Generic Docker Makefile
-----------------------
This is a generic make and dockerfile for ceph utility container. This can be used to create docker images using different ceph releases and ubuntu releases
Usage:
make CEPH_RELEASE=<release_name> UBUNTU_RELEASE=<release_name>
eg:
1. Create docker image for ceph luminous release on ubuntu xenial (16.04)
make CEPH_RELEASE=luminous UBUNTU_RELEASE=xenial
2. Create docker image for ceph mimic release on ubuntu xenial (16.04)
make CEPH_RELEASE=mimic UBUNTU_RELEASE=xenial
3. Create docker image for ceph luminous release on ubuntu bionic (18.04)
make CEPH_RELEASE=luminous UBUNTU_RELEASE=bionic
4. Create docker image for ceph mimic release on ubuntu bionic (18.04)
make CEPH_RELEASE=mimic UBUNTU_RELEASE=bionic
