From a359bc25b95f77bf142b77d68ae3b4aa5c0eee42 Mon Sep 17 00:00:00 2001
From: tanmay-9 <tanmaygarg9879@gmail.com>
Date: Thu, 26 Mar 2026 18:33:09 +0100
Subject: [PATCH 1/7] Add an option to disable selinux to make qlever commands
 work on fedora

---
 src/qlever/commands/add_text_index.py         | 10 +++++--
 src/qlever/commands/index.py                  |  8 +++++-
 src/qlever/commands/start.py                  |  4 ++-
 src/qlever/commands/system_info.py            |  9 +++++-
 src/qlever/containerize.py                    | 28 +++++++++++++++++++
 src/qlever/qleverfile.py                      | 10 +++++++
 src/qlever/util.py                            |  2 ++
 .../commands/test_index_other_methods.py      |  7 ++++-
 test/qlever/commands/test_start_execute.py    |  1 +
 .../commands/test_start_other_methods.py      |  7 ++++-
 10 files changed, 79 insertions(+), 7 deletions(-)

diff --git a/src/qlever/commands/add_text_index.py b/src/qlever/commands/add_text_index.py
index df250287..bcac8712 100644
--- a/src/qlever/commands/add_text_index.py
+++ b/src/qlever/commands/add_text_index.py
@@ -31,7 +31,12 @@ def relevant_qleverfile_arguments(self) -> dict[str, list[str]]:
                 "text_words_file",
                 "text_docs_file",
             ],
-            "runtime": ["system", "image", "index_container"],
+            "runtime": [
+                "system",
+                "image",
+                "index_container",
+                "disable_selinux",
+            ],
         }
 
     def additional_arguments(self, subparser) -> None:
@@ -54,7 +59,7 @@ def execute(self, args) -> bool:
             "from_text_records_and_literals",
         ]:
             add_text_index_cmd += (
-                f" -w {args.text_words_file}" f" -d {args.text_docs_file}"
+                f" -w {args.text_words_file} -d {args.text_docs_file}"
             )
         if args.text_index in [
             "from_literals",
@@ -73,6 +78,7 @@ def execute(self, args) -> bool:
                 args.index_container,
                 volumes=[("$(pwd)", "/index")],
                 working_directory="/index",
+                disable_selinux=args.disable_selinux == "yes",
             )
 
         # Show the command line.
diff --git a/src/qlever/commands/index.py b/src/qlever/commands/index.py
index b18bb02d..efe43db9 100644
--- a/src/qlever/commands/index.py
+++ b/src/qlever/commands/index.py
@@ -51,7 +51,12 @@ def relevant_qleverfile_arguments(self) -> dict[str, list[str]]:
                 "stxxl_memory",
                 "parser_buffer_size",
             ],
-            "runtime": ["system", "image", "index_container"],
+            "runtime": [
+                "system",
+                "image",
+                "index_container",
+                "disable_selinux",
+            ],
         }
 
     def additional_arguments(self, subparser) -> None:
@@ -265,6 +270,7 @@ def execute(self, args) -> bool:
                 args.index_container,
                 volumes=[("$(pwd)", "/index")],
                 working_directory="/index",
+                disable_selinux=args.disable_selinux == "yes",
             )
 
         # Command for writing the settings JSON to a file.
diff --git a/src/qlever/commands/start.py b/src/qlever/commands/start.py
index f55abe6d..a7e6225a 100644
--- a/src/qlever/commands/start.py
+++ b/src/qlever/commands/start.py
@@ -69,6 +69,7 @@ def wrap_command_in_container(args, start_cmd) -> str:
         volumes=[("$(pwd)", "/index")],
         ports=[(args.port, args.port)],
         working_directory="/index",
+        disable_selinux=args.disable_selinux == "yes",
     )
     return start_cmd
 
@@ -142,7 +143,8 @@ def relevant_qleverfile_arguments(self) -> dict[str, list[str]]:
                 "use_text_index",
                 "warmup_cmd",
             ],
-            "runtime": ["system", "image", "server_container"],
+            "runtime": ["system", "image", "server_container",
+                        "disable_selinux"],
         }
 
     def additional_arguments(self, subparser) -> None:
diff --git a/src/qlever/commands/system_info.py b/src/qlever/commands/system_info.py
index e8b71a2b..c48e4dd1 100644
--- a/src/qlever/commands/system_info.py
+++ b/src/qlever/commands/system_info.py
@@ -49,7 +49,14 @@ def should_have_qleverfile(self) -> bool:
         return True
 
     def relevant_qleverfile_arguments(self) -> dict[str, list[str]]:
-        return {"runtime": ["system", "image", "server_container"]}
+        return {
+            "runtime": [
+                "system",
+                "image",
+                "server_container",
+                "disable_selinux",
+            ]
+        }
 
     def additional_arguments(self, subparser) -> None:
         pass
diff --git a/src/qlever/containerize.py b/src/qlever/containerize.py
index 11150ba7..760a9070 100644
--- a/src/qlever/containerize.py
+++ b/src/qlever/containerize.py
@@ -12,6 +12,15 @@
 from qlever.util import get_random_string, run_command
 
 
+def _selinux_enforcing() -> bool:
+    """Check if SELinux is in enforcing mode by reading the kernel interface."""
+    try:
+        with open("/sys/fs/selinux/enforce") as f:
+            return f.read().strip() == "1"
+    except (FileNotFoundError, PermissionError):
+        return False
+
+
 class ContainerizeException(Exception):
     pass
 
