TIL: Use yes to provide input to terminal programs

Recently my build pipeline started failing suddenly for KVM Conjurer. Quick investigation led to a an issue in poetry. The TooManyRedirects error can be addressed by running the command poetry cache clear --all pypi. So I added this to my .gitlab-ci.yml file and pushed the change. But the build still failed!

The poetry cache clear command requires input. To fix that issue, I learned about the coreutils program yes. If you just open a terminal and type it you’ll get:

$ yes
y
y
y
y
y
y
y
y
y
y
. . .

yes outputs the given value (by default ‘y’) until it is killed. So I changed my .gitlab-ci.yml line to be:

test-job:
    . . .
    before_script:
        - yes 'yes' | poetry cache clear --all pypi
    . . .

Now the command runs successfully in the Gitlab CI pipeline!

Tags: til linux