Instantiating a SSHClient-derived class with an invalid or missing
uri parameter is accepted and fails later down the road. Raise an
Exception early on to make the error log more comprehensible.
Signed-off-by: Jan Lindemann <jan@janware.com>
The SSHClient classes Paramiko and Exec are exported via # export.
This is a bad idea, because if Paramiko is not installed, none of the
other's can be instantiated either: On the attempt to load them,
__init__.py is loaded first and fails. SSHClient.ssh_client() knows
what to do, no need to auto-import them into the lib.ec.ssh module.
Signed-off-by: Jan Lindemann <jan@janware.com>
Request a remote PTY from AsyncSSH, and wire the local terminal's
stdin up with it if interactive == True. This gives a real
interactive session if local stdin belongs to a terminal. Also,
thanks to AsyncSSH understanding that, forward terminal size changes
to the remote end.
Signed-off-by: Jan Lindemann <jan@janware.com>
Add a SSHClient implementation using AsyncSSH. This is the first and
currently only class derived from SSHClient which implements
SSHClient.Cap.LogOutput, designed to consume and log command output
as it streams in. It felt like the lower hanging fruit not to do that
with Paramiko: Paramiko doesn't provide a native async API, so it
would need to spawn additional worker threads. I think.
Signed-off-by: Jan Lindemann <jan@janware.com>
Add an optional caps ("capabilities") argument to the constructor of
SSHClient. It is meant to be used by derived classes in order to
declare that they don't want the base class to handle a default
behaviour for a certain capability, but that they want to implement
it themselves instead.
Also, give the _run_ssh() callbacks the necessary info as parameters,
so that the derived classes have the means to do so.
Signed-off-by: Jan Lindemann <jan@janware.com>
Since commit 02697af5, ExecContext.run() returns bytes for stdout and
stderr and fixes that in calling code. The thing it did not fix was
the code calling run_cmd(), which also made return bytes. This commit
catches up on that.
Signed-off-by: Jan Lindemann <jan@janware.com>
Move the code of SSHClientInternal and SSCClientCmd into lib.ec.ssh,
as "Paramiko" and "Exec", respectively. This makes the class layout
a little more modular, and along the way fixes a bug where
SSHClientInternal could be instantiated but was unusable (if the
Paramiko is not installed).
Signed-off-by: Jan Lindemann <jan@janware.com>
ExecContext's .sudo() omits many of run()'s parameters, and this
commit adds them. To avoid redundancy around repeating and massaging
the long parameter list of both functions and their return values, it
also adds some deeper changes:
- Make run(), _run(), sudo() and _sudo() always return instances of
Result. Before it was allowed to return a triplet of stdout,
stderr, and exit status.
- Have ExecContext stay out of the business of decoding the result
entirely. Result provides a convenience method .decode()
operating on stdout and stderr and leaves the decision to the
caller.
This entails miniscule adaptations in calling code, namely in
App.os_release, util.get_profile_env() and CmdListRepos._run().
- Wrap the _run() and _sudo() callbacks in a context manager object
of type CallContext to avoid code duplication.
- Consistently name the first argument to run(), _run(), sudo() and
_sudo() "cmd", not "args". The latter suggests that the caller is
omitting the executable, which is not the case.
Signed-off-by: Jan Lindemann <jan@janware.com>
Take implementation burden from the derived classes _run() callback
by moving the respective code into the run() wrapper methods of the
base class.
Signed-off-by: Jan Lindemann <jan@janware.com>
Take a positional uri argument to the constructor of ExecContext,
forcing SSHClient to follow suit. The latter was instantiated with a
hostname as only argument up to now, which still works as a special
case of an uri.
Signed-off-by: Jan Lindemann <jan@janware.com>
Don't mention "error" in log message for exit codes > 0 from spawned
processes, because sometimes they don't mean an error.
Signed-off-by: Jan Lindemann <jan@janware.com>
Remove defaults from protected callback function parameters. They
have to be decided by the base class's public API.
Signed-off-by: Jan Lindemann <jan@janware.com>
Allow to specify the ExecContext in a call to run_cmd(). This
effectively makes run_cmd() an thin wrapper around ExecContext.run(),
which is what's going to be used in the future. The wrapper is for
backwards-compatibility.
Signed-off-by: Jan Lindemann <jan@janware.com>
The code below lib.distro, as left behind by the previous commit, is
geared towards being directly used as a command-line API. This commit
introduces the abstract base class Distro, a proxy for
distribution-specific interactions. The proxy abstracts distro
specifics into an API with proper method prototypes, not
argparse.Namespace contents, and can thus be more easily driven by
arbitrary code.
The Distro class is initialized with a member variable of type
ExecContext, another new class introduced by this commit. It is
designed to abstract the communication channel to the distribution
instance. Currently only one specialization exists, Local, which
interacts with the distribution and root file system it is running
in, but is planned to be subclassed to support interaction via SSH,
serial, chroot, or chains thereof.
Signed-off-by: Jan Lindemann <jan@janware.com>
