Is it possible to reduce the output from docker build so that warnings etc are still shown, but not the very verbose default output such as the below?
I have a script that builds 15 images and it just becomes useless to follow the outcome of it. If everything is OK I want no output, but I do want the warnings.
The --quiet flag to docker build removes everything. I also tried redirecting stdout to /dev/null but keeping stderr, but then also warnings are suppressed (for example warnings from optional modules using node-gyp failing due to missing python etc - I do want to see those).
Is there any way to only log warnings?
Example output to exclude:
docker build: fetch http://dl-cdn.alpinelinux.org/alpine/v3.11/main/x86_64/APKINDEX.tar.gz
docker build: fetch http://dl-cdn.alpinelinux.org/alpine/v3.11/community/x86_64/APKINDEX.tar.gz
docker build: (1/27) Installing make (4.2.1-r2)
docker build: (2/27) Installing binutils (2.33.1-r0)
docker build: (3/27) Installing gmp (6.1.2-r1)
docker build: (4/27) Installing isl (0.18-r0)
docker build: (5/27) Installing libgomp (9.3.0-r0)
[ ... ]
docker build: OK: 232 MiB in 43 packages
docker build: fetch http://dl-cdn.alpinelinux.org/alpine/v3.11/main/x86_64/APKINDEX.tar.gz
docker build: fetch http://dl-cdn.alpinelinux.org/alpine/v3.11/community/x86_64/APKINDEX.tar.gz
docker build: OK: 232 MiB in 43 packages
docker build: fetch http://dl-cdn.alpinelinux.org/alpine/v3.11/main/x86_64/APKINDEX.tar.gz
Example output to include:
docker build: warning Error running install script for optional dependency: "/usr/app/node_modules/unix-dgram: Command failed.
docker build: gyp ERR! find Python
docker build: gyp ERR! find Python Python is not set from command line or npm configuration
Perhaps the node-gyp module is simply the culprit using stdout for warnings/errors?
Is there any better bet than piping through grep -E -i "warn|err" and hoping all relevant warnings are prefixed?