40cf349f18
The new arguments are passed to the first, respectively last, stage and are both directories. --input is read only and can be used to initialize the first stage. --output is r/w and is where the final stage should place the produced image. Signed-off-by: Tom Gundersen <teg@jklm.no>
55 lines
1.4 KiB
Markdown
55 lines
1.4 KiB
Markdown
# osbuild
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A build system for operating system images, working towards an image build
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pipeline that's more comprehensible, reproducible, and extendable.
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## Pipelines
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The build process for an image is described by a pipeline. Each
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[*stage*](/stages) in a pipeline is a program that, given some configuration,
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modifies a file system tree. Pipelines are defined as JSON files like this one:
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```json
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{
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"name": "Example Image",
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"pipeline": [
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{
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"name": "io.weldr.dnf",
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"options": {
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"packages": [ "@core", "httpd" ]
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}
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},
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{
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"name": "io.weldr.systemd",
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"options": {
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"enabled_services": [ "httpd" ]
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}
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},
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{
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"name": "io.weldr.qcow2",
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"options": {
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"target": "output.qcow2"
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}
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}
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]
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}
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```
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`osbuild` runs each of the stages in turn, isolating them from the host and
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from each other, with the exception that the first stage may be given an input
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directory, the last stage an output directory and all stages of a given
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pipeline are given the same filesystem tree to operate on.
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Each stage is passed the (appended) `options` object as JSON over stdin.
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The above pipeline has no input and produces a qcow2 image.
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## Running
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```
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osbuild [--input DIRECTORY] [--output DIRECTORY] PIPELINE
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```
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Runs `PIPELINE`. If `--input` is given, the directory is available
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read-only in the first stage. If `--output` is given it, it must be empty
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and is avialble read-write in the final stage.
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