title: docker-compose wait to launch until a host filesystem is mounted
body: <p>The focus of this question is forcing docker-compose to wait to launch a <em>mysql</em> container until a host filesystem is mounted.  In my case the host filesystem holds the mysql database files.</p>
  <p>For services that depend upon a <em>mysql</em> container, there are scripts, like <em>wait-for-it</em>, which run as part of a container entrypoint.  These scripts check for availability of services on network ports. But I don't see how to make a container launch wait for a file system to be mounted on the host.</p>
  <p>When the host is booting, NFS and RAID filesystems might not come up as fast as containers start.  If the filesystem mounts on the host after the container starts, the bound volume in the container is not updated. Then the container ends up not having access to the mounted/bound filesystem.</p>