@@ -41,6 +50,7 @@ def containerize_command(
         ports: list[tuple[int, int]] = [],
         working_directory: Optional[str] = None,
         use_bash: bool = True,
+        disable_selinux: bool = False,
     ) -> str:
         """
         Get the command to run `cmd` with the given `container_system` and the
@@ -54,6 +64,15 @@ def containerize_command(
                 f" (must be one of {Containerize.supported_systems()})"
             )
 
+        # Warn if SELinux is enforcing but not disabled for the container.
+        if _selinux_enforcing() and not disable_selinux:
+            log.warning(
+                "SELinux is enforcing, which may cause permission "
+                "errors with bind-mounted files. If you experience "
+                "issues, set DISABLE_SELINUX = yes in your "
+                "Qleverfile or use --disable-selinux yes"
+            )
+
         # Set user and group ids. This is important so that the files created
         # by the containerized command are owned by the user running the
         # command.
@@ -77,11 +96,18 @@ def containerize_command(
             f" -w {working_directory}" if working_directory is not None else ""
         )
 
+        # If SELinux is disabled for the container, add the security option
+        # so that the container can access bind-mounted host files.
+        selinux_option = (
+            " --security-opt label=disable" if disable_selinux else ""
+        )
+
         # Construct the command that runs `cmd` with the given container
         # system.
         containerized_cmd = (
             f"{container_system} {run_subcommand}"
             f"{user_option}"
+            f"{selinux_option}"
             f" -v /etc/localtime:/etc/localtime:ro"
             f"{volume_options}"
             f"{port_options}"
@@ -155,6 +181,7 @@ def run_in_container(cmd: str, args) -> Optional[str]:
         if args.system in Containerize.supported_systems():
             if not args.server_container:
                 args.server_container = get_random_string(20)
+            disable_selinux = getattr(args, "disable_selinux", "no") == "yes"
             run_cmd = Containerize().containerize_command(
                 cmd,
                 args.system,
@@ -163,5 +190,6 @@ def run_in_container(cmd: str, args) -> Optional[str]:
                 args.server_container,
                 volumes=[("$(pwd)", "/index")],
                 working_directory="/index",
+                disable_selinux=disable_selinux,
             )
             return run_command(run_cmd, return_output=True)
diff --git a/src/qlever/qleverfile.py b/src/qlever/qleverfile.py
index 83ed8794..a6412e18 100644
--- a/src/qlever/qleverfile.py
+++ b/src/qlever/qleverfile.py
@@ -380,6 +380,16 @@ def arg(*args, **kwargs):
             type=str,
             help=f"The name of the container used by `{script_name} start`",
         )
+        runtime_args["disable_selinux"] = arg(
+            "--disable-selinux",
+            choices=["yes", "no"],
+            default="no",
+            help=(
+                "Disable SELinux confinement for the container, "
+                "use this if you get permission errors on "
+                "bind-mounted files (e.g. on Fedora or RHEL)"
+            ),
+        )
 
         ui_args["ui_port"] = arg(
             "--ui-port",
diff --git a/src/qlever/util.py b/src/qlever/util.py
index 60006e40..820e6d8b 100644
--- a/src/qlever/util.py
+++ b/src/qlever/util.py
@@ -323,6 +323,7 @@ def binary_exists(binary: str, cmd_arg: str, args) -> bool:
 
     is_containerized = args.system in Containerize.supported_systems()
     cmd = f"{binary} --help"
+    disable_selinux = getattr(args, "disable_selinux", "no") == "yes"
     if is_containerized:
         cmd = Containerize().containerize_command(
             cmd,
@@ -332,6 +333,7 @@ def binary_exists(binary: str, cmd_arg: str, args) -> bool:
             "qlever.check-binary",
             volumes=[("$(pwd)", "/index")],
             working_directory="/index",
+            disable_selinux=disable_selinux,
         )
 
     try:
diff --git a/test/qlever/commands/test_index_other_methods.py b/test/qlever/commands/test_index_other_methods.py
index 2a808ad4..e0d27ec4 100644
--- a/test/qlever/commands/test_index_other_methods.py
+++ b/test/qlever/commands/test_index_other_methods.py
@@ -48,7 +48,12 @@ def test_relevant_qleverfile_arguments(self):
                     "stxxl_memory",
                     "parser_buffer_size",
                 ],
-                "runtime": ["system", "image", "index_container"],
+                "runtime": [
+                    "system",
+                    "image",
+                    "index_container",
+                    "disable_selinux",
+                ],
             },
         )
 
diff --git a/test/qlever/commands/test_start_execute.py b/test/qlever/commands/test_start_execute.py
index c5e23505..197a5638 100644
--- a/test/qlever/commands/test_start_execute.py
+++ b/test/qlever/commands/test_start_execute.py
@@ -112,6 +112,7 @@ def test_wrap_command_in_container(mock_containerize_command):
         volumes=[("$(pwd)", "/index")],
         ports=[(args.port, args.port)],
         working_directory="/index",
+        disable_selinux=args.disable_selinux == "yes",
     )
     # check start command was successfully returned
     start_command = "Test_Container_Command"
diff --git a/test/qlever/commands/test_start_other_methods.py b/test/qlever/commands/test_start_other_methods.py
index 2848dbb3..f08d8d1d 100644
--- a/test/qlever/commands/test_start_other_methods.py
+++ b/test/qlever/commands/test_start_other_methods.py
@@ -44,7 +44,12 @@ def test_relevant_qleverfile_arguments(self):
                     "use_text_index",
                     "warmup_cmd",
                 ],
-                "runtime": ["system", "image", "server_container"],
+                "runtime": [
+                    "system",
+                    "image",
+                    "server_container",
+                    "disable_selinux",
+                ],
             },
         )
 

