gyp fixes for slim docker image

packages/server/Dockerfile

@@ -1,7 +1,5 @@
 FROM node:14-slim
 
-RUN apt-get update
-
 LABEL com.centurylinklabs.watchtower.lifecycle.pre-check="scripts/watchtower-hooks/pre-check.sh"
 LABEL com.centurylinklabs.watchtower.lifecycle.pre-update="scripts/watchtower-hooks/pre-update.sh"
 LABEL com.centurylinklabs.watchtower.lifecycle.post-update="scripts/watchtower-hooks/post-update.sh"
@@ -16,8 +14,12 @@ ENV BUDIBASE_ENVIRONMENT=PRODUCTION
 # copy files and install dependencies
 COPY . ./
 # handle node-gyp
-RUN apk add --no-cache --virtual .gyp python3 make g++ \
-    && yarn && apk del .gyp
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends g++ make python \
+    && yarn \
+    && yarn cache clean \
+    && apt-get remove -y --purge --auto-remove g++ make python \
+    && rm -rf /tmp/* /root/.node-gyp /usr/local/lib/node_modules/npm/node_modules/node-gyp
 RUN yarn global add pm2
 RUN yarn build