COBOL in Docker

The image

The GnuCOBOL project publishes an official image. Pull it once and you have a compiler in a clean room, with nothing installed on your machine:

docker pull olegkunitsyn/gnucobol

Compile in a container

Run the compiler inside the container. Mount the current directory so the compiler sees your source and writes the executable back to it:

docker run --rm -v "$PWD":/src olegkunitsyn/gnucobol cobc -x -free -o /src/hello /src/hello.cob

Mount your source

Keep your sources on the host and treat the container as a tool, like a compiler version pin. The same trick works in CI: pin the image tag, and every build compiles with the exact same compiler.

Next: COBOL on mainframes

Article author: Arthur Isaev