From 5e17d47e6089216dc1de13cc160b8bfd1de66bc0 Mon Sep 17 00:00:00 2001
From: tanmay-9 <tanmaygarg9879@gmail.com>
Date: Thu, 2 Apr 2026 16:36:04 +0200
Subject: [PATCH 2/7] Add qlever index MemoryMonitor

---
 src/qlever/commands/index.py |  10 ++-
 src/qlever/memory_monitor.py | 164 +++++++++++++++++++++++++++++++++++
 2 files changed, 173 insertions(+), 1 deletion(-)
 create mode 100644 src/qlever/memory_monitor.py

diff --git a/src/qlever/commands/index.py b/src/qlever/commands/index.py
index c01b2420..19f1ab04 100644
--- a/src/qlever/commands/index.py
+++ b/src/qlever/commands/index.py
@@ -8,6 +8,7 @@
 from qlever.command import QleverCommand
 from qlever.containerize import Containerize
 from qlever.log import log
+from qlever.memory_monitor import MemoryMonitor
 from qlever.util import (
     binary_exists,
     get_existing_index_files,
@@ -328,7 +329,14 @@ def execute(self, args) -> bool:
 
         # Run the index command.
         try:
-            run_command(index_cmd, show_output=True)
+            with MemoryMonitor(
+                engine="qlever",
+                dataset=args.name,
+                cmdline_regex=args.index_binary,
+                container=args.index_container,
+                system=args.system,
+            ):
+                run_command(index_cmd, show_output=True)
         except Exception as e:
             log.error(f"Building the index failed: {e}")
             return False
diff --git a/src/qlever/memory_monitor.py b/src/qlever/memory_monitor.py
new file mode 100644
index 00000000..d7709a7c
--- /dev/null
+++ b/src/qlever/memory_monitor.py
@@ -0,0 +1,164 @@
+from __future__ import annotations
+
+import json
+import re
+import threading
+import time
+from datetime import datetime
+from pathlib import Path
+
+import psutil
+
+from qlever.containerize import Containerize
+from qlever.log import log
+from qlever.util import format_size, run_command
+
+
+def parse_container_mem_usage(usage: str) -> int:
+    """
+    Parse a memory usage string from `docker stats` / `podman stats`
+    like "4.2GiB", "150MiB", "512KiB" into bytes.
+    """
+    usage = usage.strip()
+    units = {
+        "TIB": 1024**4,
+        "GIB": 1024**3,
+        "MIB": 1024**2,
+        "KIB": 1024,
+        "B": 1,
+    }
+    for suffix, multiplier in units.items():
+        if usage.upper().endswith(suffix):
+            number = float(usage[: len(usage) - len(suffix)])
+            return int(number * multiplier)
+    return 0
+
+
+class MemoryMonitor:
+    """
+    Monitor memory usage of an index-building process. Works in both
+    native mode (via psutil) and container mode (via docker/podman stats).
+
+    Usage as a context manager:
+
+        with MemoryMonitor(engine="qlever", dataset="wikidata",
+                           cmdline_regex=r"qlever-index"):
+            run_command(cmd, show_output=True)
+
+        # For container mode:
+        with MemoryMonitor(engine="qlever", dataset="wikidata",
+                           cmdline_regex=r"qlever-index",
+                           container="qlever.index.wikidata",
+                           system="docker"):
+            run_command(cmd, show_output=True)
+    """
+
+    def __init__(
+        self,
+        engine: str,
+        dataset: str,
+        cmdline_regex: str,
+        container: str | None = None,
+        system: str | None = None,
+        interval: float = 1.0,
+        output_dir: Path = Path.cwd(),
+    ):
+        self.engine = engine
+        self.dataset = dataset
+        self.cmdline_regex = cmdline_regex
+        self.container = container
+        self.system = system
+        self.interval = interval
+        self.output_dir = Path(output_dir)
+        self.peak_rss = 0
+        self.samples: list[tuple[float, int]] = []
+        self.stop_event = threading.Event()
+        self.thread: threading.Thread | None = None
+        self.start_time: float = 0
+
+    def sample_native(self) -> int:
+        """
+        Find the index process among our children by matching its
+        command line, then sum RSS of that process and all its
+        descendants.
+        """
+        me = psutil.Process()
+        for child in me.children(recursive=True):
+            try:
+                cmdline = " ".join(child.cmdline())
+            except (psutil.NoSuchProcess, psutil.AccessDenied):
+                continue
+            if re.search(self.cmdline_regex, cmdline):
+                rss = child.memory_info().rss
+                for grandchild in child.children(recursive=True):
+                    try:
+                        rss += grandchild.memory_info().rss
+                    except (psutil.NoSuchProcess, psutil.AccessDenied):
+                        pass
+                return rss
+        return 0
+
+    def sample_container(self) -> int:
+        """
+        Query the container runtime for the memory usage of the
+        index container.
+        """
+        try:
+            output = run_command(
+                f"{self.system} stats --no-stream"
+                f" --format '{{{{.MemUsage}}}}' {self.container}",
+                return_output=True,
+            )
+            usage = output.strip().split("/")[0].strip()
+            return parse_container_mem_usage(usage)
+        except Exception:
+            return 0
+
+    def run_loop(self):
+        sample = (
+            self.sample_container
+            if self.system in Containerize.supported_systems()
+            else self.sample_native
+        )
+        while not self.stop_event.is_set():
+            rss = sample()
+            self.peak_rss = max(self.peak_rss, rss)
+            elapsed = time.monotonic() - self.start_time
+            self.samples.append((elapsed, rss))
+            self.stop_event.wait(self.interval)
+
+    def save(self):
+        path = (
+            self.output_dir / f"{self.engine}.{self.dataset}.memory-log.json"
+        )
+        data = {
+            "engine": self.engine,
+            "dataset": self.dataset,
+            "start_time": datetime.fromtimestamp(
+                time.time() - (time.monotonic() - self.start_time)
+            ).isoformat(timespec="seconds"),
+            "peak_rss_bytes": self.peak_rss,
+            "peak_rss_human": format_size(self.peak_rss),
+            "elapsed_s": (
+                round(self.samples[-1][0], 1) if self.samples else 0
+            ),
+            "samples": [
+                {"elapsed_s": round(t, 1), "rss_bytes": r}
+                for t, r in self.samples
+            ],
+        }
+        with open(path, "w") as f:
+            json.dump(data, f, indent=2)
+
+    def __enter__(self):
+        self.start_time = time.monotonic()
+        self.thread = threading.Thread(target=self.run_loop, daemon=True)
+        self.thread.start()
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.stop_event.set()
+        self.thread.join()
+        self.save()
+        log.info(f"Peak memory usage: {format_size(self.peak_rss)}")
+        return False

