在NodeJS docker容器中找不到npm命令

I created a Docker image:

我创建了Docker映像:

$ docker build -t stephaneeybert/nodejs .
Sending build context to Docker daemon  2.56 kB
Step 1 : FROM debian
 ---> 1b088884749b
Step 2 : RUN apt-get clean && apt-get update
 ---> Using cache
 ---> b12133d6342f
Step 3 : RUN apt-get install -y curl
 ---> Using cache
 ---> 22dfb4882b12
Step 4 : RUN curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.32.1/install.sh | bash
 ---> Using cache
 ---> 27f2fac45254
Step 5 : RUN . ~/.nvm/nvm.sh; nvm install stable
 ---> Using cache
 ---> 20d99d545755
Step 6 : RUN . ~/.nvm/nvm.sh; nvm use stable
 ---> Using cache
 ---> 9ec14efb2407
Step 7 : RUN . ~/.nvm/nvm.sh; npm install -g npm
 ---> Using cache
 ---> d264d38565f3
Step 8 : EXPOSE 9001
 ---> Using cache
 ---> 29e3589557e1
Step 9 : ENTRYPOINT /usr/bin/tail -f /dev/null
 ---> Using cache
 ---> 2ce499300fe1
Successfully built 2ce499300fe1
$ d