61 lines
1.8 KiB
Markdown
61 lines
1.8 KiB
Markdown
# Project Sagano tier-1 and cloud agents
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The tier-0 and tier-1 images today do not contain any special
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hypervisor-specific agents. The following specifically are not included
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for example:
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- cloud-init
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- vmware-guest-agent
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- google-guest-agent
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- qemu-guest-agent
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- ignition
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- afterburn
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etc.
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## Unnecessary on bare metal
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For deployment to bare metal using e.g. Anaconda or `bootc install`, none of
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these are necessary.
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## Unnecessary for "immutable infrastructure" on hypervisors
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A model we aim to emphasize is having the container image define the
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"source of truth" for system state. This conflicts with using e.g. `cloud-init`
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and having it fetch instance metadata and raises questions around changes to the
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instance metadata and when they apply.
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Related to this, `vmware-guest-agent` includes a full "backdoor" mechanism to
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log into the OS.
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## Should be containerized anyways
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In general particularly for e.g. `vmware-guest-agent`, it makes more sense to
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containerize it.
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## Easy to install afterward
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Many of these (particularly the first ones mentioned) are easy to install in a
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custom image.
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You can build your own derived image that includes e.g. vmware-guest-agent if
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required alongside all other desired customizations.
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## Fully supported if installed
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It is supported to include these agents in your image if desired (whether as
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part of the base image or containerized).
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## What about Ignition
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Ignition as shipped by CoreOS Container Linux derivatives has a lot of
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advantages in providing a model that works smoothly across both bare metal and
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virtualized scenarios.
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It also has some compelling advantages over cloud-init at a technical level.
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However, there is also significant overlap between a container-focused model of
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the world and an Ignition-focused model.
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More on this topic in [coreos.md](coreos.md).
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