Before we start, let’s pull down a few buildpacks from our samples repo.
# clone the repo
git clone https://github.com/buildpacks/samples
package.tomlWe will need to create a package.toml file in order to tell pack where to find the dependencies of the buildpack
being packaged.
touch package.toml
Let’s start off by specifying the location of the buildpack we are packaging. In this example, we’re packaging
the hello-universe.
package.toml:
[buildpack]
uri = "samples/buildpacks/hello-universe/"
Next, by looking at the [[order]] of the hello-universe, we know that it depends on the hello-world and hello-moon
buildpacks. We will need to declare the location of those dependencies as well.
package.toml:
[buildpack]
uri = "samples/buildpacks/hello-universe/"
[[dependencies]]
uri = "samples/buildpacks/hello-moon"
[[dependencies]]
uri = "docker://cnbs/sample-package:hello-world"
For more information about the configuration, see package.toml config.
Lastly, we’ll run the buildpack package command to package the buildpack as an OCI image.
pack buildpack package my-buildpack --config ./package.toml
TIP: You can verify that the image was created by running
docker images.
That’s it! Your buildpack is now packaged for distribution.
You may now use standard docker push to host your buildpack on any OCI registry of your choosing.
Alternatively, you can run pack buildpack package with --publish to publish it directly to the registry.
You can also run buildpack package with a --format file flag to save the packaged buildpack as a local file.
pack buildpack package my-buildpack.cnb --config ./package.toml --format file
You can then use this file (called a .cnb file) as an input to buildpack package, among other commands.