Re: [PATCH v7 15/21] dts: os session docstring update

[Yoan Picchi <yoan.picchi@foss.arm.com>]

On 11/15/23 13:09, Juraj Linkeš wrote:
> Format according to the Google format and PEP257, with slight
> deviations.
> 
> Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> ---
>   dts/framework/testbed_model/os_session.py | 275 ++++++++++++++++------
>   1 file changed, 208 insertions(+), 67 deletions(-)
> 
> diff --git a/dts/framework/testbed_model/os_session.py b/dts/framework/testbed_model/os_session.py
> index 76e595a518..72b9193a61 100644
> --- a/dts/framework/testbed_model/os_session.py
> +++ b/dts/framework/testbed_model/os_session.py
> @@ -2,6 +2,29 @@
>   # Copyright(c) 2023 PANTHEON.tech s.r.o.
>   # Copyright(c) 2023 University of New Hampshire
>   
> +"""OS-aware remote session.
> +
> +DPDK supports multiple different operating systems, meaning it can run on these different operating
> +systems. This module defines the common API that OS-unaware layers use and translates the API into
> +OS-aware calls/utility usage.
> +
> +Note:
> +    Running commands with administrative privileges requires OS awareness. This is the only layer
> +    that's aware of OS differences, so this is where non-privileged command get converted
> +    to privileged commands.
> +
> +Example:
> +    A user wishes to remove a directory on
> +    a remote :class:`~framework.testbed_model.sut_node.SutNode`.
> +    The :class:`~framework.testbed_model.sut_node.SutNode` object isn't aware what OS the node
> +    is running - it delegates the OS translation logic
> +    to :attr:`~framework.testbed_model.node.Node.main_session`. The SUT node calls
> +    :meth:`~OSSession.remove_remote_dir` with a generic, OS-unaware path and
> +    the :attr:`~framework.testbed_model.node.Node.main_session` translates that
> +    to ``rm -rf`` if the node's OS is Linux and other commands for other OSs.
> +    It also translates the path to match the underlying OS.
> +"""
> +
>   from abc import ABC, abstractmethod
>   from collections.abc import Iterable
>   from ipaddress import IPv4Interface, IPv6Interface
> @@ -28,10 +51,16 @@
>   
>   
>   class OSSession(ABC):
> -    """
> -    The OS classes create a DTS node remote session and implement OS specific
> +    """OS-unaware to OS-aware translation API definition.
> +
> +    The OSSession classes create a remote session to a DTS node and implement OS specific
>       behavior. There a few control methods implemented by the base class, the rest need
> -    to be implemented by derived classes.
> +    to be implemented by subclasses.
> +
> +    Attributes:
> +        name: The name of the session.
> +        remote_session: The remote session maintaining the connection to the node.
> +        interactive_session: The interactive remote session maintaining the connection to the node.
>       """
>   
>       _config: NodeConfiguration
> @@ -46,6 +75,15 @@ def __init__(
>           name: str,
>           logger: DTSLOG,
>       ):
> +        """Initialize the OS-aware session.
> +
> +        Connect to the node right away and also create an interactive remote session.
> +
> +        Args:
> +            node_config: The test run configuration of the node to connect to.
> +            name: The name of the session.
> +            logger: The logger instance this session will use.
> +        """
>           self._config = node_config
>           self.name = name
>           self._logger = logger
> @@ -53,15 +91,15 @@ def __init__(
>           self.interactive_session = create_interactive_session(node_config, logger)
>   
>       def close(self, force: bool = False) -> None:
> -        """
> -        Close the remote session.
> +        """Close the underlying remote session.
> +
> +        Args:
> +            force: Force the closure of the connection.
>           """
>           self.remote_session.close(force)
>   
>       def is_alive(self) -> bool:
> -        """
> -        Check whether the remote session is still responding.
> -        """
> +        """Check whether the underlying remote session is still responding."""
>           return self.remote_session.is_alive()
>   
>       def send_command(
> @@ -72,10 +110,23 @@ def send_command(
>           verify: bool = False,
>           env: dict | None = None,
>       ) -> CommandResult:
> -        """
> -        An all-purpose API in case the command to be executed is already
> -        OS-agnostic, such as when the path to the executed command has been
> -        constructed beforehand.
> +        """An all-purpose API for OS-agnostic commands.
> +
> +        This can be used for an execution of a portable command that's executed the same way
> +        on all operating systems, such as Python.
> +
> +        The :option:`--timeout` command line argument and the :envvar:`DTS_TIMEOUT`
> +        environment variable configure the timeout of command execution.
> +
> +        Args:
> +            command: The command to execute.
> +            timeout: Wait at most this long in seconds to execute the command.

