npm install git+ssh failing in docker (node16)

Question

Can anyone explain why switching from node:14-alpine to node:16-alpine would cause npm install to fail?

 > [ 8/10] RUN --mount=type=ssh npm i:
#14 14.27 npm ERR! code 128
#14 14.28 npm ERR! An unknown git error occurred
#14 14.28 npm ERR! command git --no-replace-objects ls-remote ssh://[email protected]/(somerepo).git
#14 14.28 npm ERR! Warning: Permanently added 'github.com' (RSA) to the list of known hosts.
#14 14.28 npm ERR! [email protected]: Permission denied (publickey).
#14 14.28 npm ERR! fatal: Could not read from remote repository.
#14 14.28 npm ERR! 
#14 14.28 npm ERR! Please make sure you have the correct access rights
#14 14.28 npm ERR! and the repository exists.

This is a:

git+ssh://[email protected]:someorg/somerepo

dependency. And the build is run using:

DOCKER_BUILDKIT=1 docker build --ssh default .

I couldn't find any obvious changes in the image, which makes me suspect npm (gone from 6.14.15 to 8.1.0), but I can't find anything documented (and it works fine, outside the container)

EDIT: the Dockerfile looks like this:

# syntax=docker/dockerfile:experimental
FROM node:16-alpine

RUN apk --no-cache --virtual build-dependencies add \
    python2 \
    make \
    g++ \
    git \
    openssh

# Download public key for github.com
RUN mkdir -p /root/.ssh && \
    chmod 0700 /root/.ssh && \
    ssh-keyscan github.com >> /root/.ssh/known_hosts

WORKDIR /app/
RUN chown -R node $PWD

RUN apk add postgresql-client
ADD ./service/package.json .

RUN --mount=type=ssh npm i
RUN apk del build-dependencies && rm -r /root/.ssh

ADD ./service/ .

CMD node ./app.js

USER node

the only change I made was the FROM

EDIT 2: if I update npm (to 8.1.3) in the node 14 image, I get the same problem. but running ssh -Tv [email protected] fails even in the working version, so I have no idea what dark magic build kit has been using up till now

Answer 1

this seems to be an issue with npm8, and git+ssh

use yarn