From c8d913953739e9c93f1e3cf8b352e17bda4a4f03 Mon Sep 17 00:00:00 2001
From: tanmay-9 <tanmaygarg9879@gmail.com>
Date: Thu, 2 Apr 2026 16:36:28 +0200
Subject: [PATCH 3/7] Change default host to use 127.0.0.1 ipv4 address

---
 src/qlever/commands/start.py | 13 ++++++-------
 src/qlever/qleverfile.py     | 16 ++++++----------
 2 files changed, 12 insertions(+), 17 deletions(-)

diff --git a/src/qlever/commands/start.py b/src/qlever/commands/start.py
index ea21960b..2bfb2132 100644
--- a/src/qlever/commands/start.py
+++ b/src/qlever/commands/start.py
@@ -1,6 +1,5 @@
 from __future__ import annotations
 
-import subprocess
 import time
 from pathlib import Path
 
@@ -84,9 +83,9 @@ def wrap_command_in_container(args, start_cmd) -> str:
 
 
 # Set the index description.
-def set_index_description(access_arg, port, desc) -> bool:
+def set_index_description(access_arg, endpoint_url, desc) -> bool:
     curl_cmd = (
-        f"curl -Gs http://localhost:{port}/api"
+        f"curl -Gs {endpoint_url}/api"
         f' --data-urlencode "index-description={desc}"'
         f" {access_arg} > /dev/null"
     )
@@ -100,9 +99,9 @@ def set_index_description(access_arg, port, desc) -> bool:
 
 
 # Set the text description.
-def set_text_description(access_arg, port, text_desc) -> bool:
+def set_text_description(access_arg, endpoint_url, text_desc) -> bool:
     curl_cmd = (
-        f"curl -Gs http://localhost:{port}/api"
+        f"curl -Gs {endpoint_url}/api"
         f' --data-urlencode "text-description={text_desc}"'
         f" {access_arg} > /dev/null"
     )
@@ -306,13 +305,13 @@ def execute(self, args) -> bool:
         access_arg = f'--data-urlencode "access-token={args.access_token}"'
         if args.description:
             ret = set_index_description(
-                access_arg, args.port, args.description
+                access_arg, args.endpoint_url, args.description
             )
             if not ret:
                 return False
         if args.text_description:
             ret = set_text_description(
-                access_arg, args.port, args.text_description
+                access_arg, args.endpoint_url, args.text_description
             )
             if not ret:
                 return False
diff --git a/src/qlever/qleverfile.py b/src/qlever/qleverfile.py
index 70363e67..0d1820c5 100644
--- a/src/qlever/qleverfile.py
+++ b/src/qlever/qleverfile.py
@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import re
-import socket
 import subprocess
 from configparser import ConfigParser, ExtendedInterpolation, RawConfigParser
 from importlib import import_module
@@ -512,15 +511,12 @@ def read(qleverfile_path):
         if index.get("use_patterns", None) == "no":
             server["use_patterns"] = "no"
 
-        # Add other non-trivial default values.
-        try:
-            if config["server"].get("host_name") is None:
-                config["server"]["host_name"] = socket.gethostname()
-        except Exception:
-            log.warning(
-                "Could not get the hostname, using `localhost` as default"
-            )
-            pass
+        # Add other non-trivial default values. We use 127.0.0.1 as the
+        # default host name because it avoids IPv6 resolution issues with
+        # container port forwarding (podman/docker rootless only forward on
+        # IPv4). Users who need remote access should set HOST_NAME explicitly.
+        if config["server"].get("host_name") is None:
+            config["server"]["host_name"] = "127.0.0.1"
 
