Resolve prefix variables.

assets/check

@@ -6,7 +6,7 @@ source "$(dirname $0)/common.sh"
 
 payload=`cat`
 bucket=$(get_bucket)
-prefix="$(echo "$payload" | jq -r '.params.prefix // ""')"
+prefix=$(get_prefix)
 
 export_aws_vars
 

assets/common.sh

@@ -5,6 +5,14 @@ get_bucket() {
   echo $bucket
 }
 
+get_prefix() {
+  local prefix=$(echo "$payload" | jq -r '.params.prefix // ""')
+  if [ -n "$prefix" ]; then
+    prefix=$(eval $prefix) # Resolve variables like $BUILD_NAME, etc.
+  fi
+  echo $prefix
+}
+
 export_aws_vars() {
   local access_key_id=$(echo "$payload" | jq -r '.source.access_key_id // empty')
   local secret_access_key=$(echo "$payload" | jq -r '.source.secret_access_key // empty')

assets/in

@@ -16,7 +16,7 @@ source "$(dirname $0)/common.sh"
 
 payload=`cat`
 bucket=$(get_bucket)
-prefix=$(echo "$payload" | jq -r '.params.prefix // ""')
+prefix=$(get_prefix)
 options=$(echo "$payload" | jq -r '.params.options // [] | join(" ")')
 skip_download=$(echo "$payload" | jq -r '.params.skip_download // false')
 

assets/out

@@ -16,7 +16,7 @@ source "$(dirname $0)/common.sh"
 
 payload=`cat`
 bucket=$(get_bucket)
-prefix=$(echo "$payload" | jq -r '.params.prefix // ""')
+prefix=$(get_prefix)
 options=$(echo "$payload" | jq -r '.params.options // [] | join(" ")')
 source_dir=$(echo "$payload" | jq -r '.params.source_dir // "."')
 test -z "$source_dir" && { echo "Must supply params.source_dir" >&2; exit 1; }