feat: default shell for alpine images

[damiankoper]

npm defaults shell and script-shell config settings to bash, which is not available in alpine image.
Npm 7 respects this setting and tries to call bash -c 'git rev-parse ...' while trying to install package directly from git.

Fixes #1378

[LaurentGoderre]

The change looks good but would it be possible to exclude the Yarn and signature key changes from the PR?

[damiankoper]

Sure. I ran ./update.sh and thought that's ok.
Ready to go.

[SimenB]

FWIW, I don't think it should be up to the docker image to tell npm not to "misbehave". Then again, this isn't a huge burden for us, so 🤷

/cc @nodejs/npm thoughts?

[ruyadorno]

Checked with the team and it does sounds like the default should be sh instead, we'll fix it soon 😊 thanks for the heads up @SimenB

[PeterDaveHello]

@ruyadorno thanks! Please let us know when it's fixed, so we can close this issue ;)

[ruyadorno]

@PeterDaveHello the fix went out in the npm@7.0.7 release which has already been merged to node master and is going out in the node@15.1.0 release: nodejs/node#35948 let me know once that's out if all related issues are solved 😊

[PeterDaveHello]

Sure, thanks @ruyadorno

[nschonni]

Closing as the 15.1.0 images have been pushed to the docker hub

[SimenB]

For reference: npm/cli#2067