use the same strategy for instance profiles as jdub/packer-resource

Author: Chris Nelson

bin/check

@@ -6,14 +6,19 @@ cat | jq . <&0 > /tmp/input
 
 AMI=$(jq -r '.version.ami // empty' /tmp/input)
 
-AWS_ACCESS_KEY_ID=$(jq -r '.source.aws_access_key_id // empty' /tmp/input)
-AWS_SECRET_ACCESS_KEY=$(jq -r '.source.aws_secret_access_key // empty' /tmp/input)
-if [ -n "${AWS_ACCESS_KEY_ID}" ] && [ -n "${AWS_SECRET_ACCESS_KEY}" ]; then
-    export AWS_ACCESS_KEY_ID
-    export AWS_SECRET_ACCESS_KEY
-fi
+export AWS_ACCESS_KEY_ID=$(jq -r '.source.aws_access_key_id // empty' /tmp/input)
+export AWS_SECRET_ACCESS_KEY=$(jq -r '.source.aws_secret_access_key // empty' /tmp/input)
 export AWS_DEFAULT_REGION=$(jq -r '.source.region // empty' /tmp/input)
 
+# remove any empty credentials vars so the AWS client will try instance profiles
+if [ -z "$AWS_ACCESS_KEY_ID" ]; then
+  unset AWS_ACCESS_KEY_ID
+fi
+
+if [ -z "$AWS_SECRET_ACCESS_KEY" ]; then
+  unset AWS_SECRET_ACCESS_KEY
+fi
+
 jq '.source.filters | to_entries | map({"Name": .key, "Values": [(.value|select(type!="array") = [.])|.[]|tostring]})' /tmp/input > /tmp/filters.json
 
 aws ec2 describe-images \

bin/in

@@ -8,14 +8,19 @@ DEST="$1"
 
 AMI=$(jq -r '.version.ami // empty' /tmp/input)
 
-AWS_ACCESS_KEY_ID=$(jq -r '.source.aws_access_key_id // empty' /tmp/input)
-AWS_SECRET_ACCESS_KEY=$(jq -r '.source.aws_secret_access_key // empty' /tmp/input)
-if [ -n "${AWS_ACCESS_KEY_ID}" ] && [ -n "${AWS_SECRET_ACCESS_KEY}" ]; then
-    export AWS_ACCESS_KEY_ID
-    export AWS_SECRET_ACCESS_KEY
-fi
+export AWS_ACCESS_KEY_ID=$(jq -r '.source.aws_access_key_id // empty' /tmp/input)
+export AWS_SECRET_ACCESS_KEY=$(jq -r '.source.aws_secret_access_key // empty' /tmp/input)
 export AWS_DEFAULT_REGION=$(jq -r '.source.region // empty' /tmp/input)
 
+# remove any empty credentials vars so the AWS client will try instance profiles
+if [ -z "$AWS_ACCESS_KEY_ID" ]; then
+  unset AWS_ACCESS_KEY_ID
+fi
+
+if [ -z "$AWS_SECRET_ACCESS_KEY" ]; then
+  unset AWS_SECRET_ACCESS_KEY
+fi
+
 aws ec2 describe-images --image-ids "$AMI" --query 'Images[0]' \
   | tee "$DEST/output.json"