absent: true on a package has the host remove it through the machine's own
package manager when it is installed and leave alone a machine that never had
it; read back either way. Undeclaring a package still removes nothing. A
found firewall whose command is gone is recorded as removed, said once, and
asked nothing of.
Exactly the names declared reach the runtime, named in the spec so a change
recreates the container; a name that is not a capability's is refused and a
privileged container stays undeclarable. For a seat holder whose runtime
changes the machine's packet filter.
A container may name networks it also joins once created, for the per-machine
setting that keeps a found network while a neighbour still resolves it there:
joined after the run, part of the spec, refused when it cannot be joined.
A declaration may say which modules the mesh left out because a stored setting
cannot compose with its definition. Absence used to read as removal; a left-out
module's records are kept and said, and its holds are not released.
Genesis raises the bootstrap forge under the gitea module's container name, with
its image digest and its data directory mounted at /data, so the module holds it
by the found rule instead of raising a second forge beside it (issue 090). The
network is the one difference left for a take to say. Before this the forge had
no volume: its repositories were the container's, lost with it.
jschoubben