docker-library
/
docs
mirror of https://github.com/docker-library/docs.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

copied onbuild variant to python

This commit is contained in:
Ekevoo 2015-10-07 09:04:25 -04:00
parent e9e46eed07
commit f5d99d694a
1 changed files with 7 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
python/variant-onbuild.md Normal file
View File

@ -0,0 +1,7 @@
## `%%REPO%%:onbuild`
This image makes building derivative images easier. For most use cases, creating a `Dockerfile` in the base of your project directory with the line `FROM %%REPO%%:onbuild` will be enough to create a stand-alone image for your project.
While the `onbuild` variant is really useful for "getting off the ground running" (zero to Dockerized in a short period of time), it's not recommended for long-term usage within a project due to the lack of control over *when* the `ONBUILD` triggers fire (see also [`docker/docker#5714`](https://github.com/docker/docker/issues/5714), [`docker/docker#8240`](https://github.com/docker/docker/issues/8240), [`docker/docker#11917`](https://github.com/docker/docker/issues/11917)).
Once you've got a handle on how your project functions within Docker, you'll probably want to adjust your `Dockerfile` to inherit from a non-`onbuild` variant and copy the commands from the `onbuild` variant `Dockerfile` (moving the `ONBUILD` lines to the end and removing the `ONBUILD` keywords) into your own file so that you have tighter control over them and more transparency for yourself and others looking at your `Dockerfile` as to what it does. This also makes it easier to add additional requirements as time goes on (such as installing more packages before performing the previously-`ONBUILD` steps).