         # Return the parsed Qleverfile with the added inherited values.
         return config

From e0607fd614e300a8bce0a3348800ccd3b894ffd8 Mon Sep 17 00:00:00 2001
From: tanmay-9 <tanmaygarg9879@gmail.com>
Date: Tue, 7 Apr 2026 16:16:05 +0200
Subject: [PATCH 4/7] Revert "Add qlever index MemoryMonitor"

This reverts commit 5e17d47e6089216dc1de13cc160b8bfd1de66bc0.
---
 src/qlever/commands/index.py |  10 +--
 src/qlever/memory_monitor.py | 164 -----------------------------------
 2 files changed, 1 insertion(+), 173 deletions(-)
 delete mode 100644 src/qlever/memory_monitor.py

diff --git a/src/qlever/commands/index.py b/src/qlever/commands/index.py
index 19f1ab04..c01b2420 100644
--- a/src/qlever/commands/index.py
+++ b/src/qlever/commands/index.py
@@ -8,7 +8,6 @@
 from qlever.command import QleverCommand
 from qlever.containerize import Containerize
 from qlever.log import log
-from qlever.memory_monitor import MemoryMonitor
 from qlever.util import (
     binary_exists,
     get_existing_index_files,
@@ -329,14 +328,7 @@ def execute(self, args) -> bool:
 
         # Run the index command.
         try:
-            with MemoryMonitor(
-                engine="qlever",
-                dataset=args.name,
-                cmdline_regex=args.index_binary,
-                container=args.index_container,
-                system=args.system,
-            ):
-                run_command(index_cmd, show_output=True)
+            run_command(index_cmd, show_output=True)
         except Exception as e:
             log.error(f"Building the index failed: {e}")
             return False
diff --git a/src/qlever/memory_monitor.py b/src/qlever/memory_monitor.py
deleted file mode 100644
index d7709a7c..00000000
--- a/src/qlever/memory_monitor.py
+++ /dev/null
@@ -1,164 +0,0 @@
-from __future__ import annotations
-
-import json
-import re
-import threading
-import time
-from datetime import datetime
-from pathlib import Path
-
-import psutil
-
-from qlever.containerize import Containerize
-from qlever.log import log
-from qlever.util import format_size, run_command
-
-
-def parse_container_mem_usage(usage: str) -> int:
-    """
-    Parse a memory usage string from `docker stats` / `podman stats`
-    like "4.2GiB", "150MiB", "512KiB" into bytes.
-    """
-    usage = usage.strip()
-    units = {
-        "TIB": 1024**4,
-        "GIB": 1024**3,
-        "MIB": 1024**2,
-        "KIB": 1024,
-        "B": 1,
-    }
-    for suffix, multiplier in units.items():
-        if usage.upper().endswith(suffix):
-            number = float(usage[: len(usage) - len(suffix)])
-            return int(number * multiplier)
-    return 0
-
-
-class MemoryMonitor:
-    """
-    Monitor memory usage of an index-building process. Works in both
-    native mode (via psutil) and container mode (via docker/podman stats).
-
-    Usage as a context manager:
-
-        with MemoryMonitor(engine="qlever", dataset="wikidata",
-                           cmdline_regex=r"qlever-index"):
-            run_command(cmd, show_output=True)
-
-        # For container mode:
-        with MemoryMonitor(engine="qlever", dataset="wikidata",
-                           cmdline_regex=r"qlever-index",
-                           container="qlever.index.wikidata",
-                           system="docker"):
-            run_command(cmd, show_output=True)
-    """
-
-    def __init__(
-        self,
-        engine: str,
-        dataset: str,
-        cmdline_regex: str,
-        container: str | None = None,
-        system: str | None = None,
-        interval: float = 1.0,
-        output_dir: Path = Path.cwd(),
-    ):
-        self.engine = engine
-        self.dataset = dataset
-        self.cmdline_regex = cmdline_regex
-        self.container = container
-        self.system = system
-        self.interval = interval
-        self.output_dir = Path(output_dir)
-        self.peak_rss = 0
-        self.samples: list[tuple[float, int]] = []
-        self.stop_event = threading.Event()
-        self.thread: threading.Thread | None = None
-        self.start_time: float = 0
-
-    def sample_native(self) -> int:
-        """
-        Find the index process among our children by matching its
-        command line, then sum RSS of that process and all its
-        descendants.
-        """
-        me = psutil.Process()
-        for child in me.children(recursive=True):
-            try:
-                cmdline = " ".join(child.cmdline())
-            except (psutil.NoSuchProcess, psutil.AccessDenied):
-                continue
-            if re.search(self.cmdline_regex, cmdline):
-                rss = child.memory_info().rss
-                for grandchild in child.children(recursive=True):
-                    try:
-                        rss += grandchild.memory_info().rss
-                    except (psutil.NoSuchProcess, psutil.AccessDenied):
-                        pass
-                return rss
-        return 0
-
-    def sample_container(self) -> int:
-        """
-        Query the container runtime for the memory usage of the
-        index container.
-        """
-        try:
-            output = run_command(
-                f"{self.system} stats --no-stream"
-                f" --format '{{{{.MemUsage}}}}' {self.container}",
-                return_output=True,
-            )
-            usage = output.strip().split("/")[0].strip()
-            return parse_container_mem_usage(usage)
-        except Exception:
-            return 0
-
-    def run_loop(self):
-        sample = (
-            self.sample_container
-            if self.system in Containerize.supported_systems()
-            else self.sample_native
-        )
-        while not self.stop_event.is_set():
-            rss = sample()
-            self.peak_rss = max(self.peak_rss, rss)
-            elapsed = time.monotonic() - self.start_time
-            self.samples.append((elapsed, rss))
-            self.stop_event.wait(self.interval)
-
-    def save(self):
-        path = (
-            self.output_dir / f"{self.engine}.{self.dataset}.memory-log.json"
-        )
-        data = {
-            "engine": self.engine,
-            "dataset": self.dataset,
-            "start_time": datetime.fromtimestamp(
-                time.time() - (time.monotonic() - self.start_time)
-            ).isoformat(timespec="seconds"),
-            "peak_rss_bytes": self.peak_rss,
-            "peak_rss_human": format_size(self.peak_rss),
-            "elapsed_s": (
-                round(self.samples[-1][0], 1) if self.samples else 0
-            ),
-            "samples": [
-                {"elapsed_s": round(t, 1), "rss_bytes": r}
-                for t, r in self.samples
-            ],
-        }
-        with open(path, "w") as f:
-            json.dump(data, f, indent=2)
-
-    def __enter__(self):
-        self.start_time = time.monotonic()
-        self.thread = threading.Thread(target=self.run_loop, daemon=True)
-        self.thread.start()
-        return self
-
-    def __exit__(self, exc_type, exc_val, exc_tb):
-        self.stop_event.set()
-        self.thread.join()
-        self.save()
-        log.info(f"Peak memory usage: {format_size(self.peak_rss)}")
-        return False

