Do Docker "node" images have ssh-keygen?

I tested with node:20 and node:20-alpine and can confirm that:

On Alpine, you can install ssh-keygen using apk.

Typically, this means you have to build your own docker image based no node:20-alpine. In your Dockerfile, add

RUN   apk update && \
      apk add --no-cache \
      openssh-keygen