confusing start/end of execution

> +            privileged: Whether to run the command with administrative privileges.
> +            verify: If :data:`True`, will check the exit code of the command.
> +            env: A dictionary with environment variables to be used with the command execution.
> +
> +        Raises:
> +            RemoteCommandExecutionError: If verify is :data:`True` and the command failed.
>           """
>           if privileged:
>               command = self._get_privileged_command(command)
> @@ -89,8 +140,20 @@ def create_interactive_shell(
>           privileged: bool,
>           app_args: str,
>       ) -> InteractiveShellType:
> -        """
> -        See "create_interactive_shell" in SutNode
> +        """Factory for interactive session handlers.
> +
> +        Instantiate `shell_cls` according to the remote OS specifics.
> +
> +        Args:
> +            shell_cls: The class of the shell.
> +            timeout: Timeout for reading output from the SSH channel. If you are
> +                reading from the buffer and don't receive any data within the timeout
> +                it will throw an error.
> +            privileged: Whether to run the shell with administrative privileges.
> +            app_args: The arguments to be passed to the application.
> +
> +        Returns:
> +            An instance of the desired interactive application shell.
>           """
>           return shell_cls(
>               self.interactive_session.session,
> @@ -114,27 +177,42 @@ def _get_privileged_command(command: str) -> str:
>   
>       @abstractmethod
>       def guess_dpdk_remote_dir(self, remote_dir: str | PurePath) -> PurePath:
> -        """
> -        Try to find DPDK remote dir in remote_dir.
> +        """Try to find DPDK directory in `remote_dir`.
> +
> +        The directory is the one which is created after the extraction of the tarball. The files
> +        are usually extracted into a directory starting with ``dpdk-``.
> +
> +        Returns:
> +            The absolute path of the DPDK remote directory, empty path if not found.
>           """
>   
>       @abstractmethod
>       def get_remote_tmp_dir(self) -> PurePath:
> -        """
> -        Get the path of the temporary directory of the remote OS.
> +        """Get the path of the temporary directory of the remote OS.
> +
> +        Returns:
> +            The absolute path of the temporary directory.
>           """
>   
>       @abstractmethod
>       def get_dpdk_build_env_vars(self, arch: Architecture) -> dict:
> -        """
> -        Create extra environment variables needed for the target architecture. Get
> -        information from the node if needed.
> +        """Create extra environment variables needed for the target architecture.
> +
> +        Different architectures may require different configuration, such as setting 32-bit CFLAGS.
> +
> +        Returns:
> +            A dictionary with keys as environment variables.
>           """
>   
>       @abstractmethod
>       def join_remote_path(self, *args: str | PurePath) -> PurePath:
> -        """
> -        Join path parts using the path separator that fits the remote OS.
> +        """Join path parts using the path separator that fits the remote OS.
> +
> +        Args:
> +            args: Any number of paths to join.
> +
> +        Returns:
> +            The resulting joined path.
>           """
>   
>       @abstractmethod
> @@ -143,13 +221,13 @@ def copy_from(
>           source_file: str | PurePath,
>           destination_file: str | PurePath,
>       ) -> None:
> -        """Copy a file from the remote Node to the local filesystem.
> +        """Copy a file from the remote node to the local filesystem.
>   
> -        Copy source_file from the remote Node associated with this remote
> -        session to destination_file on the local filesystem.