From 163af87a3f9fd5a1d7fe864072146bb3d0d6da3b Mon Sep 17 00:00:00 2001
From: tanmay-9 <tanmaygarg9879@gmail.com>
Date: Tue, 7 Apr 2026 17:29:45 +0200
Subject: [PATCH 5/7] Add a warning if the hostname on user's system resolves
 to IPV6 first in containerized mode

---
 src/qlever/config.py     | 23 +++++++++++++++++++++++
 src/qlever/qleverfile.py | 16 ++++++++++------
 2 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/src/qlever/config.py b/src/qlever/config.py
index f877512a..ead7e28a 100644
--- a/src/qlever/config.py
+++ b/src/qlever/config.py
@@ -2,6 +2,7 @@
 
 import argparse
 import os
+import socket
 import traceback
 from importlib.metadata import version
 from pathlib import Path
@@ -10,6 +11,7 @@
 from termcolor import colored
 
 from qlever import command_objects, engine_name, script_name
+from qlever.containerize import Containerize
 from qlever.log import log, log_levels
 from qlever.qleverfile import Qleverfile
 
@@ -226,6 +228,27 @@ def add_qleverfile_option(parser):
                             "arguments on the command line. This is possible, "
                             "but not recommended.")
 
+        # Warn if the host name resolves to IPv6 first and the system is
+        # a container runtime. Container port forwarding (podman/docker in
+        # rootless mode) typically only forwards on IPv4, so curl will
+        # connect via IPv6 and fail.
+        host_name = getattr(args, "host_name", None)
+        system = getattr(args, "system", "native")
+        if host_name and system in Containerize.supported_systems():
+            try:
+                addrinfo = socket.getaddrinfo(host_name, None)
+                if addrinfo and addrinfo[0][0] == socket.AF_INET6:
+                    log.warning(
+                        f"Your system resolves '{host_name}' to an "
+                        "IPv6 address first, which may cause connection "
+                        "failures with containerized servers. If you face "
+                        "connection issues, consider setting HOST_NAME to an "
+                        "IPv4 address in your Qleverfile or using "
+                        "--host-name 127.0.0.1"
+                    )
+            except Exception:
+                pass
+
         # Warn if the old binary names are still being used.
         if "IndexBuilderMain" in getattr(args, "index_binary", ""):
             log.warning("The index binary has been renamed from "
diff --git a/src/qlever/qleverfile.py b/src/qlever/qleverfile.py
index 0d1820c5..b7d0086e 100644
--- a/src/qlever/qleverfile.py
+++ b/src/qlever/qleverfile.py
@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import re
+import socket
 import subprocess
 from configparser import ConfigParser, ExtendedInterpolation, RawConfigParser
 from importlib import import_module
@@ -511,12 +512,15 @@ def read(qleverfile_path):
         if index.get("use_patterns", None) == "no":
             server["use_patterns"] = "no"
 
-        # Add other non-trivial default values. We use 127.0.0.1 as the
-        # default host name because it avoids IPv6 resolution issues with
-        # container port forwarding (podman/docker rootless only forward on
-        # IPv4). Users who need remote access should set HOST_NAME explicitly.
-        if config["server"].get("host_name") is None:
-            config["server"]["host_name"] = "127.0.0.1"
+        # Add other non-trivial default values.
+        try:
+            if config["server"].get("host_name") is None:
+                config["server"]["host_name"] = socket.gethostname()
+        except Exception:
+            log.warning(
+                "Could not get the hostname, using `localhost` as default"
+            )
+            config["server"]["host_name"] = "localhost"
 
         # Return the parsed Qleverfile with the added inherited values.
         return config

From 8ccd3dad16b86f4c07d371f8f2286750f538d19a Mon Sep 17 00:00:00 2001
From: tanmay-9 <tanmaygarg9879@gmail.com>
Date: Tue, 7 Apr 2026 17:36:14 +0200
Subject: [PATCH 6/7] Fix failing tests because of using args.host_name instead
 of hard-code localhost in start.py

