Support QLEVER_IS_RUNNING_IN_CONTAINER (#84)

With ad-freiburg/qlever#1439, the recommended way to run QLever inside a container is to use the https://github.com/ad-freiburg/qlever-control script. Inside of the container, the environment variable `QLEVER_IS_RUNNING_IN_CONTAINER` is set, with the following two effects:

1. After `qlever setup-config <config name>`, the Qleverfile will contain the setting `SYSTEM = native` and not `SYSTEM = docker` and a warning message will be displayed that that is the case
2. When running `qlever ui`, an error message will be displayed that this command is disabled (reason: `qlever ui` runs another container, and we don't want containers inside of containers).

src/qlever/commands/setup_config.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import subprocess
+from os import environ
 from pathlib import Path
 
 from qlever.command import QleverCommand
@@ -15,33 +16,48 @@ class SetupConfigCommand(QleverCommand):
 
     def __init__(self):
         self.qleverfiles_path = Path(__file__).parent.parent / "Qleverfiles"
-        self.qleverfile_names = \
-            [p.name.split(".")[1]
-             for p in self.qleverfiles_path.glob("Qleverfile.*")]
+        self.qleverfile_names = [
+            p.name.split(".")[1] for p in self.qleverfiles_path.glob("Qleverfile.*")
+        ]
 
     def description(self) -> str:
         return "Get a pre-configured Qleverfile"
 
     def should_have_qleverfile(self) -> bool:
         return False
 
-    def relevant_qleverfile_arguments(self) -> dict[str: list[str]]:
+    def relevant_qleverfile_arguments(self) -> dict[str : list[str]]:
         return {}
 
     def additional_arguments(self, subparser) -> None:
         subparser.add_argument(
-                "config_name", type=str,
-                choices=self.qleverfile_names,
-                help="The name of the pre-configured Qleverfile to create")
+            "config_name",
+            type=str,
+            choices=self.qleverfile_names,
+            help="The name of the pre-configured Qleverfile to create",
+        )
 
     def execute(self, args) -> bool:
+        # Show a warning if `QLEVER_OVERRIDE_SYSTEM_NATIVE` is set.
+        qlever_is_running_in_container = environ.get("QLEVER_IS_RUNNING_IN_CONTAINER")
+        if qlever_is_running_in_container:
+            log.warning(
+                "The environment variable `QLEVER_IS_RUNNING_IN_CONTAINER` is set, "
+                "therefore the Qleverfile is modified to use `SYSTEM = native` "
+                "(since inside the container, QLever should run natively)"
+            )
+            log.info("")
         # Construct the command line and show it.
-        qleverfile_path = (self.qleverfiles_path
-                           / f"Qleverfile.{args.config_name}")
+        qleverfile_path = self.qleverfiles_path / f"Qleverfile.{args.config_name}"
         setup_config_cmd = (
-                f"cat {qleverfile_path}"
-                f" | sed -E 's/(^ACCESS_TOKEN.*)/\\1_{get_random_string(12)}/'"
-                f"> Qleverfile")
+            f"cat {qleverfile_path}"
+            f" | sed -E 's/(^ACCESS_TOKEN.*)/\\1_{get_random_string(12)}/'"
+        )
+        if qlever_is_running_in_container:
+            setup_config_cmd += (
+                " | sed -E 's/(^SYSTEM[[:space:]]*=[[:space:]]*).*/\\1native/'"
+            )
+        setup_config_cmd += "> Qleverfile"
         self.show(setup_config_cmd, only_show=args.show)
         if args.show:
             return False
@@ -51,31 +67,31 @@ def execute(self, args) -> bool:
         if qleverfile_path.exists():
             log.error("`Qleverfile` already exists in current directory")
             log.info("")
-            log.info("If you want to create a new Qleverfile using "
-                     "`qlever setup-config`, delete the existing Qleverfile "
-                     "first")
+            log.info(
+                "If you want to create a new Qleverfile using "
+                "`qlever setup-config`, delete the existing Qleverfile "
+                "first"
+            )
             return False
 
         # Copy the Qleverfile to the current directory.
         try:
-            subprocess.run(setup_config_cmd, shell=True, check=True,
-                           stdin=subprocess.DEVNULL, stdout=subprocess.DEVNULL)
+            subprocess.run(
+                setup_config_cmd,
+                shell=True,
+                check=True,
+                stdin=subprocess.DEVNULL,
+                stdout=subprocess.DEVNULL,
+            )
         except Exception as e:
-            log.error(f"Could not copy \"{qleverfile_path}\""
-                      f" to current directory: {e}")
+            log.error(
+                f'Could not copy "{qleverfile_path}"' f" to current directory: {e}"
+            )
             return False
 
