# Managed by the mesh (module networkmanager). Replaced on every push; edit the
# catalogue instead.
#
# This machine's uplink is NetworkManager's, and this file is the whole of what
# the mesh asks of it (novox/hq ADR 0117): leave the resolver file to the mesh,
# and leave the private network's interface alone. Nothing more. The mesh never
# declares a connection profile, an address, a route, a wireless network or its
# credentials — those are joined at the machine, by the person using it, and
# the link they make is the only channel the mesh reaches this machine over. A
# push that got a link wrong could not be undone by the next one.
#
# A drop-in of the mesh's own, beside NetworkManager.conf and whatever else the
# operator keeps in this directory. NetworkManager reads the files here sorted by
# name and a later one wins a key it sets again — so a file of the operator's
# that sorts after this one (any name starting with a letter does) and sets dns=
# or unmanaged-devices= overrides it. That is the operator's to decide, and the
# reason this file sets nothing but the two keys it must.
#
# NetworkManager itself is the machine's: the mesh never starts, stops, enables
# or disables it (its service is declared with no state), because stopping it
# takes every link down, this machine's channel to the mesh included — and a
# module unassigned by mistake must not be able to do that. When this file
# changes, a running NetworkManager is reloaded (its D-Bus Reload call, which
# re-reads its configuration — NetworkManager(8)), never restarted.

[main]
# The resolver file is the mesh's: this module writes /etc/resolv.conf itself,
# listing the mesh's resolvers (novox/hq ADR 0223). Without this line
# NetworkManager rewrites that file on
# every connectivity change — every network joined, every lease renewed —
# and the mesh's resolver is silently replaced while every surface of the mesh
# still reads green. none: "NetworkManager will not modify resolv.conf. This
# implies rc-manager unmanaged" (NetworkManager.conf(5), 1.58). On an adopted
# machine the predecessor wrote the same line in a file of its own; both say one
# thing, and the predecessor's is retired by hand after the take.
#
# Not NetworkManager's own global DNS ([global-dns-domain-*] with rc-manager=file):
# it writes its own header and composes the options line itself, so it cannot
# write the mesh's file byte for byte, and the three uplink modules would write
# three different files for one fact. dns=none, and the file declared beside it.
dns=none

[keyfile]
# mesh0 is the private network's interface: the mesh brings it up and the mesh
# alone configures it. A manager that considers every interface its own could
# try to configure it, or tear it down on a profile change.
#
# unmanaged-devices rather than a [device-mesh0] section with managed=0, because
# NetworkManager.conf(5) says a device unmanaged by this key "is strictly
# unmanaged and cannot be overruled by using the API like nmcli device set
# $IFNAME managed yes", while device*.managed "can be overruled at runtime via
# D-Bus". The same page adds that device*.managed "may be a better choice" for
# exactly those reasons — for an interface the operator might want to hand back
# at runtime. For the mesh's own interface, strict is the point.
#
# += rather than =: the same page documents appending to a list-valued key set
# earlier ("plugins+=another-plugin") as an extension of its key file format,
# and unmanaged-devices is a device list. = would replace whatever devices the
# operator already keeps NetworkManager away from; += adds this one to them
# (novox/hq ADR 0102: a list is added to, never replaced). A file of the
# operator's read after this one that sets the key with = replaces it again;
# that is the operator's to decide.
unmanaged-devices+=interface-name:mesh0