4a40c6d2d6
Usage was updated to reflect changes of osbuild arguments. Detailed information how to run osbuild the first time (hello world example) was added.
116 lines
3.6 KiB
Markdown
116 lines
3.6 KiB
Markdown
# osbuild
|
|
|
|
A build system for operating system images, working towards an image build
|
|
pipeline that's more comprehensible, reproducible, and extendable.
|
|
|
|
## Pipelines
|
|
|
|
The build process for an image is described by a pipeline. Each
|
|
[*stage*](/stages) in a pipeline is a program that, given some configuration,
|
|
modifies a file system tree. Finally, an assembler takes a filesystem tree, and
|
|
assembles it into an image. Pipelines are defined as JSON files like this one:
|
|
|
|
```json
|
|
{
|
|
"name": "Example Image",
|
|
"stages": [
|
|
{
|
|
"name": "org.osbuild.dnf",
|
|
"options": {
|
|
"releasever": "30",
|
|
"repos": {
|
|
"fedora": {
|
|
"name": "Fedora",
|
|
"metalink": "https://mirrors.fedoraproject.org/metalink?repo=fedora-$releasever&arch=$basearch",
|
|
"gpgkey": "file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-$releasever-$basearch"
|
|
}
|
|
},
|
|
"packages": [ "@Core", "grub2-pc", "httpd" ]
|
|
}
|
|
},
|
|
{
|
|
"name": "org.osbuild.systemd",
|
|
"options": {
|
|
"enabled_services": [ "httpd" ]
|
|
}
|
|
},
|
|
{
|
|
"name": "org.osbuild.grub2",
|
|
"options": {
|
|
"root_fs_uuid": "76a22bf4-f153-4541-b6c7-0332c0dfaeac"
|
|
}
|
|
}
|
|
],
|
|
"assembler": {
|
|
"name": "org.osbuild.qcow2",
|
|
"options": {
|
|
"filename": "example.qcow2",
|
|
"root_fs_uuid": "76a22bf4-f153-4541-b6c7-0332c0dfaeac",
|
|
"size": 3221225472
|
|
}
|
|
}
|
|
}
|
|
```
|
|
|
|
`osbuild` runs each of the stages in turn, isolating them from the host and
|
|
from each other, with the exception that they all operate on the same
|
|
filesystem-tree. The assembler is similarly isolated, and given the same
|
|
tree, in read-only mode and assembles it into an image without altering
|
|
its contents.
|
|
|
|
The filesystem tree produced by the final stage of a pipeline, is named
|
|
and optionally saved to be reused as the base for future pipelines.
|
|
|
|
Each stage is passed the (appended) `options` object as JSON over stdin.
|
|
|
|
The above pipeline has no base and produces a qcow2 image.
|
|
|
|
## Running
|
|
|
|
```
|
|
usage: python3 -m osbuild [-h] [--build-pipeline PIPELINE] [--store DIRECTORY]
|
|
[-l DIRECTORY] -o DIRECTORY
|
|
PIPELINE
|
|
|
|
Build operating system images
|
|
|
|
positional arguments:
|
|
PIPELINE json file containing the pipeline that should be built
|
|
|
|
optional arguments:
|
|
-h, --help show this help message and exit
|
|
--build-pipeline PIPELINE
|
|
json file containing the pipeline to create a build
|
|
environment
|
|
--store DIRECTORY the directory where intermediary os trees are stored
|
|
-l DIRECTORY, --libdir DIRECTORY
|
|
the directory containing stages, assemblers, and the
|
|
osbuild library
|
|
|
|
required named arguments:
|
|
-o DIRECTORY, --output DIRECTORY
|
|
provide the empty DIRECTORY as output argument to the
|
|
last stage
|
|
```
|
|
|
|
### Running example
|
|
|
|
You can build basic qcow2 image of Fedora 30 by running a following command:
|
|
|
|
```
|
|
sudo python3 -m osbuild -o output --libdir . samples/base-qcow2.json
|
|
```
|
|
|
|
- Root rights are required because osbuild heavily relies on creating
|
|
systemd containers and bind mounting.
|
|
|
|
It shouldn't interfere with host OS but please be **careful**! It's still under
|
|
development!
|
|
|
|
- `--libdir` argument is required because `osbuild` expects itself to be
|
|
installed in directories under `/usr`. Using this argument you can change
|
|
the expected path.
|
|
|
|
- You don't need to use any kind of virtual environment, modern version of
|
|
Python 3 is enough. `osbuild` uses only standard library and linux commands.
|
|
|