There are currently problems with "swarm init" and "swarm join" when an
explicit --listen-addr flag is not provided. swarmkit defaults to
finding the IP address associated with the default route, and in cloud
setups this is often the wrong choice.
Introduce a notion of "advertised address", with the client flag
--advertise-addr, and the daemon flag --swarm-default-advertise-addr to
provide a default. The default listening address is now 0.0.0.0, but a
valid advertised address must be detected or specified.
If no explicit advertised address is specified, error out if there is
more than one usable candidate IP address on the system. This requires a
user to explicitly choose instead of letting swarmkit make the wrong
choice. For the purposes of this autodetection, we ignore certain
interfaces that are unlikely to be relevant (currently docker*).
The user is also required to choose a listen address on swarm init if
they specify an explicit advertise address that is a hostname or an IP
address that's not local to the system. This is a requirement for
overlay networking.
Also support specifying interface names to --listen-addr,
--advertise-addr, and the daemon flag --swarm-default-advertise-addr.
This will fail if the interface has multiple IP addresses (unless it has
a single IPv4 address and a single IPv6 address - then we resolve the
tie in favor of IPv4).
This change also exposes the node's externally-reachable address in
docker info, as requested by #24017.
Make corresponding API and CLI docs changes.
Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
Implement the proposal from
https://github.com/docker/docker/issues/24430#issuecomment-233100121
Removes acceptance policy and secret in favor of an automatically
generated join token that combines the secret, CA hash, and
manager/worker role into a single opaque string.
Adds a docker swarm join-token subcommand to inspect and rotate the
tokens.
Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
The current behavior of `docker swarm init` is to set up a swarm that
has no secret for joining, and does not require manual acceptance for
workers. Since workers may sometimes receive sensitive data such as pull
credentials, it makes sense to harden the defaults.
This change makes `docker swarm init` generate a random secret if none
is provided, and print it to the terminal. This secret will be needed to
join workers or managers to the swarm. In addition to improving access
control to the cluster, this setup removes an avenue for
denial-of-service attacks, since the secret is necessary to even create
an entry in the node list.
`docker swarm init --secret ""` will set up a swarm without a secret,
matching the old behavior. `docker swarm update --secret ""` removes the
automatically generated secret after `docker swarm init`.
Closes#23785
Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
As described in our ROADMAP.md, introduce new Swarm management commands
to call to the corresponding API endpoints.
This PR is fully backward compatible (joining a Swarm is an optional
feature of the Engine, and existing commands are not impacted).
Signed-off-by: Daniel Nephin <dnephin@docker.com>
Signed-off-by: Victor Vieux <vieux@docker.com>
Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
Aaron Lehmann