Merge pull request guardian#5 from guardian/aa-custom-channels

add support for multiple stacks pushing to custom channels

cf-notify.json

@@ -3,11 +3,7 @@
     "Description": "cf notify stack",
     "Parameters": {
         "Bucket": {
-            "Description": "S3 bucket to locate lambda function (cf-notify-$CHANNEL.zip)",
-            "Type": "String"
-        },
-        "Channel": {
-            "Description": "Slack channel name",
+            "Description": "S3 bucket to locate lambda function (cf-notify.zip)",
             "Type": "String"
         }
     },
@@ -77,7 +73,7 @@
                 },
                 "Code": {
                     "S3Bucket": { "Ref": "Bucket" },
-                    "S3Key": { "Fn::Join": [ "", [ "cf-notify-", { "Ref": "Channel" }, ".zip" ] ] }
+                    "S3Key": "cf-notify.zip"
                 },
                 "Runtime": "python2.7",
                 "Timeout": "30"

deploy.sh

@@ -49,35 +49,38 @@ fi
 CHANNEL_NAME=`echo ${CHANNEL:1} | tr '[:upper:]' '[:lower:]'`
 
 echo 'Creating bucket'
-BUCKET="cf-notify-$CHANNEL_NAME-`pwgen -1 --no-capitalize 5`"
+BUCKET="cf-notify-`pwgen -1 --no-capitalize 5`"
 echo $BUCKET
 aws s3 mb "s3://$BUCKET" --profile $PROFILE
 echo "Bucket $BUCKET created"
 
 
 echo 'Creating lambda zip artifact'
-cat > slack.py <<EOL
-WEBHOOK='$WEBHOOK'
-CHANNEL='$CHANNEL'
+
+if [ ! -f slack.py ]; then
+    cat > slack.py <<EOL
+    WEBHOOK='$WEBHOOK'
+    CHANNEL='$CHANNEL'
+    CUSTOM_CHANNELS={}
 EOL
+fi
 
 zip cf-notify.zip lambda_notify.py slack.py
 echo 'Lambda artifact created'
 
 
 echo 'Moving lambda artifact to S3'
-aws s3 cp cf-notify.zip s3://$BUCKET/cf-notify-$CHANNEL_NAME.zip --profile $PROFILE
+aws s3 cp cf-notify.zip s3://$BUCKET/cf-notify.zip --profile $PROFILE
 
-rm slack.py
 rm cf-notify.zip
 echo 'Lambda artifact moved'
 
 echo 'Creating stack'
 aws cloudformation create-stack \
     --template-body file://cf-notify.json \
-    --stack-name cf-notify-$CHANNEL_NAME \
+    --stack-name cf-notify \
     --capabilities CAPABILITY_IAM \
-    --parameters ParameterKey=Bucket,ParameterValue=$BUCKET ParameterKey=Channel,ParameterValue=$CHANNEL_NAME \
+    --parameters ParameterKey=Bucket,ParameterValue=$BUCKET \
     --profile $PROFILE
 
 if [[ $? != 0 ]];

lambda_notify.py

@@ -74,12 +74,23 @@ def get_stack_update_message(cf_message):
         'attachments': attachments
     }
 
-    if slack.CHANNEL:
-        message['channel'] = slack.CHANNEL
+    channel = get_channel(cf_message['StackName'])
+
+    if channel:
+        message['channel'] = channel
 
     return message
 
 
+def get_channel(stack_name):
+    default = slack.CHANNEL if hasattr(slack, 'CHANNEL') else None
+
+    if hasattr(slack, 'CUSTOM_CHANNELS'):
+        return slack.CUSTOM_CHANNELS.get(stack_name, default)
+
+    return default
+
+
 def get_stack_update_attachment(cf_message):
     title = 'Stack {stack} is now status {status}'.format(
         stack=cf_message['StackName'],