umami declared its port reachable from anywhere, reasoning that the collection
endpoint tracked browsers POST to must be public. That is true of the name and
not of the port: both its surfaces are served through the proxy by name, so the
port is how the proxy reaches it and nothing else (ADR 0045).
Measured, which is how this was found: with the port open to the internet, the
dashboard's login page was served over plain HTTP directly on the machine's port,
bypassing every rule the proxy applies by path. The route stays exactly as it was,
so the collection endpoint keeps working.
It declared udp/53 only. The daemon listens on tcp/53 as well, and a resolver is
asked over tcp whenever an answer will not fit in a datagram — so on every
converged machine that port is closed while the service reports itself healthy
and the manifest reads as though the resolver were fully declared.
The same fault as issue 136 in miniature: the declaration covers part of what the
service does, and the gap is silent because nothing compares the two.
The module said the service must be running and nothing about boot, so the
machine's own way back in was enabled only because something before the mesh
had enabled it. All four machines happen to be enabled today; none of them is
enabled because the mesh says so, and a machine adopted tomorrow would run ssh
until its first reboot.
Not `state: running` alone for the same reason the module exists: this is the
one daemon whose absence cannot be fixed remotely.
jail.local named ufw as the ban action. Two machines on this mesh have no ufw,
and fail2ban does not check: it starts, the jail reads the log, counts the
attempts, runs the ban command, gets 127 -- 'ufw: command not found' -- and
logs an error nobody reads. The service is active, the mesh reports the module
applied, and the machine is not protected. Proven by banning a documentation
address on such a machine today.
The replacement is this module's own dualchain action, already used by the
recidive jail on all four machines, so it is not a new dependency. It bans in
DOCKER-USER as well as INPUT, which ufw's action did not, and it bans all
ports, which ufw's action did.
"why":"every name for this machine and what it runs \u2014 the mesh's own answered here, the rest forwarded",
"fixed":true
},
{
"port":53,
"protocol":"tcp",
"from":"mesh",
"why":"the same names over tcp, which a resolver answers on as well and is asked for whenever an answer will not fit in a datagram. Declared because the daemon serves it: a declaration that covers one of the two protocols its own service listens on leaves the other closed while everything reports success",
"content":"[INCLUDES]\n\nbefore = paths-arch.conf\n\n[DEFAULT]\n\n# Never act on the machine itself or on a tunnel peer: the mesh's private range is\n# ${machine:mesh-range}, named here rather than written as a value the module cannot\n# know (novox/hq ADR 0112). Without this, fail2ban could ban the mesh's own nodes.\nignoreip = 127.0.0.1/8 ::1 ${machine:mesh-range}\n\nbantime = 10m\nfindtime = 10m\nmaxretry = 5\n\nbanaction = ufw\nbanaction_allports = iptables-allports\n\n[sshd]\nenabled = true\nport = ssh\nlogpath = %(sshd_log)s\nbackend = %(sshd_backend)s\n"
"content":"[INCLUDES]\n\nbefore = paths-arch.conf\n\n[DEFAULT]\n\n# Never act on the machine itself or on a tunnel peer: the mesh's private range is\n# ${machine:mesh-range}, named here rather than written as a value the module cannot\n# know (novox/hq ADR 0112). Without this, fail2ban could ban the mesh's own nodes.\nignoreip = 127.0.0.1/8 ::1 ${machine:mesh-range}\n\nbantime = 10m\nfindtime = 10m\nmaxretry = 5\n\n# Ban through iptables, not through a firewall front-end the machine may not have. ufw is\n# installed on two of this mesh's machines and absent on the other two, and fail2ban finds out\n# only at ban time: the service reports healthy, the jail counts the attempt, the ban command\n# exits 127, and nothing is blocked. Proven on 2026-09-28 -- 'ufw: command not found' on a\n# machine the mesh reported as protected.\n#\n# The action below is this module's own, already used by the recidive jail on every machine\n# here, and it bans in DOCKER-USER as well as INPUT, so a container's published port is\n# covered too.\nbanaction = iptables-allports-dualchain\nbanaction_allports = iptables-allports-dualchain\n\n[sshd]\nenabled = true\nport = ssh\nlogpath = %(sshd_log)s\nbackend = %(sshd_backend)s\n"
"why":"one port serves two surfaces: the dashboard (the proxy gates it to the mesh) and the public collection endpoint that the browsers of every tracked site POST to \u2014 so the port itself must be reachable from anywhere"
"from":"mesh",
"why":"one port serves two surfaces \u2014 the dashboard and the collection endpoint that the browsers of every tracked site POST to. Both are reached through the proxy, by name, so the port is how the proxy reaches this module and nothing else (novox/hq ADR 0045). It said \"anywhere\" and gave the reason that the collection endpoint must be public, which is true of the name and not of the port: opened, the machine-side port served the dashboard over plain HTTP to the internet, bypassing every rule the proxy applies by path"
}
],
"resources":[
Reference in New Issue
Block a user
Blocking a user prevents them from interacting with repositories, such as opening or commenting on pull requests or issues. Learn more about blocking a user.
mesh-admin
jschoubben