Commit a19679fec reverted the first attempt to make AsyncSSH reuse one connection during an instance lifetime. That failed because a lot of distribution-specific properties were filled in a new event loop thread started by AsyncRunner, and AsyncSSH didn't like that.
This commit is the first part of the solution: Move those properties from the App class to the Distro class, and load the Distro class in an async loader. As soon as it's instantiated, it can provide all its properties without cluttering the code with async keywords.
CmdInfo._expand_macros() raises a custom exception during exception handling. Replace that by logging some details and raising the original exception to keep the stack trace readable.
DistroBase's option --id is now redundant to the new global option --distro-id in the App class, so remove --id. The only added value DistroBase then brings to the table is its .distro property, which can be provided by App just fine at this point, given that App has all it needs to construct a Distro object, so add .distro to App and remove the entire DistroBase class.
For convenience, also make App.distro available as a newly added cmds.Cmd.distro property. This also obviates the need for the distro-related properties in the .distro.Cmd class, remove all that.
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.
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.
Functions abstracting the distribution are not only needed in the context of the distro subcommand, but also by other code, so make the bulk of the code abstracting the distribution available in some place more universally useful than below cmds.distro.
This commit leaves the source files mostly unchanged. They are only patched to fix import paths, so that functionality is preserved. Refactoring the code from command-line API to library API will be done by the next commit.
--fix-broken is added to apt-get options in non-interactive mode, but seems to work only with apt-get install, not with apt-get update. Don't add it at all for now.
Replace all_installed_packages() by query_packages(). The function takes an optional list of packages to be queried. If it's empty, a list of all installed packages are returned.
Add --download-only to the options of jw-pkg.py distro dup, which makes the command only download packages from the repositories without installing them.
Add the command distro.CmdRebootRequired, adding support for "distro reboot-required". The command exits with status code 1 if a reboot is required and 0 otherwise.
Most run_xxx() return stdout and stderr. There's no way, really, for the caller to get hold of the exit code of the spawned executable. It can pass throw=true, catch, and assume a non-zero exit status. But that's not semantically clean, since the spawned function can well be a test function which is expected to return a non-zero status code, and the caller might be interested in what code that was, exactly.
The clearest way to solve this is to return the exit code as well. This commit does that.
get-os.sh returned "suse" for SuSE-like distros, and that seems more appropriate since SLES is not OpenSUSE but should share and ID with other SuSE variants.
App.distro_id used to return "opensuse-tumbleweed", analogous to what's in ID@/etc/os-release, but now returns "opensuse", and the "tumbleweed" goes into "codename". That matches more what Debian-like distributions do, but it confuses _backend_path. Adapt it to map the new distro_id correctly.
CmdInfo provides what "projects os-cascade" provided as "distro info --format '%{cascade}'" plus additional macros: %{id}, %{name}, %{codename} and ${gnu-triplet}.
This is a code maintenance commit: some run_xxx() helper functions take a string, some a list, and some just digest all arguments and pass them on as a list to exec() to be executed. That's highly inconsistent. This commit changes that to list-only.
Except for the run_cmd() method of SSHClient, which is still run as a shell method, because, erm, it's a shell. Might be changed in the future for consistency reasons.
