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About time we start this.
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# Configuring systems via container builds | ||
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A key part of the idea of this project is that every tool and technique | ||
one knows for building application container images should apply | ||
to building bootable host systems. | ||
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Most configuration for a Linux system boils down to writing a file (`COPY`) | ||
or executing a command (`RUN`). | ||
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## Embedding application containers | ||
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A common pattern is to add "application" containers that have references | ||
embedded in the bootable host container. | ||
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For example, one can use the [podman systemd](https://docs.podman.io/en/latest/markdown/podman-systemd.unit.5.html) | ||
configuration files, embedded via a container build instruction: | ||
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``` | ||
FROM <base> | ||
COPY foo.container /usr/share/containers/systemd | ||
``` | ||
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In this model, the application containers will be fetched and run on firstboot. | ||
A key choice is whether to refer to images by digest, or by tag. Referring | ||
to images by digest ensures repeatable deployments, but requires shipping | ||
host OS updates to update the workload containers. Referring to images | ||
by tag allows you to use other tooling to dynamically update the workload | ||
containers. | ||
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## Example repositories | ||
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The following git repositories have some useful examples: | ||
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- https://github.com/coreos/layering-examples | ||
- https://github.com/openshift/rhcos-image-layering-examples/ |