General purpose docker images repo
For Makefile images, you can build an image by specifying the component, tag and upstream version on the commandline. For most images, the upstream version is a combination of the VERSION and EXTRAVERSION, but this may differ for some.
$ cd alpine-base-php-fpm/php5
$ make VERSION=2.6.28-r0 EXTRAVERSION=-201701-01 build tag
$ cd alpine-php-fpm-drupal7/php5
$ make VERSION=2.6.28-r0 EXTRAVERSION=-201701-01 UPSTREAM-2.6.28-r0-201701-01
A notable difference are the NewRelic images for HRINFO.