title: Alpine Linux install package without internet (docker)
body: <p>I'm trying to build a Docker image with Alpine and only need to install some packages (<code>apk add</code>) but without internet because our dev environment allows no internet connection. 
  So I COPY the apk's in /temp and try to install from there. Like is written in the docs <a href="https://wiki.alpinelinux.org/wiki/Alpine_Linux_package_management#Add_a_local_Package" rel="noreferrer">add local package</a> 
  But still it tries to get to the internet to fetch an index... I don't want that.
  Is that possible?</p>
  
  <pre><code>FROM alpine:3.8
  COPY ./apk/* /tmp/
  RUN apk add --allow-untrusted --no-network --no-cache /tmp/ca-certificates-20171114-r3.apk /tmp/libcurl-7.61.1-r1.apk /tmp/libssh2-1.8.0-r3.apk /tmp/nghttp2-libs-1.32.0-r0.apk /tmp/curl-7.61.1-r1.apk
  
  ENTRYPOINT ["/usr/bin/curl"]
  </code></pre>
  
  <p>(and yes, this image is available on DockerHub, but we need to build it ourselves)</p>