Commands executed by ExecContext and its derived classes don't populate the "cmd" parameter of "Result"'s constructor. Fixing that makes for nicer error messages.
Define default parameter values for Result's constructor, namely None for exit status, stdout and stderr.
Instantiating a Result object without parameters signifies "this object doesn't contain data from a real process's exit event". Up to now, similar meaning has been hand-crafted by ExecContext's run() and friends by using an error exit status (1) to make sure it wasn't mistaken for success. This commit formalizes that into the Result structure itself, but uses None instead for the exit status.
Controlling default values in Result itself also means that the Result class gets better awareness of what it contains, and its log messages and stdin / stdout can be more fitting:
- If a real process failed, make stdout return at least b'' - If a real process succeeded, make stdout return at least b''
Returning something from .stdout on success fixes a real bug: An attempt to access what "rpm -U somepackage.rpm" returns, namely nothing, raises a bogus exception, because stdout is None.
Make the log delimiter look more consistent: Whether a CallContext was constructed with a title parameter or without, prefix its .log_delimiter property with a "----".
Ignore newline at the end of Result.stdout_str if only one line of output is wanted from an executed shell command. The output of both uname and mktemp are used wrongly in that regard.
Fix another regression of commit 6db73873e7: lib.ExecContext.CallContext.__exit__() returns True, which swallows all exceptions thrown in the context of _run() and _sudo(). Fix that.
The previous commits have put rules for linting and formatting via ruff, yapf, mypy and pyright into place. They are checked with the make check target, and this commit adds the fixes for the target to succeed.
It does some refactoring where type checking dug up dirty bits, and also adds lots of churn in the Python code. To a good deal, that's owed to mere formatting changes. It would have been better to seperate those from syntax and refactoring fixes into multiple commits, so that the interesting changes don't drown in the formatting nose. However, that would have been a lot of additional work only to be thrown away by later commits, hence this commit has a big diff in one piece. The size of the diff is regrettable but hopefully a one-off: What it buys is automatic format checking for CI and predictble formats for smaller diffs in the future.
Rules that "make check" enforces are, in the following order
- Syntax checkers:
- ruff check .
- mypy .
- pyright
- Format check:
- yapf --diff --recursive .
The refactoring includes:
- Turn the Result class into a more elaborate object, capable of
doing more heavy lifting around stderr and stdout decoding,
summarizing outcome, and matching error strings.
Aside from fixing broken type checks, this also removes lots of
boilerplate calling code which is currently used for handling
possible call outcome scenarios. Trying to access an inexistent,
decoded string should raise a meaningful exception by itself now,
which removes lots of code with case distinctions.
- Fix Cmd type hierarchy:
- Add the AbstractCmd class above Cmd. This is necessary because
the checker rightfully complains it can't instantiate a Cmd
instance where constructor arguments were needed. They never
were, but the type used at the instantiating code's location in
jw.pkg.App so claims.
- Lots of sub- and sub-subcommands are derived from the base
class of the invoking command. That provides some properties
shared across the ancestor hierarchy of a command, but is
semantically unsound. Fix that by introducing jw.pkg.BaseCmd
class as a place to provide basic helpers shared across all
commands used in a jw.pkg.App's context, and derive all command
classes from that afresh. The parent command is still reachable
via a common parent property.
Formatting changes are conforming to PEP-8, mostly, with minor tweaks. All in all they include the following changes.
- Remove # -*- coding: utf-8 -*-
The line was needed by Python 2 which is not supported anylonger.
For Python 3, the default encoding is UTF-8, anyway.
- Allow to run "make py-format" without having it produce any
changes. It's basically "yapf --in-place --recursive ." with some
code style settings, see conf/topdir/pyproject.toml. The settings
may be debatable. I've had custom tweaks in place on that target,
too, but then again, IDEs would have more hassle to integrate
that.
- Introduce a 88 character line length limit
- One import per line, reshuffle them semantically, see
[tool.isort] in pyproject.toml.
- Hide imports needed for type-checking only behind
if TYPE_CHECKING
- Spaces around assignments accounts for much churn. Having having
no spaces in inline parameter list assignments and default
parameter values would arguably be more compact where it's
useful. On the other hand, I have not found a code formatter
which allows spaces around assignments in parameter lists broken
into one per line and that's often better than a wall of text.
