Before commit 4f09af6, when allocating host ports for a new
port mapping, iptables rules were set up then docker-proxy was
started. If the host port was already in-use, docker-proxy exited
with an error, and the iptables rules were removed. That could
potentially interfere with a non-docker service that was already
using the host port for something unrelated.
Commit 4f09af6 swapped that problem for a different one... in
order to check that a port was available before creating iptables
rules, it attempted to start docker-proxy first. If it failed, it
could then try a different host port, without interfering with
any other service. The problem with that is docker-proxy would
start listening before the iptables rules were in place, so it
could accept connections then become unusable because new NAT
rules diverted packets directly to the container. This would leave
the client with a broken connection, causing at-least a delay
while it figured that out and reconnected.
This change creates and binds the socket in the daemon, before
creating iptables rules. If the bind fails, it may try a different
port. When or if the bind succeeds, iptables rules are created,
then the daemon calls listen on the socket. If docker-proxy is
needed, the socket is handed over to it at that point.
In rootless mode, the ports have to be bound to an address in the
rootless network namespace (where dockerd is running). DNAT rules
now use the same address.
If docker-proxy is not needed ("--userland-proxy=false"), the daemon
still listens on TCP sockets as the old dummyProxy would have done.
This makes the socket show up in "netstat" output.
The dummyProxy is no longer needed on Linux. Its job was to bind the
host ports if docker-proxy was disabled, but that's now already
handled by binding the sockets early.
This change doesn't affect SCTP, because it's not currently possible
for docker-proxy to convert the file descriptor into an SCTPListener.
So, docker-proxy is still started early, and the window for lost
connections remains.
If the user has an old docker-proxy in their path and it's given a
listener docker with '-use-listen-fd', it'll fail because of the
unknown option. In this case, the daemon's error message suggests
checking $PATH.
Signed-off-by: Rob Murray <rob.murray@docker.com>
The bridge driver now does its own port-mapping, rather than using the
portmapper module (which ran as two completely separate instances, for
IPv4 and IPv6).
When asked for a mapping from any host address (0.0.0.0/0) with a range
of host ports, the same port will be allocated for IPv4 and IPv6, or the
mapping will fail with an error if that's not possible.
The bridge driver now manages its own port mappings. So, remove
linux-specific PortMapper code and make what's left Windows-only.
Also, replace the portmapper.userlandProxy interface with StartProxy().
Signed-off-by: Rob Murray <rob.murray@docker.com>
This function never returned an error, and was not matching an interface, so
remove the error-return.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
When mapping a port with the userland-proxy enabled, the daemon would
perform an "exec.LookPath" for every mapped port (which, in case of
a range of ports, would be for every port in the range).
This was both inefficient (looking up the binary for each port), inconsistent
(when running in rootless-mode, the binary was looked-up once), as well as
inconvenient, because a missing binary, or a mis-configureed userland-proxy-path
would not be detected daeemon startup, and not produce an error until starting
the container;
docker run -d -P nginx:alpine
4f7b6589a1680f883d98d03db12203973387f9061e7a963331776170e4414194
docker: Error response from daemon: driver failed programming external connectivity on endpoint romantic_wiles (7cfdc361821f75cbc665564cf49856cf216a5b09046d3c22d5b9988836ee088d): fork/exec docker-proxy: no such file or directory.
However, the container would still be created (but invalid);
docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
869f41d7e94f nginx:alpine "/docker-entrypoint.…" 10 seconds ago Created romantic_wiles
This patch changes how the userland-proxy is configured;
- The path of the userland-proxy is now looked up / configured at daemon
startup; this is similar to how the proxy is configured in rootless-mode.
- A warning is logged when failing to lookup the binary.
- If the daemon is configured with "userland-proxy" enabled, an error is
produced, and the daemon will refuse to start.
- The "proxyPath" argument for newProxyCommand() (in libnetwork/portmapper)
is now required to be set. It no longer looks up the executable, and
produces an error if no path was provided. While this change was not
required, it makes the daemon config the canonical source of truth, instead
of logic spread accross multiplee locations.
Some of this logic is a change of behavior, but these changes were made with
the assumption that we don't want to support;
- installing the userland proxy _after_ the daemon was started
- moving the userland proxy (or installing a proxy with a higher
preference in PATH)
With this patch:
Validating the config produces an error if the binary is not found:
dockerd --validate
WARN[2023-12-29T11:36:39.748699591Z] failed to lookup default userland-proxy binary error="exec: \"docker-proxy\": executable file not found in $PATH"
userland-proxy is enabled, but userland-proxy-path is not set
Disabling userland-proxy prints a warning, but validates as "OK":
dockerd --userland-proxy=false --validate
WARN[2023-12-29T11:38:30.752523879Z] ffailed to lookup default userland-proxy binary error="exec: \"docker-proxy\": executable file not found in $PATH"
configuration OK
Speficying a non-absolute path produces an error:
dockerd --userland-proxy-path=docker-proxy --validate
invalid userland-proxy-path: must be an absolute path: docker-proxy
Befor this patch, we would not validate this path, which would allow the daemon
to start, but fail to map a port;
docker run -d -P nginx:alpine
4f7b6589a1680f883d98d03db12203973387f9061e7a963331776170e4414194
docker: Error response from daemon: driver failed programming external connectivity on endpoint romantic_wiles (7cfdc361821f75cbc665564cf49856cf216a5b09046d3c22d5b9988836ee088d): fork/exec docker-proxy: no such file or directory.
