Startup script in dockerfile never runs

Question

I have a docker container that relies on a database being created and populated before it can run successfully. I have tried to accomodate for this by running a wait-for-it script before the main entrypoint of the container, problem is, the script never seems to run. I wont copy the entirety of the error because it is massive, but the gist is that there is an echo statement in my script that I cannot spot in the output.

My Dockerfile:

FROM mcr.microsoft.com/dotnet/core/sdk:3.1 AS dev
WORKDIR /app

RUN mkdir -p startup
COPY ./waitForIt.sh /startup/
COPY ./appEntryPoint.sh /startup/
RUN chmod +x /startup/appEntryPoint.sh

COPY App.WebUI/App.WebUI.csproj ./
RUN dotnet restore

COPY . ./
RUN dotnet publish App.sln -c Release -o out

FROM mcr.microsoft.com/dotnet/core/aspnet:3.1
WORKDIR /app
EXPOSE 80
COPY --from=dev /app/out .
ENTRYPOINT ["/startup/appEntryPoint.sh"]
CMD ["dotnet", "App.WebUI.dll"]

and my docker-compose:

services:
  web:
    container_name: web_container
    depends_on:
      - "postgres"
    build:
      context: .
      dockerfile: Dockerfile.dedc
    ports:
      - "5000:80"
    networks:
      - de_network

  postgres:
    container_name: postgres_container
    image: postgres:latest
    build:
      context: .
      dockerfile: Dockerfile.pgdc
    environment:
      POSTGRES_PASSWORD: xxxxxxxx
      POSTGRES_USER: xxxxxxxx
      POSTGRES_DB: xxxxxxxx
    ports:
      - "5432:5432"
    networks:
      - de_network

networks:
  de_network:
    driver: bridge

and appEntryPoint.sh:

#!/bin/sh

echo "startup script is running"

chmod +x ./waitForIt.sh

./waitForIt.sh http://localhost:5432

exec "$@"

I have not included the wait-for-it.sh script because the error must occur before that point if the echo command is never reached. I must have set something up incorrectly, any help appreciated.

user_11925067 · Answer

Why not modify appEntryPoint.sh to be:

#!/bin/sh

echo "startup script is running"

chmod +x ./waitForIt.sh

./waitForIt.sh http://localhost:5432

dotnet App.WebUI.dll

This will make the script run at runtime and not build time.

The script will also take care of starting the app, so you only have one point of entry.

You can also change your Dockerfile to be:

FROM mcr.microsoft.com/dotnet/core/sdk:3.1 AS dev
WORKDIR /app

RUN mkdir -p startup
COPY ./waitForIt.sh /startup/
COPY ./appEntryPoint.sh /startup/
RUN chmod +x /startup/appEntryPoint.sh

COPY App.WebUI/App.WebUI.csproj ./
RUN dotnet restore

COPY . ./
RUN dotnet publish App.sln -c Release -o out

FROM mcr.microsoft.com/dotnet/core/aspnet:3.1
WORKDIR /app
EXPOSE 80
COPY --from=dev /app/out .
ENTRYPOINT ["/startup/appEntryPoint.sh"]

Startup script in dockerfile never runs

1 Answers