> +        Copy `source_file` from the remote node associated with this remote
> +        session to `destination_file` on the local filesystem.
>   
>           Args:
> -            source_file: the file on the remote Node.
> +            source_file: the file on the remote node.
>               destination_file: a file or directory path on the local filesystem.
>           """
>   
> @@ -159,14 +237,14 @@ def copy_to(
>           source_file: str | PurePath,
>           destination_file: str | PurePath,
>       ) -> None:
> -        """Copy a file from local filesystem to the remote Node.
> +        """Copy a file from local filesystem to the remote node.
>   
> -        Copy source_file from local filesystem to destination_file
> -        on the remote Node associated with this remote session.
> +        Copy `source_file` from local filesystem to `destination_file`
> +        on the remote node associated with this remote session.
>   
>           Args:
>               source_file: the file on the local filesystem.
> -            destination_file: a file or directory path on the remote Node.
> +            destination_file: a file or directory path on the remote node.
>           """
>   
>       @abstractmethod
> @@ -176,8 +254,12 @@ def remove_remote_dir(
>           recursive: bool = True,
>           force: bool = True,
>       ) -> None:
> -        """
> -        Remove remote directory, by default remove recursively and forcefully.
> +        """Remove remote directory, by default remove recursively and forcefully.
> +
> +        Args:
> +            remote_dir_path: The path of the directory to remove.
> +            recursive: If :data:`True`, also remove all contents inside the directory.
> +            force: If :data:`True`, ignore all warnings and try to remove at all costs.
>           """
>   
>       @abstractmethod
> @@ -186,9 +268,12 @@ def extract_remote_tarball(
>           remote_tarball_path: str | PurePath,
>           expected_dir: str | PurePath | None = None,
>       ) -> None:
> -        """
> -        Extract remote tarball in place. If expected_dir is a non-empty string, check
> -        whether the dir exists after extracting the archive.
> +        """Extract remote tarball in its remote directory.
> +
> +        Args:
> +            remote_tarball_path: The path of the tarball on the remote node.
> +            expected_dir: If non-empty, check whether `expected_dir` exists after extracting
> +                the archive.
>           """
>   
>       @abstractmethod
> @@ -201,69 +286,119 @@ def build_dpdk(
>           rebuild: bool = False,
>           timeout: float = SETTINGS.compile_timeout,
>       ) -> None:
> -        """
> -        Build DPDK in the input dir with specified environment variables and meson
> -        arguments.
> +        """Build DPDK on the remote node.
> +
> +        An extracted DPDK tarball must be present on the node. The build consists of two steps::
> +
> +            meson setup <meson args> remote_dpdk_dir remote_dpdk_build_dir
> +            ninja -C remote_dpdk_build_dir
> +
> +        The :option:`--compile-timeout` command line argument and the :envvar:`DTS_COMPILE_TIMEOUT`
> +        environment variable configure the timeout of DPDK build.
> +
> +        Args:
> +            env_vars: Use these environment variables then building DPDK.
> +            meson_args: Use these meson arguments when building DPDK.
> +            remote_dpdk_dir: The directory on the remote node where DPDK will be built.
> +            remote_dpdk_build_dir: The target build directory on the remote node.
> +            rebuild: If :data:`True`, do a subsequent build with ``meson configure`` instead
> +                of ``meson setup``.
> +            timeout: Wait at most this long in seconds for the build to execute.

