Snippet from my 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:
=> [7/18] RUN echo "hello world" 0.9s
The output I am seeing after building finishes:
=> CACHED [6/18] RUN apt-get install postgresql -y 0.0s
=> [7/18] RUN echo "hello world" 6.4s
=> [8/18] RUN psql --version 17.1s
The Dockerfile
is created from node:12.18.0 which is based on Debian 9.
Docker version 19.03.13, build 4484c46d9d.
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 not 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 ...
Just use this flag --progress=plain
after build
.
For example:
docker-compose build --progress=plain <container_name>
OR
docker build --progress=plain .
If you don't want to use this flag every time, then permanently tell docker to use this flag by doing:
export BUILDKIT_PROGRESS=plain
Here is the official documentation when you type docker build --help
.
--progress string Set type of progress output (auto, plain, tty). Use plain to show container output (default "auto")
docker system prune
unknown flag: --progress
docker-compose -v
@PeterKionga-Kamau
docker-compose -p output-test -f docker-compose.custom.yml --verbose up -d --build --progress=plain
In Docker 20.10 i had to use the --no-cache flag, too. Otherwise cached output is not shown.
docker build --progress=plain --no-cache .
--no-cache
doesn't just hide the cached output, it disables Docker's layer caching completely. You certainly don't want to use that all the time.
As an alternative to specifying the --progress=plain
option, you can also permanently disable the "pretty" output by setting this env variable in your shell config:
export BUILDKIT_PROGRESS=plain
Success story sharing
--progress=plain
does not appear to work anymore. On OS X for me, it merely spits out the command, hash, and step result (e.g. "CACHED"). Only forcibly disabling buildkit returns any useful output now. Is this a recent change, or different depending on platform?docker build --progress=plain --no-cache ...
to disable caching and print all output