---
 test/qlever/commands/test_start_execute.py | 30 ++++++++++++++--------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/test/qlever/commands/test_start_execute.py b/test/qlever/commands/test_start_execute.py
index ee0686d3..c356af4e 100644
--- a/test/qlever/commands/test_start_execute.py
+++ b/test/qlever/commands/test_start_execute.py
@@ -180,17 +180,19 @@ def test_set_index_description_success(mock_log, mock_run_cmd):
     # Setup args
     args = MagicMock()
     args.access_token = True
+    args.host_name = "localhost"
     args.port = 1234
     args.description = "TestDescription"
     access_arg = f'--data-urlencode "access-token={args.access_token}"'
+    endpoint_url = f"http://{args.host_name}:{args.port}"
 
     # Execute the function
     qlever.commands.start.set_index_description(
-        access_arg, args.port, args.description
+        access_arg, endpoint_url, args.description
     )
     # Asserts
     curl_cmd = (
-        f"curl -Gs http://localhost:{args.port}/api"
+        f"curl -Gs {endpoint_url}/api"
         f' --data-urlencode "index-description={args.description}"'
         f" {access_arg} > /dev/null"
     )
@@ -208,21 +210,23 @@ def test_set_index_description_exception(mock_log, mock_run_cmd):
     # Setup args
     args = MagicMock()
     args.access_token = True
+    args.host_name = "localhost"
     args.port = 1234
     args.description = "ErrorDescription"
     access_arg = f'--data-urlencode "access-token={args.access_token}"'
+    endpoint_url = f"http://{args.host_name}:{args.port}"
 
     # Simulate an exception when run_command is called
     mock_run_cmd.side_effect = Exception("Mocked command failure")
 
     # Execute the function
     qlever.commands.start.set_index_description(
-        access_arg, args.port, args.description
+        access_arg, endpoint_url, args.description
     )
 
     # Asserts
     curl_cmd = (
-        f"curl -Gs http://localhost:{args.port}/api"
+        f"curl -Gs {endpoint_url}/api"
         f' --data-urlencode "index-description={args.description}"'
         f" {access_arg} > /dev/null"
     )
@@ -244,17 +248,19 @@ def test_set_text_description_success(mock_log, mock_run_cmd):
     # Setup args
     args = MagicMock()
     args.access_token = True
+    args.host_name = "localhost"
     args.port = 1234
     args.description = "TestDescription"
     access_arg = f'--data-urlencode "access-token={args.access_token}"'
+    endpoint_url = f"http://{args.host_name}:{args.port}"
 
     # Execute the function
     qlever.commands.start.set_text_description(
-        access_arg, args.port, args.description
+        access_arg, endpoint_url, args.description
     )
     # Asserts
     curl_cmd = (
-        f"curl -Gs http://localhost:{args.port}/api"
+        f"curl -Gs {endpoint_url}/api"
         f' --data-urlencode "text-description={args.description}"'
         f" {access_arg} > /dev/null"
     )
@@ -272,21 +278,23 @@ def test_set_text_description_exception(mock_log, mock_run_cmd):
     # Setup args
     args = MagicMock()
     args.access_token = True
+    args.host_name = "localhost"
     args.port = 1234
     args.description = "ErrorDescription"
     access_arg = f'--data-urlencode "access-token={args.access_token}"'
+    endpoint_url = f"http://{args.host_name}:{args.port}"
 
     # Simulate an exception when run_command is called
     mock_run_cmd.side_effect = Exception("Mocked command failure")
 
     # Execute the function
     qlever.commands.start.set_text_description(
-        access_arg, args.port, args.description
+        access_arg, endpoint_url, args.description
     )
 
     # Asserts
     curl_cmd = (
-        f"curl -Gs http://localhost:{args.port}/api"
+        f"curl -Gs {endpoint_url}/api"
         f' --data-urlencode "text-description={args.description}"'
         f" {access_arg} > /dev/null"
     )
@@ -620,6 +628,7 @@ def test_execute_containerize_and_description(
         # Setup args
         args = MagicMock()
         args.kill_existing_with_same_port = True
+        args.host_name = "localhost"
         args.port = 1234
         args.server_binary = "/test/path/server_binary"
         args.name = "TestName"
@@ -672,13 +681,14 @@ def test_execute_containerize_and_description(
         run_call_1 = f"{args.system} rm -f {args.server_container}"
         run_call_2 = "TestStart2"
         access_arg = f'--data-urlencode "access-token={args.access_token}"'
+        endpoint_url = f"http://{args.host_name}:{args.port}"
         run_call_3 = (
-            f"curl -Gs http://localhost:{args.port}/api"
+            f"curl -Gs {endpoint_url}/api"
             f' --data-urlencode "index-description={args.description}"'
             f" {access_arg} > /dev/null"
         )
         run_call_4 = (
-            f"curl -Gs http://localhost:{args.port}/api"
+            f"curl -Gs {endpoint_url}/api"
             f' --data-urlencode "text-description='
             f'{args.text_description}"'
             f" {access_arg} > /dev/null"

From e2f02377d079a6db4309cabbda0236757eea7aa5 Mon Sep 17 00:00:00 2001
From: tanmay-9 <tanmaygarg9879@gmail.com>
Date: Wed, 8 Apr 2026 16:00:17 +0200
Subject: [PATCH 7/7] Add disable_selinux and ipv6 warning to qlever ui as well

