Support dynamic replacement of the Nomad binary at run-time

terraform/aws/README.md

@@ -43,15 +43,27 @@ a custom AMI:
 
 ```bash
 region                  = "us-east-1"
-ami                     = "ami-d42d74ae"
+ami                     = "ami-540cd929"
 instance_type           = "t2.medium"
 key_name                = "KEY_NAME"
 server_count            = "3"
 client_count            = "4"
 ```
 
-You can also modify the `region`, `instance_type`, `server_count`, and `client_count`. 
-At least one client and one server are required.
+Modify the `region`, `instance_type`, `server_count`, and `client_count` variables
+as appropriate. At least one client and one server are required. You can 
+optionally replace the Nomad binary at runtime by adding the `nomad_binary` 
+variable like so:
+
+```bash
+region                  = "us-east-1"
+ami                     = "ami-540cd929"
+instance_type           = "t2.medium"
+key_name                = "KEY_NAME"
+server_count            = "3"
+client_count            = "4"
+nomad_binary            = "https://releases.hashicorp.com/nomad/0.7.0/nomad_0.7.0_linux_amd64.zip"
+```
 
 Provision the cluster:
 

terraform/aws/env/us-east/main.tf

@@ -27,6 +27,11 @@ variable "retry_join" {
   default     = "provider=aws tag_key=ConsulAutoJoin tag_value=auto-join"
 }
 
+variable "nomad_binary" {
+  description = "Used to replace the machine image installed Nomad binary."
+  default     = "none"
+}
+
 provider "aws" {
   region = "${var.region}"
 }
@@ -41,6 +46,7 @@ module "hashistack" {
   server_count  = "${var.server_count}"
   client_count  = "${var.client_count}"
   retry_join    = "${var.retry_join}"
+  nomad_binary  = "${var.nomad_binary}"
 }
 
 output "IP_Addresses" {

terraform/aws/env/us-east/terraform.tfvars

@@ -1,5 +1,5 @@
 region            = "us-east-1"
-ami               = "ami-d42d74ae"
+ami               = "ami-540cd929"
 instance_type     = "t2.medium"
 key_name          = "KEY_NAME"
 server_count      = "3"

terraform/aws/env/us-east/user-data-client.sh

@@ -3,4 +3,4 @@
 set -e
 
 exec > >(sudo tee /var/log/user-data.log|logger -t user-data -s 2>/dev/console) 2>&1
-sudo bash /ops/shared/scripts/client.sh "aws" "${retry_join}"
+sudo bash /ops/shared/scripts/client.sh "aws" "${retry_join}" "${nomad_binary}"

terraform/aws/env/us-east/user-data-server.sh

@@ -3,4 +3,4 @@
 set -e
 
 exec > >(sudo tee /var/log/user-data.log|logger -t user-data -s 2>/dev/console) 2>&1
-sudo bash /ops/shared/scripts/server.sh "aws" "${server_count}" "${retry_join}"
+sudo bash /ops/shared/scripts/server.sh "aws" "${server_count}" "${retry_join}" "${nomad_binary}"

terraform/aws/modules/hashistack/hashistack.tf

@@ -5,6 +5,7 @@ variable "key_name" {}
 variable "server_count" {}
 variable "client_count" {}
 variable "retry_join" {}
+variable "nomad_binary" {}
 
 data "aws_vpc" "default" {
   default = true
@@ -83,6 +84,7 @@ data "template_file" "user_data_server" {
     server_count = "${var.server_count}"
     region       = "${var.region}"
     retry_join   = "${var.retry_join}"
+    nomad_binary = "${var.nomad_binary}"
   }
 }
 
@@ -92,6 +94,7 @@ data "template_file" "user_data_client" {
   vars {
     region     = "${var.region}"
     retry_join = "${var.retry_join}"
+    nomad_binary = "${var.nomad_binary}"
   }
 }
 
@@ -126,6 +129,13 @@ resource "aws_instance" "client" {
     ConsulAutoJoin = "auto-join"
   }
 
+  ebs_block_device =  {
+    device_name                 = "/dev/xvdd"
+    volume_type                 = "gp2"
+    volume_size                 = "50"
+    delete_on_termination       = "true"
+  }
+
   user_data            = "${data.template_file.user_data_client.rendered}"
   iam_instance_profile = "${aws_iam_instance_profile.instance_profile.name}"
 }

terraform/shared/scripts/client.sh

@@ -18,6 +18,7 @@ IP_ADDRESS="$(/sbin/ifconfig eth0 | grep 'inet addr:' | cut -d: -f2 | awk '{ pri
 DOCKER_BRIDGE_IP_ADDRESS=(`ifconfig docker0 2>/dev/null|awk '/inet addr:/ {print $2}'|sed 's/addr://'`)
 CLOUD=$1
 RETRY_JOIN=$2
+NOMAD_BINARY=$3
 
 # Consul
 sed -i "s/IP_ADDRESS/$IP_ADDRESS/g" $CONFIGDIR/consul_client.json
@@ -29,6 +30,15 @@ sudo systemctl start consul.service
 sleep 10
 
 # Nomad
+
+## Replace existing Nomad binary if remote file exists
+if [[ `wget -S --spider $NOMAD_BINARY  2>&1 | grep 'HTTP/1.1 200 OK'` ]]; then
+  curl -L $NOMAD_BINARY > nomad.zip
+  sudo unzip -o nomad.zip -d /usr/local/bin
+  sudo chmod 0755 /usr/local/bin/nomad
+  sudo chown root:root /usr/local/bin/nomad
+fi
+
 sudo cp $CONFIGDIR/nomad_client.hcl $NOMADCONFIGDIR/nomad.hcl
 sudo cp $CONFIGDIR/nomad.service /etc/systemd/system/nomad.service
 

terraform/shared/scripts/server.sh

@@ -20,6 +20,7 @@ DOCKER_BRIDGE_IP_ADDRESS=(`ifconfig docker0 2>/dev/null|awk '/inet addr:/ {print
 CLOUD=$1
 SERVER_COUNT=$2
 RETRY_JOIN=$3
+NOMAD_BINARY=$4
 
 # Consul
 sed -i "s/IP_ADDRESS/$IP_ADDRESS/g" $CONFIGDIR/consul.json
@@ -41,6 +42,15 @@ sudo cp $CONFIGDIR/vault.service /etc/systemd/system/vault.service
 sudo systemctl start vault.service
 
 # Nomad
+
+## Replace existing Nomad binary if remote file exists
+if [[ `wget -S --spider $NOMAD_BINARY  2>&1 | grep 'HTTP/1.1 200 OK'` ]]; then
+  curl -L $NOMAD_BINARY > nomad.zip
+  sudo unzip -o nomad.zip -d /usr/local/bin
+  sudo chmod 0755 /usr/local/bin/nomad
+  sudo chown root:root /usr/local/bin/nomad
+fi
+
 sed -i "s/SERVER_COUNT/$SERVER_COUNT/g" $CONFIGDIR/nomad.hcl
 sudo cp $CONFIGDIR/nomad.hcl $NOMADCONFIGDIR
 sudo cp $CONFIGDIR/nomad.service /etc/systemd/system/nomad.service