lima-sequence-diagram.puml

@startuml
'https://plantuml.com/sequence-diagram

autonumber

actor User
participant limactl
participant "lima hostagent"
participant qemu
participant "guest os"
participant "lima guestagent"
participant nerdctl

== start ==

User -> limactl: start
activate limactl
limactl -> "lima hostagent": launch host agent
activate "lima hostagent"
deactivate limactl
"lima hostagent" -> "lima hostagent": find free ports
"lima hostagent" -> "lima hostagent": generate cloud-init data & CD-ROM image
"lima hostagent" -> "lima hostagent": generate QEMU command line
"lima hostagent" -> "lima hostagent": set up port forwarding
"lima hostagent" -> qemu: start
activate qemu
qemu -> "guest os": boot
activate "guest os"
"guest os" -> "guest os": run setup commands from CD-ROM
"guest os" -> "lima guestagent": start
activate "lima guestagent"
"lima hostagent" -> "guest os": set up sshfs mounts
"lima hostagent" -> "guest os": set up socket forwarding with SSH
loop periodically
"lima guestagent" -> "guest os": read /proc/net/tcp* and iptables
end loop
loop periodically
"lima hostagent" -> "lima guestagent": connect to guest agent (query info)
"lima guestagent" -> "lima hostagent": IP/port pairs (from /proc/net/tcp* and iptables)
"lima hostagent" -> "lima guestagent": subscribe to port add/remove events
"lima guestagent" -> "lima hostagent": (ongoing) return port add/remove events
end loop
"lima hostagent" -> "guest os": query for requirements/boot status/readiness probes

== command execution ==

User -> limactl: shell "command"
activate limactl
limactl -> "guest os": ssh "command"
"guest os" -> limactl: command output
limactl -> User: command output
deactivate limactl

== nerdctl run ==

User -> limactl: "nerdctl run"
activate limactl
limactl -> "guest os": ssh "nerdctl run"
"guest os" -> nerdctl: run container
activate nerdctl
loop periodically
"lima guestagent" -> "guest os": read /proc/net/tcp* and iptables
end loop
loop periodically
"lima hostagent" -> "lima guestagent": query events
"lima guestagent" -> "lima hostagent": return port add/remove events
"lima hostagent" -> "lima hostagent": set up new port forwarding
end loop
nerdctl -> nerdctl: container exits
nerdctl -> limactl: container output
deactivate nerdctl
limactl -> User: container output
deactivate limactl
loop periodically
"lima guestagent" -> "guest os": read /proc/net/tcp* and iptables
end loop
loop periodically
"lima hostagent" -> "lima guestagent": query events
"lima guestagent" -> "lima hostagent": return port add/remove events
"lima hostagent" -> "lima hostagent": remove old port forwarding
end loop

== stop ==

User -> limactl: stop
activate limactl
limactl -> "lima hostagent": SIGINT
"lima hostagent" -> qemu: ACPI shutdown
qemu -> "guest os": ACPI shutdown
"guest os" -> "lima guestagent": SIGTERM
deactivate "lima guestagent"
deactivate "guest os"
"lima hostagent" -> "lima hostagent": wait up to 3 minutes for shutdown
deactivate qemu
"lima hostagent" -> limactl: emit exit event
deactivate "lima hostagent"
limactl -> User: stopped
deactivate limactl
@enduml