feat(contrib/aws): allow easier selection of CoreOS version

This change allows an AWS user to quickly switch the CoreOS
version of the CloudFormation template. Should also help
reduce the work needed by Deis maintainers.

Author: fabiob

contrib/aws/deis.template.json

@@ -127,18 +127,7 @@
   },
 
   "Mappings" : {
-    "CoreOSAMIs" : {
-      "eu-central-1"   : { "PV" : "ami-fe6b52e3", "HVM" : "ami-f86b52e5" },
-      "ap-northeast-1" : { "PV" : "ami-9ec1119e", "HVM" : "ami-9cc1119c" },
-      "us-gov-west-1"  : { "PV" : "ami-854828a6", "HVM" : "ami-874828a4" },
-      "sa-east-1"      : { "PV" : "ami-d9b839c4", "HVM" : "ami-d5b839c8" },
-      "ap-southeast-2" : { "PV" : "ami-7985fc43", "HVM" : "ami-7b85fc41" },
-      "ap-southeast-1" : { "PV" : "ami-d4033b86", "HVM" : "ami-da033b88" },
-      "us-east-1"      : { "PV" : "ami-c16583aa", "HVM" : "ami-c36583a8" },
-      "us-west-2"      : { "PV" : "ami-995f60a9", "HVM" : "ami-975f60a7" },
-      "us-west-1"      : { "PV" : "ami-877a92c3", "HVM" : "ami-857a92c1" },
-      "eu-west-1"      : { "PV" : "ami-e38cfc94", "HVM" : "ami-e18cfc96" }
-    },
+    "CoreOSAMIs" : {},
     "RootDevices" : {
       "HVM" : { "Name": "/dev/xvda" },
       "PV"  : { "Name": "/dev/sda" }

contrib/aws/gen-json.py

@@ -1,8 +1,17 @@
 #!/usr/bin/env python
+import argparse
 import json
 import os
+import urllib
 import yaml
 
+parser = argparse.ArgumentParser()
+parser.add_argument('--channel', help='the CoreOS channel to use', default='stable')
+parser.add_argument('--version', help='the CoreOS version to use', default='current')
+args = vars(parser.parse_args())
+
+amis = json.load(urllib.urlopen("http://%(channel)s.release.core-os.net/amd64-usr/%(version)s/coreos_production_ami_all.json" % args))
+
 CURR_DIR = os.path.dirname(os.path.realpath(__file__))
 
 # Add AWS-specific units to the shared user-data
@@ -97,6 +106,7 @@
 
 template['Resources']['CoreOSServerLaunchConfig']['Properties']['UserData']['Fn::Base64']['Fn::Join'] = [ "\n", header + dump.split("\n") ]
 template['Parameters']['ClusterSize']['Default'] = str(os.getenv('DEIS_NUM_INSTANCES', 3))
+template['Mappings']['CoreOSAMIs'] = dict(map(lambda n: (n['name'], dict(PV=n['pv'], HVM=n['hvm'])), amis['amis']))
 
 VPC_ID = os.getenv('VPC_ID', None)
 VPC_SUBNETS = os.getenv('VPC_SUBNETS', None)

contrib/aws/provision-aws-cluster.sh

@@ -49,7 +49,7 @@ bailout() {
 
 # create an AWS cloudformation stack based on CoreOS's default template
 aws cloudformation create-stack \
-    --template-body "$($THIS_DIR/gen-json.py)" \
+    --template-body "$($THIS_DIR/gen-json.py --channel $COREOS_CHANNEL --version $COREOS_VERSION)" \
     --stack-name $STACK_NAME \
     --parameters "$(<$THIS_DIR/cloudformation.json)" \
     $EXTRA_AWS_CLI_ARGS

contrib/aws/update-aws-cluster.sh

@@ -32,7 +32,7 @@ $CONTRIB_DIR/util/check-user-data.sh
 
 # update the AWS CloudFormation stack
 aws cloudformation update-stack \
-    --template-body "$($THIS_DIR/gen-json.py)" \
+    --template-body "$($THIS_DIR/gen-json.py --channel $COREOS_CHANNEL --version $COREOS_VERSION)" \
     --stack-name $NAME \
     --parameters "$(<$THIS_DIR/cloudformation.json)" \
     $EXTRA_AWS_CLI_ARGS

contrib/utils.sh

@@ -11,3 +11,6 @@ function echo_red {
 function echo_green {
   echo -e "\033[0;32m$1\033[0m"
 }
+
+COREOS_CHANNEL=${COREOS_CHANNEL:-stable}
+COREOS_VERSION=${COREOS_VERSION:-647.2.0}