Maybe with ENV vars?

.drone.yml

@@ -126,9 +126,9 @@ steps:
     repo: git.mifi.dev/mifi/auth-service
     registry: git.mifi.dev
     build_args:
-      MONGO_ENTRY_FILE: latest
-      MONGO_VERSION: latest
-      NPM_TOKEN:
+      - MONGO_ENTRY_FILE=latest
+      - MONGO_VERSION=latest
+      - NPM_TOKEN:
         from_secret: reg_token
     ssh-agent-key:
       from_secret: reg_token    

Dockerfile

@@ -8,6 +8,8 @@ ARG MONGO_VERSION=${MONGO_VERSION:-latest}
 ## mongo build stage
 FROM mongo:$MONGO_VERSION AS database
 ENV NODE_ENV $ENV
+ENV MONGO_ENTRY_FILE $MONGO_ENTRY_FILE
+ENV MONGO_VERSION $MONGO_VERSION
 COPY docker-entrypoint-initdb.d/mongo-init-$MONGO_ENTRY_FILE.sh ./docker-entrypoint-initdb.d/mongo-init.sh
 
 ## stage one, build the service

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@mifi/auth-service",
-  "version": "1.0.8",
+  "version": "1.0.10",
   "author": "mifi (Mike Fitzpatrick)",
   "license": "MIT",
   "scripts": {