---
 src/qlever/commands/ui.py  |  2 ++
 src/qlever/config.py       | 29 +++++++++++++++++++++++++----
 src/qlever/containerize.py | 18 ------------------
 src/qlever/util.py         |  9 +++++++++
 4 files changed, 36 insertions(+), 22 deletions(-)

diff --git a/src/qlever/commands/ui.py b/src/qlever/commands/ui.py
index 5c12e1d1..f6a30b7a 100644
--- a/src/qlever/commands/ui.py
+++ b/src/qlever/commands/ui.py
@@ -56,6 +56,7 @@ def relevant_qleverfile_arguments(self) -> dict[str, list[str]]:
         return {
             "data": ["name"],
             "server": ["host_name", "port"],
+            "runtime": ["disable_selinux"],
             "ui": [
                 "ui_port",
                 "ui_config",
@@ -130,6 +131,7 @@ def execute(self, args) -> bool:
         start_ui_cmd = (
             f"{args.ui_system} run -d "
             f"--volume $(pwd):/app/db "
+            f"{'--security-opt label=disable ' if args.disable_selinux == 'yes' else ''}"
             f"--env QLEVERUI_DATABASE_URL=sqlite:////app/db/{ui_db_file} "
             f"--publish {args.ui_port}:7000 "
             f"--name {args.ui_container} "
diff --git a/src/qlever/config.py b/src/qlever/config.py
index ead7e28a..826d780c 100644
--- a/src/qlever/config.py
+++ b/src/qlever/config.py
@@ -14,6 +14,7 @@
 from qlever.containerize import Containerize
 from qlever.log import log, log_levels
 from qlever.qleverfile import Qleverfile
+from qlever.util import selinux_enforcing
 
 
 # Simple exception class for configuration errors (the class need not do
@@ -233,7 +234,10 @@ def add_qleverfile_option(parser):
         # rootless mode) typically only forwards on IPv4, so curl will
         # connect via IPv6 and fail.
         host_name = getattr(args, "host_name", None)
-        system = getattr(args, "system", "native")
+        system = getattr(args, "ui_system", None) or getattr(
+            args, "system", "native"
+        )
+        ipv6_warning = False
         if host_name and system in Containerize.supported_systems():
             try:
                 addrinfo = socket.getaddrinfo(host_name, None)
@@ -242,13 +246,30 @@ def add_qleverfile_option(parser):
                         f"Your system resolves '{host_name}' to an "
                         "IPv6 address first, which may cause connection "
                         "failures with containerized servers. If you face "
-                        "connection issues, consider setting HOST_NAME to an "
-                        "IPv4 address in your Qleverfile or using "
-                        "--host-name 127.0.0.1"
+                        "connection issues, consider using an explicit "
+                        "IPv4 address like 127.0.0.1 (via HOST_NAME in "
+                        "your Qleverfile or --host-name on the command line)"
                     )
+                    ipv6_warning = True
             except Exception:
                 pass
 
+        # Warn if SELinux is enforcing but not disabled for the container.
+        disable_selinux = getattr(args, "disable_selinux", None)
+        if (
+            system in Containerize.supported_systems()
+            and disable_selinux == "no"
+            and selinux_enforcing()
+        ):
+            if ipv6_warning:
+                log.info("")
+            log.warning(
+                "SELinux is enforcing, which may cause permission "
+                "errors with bind-mounted files. If you experience "
+                "issues, set DISABLE_SELINUX = yes in your "
+                "Qleverfile or use --disable-selinux yes"
+            )
+
         # Warn if the old binary names are still being used.
         if "IndexBuilderMain" in getattr(args, "index_binary", ""):
             log.warning("The index binary has been renamed from "
diff --git a/src/qlever/containerize.py b/src/qlever/containerize.py
index 760a9070..82b350f0 100644
--- a/src/qlever/containerize.py
+++ b/src/qlever/containerize.py
@@ -12,15 +12,6 @@
 from qlever.util import get_random_string, run_command
 
 
-def _selinux_enforcing() -> bool:
-    """Check if SELinux is in enforcing mode by reading the kernel interface."""
-    try:
-        with open("/sys/fs/selinux/enforce") as f:
-            return f.read().strip() == "1"
-    except (FileNotFoundError, PermissionError):
-        return False
-
-
 class ContainerizeException(Exception):
     pass
 
@@ -64,15 +55,6 @@ def containerize_command(
                 f" (must be one of {Containerize.supported_systems()})"
             )
 
-        # Warn if SELinux is enforcing but not disabled for the container.
-        if _selinux_enforcing() and not disable_selinux:
-            log.warning(
-                "SELinux is enforcing, which may cause permission "
-                "errors with bind-mounted files. If you experience "
-                "issues, set DISABLE_SELINUX = yes in your "
-                "Qleverfile or use --disable-selinux yes"
-            )
-
         # Set user and group ids. This is important so that the files created
         # by the containerized command are owned by the user running the
         # command.
diff --git a/src/qlever/util.py b/src/qlever/util.py
index f346ea95..2b29ff03 100644
--- a/src/qlever/util.py
+++ b/src/qlever/util.py
@@ -402,6 +402,15 @@ def input_files_exist(input_files: str) -> bool:
     return True
 
 
+def selinux_enforcing() -> bool:
+    """Check if SELinux is in enforcing mode by reading the kernel interface."""
+    try:
+        with open("/sys/fs/selinux/enforce") as f:
+            return f.read().strip() == "1"
+    except (FileNotFoundError, PermissionError):
+        return False
+
+
 def build_image(build_cmd: str, system: str, image: str) -> bool:
     """
     Build a container image using the build command, container system and