On Thu, Nov 23, 2023 at 10:14 AM Juraj Linkeš <juraj.linkes@pantheon.tech>
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 | 272 ++++++++++++++++------
>  1 file changed, 205 insertions(+), 67 deletions(-)
>
> diff --git a/dts/framework/testbed_model/os_session.py
> b/dts/framework/testbed_model/os_session.py
> index 76e595a518..cfdbd1c4bd 100644
> --- a/dts/framework/testbed_model/os_session.py
> +++ b/dts/framework/testbed_model/os_session.py
> @@ -2,6 +2,26 @@
>  # 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:`~.sut_node.SutNode`.
> +    The :class:`~.sut_node.SutNode` object isn't aware what OS the node
> is running - it delegates
> +    the OS translation logic to :attr:`~.node.Node.main_session`. The SUT
> node calls
> +    :meth:`~OSSession.remove_remote_dir` with a generic, OS-unaware path
> and
> +    the :attr:`~.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 +48,16 @@
>
>
>  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 +72,15 @@ 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 +88,15 @@ 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 +107,23 @@ 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 for `command`
> execution to complete.
> +            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 +137,20 @@ 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 +174,42 @@ 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 +218,13 @@ 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 +234,14 @@ 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 +251,12 @@ 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 +265,12 @@ 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 +283,119 @@ 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.
>

I think this is meant to be "when building DPDK" instead.


> +            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
> execution to complete.
>          """
>
>      @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:`~.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 numa node.
>          """
>
>      @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 +405,18 @@ 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.
>          """
> --
> 2.34.1
>
>