Specifying an invalid userland-proxy-path produces an error as well:
dockerd --userland-proxy-path=/usr/local/bin/no-such-binary --validate
userland-proxy-path is invalid: stat /usr/local/bin/no-such-binary: no such file or directory
mkdir -p /usr/local/bin/not-a-file
dockerd --userland-proxy-path=/usr/local/bin/not-a-file --validate
userland-proxy-path is invalid: exec: "/usr/local/bin/not-a-file": is a directory
touch /usr/local/bin/not-an-executable
dockerd --userland-proxy-path=/usr/local/bin/not-an-executable --validate
userland-proxy-path is invalid: exec: "/usr/local/bin/not-an-executable": permission denied
Same when using the daemon.json config-file;
echo '{"userland-proxy-path":"no-such-binary"}' > /etc/docker/daemon.json
dockerd --validate
unable to configure the Docker daemon with file /etc/docker/daemon.json: merged configuration validation from file and command line flags failed: invalid userland-proxy-path: must be an absolute path: no-such-binary
dockerd --userland-proxy-path=hello --validate
unable to configure the Docker daemon with file /etc/docker/daemon.json: the following directives are specified both as a flag and in the configuration file: userland-proxy-path: (from flag: hello, from file: /usr/local/bin/docker-proxy)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
The cleanup function never returns an error, so didn't add much value. This
patch removes the closure, and calls it inline to remove the extra
indirection, and removes the error which would never be returned.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
The defer was set after the switch, but various code-paths inside the switch
could return with an error after the port was allocated / reserved, which
could result in those ports not being released.
This patch moves the defer into each individual branch of the switch to set
it immediately after succesfully reserving the port.
We can also remove a redundant ReleasePort from the cleanup function, as
it's only called if an error occurs, and the defers already take care of
that.
Note that the cleanup function was handling errors returned by ReleasePort,
but this function never returns an error, so it was fully redundant.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Prevent accidentally shadowing the error, which is used in a defer.
Also re-format the code to make it more clear we're not acting on
a locally-scoped "allocatedHostPort" variable.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
The github.com/containerd/containerd/log package was moved to a separate
module, which will also be used by upcoming (patch) releases of containerd.
This patch moves our own uses of the package to use the new module.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
None of the code using this function was setting the value, so let's
simplify and remove the argument.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
On Linux, when (os/exec.Cmd).SysProcAttr.Pdeathsig is set, the signal
will be sent to the process when the OS thread on which cmd.Start() was
executed dies. The runtime terminates an OS thread when a goroutine
exits after being wired to the thread with runtime.LockOSThread(). If
other goroutines are allowed to be scheduled onto a thread which called
cmd.Start(), an unrelated goroutine could cause the thread to be
terminated and prematurely signal the command. See
https://github.com/golang/go/issues/27505 for more information.
Prevent started subprocesses with Pdeathsig from getting signaled
prematurely by wiring the starting goroutine to the OS thread until the
subprocess has exited. No other goroutines can be scheduled onto a
locked thread so it will remain alive until unlocked or the daemon
process exits.
Signed-off-by: Cory Snider <csnider@mirantis.com>
The io/ioutil package has been deprecated in Go 1.16. This commit
replaces the existing io/ioutil functions with their new definitions in
io and os packages.
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
Perhaps the testutils package in the past had an `init()` function to set up
specific things, but it no longer has. so these imports were doing nothing.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
After moving libnetwork to this repo, we need to update all the import
paths for libnetwork to point to docker/docker/libnetwork instead of
docker/libnetwork.
This change implements that.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
1. Allocate either a IPv4 and/or IPv6 Port Binding (HostIP, HostPort, ContainerIP,
ContainerPort) based on the input and system parameters
2. Update the userland proxy as well as dummy proxy (inside port mapper) to
specifically listen on either the IPv4 or IPv6 network
Signed-off-by: Arko Dasgupta <arko.dasgupta@docker.com>
This commit updates the vendored ishidawataru/sctp and adapts its used
types.
Signed-off-by: Sascha Grunert <sgrunert@suse.com>
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
For overlay, l2bridge, and l2tunnel, if the user does not specify a host port, windows driver will select a random port for them. This matches linux behavior.
For ics and nat networks the windows OS will choose the port.
Signed-off-by: Pradip Dhara <pradipd@microsoft.com>
Solaris support for Docker will likely not reach completion,
so removing these files as they are not in use and not
maintained.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Rather than re-execing docker as the proxy, create a new command docker-proxy
that is much smaller to save memory in the case where there are a lot of
procies being created. Also allows the proxy to be replaced, for example
in Docker for Mac we have a proxy that proxies to osx instead of locally.
This is the vendoring pull for https://github.com/docker/docker/pull/23312
Signed-off-by: Justin Cormack <justin.cormack@docker.com>
This way we won't vendor test related functions in docker anymore.
It also moves netns related functions to a new ns package to be able to
call the ns init function in tests. I think this also helps with the
overall package isolation.
Signed-off-by: David Calavera <david.calavera@gmail.com>
for the bridge driver.
Moves two config options, namely EnableIPTables and EnableUserlandProxy
from networks to the driver.
Closes#242
Signed-off-by: Mohammad Banikazemi <MBanikazemi@gmail.com>
It is needed in cases when mapped port is already bound, or another
application bind mapped port. All this will be undetected because we use
iptables and not net.Listen.
Signed-off-by: Alexander Morozov <lk4d4@docker.com>
