This topic lists and describes the Dockerfile file from the Hello World Docker demonstration. The Dockerfile is listed in its entirety and a following table describes the various Dockerfile commands. The line numbers in the listings of the Dockerfile have been added to aid readability. They are not present in the supplied Dockerfile.
001 # Copyright (C) Micro Focus 2018. All rights reserved.
002 # This sample code is supplied for demonstration purposes only
003 # on an "as is" basis and is for use at your own risk.
004
005 # use the -build image, as we are using msbuild
006 ARG MFPRODBASE=
007 ARG DTAG=
008 FROM microfocus/vcbuildtools-build:${DTAG} as build-env
009
010 LABEL com.microfocus.is-example="true"
011 ARG Config=Release
012
013 # Copy the src folder to c:\src in the container
014 COPY src "c:\\src"
015 WORKDIR "c:\\src"
016
017 # Build the source using the msbuild project file with a output directory of c:\app
018 ARG Platform=x86
019 ENV BLDPlatform ${Platform}
020 ENV BLDConfig ${Config}
021 RUN msbuild /p:OutDir=c:\app /p:Configuration=%BLDConfig%;Platform=%BLDPlatform% HelloWorld.sln
022
023 # Build runtime image for development or production
024 FROM ${MFPRODBASE}
025 WORKDIR "c:\\app"
026
027 # Copy the c:\app folder from the build-env step
028 COPY --from=build-env "c:\\app" "c:\\app"
029 ENTRYPOINT ["HelloWorld.exe"]
The commands on the lines in this Dockerfile are as follows:
| Lines | Description |
|---|---|
| 006 - 008 | Specifies that the base image to use is the "-build" version of the Visual COBOL base image, and gives the name "build-env" for this build stage. |
| 010 | Specify the metadata labels for the image that will be created. These labels can be queried using the docker inspect command. |
| 011 | Defines a build argument passed by the
docker build command.
Config specifies the Configuration property to use when building. |
| 014 - 015 | Copy the Hello World source files to a folder in the image's filesystem and set this folder to be the Docker working directory. |
| 018 |
Defines a build argument passed by the
docker build command.
Platform specifies the Platform property to use when building. |
| 019 - 020 | Create environment variables set to the values of the Platform and Config build arguments. |
| 021 | Build the Hello World application, putting the build output in c:\app. |
| 024 | Specifies the start of a new build stage that uses the Visual COBOL base image (as specified by the MFPRODBASE) build argument). |
| 025 - 028 | Sets the Docker working directory to be c:\app then copies the files from the "build-env" build stage into it. |
| 029 | Specifies that running the image runs the Hello World application. |