feat(foreground): Add foreground command

devservices/commands/foreground.py

@@ -0,0 +1,133 @@
+from __future__ import annotations
+
+import os
+import pty
+import shlex
+from argparse import _SubParsersAction
+from argparse import ArgumentParser
+from argparse import Namespace
+
+from sentry_sdk import capture_exception
+
+from devservices.constants import DependencyType
+from devservices.constants import DEVSERVICES_DIR_NAME
+from devservices.constants import PROGRAMS_CONF_FILE_NAME
+from devservices.exceptions import ConfigError
+from devservices.exceptions import ConfigNotFoundError
+from devservices.exceptions import ServiceNotFoundError
+from devservices.exceptions import SupervisorConfigError
+from devservices.exceptions import SupervisorProcessError
+from devservices.utils.console import Console
+from devservices.utils.services import find_matching_service
+from devservices.utils.state import State
+from devservices.utils.state import StateTables
+from devservices.utils.supervisor import SupervisorManager
+
+
+def add_parser(subparsers: _SubParsersAction[ArgumentParser]) -> None:
+    parser = subparsers.add_parser(
+        "foreground", help="Run a service's program in the foreground"
+    )
+    parser.add_argument(
+        "program_name", help="Name of the program to run in the foreground"
+    )
+    parser.set_defaults(func=foreground)
+
+
+def foreground(args: Namespace) -> None:
+    """Run a service's program in the foreground."""
+    console = Console()
+    program_name = args.program_name
+    try:
+        service = find_matching_service()
+    except ConfigNotFoundError as e:
+        capture_exception(e, level="info")
+        console.failure(
+            f"{str(e)}. Please specify a service (i.e. `devservices down sentry`) or run the command from a directory with a devservices configuration."
+        )
+        exit(1)
+    except ConfigError as e:
+        capture_exception(e)
+        console.failure(str(e))
+        exit(1)
+    except ServiceNotFoundError as e:
+        console.failure(str(e))
+        exit(1)
+    modes = service.config.modes
+    if program_name not in service.config.dependencies:
+        console.failure(
+            f"Program {program_name} does not exist in the service's config"
+        )
+        return
+    state = State()
+    starting_services = set(state.get_service_entries(StateTables.STARTING_SERVICES))
+    started_services = set(state.get_service_entries(StateTables.STARTED_SERVICES))
+    active_services = starting_services.union(started_services)
+    if service.name not in active_services:
+        console.warning(f"{service.name} is not running")
+        return
+    active_starting_modes = state.get_active_modes_for_service(
+        service.name, StateTables.STARTING_SERVICES
+    )
+    active_started_modes = state.get_active_modes_for_service(
+        service.name, StateTables.STARTED_SERVICES
+    )
+    active_modes = active_starting_modes or active_started_modes
+    mode_dependencies = set()
+    for active_mode in active_modes:
+        active_mode_dependencies = modes.get(active_mode, [])
+        mode_dependencies.update(active_mode_dependencies)
+
+    supervisor_programs = [
+        dep
+        for dep in mode_dependencies
+        if dep in service.config.dependencies
+        and service.config.dependencies[dep].dependency_type
+        == DependencyType.SUPERVISOR
+    ]
+
+    if program_name not in supervisor_programs:
+        console.failure(
+            f"Program {program_name} is not running in any active modes of {service.name}"
+        )
+        return
+
+    programs_config_path = os.path.join(
+        service.repo_path, f"{DEVSERVICES_DIR_NAME}/{PROGRAMS_CONF_FILE_NAME}"
+    )
+
+    manager = SupervisorManager(
+        programs_config_path,
+        service_name=service.name,
+    )
+
+    try:
+        program_command = manager.get_program_command(program_name)
+    except SupervisorConfigError as e:
+        capture_exception(e, level="info")
+        console.failure(f"Error when getting program command: {str(e)}")
+        return
+
+    try:
+        # Stop the supervisor process before running in foreground
+        console.info(f"Stopping {program_name} in supervisor")
+        manager.stop_process(program_name)
+        console.info(f"Starting {program_name} in foreground")
+        argv = shlex.split(program_command)
+
+        # Run the process in foreground
+        pty.spawn(argv)
+
+    except SupervisorProcessError as e:
+        capture_exception(e)
+        console.failure(f"Error stopping {program_name} in supervisor: {str(e)}")
+    except (OSError, FileNotFoundError, PermissionError) as e:
+        capture_exception(e)
+        console.failure(f"Error running {program_name} in foreground: {str(e)}")
+
+    try:
+        console.info(f"Restarting {program_name} in background")
+        manager.start_process(program_name)
+    except SupervisorProcessError as e:
+        capture_exception(e)
+        console.failure(f"Error restarting {program_name} in background: {str(e)}")

devservices/main.py

@@ -20,6 +20,7 @@
 from sentry_sdk.types import Hint
 
 from devservices.commands import down
+from devservices.commands import foreground
 from devservices.commands import list_dependencies
 from devservices.commands import list_services
 from devservices.commands import logs
@@ -150,6 +151,7 @@ def main() -> None:
     purge.add_parser(subparsers)
     serve.add_parser(subparsers)
     toggle.add_parser(subparsers)
+    foreground.add_parser(subparsers)
     reset.add_parser(subparsers)
 
     args = parser.parse_args()