How do I maintain a folder structure in dockerfile

Question

I'm trying to move my nestjs app into container. But I met some problems. I used grpc in my project and my proto files are stored in a protos folder which is the same level as the src folder. My file structure is like this.

-project folder
--protos
---...proto files
--src
---...other codes

And in my docker file, I copied the proto folders, however, when I run the docker-compose up, it shows it cannot find my proto files. But if I just go with npm run start, it runs normally. Here is my dockerfile:

FROM node:14 AS builder

# Create app directory
WORKDIR /app

# A wildcard is used to ensure both package.json AND package-lock.json are copied
COPY package*.json ./
COPY prisma ./prisma/
COPY protos ./protos/

# Install app dependencies
RUN npm install

COPY . .

RUN npm run build

FROM node:14

COPY --from=builder /app/node_modules ./node_modules
COPY --from=builder /app/package*.json ./
COPY --from=builder /app/dist ./dist
COPY --from=builder /app/protos ./protos


EXPOSE 5273
CMD [ "npm", "run", "start:dev" ]
    enter code here

Am I missing something here? Any advises will be appreciated.