confusing start/end of execution

>           """
>   
>       @abstractmethod
>       def get_dpdk_version(self, version_path: str | PurePath) -> str:
> -        """
> -        Inspect DPDK version on the remote node from version_path.
> +        """Inspect the DPDK version on the remote node.
> +
> +        Args:
> +            version_path: The path to the VERSION file containing the DPDK version.
> +
> +        Returns:
> +            The DPDK version.
>           """
>   
>       @abstractmethod
>       def get_remote_cpus(self, use_first_core: bool) -> list[LogicalCore]:
> -        """
> -        Compose a list of LogicalCores present on the remote node.
> -        If use_first_core is False, the first physical core won't be used.
> +        r"""Get the list of :class:`~framework.testbed_model.cpu.LogicalCore`\s on the remote node.
> +
> +        Args:
> +            use_first_core: If :data:`False`, the first physical core won't be used.
> +
> +        Returns:
> +            The logical cores present on the node.
>           """
>   
>       @abstractmethod
>       def kill_cleanup_dpdk_apps(self, dpdk_prefix_list: Iterable[str]) -> None:
> -        """
> -        Kill and cleanup all DPDK apps identified by dpdk_prefix_list. If
> -        dpdk_prefix_list is empty, attempt to find running DPDK apps to kill and clean.
> +        """Kill and cleanup all DPDK apps.
> +
> +        Args:
> +            dpdk_prefix_list: Kill all apps identified by `dpdk_prefix_list`.
> +                If `dpdk_prefix_list` is empty, attempt to find running DPDK apps to kill and clean.
>           """
>   
>       @abstractmethod
>       def get_dpdk_file_prefix(self, dpdk_prefix: str) -> str:
> -        """
> -        Get the DPDK file prefix that will be used when running DPDK apps.
> +        """Make OS-specific modification to the DPDK file prefix.
> +
> +        Args:
> +           dpdk_prefix: The OS-unaware file prefix.
> +
> +        Returns:
> +            The OS-specific file prefix.
>           """
>   
>       @abstractmethod
> -    def setup_hugepages(self, hugepage_amount: int, force_first_numa: bool) -> None:
> -        """
> -        Get the node's Hugepage Size, configure the specified amount of hugepages
> +    def setup_hugepages(self, hugepage_count: int, force_first_numa: bool) -> None:
> +        """Configure hugepages on the node.
> +
> +        Get the node's Hugepage Size, configure the specified count of hugepages
>           if needed and mount the hugepages if needed.
> -        If force_first_numa is True, configure hugepages just on the first socket.
> +
> +        Args:
> +            hugepage_count: Configure this many hugepages.
> +            force_first_numa:  If :data:`True`, configure hugepages just on the first socket.

force *numa* configures the first *socket* ?

>           """
>   
>       @abstractmethod
>       def get_compiler_version(self, compiler_name: str) -> str:
> -        """
> -        Get installed version of compiler used for DPDK
> +        """Get installed version of compiler used for DPDK.
> +
> +        Args:
> +            compiler_name: The name of the compiler executable.
> +
> +        Returns:
> +            The compiler's version.
>           """
>   
>       @abstractmethod
>       def get_node_info(self) -> NodeInfo:
> -        """
> -        Collect information about the node
> +        """Collect additional information about the node.
> +
> +        Returns:
> +            Node information.
>           """
>   
>       @abstractmethod
>       def update_ports(self, ports: list[Port]) -> None:
> -        """
> -        Get additional information about ports:
> -            Logical name (e.g. enp7s0) if applicable
> -            Mac address
> +        """Get additional information about ports from the operating system and update them.
> +
> +        The additional information is:
> +
> +            * Logical name (e.g. ``enp7s0``) if applicable,
> +            * Mac address.
> +
> +        Args:
> +            ports: The ports to update.
>           """
>   
>       @abstractmethod
>       def configure_port_state(self, port: Port, enable: bool) -> None:
> -        """
> -        Enable/disable port.
> +        """Enable/disable `port` in the operating system.
> +
> +        Args:
> +            port: The port to configure.
> +            enable: If :data:`True`, enable the port, otherwise shut it down.
>           """
>   
>       @abstractmethod
> @@ -273,12 +408,18 @@ def configure_port_ip_address(
>           port: Port,
>           delete: bool,
>       ) -> None:
> -        """
> -        Configure (add or delete) an IP address of the input port.
> +        """Configure an IP address on `port` in the operating system.
> +
> +        Args:
> +            address: The address to configure.
> +            port: The port to configure.
> +            delete: If :data:`True`, remove the IP address, otherwise configure it.
>           """
>   
>       @abstractmethod
>       def configure_ipv4_forwarding(self, enable: bool) -> None:
> -        """
> -        Enable IPv4 forwarding in the underlying OS.
> +        """Enable IPv4 forwarding in the operating system.
> +
> +        Args:
> +            enable: If :data:`True`, enable the forwarding, otherwise disable it.
>           """