When connecting to a remote daemon through an ssh:// connection,
the CLI connects with the remote host using ssh, executing the
`docker system dial-stdio` command on the remote host to connect
to the daemon API's unix socket.
By default, the `docker system dial-stdio` command connects with the
daemon using the default location (/var/run/docker.sock), or the
location as configured on the remote host.
Commit 25ebf0ec9c (included in docker
CLI v24.0.0-rc.2 and higher) introduced a feature to allow the location
of the socket to be specified through the host connection string, for
example:
DOCKER_HOST='ssh://example.test/run/custom-docker.sock'
The custom path is included as part of the ssh command executed from
the client machine to connect with the remote host. THe example above
would execute the following command from the client machine;
ssh -o ConnectTimeout=30 -T -- example.test docker --host unix:///run/custom-docker.sock system dial-stdio
ssh executes remote commands in a shell environment, and no quoting
was in place, which allowed for a connection string to include additional
content, which would be expanded / executed on the remote machine.
For example, the following example would execute `echo hello > /hello.txt`
on the remote machine;
export DOCKER_HOST='ssh://example.test/var/run/docker.sock $(echo hello > /hello.txt)'
docker info
# (output of docker info from the remote machine)
While this doesn't allow the user to do anything they're not already
able to do so (by directly using the same SSH connection), the behavior
is not expected, so this patch adds quoting to prevent such URLs from
resulting in expansion.
This patch updates the cli/connhelper and cli/connhelper/ssh package to
quote parameters used in the ssh command to prevent code execution and
expansion of variables on the remote machine. Quoting is also applied to
other parameters that are obtained from the DOCKER_HOST url, such as username
and hostname.
- The existing `Spec.Args()` method inthe cli/connhelper/ssh package now
quotes arguments, and returns a nil slice when failing to quote. Users
of this package should therefore check the returned arguments before
consuming. This method did not provide an error-return, and adding
one would be a breaking change.
- A new `Spec.Command` method is introduced, which (unlike the `Spec.Args()`
method) provides an error return. Users are recommended to use this new
method instead of the `Spec.Args()` method.
Some minor additional changes in behavior are included in this patch;
- Connection URLs with a trailing slash (e.g. `ssh://example.test/`)
would previously result in `unix:///` being used as custom socket
path. After this patch, the trailing slash is ignored, and no custom
socket path is used.
- Specifying a remote command is now required. When passing an empty
remote command, `Spec.Args()` now results in a `nil` value to be
returned (or an `no remote command specified` error when using
`Spec.Comnmand()`.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
This function was parsing the same URL twice; first to detect the
scheme, then again (through ssh.ParseURL) to construct a ssh.Spec.
Change the function to use the URL that's parsed, and use ssh.NewSpec
instead.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
The addSSHTimeout and disablePseudoTerminalAllocation were added in commits
a5ebe2282a and f3c2c26b10,
and called inside the Dialer function, which means they're called every
time the Dialer is called. Given that the sshFlags slice is not mutated
by the Dialer, we can call these functions once.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
avoided the join, also did manual iteration
added test, also added reflect for the DeepEqual comparison
Signed-off-by: Archimedes Trajano <developer@trajano.net>
---
commandconn: fix race on `Close()`
During normal operation, if a `Read()` or `Write()` call results
in an EOF, we call `onEOF()` to handle the terminating command,
and store it's exit value.
However, if a Read/Write call was blocked while `Close()` is called
the in/out pipes are immediately closed which causes an EOF to be
returned. Here, we shouldn't call `onEOF()`, since the reason why
we got an EOF is because we're already terminating the connection.
This also prevents a race between two calls to the commands `Wait()`,
in the `Close()` call and `onEOF()`
---
Add CLI init timeout to SSH connections
---
connhelper: add 30s ssh default dialer timeout
(same as non-ssh dialer)
Signed-off-by: Laura Brehm <laurabrehm@hey.com>
Some tests were using domain names that were intended to be "fake", but are
actually registered domain names (such as mycorp.com).
Even though we were not actually making connections to these domains, it's
better to use domains that are designated for testing/examples in RFC2606:
https://tools.ietf.org/html/rfc2606
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
This means that plugins can use whatever methods the monolithic CLI supports,
which is good for consistency.
This relies on `os.Args[0]` being something which can be executed again to
reach the same binary, since it is propagated (via an envvar) to the plugin for
this purpose. This essentially requires that the current working directory and
path are not modified by the monolithic CLI before it launches the plugin nor
by the plugin before it initializes the client. This should be the case.
Previously the fake apiclient used by `TestExperimentalCLI` was not being used,
since `cli.Initialize` was unconditionally overwriting it with a real one
(talking to a real daemon during unit testing, it seems). This wasn't expected
nor desirable and no longer happens with the new arrangements, exposing the
fact that no `pingFunc` is provided, leading to a panic. Add a `pingFunc` to
the fake client to avoid this.
Signed-off-by: Ian Campbell <ijc@docker.com>
e.g. docker -H ssh://me@server
The `docker` CLI also needs to be installed on the remote host to
provide `docker system dial-stdio`, which proxies the daemon socket to stdio.
Please refer to docs/reference/commandline/dockerd.md .
Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
