Enable non-root container build

Closes #308.

.docker/Dockerfile

@@ -22,8 +22,12 @@ COPY --from=builder /app /app
 
 WORKDIR /app
 
+RUN chown -R node:node .
+
 EXPOSE 5005
 
+USER node
+
 ENV NODE_ENV=production
 ENV PASSWORD=flame_password
 

.docker/Dockerfile.multiarch

@@ -23,8 +23,12 @@ COPY --from=builder /app /app
 
 WORKDIR /app
 
+RUN chown -R node:node .
+
 EXPOSE 5005
 
+USER node
+
 ENV NODE_ENV=production
 ENV PASSWORD=flame_password