -u ubuntu
     ;;
 "down") echo  "Destroying DataBox"
+
     # If I don't specify the region use a default value
+
     if [ -z "${REGION+x}" ]; then
         export REGION="eu-west-2"
     fi
 
+    if [ -z "${CREATE_SNAPSHOT+x}" ]; then
+        export CREATE_SNAPSHOT=""
+    fi
+
     # Get DataBox IP from state after the script completes
     export DATABOX_IP=`terraform output ec2_ip`
 
     # Run ansible teardown tasks
     ansible-playbook -i "$DATABOX_IP," -K playbooks/teardown.yml -u ubuntu
 
-    terraform destroy --var aws_region=$REGION
+    terraform destroy --var aws_region=$REGION --var create_snapshot=$CREATE_SNAPSHOT
     ;;
 *)  echo "DataBox - create and destroy AWS instances for Data Science"
+    echo ""
     echo "./databox.sh up - Create a DataBox"
     echo " -- options -- "
     echo "  -r|--region - AWS region"
@@ -111,4 +123,8 @@ case "$1" in
     echo "  -p|--playbook - Ansible playbook for post deployment tasks"
     echo "  -s|--snapshot_id - Id of the snapshot from which to create volume"
     echo "./databox.sh down - Destroy the DataBox"
+    echo " -- options -- "
+    echo "  -r|--region          - Must match region specified at creation"
+    echo "  -c|--create_snapshot - Set this to 1 to create a snapshot of"
+    echo "			 the mounted volume prior to destruction."
 esac

main.tf

@@ -1,7 +1,9 @@
 variable "aws_region" { default = "eu-west-2" } # London
 variable "username" { default = "databoxuser"}
-variable "instance_type" {default = "t2.micro" }
-variable "volume_size" {default = "40" }
+variable "instance_type" { default = "t2.micro" }
+variable "volume_size" { default = "40" }
+variable "profile" { default = "gds-data" }
+variable "create_snapshot" { default = "" }
 variable "snapshot_id" {
   default = ""
   description = "Specify a snapshot_id to be used when creating the EBS Volume. Note that this snapshot must be in the same region as the instance, and must be the same size or smaller than the volume as specified in volume_size."
@@ -19,7 +21,7 @@ variable "ami_id" {
 
 provider "aws" {
     region = "${var.aws_region}"
-    profile = "gds-data"
+    profile = "${var.profile}"
 }
 
 resource "aws_security_group" "allow_ssh_from_gds" {
@@ -101,6 +103,12 @@ resource "aws_ebs_volume" "volume" {
     tags {
         Name = "DataBoxVolume"
     }
+
+    provisioner "local-exec" {
+	when = "destroy"
+	command = "if [ ${var.create_snapshot} ]; then aws ec2 create-snapshot --volume-id ${aws_ebs_volume.volume.id} --region ${var.aws_region}  --profile ${var.profile} ; fi;"
+	on_failure = "fail"
+    }
 }
 
 resource "aws_volume_attachment" "ebs_att" {