Docker build not showing any output from commands

Question

Snippet from dockerfile:

FROM node:12.18.0
RUN echo "hello world"
RUN psql --version

When I run docker build . I don't see any output from these two commands even if they are not cached. The documentation says that docker build is verbose by default. Why am I not seeing the output from commands? I used to see them before.

The output while building: The output I am seeing after building finishes:

Dockerfile is created from node:12.18.0 which is based on Debian 9

Docker version 19.03.13, build 4484c46d9d.

Answer 1

The output you are showing is from buildkit, which is a replacement for the classic build engine that docker ships with. You can adjust output from this with the --progress option:

  --progress string         Set type of progress output (auto, plain, tty). Use plain to show container output
                            (default "auto")

Adding --progress=plain will show the output of the run commands that were no loaded from the cache.

---

If you don't want to use buildkit, you can revert to the older build engine by exporting DOCKER_BUILDKIT=0 in your shell, e.g.:

DOCKER_BUILDKIT=0 docker build ...

or

export DOCKER_BUILDKIT=0
docker build ...