lerna bootstrap command does not install the local yarn packages

I am trying to install my local npm packages (using yarn workspaces) in my docker container but it does not seem to be installing the local packages. Though it does install the global packages successfully.

Also, when I bash into the container and run "lerna bootstrap", that installs my local packages successfully. I have been searching all over the internet why is this happening.

My docker file's content looks like

FROM node:12.4.0-alpine

RUN apk add --no-cache bash
RUN apk add --no-cache yarn
WORKDIR "/app"


RUN yarn global add lerna
COPY . .
RUN yarn install
RUN lerna bootstrap


CMD ["npm", "run", "dev"]

My root package.json file looks like

{
  "name": "my-test",
  "version": "1.0.0",
  "description": "Test",
  "main": "app.js",
  "private": true,
  "workspaces": [
    "packages/**"
  ],
  "scripts": {
    "start": "node app.js",
    "dev": "nodemon -L app.js"
  },
  "author": "Phantom",
  "license": "ISC",
  "dependencies": {
    "config": "3.0.1",
    "dotenv": "7.0.0",
    "express": "4.16.4",
    "node-locale": "2.0.0",
  },
  "devDependencies": {
    "lerna": "^3.15.0",
    "@lerna/bootstrap": "3.8.5",
    "nodemon": "1.18.10",
  }
}

My lerna.json file looks like

{
  "version": "1.0.0",
  "npmClient": "yarn",
  "useWorkspaces": true,
  "packages": ["packages/*"]
}

As a workaround, I am runing the following docker command once the container is up.

docker exec -w /app <my-container-name> lerna bootstrap

I know this is not a proper solution, so can someone please help me out?