By default, there's an expectation that the app's
build task that takes care of all sorts of build-time
concerns (e.g. pulling dependencies from repos eagerly). If a more
complicated logic is desired at build-time, it can be overriden by
BOOTBUILD_CMD var that contains, say, a more complex boot
pipeline. For instance:
BOOTBUILD_CMD="boot foo -x -- bar --blah -q -- qaz"
boot executable version is pinned and will be updated from to time
to the most recent one. It can be controlled by setting
latest or to a desired version. For example:
boot-clj framework version used by this buildpack is pinned and
will be updated from to time to the most recent one. It can be set
to a desired version by setting
BOOT_VERSION. For example:
To expose more config vars at build-time, set a
BOOTBUILD_CONFIG_WHITELIST config var containing a space-delimited
list of config var names. Note that this can result in unpredictable
behaviour since changing your app's config does not result in a
rebuild of your app. So it's easy to get into a situation where your
build is broken, but you don't notice it until later when you
push. For this reason it's recommended to take care with this feature
and always push after changing a whitelisted config value.
By default you will get OpenJDK 1.8. To use a different version, you
can commit a
system.properties file to your app.
$ echo "java.runtime.version=1.7" > system.properties $ git add system.properties $ git commit -m "JDK 7"
You can either test this buildpack locally with Docker, or run the tests on Heroku. To use Heroku, create a new app with the testrunner buildpack, push the buildpack code, and then run the tests:
$ heroku create --buildpack https://github.com/heroku/heroku-buildpack-testrunner $ git push heroku master $ heroku run tests ... ------ ALL OK 239 SECONDS
To test with Docker, first build the testrunner image
and then run the
tests-with-caching target fails when downloading the boot.sh binary.
You may get into situation where some wrong version of
boot executable or the framework
is cached in the app's build cache. You can purge this cache like so:
$ heroku plugins:install heroku-repo # <- one time installation step $ heroku repo:purge_cache -a appname
After a pruge, you will need to push another build of your app to have it fully
rebuilt with the build cache in clean state. Alternatively, you can reset Heroku's
app source code repository by doing
heroku repo:reset -a appname.
Thanks to the authors of various official Heroku buildpacks for providing excellent documentation and clearly written source code. In particular, config var whitelisting has been inspired by Clojure buildpack.
Copy the snippet above into CLI.