         # If we get here, everything went well.
-        log.info(f"Created Qleverfile for config \"{args.config_name}\""
-                 f" in current directory")
+        log.info(
+            f'Created Qleverfile for config "{args.config_name}"'
+            f" in current directory"
+        )
         return True
-
-        # if config_name == "default":
-        #     log.info("Since this is the default Qleverfile, you need to "
-        #              "edit it before you can continue")
-        #     log.info("")
-        #     log.info("Afterwards, run `qlever` without arguments to see "
-        #              "which actions are available")
-        # else:
-        #     show_available_action_names()
-        # log.info("")

src/qlever/commands/ui.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import subprocess
+from os import environ
 
 from qlever.command import QleverCommand
 from qlever.containerize import Containerize
@@ -17,46 +18,70 @@ def __init__(self):
         pass
 
     def description(self) -> str:
-        return ("Launch the QLever UI web application")
+        return "Launch the QLever UI web application"
 
     def should_have_qleverfile(self) -> bool:
         return True
 
-    def relevant_qleverfile_arguments(self) -> dict[str: list[str]]:
-        return {"data": ["name"],
-                "server": ["host_name", "port"],
-                "ui": ["ui_port", "ui_config",
-                       "ui_system", "ui_image", "ui_container"]}
+    def relevant_qleverfile_arguments(self) -> dict[str : list[str]]:
+        return {
+            "data": ["name"],
+            "server": ["host_name", "port"],
+            "ui": ["ui_port", "ui_config", "ui_system", "ui_image", "ui_container"],
+        }
 
     def additional_arguments(self, subparser) -> None:
         pass
 
     def execute(self, args) -> bool:
+        # If QLEVER_OVERRIDE_DISABLE_UI is set, this command is disabled.
+        qlever_is_running_in_container = environ.get("QLEVER_IS_RUNNING_IN_CONTAINER")
+        if qlever_is_running_in_container:
+            log.error(
+                "The environment variable `QLEVER_OVERRIDE_DISABLE_UI` is set, "
+                "therefore `qlever ui` is not available (it should not be called "
+                "from inside a container)"
+            )
+            log.info("")
+            if not args.show:
+                log.info(
+                    "For your information, showing the commands that are "
+                    "executed when `qlever ui` is available:"
+                )
+                log.info("")
+
         # Construct commands and show them.
         server_url = f"http://{args.host_name}:{args.port}"
         ui_url = f"http://{args.host_name}:{args.ui_port}"
         pull_cmd = f"{args.ui_system} pull -q {args.ui_image}"
-        run_cmd = f"{args.ui_system} run -d " \
-                  f"--publish {args.ui_port}:7000 " \
-                  f"--name {args.ui_container} " \
-                  f"{args.ui_image}"
-        exec_cmd = f"{args.ui_system} exec -it " \
-                   f"{args.ui_container} " \
-                   f"bash -c \"python manage.py configure " \
-                   f"{args.ui_config} {server_url}\""
-        self.show("\n".join(["Stop running containers",
-                            pull_cmd, run_cmd, exec_cmd]), only_show=args.show)
-        if args.show:
+        run_cmd = (
+            f"{args.ui_system} run -d "
+            f"--publish {args.ui_port}:7000 "
+            f"--name {args.ui_container} "
+            f"{args.ui_image}"
+        )
+        exec_cmd = (
+            f"{args.ui_system} exec -it "
+            f"{args.ui_container} "
+            f'bash -c "python manage.py configure '
+            f'{args.ui_config} {server_url}"'
+        )
+        self.show(
+            "\n".join(["Stop running containers", pull_cmd, run_cmd, exec_cmd]),
+            only_show=args.show,
+        )
+        if qlever_is_running_in_container or args.show:
             return False
 
         # Stop running containers.
         for container_system in Containerize.supported_systems():
-            Containerize.stop_and_remove_container(
-                    container_system, args.ui_container)
+            Containerize.stop_and_remove_container(container_system, args.ui_container)
 
         # Check if the UI port is already being used.
         if is_port_used(args.ui_port):
-            log.warning(f"It looks like the specified port for the UI ({args.ui_port}) is already in use. You can set another port in the Qleverfile in the [ui] section with the UI_PORT variable.")
+            log.warning(
+                f"It looks like the specified port for the UI ({args.ui_port}) is already in use. You can set another port in the Qleverfile in the [ui] section with the UI_PORT variable."
+            )
 
         # Try to start the QLever UI.
         try:
@@ -68,7 +93,9 @@ def execute(self, args) -> bool:
             return False
 
         # Success.
-        log.info(f"The QLever UI should now be up at {ui_url} ..."
-                 f"You can log in as QLever UI admin with username and "
-                 f"password \"demo\"")
+        log.info(
+            f"The QLever UI should now be up at {ui_url} ..."
+            f"You can log in as QLever UI admin with username and "
+            f'password "demo"'
+        )
         return True