- Add two spaces before # export, as this seems to be mandated by
PEP-8
Enclose ExecContext._run() in an open() / close() - pair. This is convenient for the caller in that it doesn't need to take care of opening and closing for one call only, and inconvenient in that it forces the caller to conciously add an open() / close() - pair around multiple run() calls where it wants the context to stay open in between. Or use the ExecContext as a context manager.
There are a couple of assert statements in the codebase which can make jw-pkg fail without any detail whatsoever if --backtrace is not specified, fix that.
The name of the env parameter to ExecContext.run() and .sudo() is not descriptive enough for which environment is supposed to be modified and how, so rename and split it up as follows:
- .run(): env -> mod_env
- .sudo(): env -> mod_env_sudo and mod_env_cmd
The parameters have the following meaning:
- "mod_env*" means that the environment is modified, not replaced
- "mod_env" and "mod_env_cmd" modify the environment "cmd" runs in
- "mod_env_sudo" modifies the environment sudo runs in
Fix the fallout of the API change all over jw-pkg.
All methods are async and call their protected counterpart, which is designed to be overridden. If possible, default implementations do something meaningful, if not, they just raise plain NotImplementedError.
Add the parameter "atomic" to put() / _put(). If instructs the implementation to take extra precautions to make sure the operation either succeeds or fails entirely, i.e. doesn't leave a broken target file behind.
.put() has some commands to _run(), and it uses its own CallContext for them. Since that pattern only replicates what run() does anyway, we could just as well use run() itself with less code, so do that.
ExecContext has get() / _get() and put() / _put(), which make a fine API for a file transfer class. A class supporting file transfer should not, however, be forced to implement _run() and _sudo(), so place this functionality in a new class FileTransfer, and derive ExecContext from it.
For now, move the definiions of Result, Input and InputMode from ExecContext into lib.base. Having to import them from the ExecContect module is too heavy-handed for those simple types.
Add wrapper methods get() and put(), plus their wrapped methods _get() and _put(). The wrapped methods have default implementations, using POSIX utilities on the target machine over _run().
ExecContext.create() relies on properly formed URLs with a schema for deciding which backend gets created. Create a Local instance if an URL doesn't have schema.
The Input instance passed as cmd_input to ExecContext.run() and .sudo() currently may be of type str. Allow to pass bytes, too.
At the same time, disallow None to be passed as cmd_input. Force the caller to be more explicit how it wants input to be handled, notably with respect to interactivity.
Along the way fix a bug: Content in cmd_input should result in CallContext.interactive == False but doesn't. Fix that.
To have a pattern in lib.ExecContext and avoid future churn: If a
public wrapper calls a protected method, define the protected
method above the respective wrapper.
- sudo(): Make cmd_input default equal to run(): InputMode.OptInteractive
- CallContext: Expose parameters throw, wd, cmd as properties for
later use
lib.ExecContext.log_delim() logs a header not designed for enclosing command output, and, hence, no footer should be output. This commit suppresses it.
This commit introduces two new types, Input and InputMode. They replace the more error-prone special strings cmd_input could be used with. InputMode is an Enum, and Input can be either IntputMode, a string or None.
Whether or not the CallContext.interactive property should be True or False, and hence, a call should be processed interactively, depends on multiple factors, constituting matrix of options with multiple preferences.
--interactive is the application default and can be true, false,
or auto
- A call can be explicitly invoked as interactive, non-interactive
or auto via the cmd_input parameter to ExecContext.run()
This commit adds more "mode:" options to make the latter more explicit. It takes preference over the global --interactive parameter: Global --interactive is only given a chance to decide if cmd_input is None (default) or mode:opt-interactive.
This commit also fixes a bug: --interactive is ignored because the interactive argument passed to ExecContext's constructor is ignored later on in calls to the wrapped _run() and _sudo() methods.
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.
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.
Add the --verbose global option, which is made available as the App.verbose property.
Some functions still take a verbose parameter, but the type of these parameters is converted from bool to bool|None. The idea is that, if they are None, their verbosity falls back to the global default.
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.
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.
