Fix container overriding output-dir/outputs (#486)

## Summary

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Include a short paragraph of the changes introduced in this PR.
If this PR requires additional context or rationale, explain why
the changes are necessary.
-->
Ensure we are setting `GUIDELLM_OUTPUT_DIR` rather than
`GUIDELLM_OUTPUT_PATH` in the container to allow `--output-dir` and
`--outputs` to function. Additionally add a warning when environment
variable are set.

## Details

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Provide a detailed list of all changes introduced in this pull request.
-->
The container image sets `GUIDELLM_OUTPUT_PATH=/results`. Due to the way
output-path interacts with the new output-dir and outputs options,
output-path overrules their settings.

## Test Plan

<!--
List the steps needed to test this PR.
-->
- Run container with `--output-dir /test/path --outputs
test.json,test.csv`

## Related Issues

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Link any relevant issues that this PR addresses.
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- Resolves #

---

- [x] "I certify that all code in this PR is my own, except as noted
below."

## Use of AI

- [ ] Includes AI-assisted code completion
- [ ] Includes code generated by an AI application
- [ ] Includes AI-generated tests (NOTE: AI written tests should have a
docstring that includes `## WRITTEN BY AI ##`)

Author: sjmonson

Containerfile

@@ -1,4 +1,3 @@
-# TODO: Update to official python-3.13-minimal image when available
 ARG BASE_IMAGE=quay.io/fedora/python-313-minimal:latest
 
 # Use a multi-stage build to create a lightweight production image
@@ -51,7 +50,7 @@ USER 1001:0
 # Add guidellm bin to PATH
 # Argument defaults can be set with GUIDELLM_<ARG>
 ENV HOME="/home/guidellm" \
-    GUIDELLM_OUTPUT_PATH="/results/benchmarks.json"
+    GUIDELLM_OUTPUT_DIR="/results"
 
 # Create the user home dir
 WORKDIR $HOME

src/guidellm/__main__.py

@@ -402,6 +402,8 @@ def run(**kwargs):
 
     # Handle output path remapping
     if (output_path := kwargs.pop("output_path", None)) is not None:
+        if kwargs.get("outputs_dir", None) is not None:
+            raise click.BadParameter("Cannot use --output-path with --output-dir.")
         path = Path(output_path)
         if path.is_dir():
             kwargs["output_dir"] = path
@@ -414,6 +416,17 @@ def run(**kwargs):
     disable_console_interactive = (
         kwargs.pop("disable_console_interactive", False) or disable_console
     )
+    console = Console() if not disable_console else None
+    envs = cli_tools.list_set_env()
+    if console and envs:
+        console.print_update(
+            title=(
+                "Note: the following environment variables "
+                "are set and **may** affect configuration"
+            ),
+            details=", ".join(envs),
+            status="warning",
+        )
 
     try:
         args = BenchmarkGenerativeTextArgs.create(
@@ -437,7 +450,7 @@ def run(**kwargs):
                 if not disable_console_interactive
                 else None
             ),
-            console=Console() if not disable_console else None,
+            console=console,
         )
     )
 
@@ -523,8 +536,8 @@ def preprocess():
         "PreprocessDatasetConfig as JSON string, key=value pairs, "
         "or file path (.json, .yaml, .yml, .config). "
         "Example: 'prompt_tokens=100,output_tokens=50,prefix_tokens_max=10'"
-        " or '{\"prompt_tokens\": 100, \"output_tokens\": 50, "
-        "\"prefix_tokens_max\": 10}'"
+        ' or \'{"prompt_tokens": 100, "output_tokens": 50, '
+        '"prefix_tokens_max": 10}\''
     ),
 )
 @click.option(

src/guidellm/utils/cli.py

@@ -1,19 +1,31 @@
 import contextlib
 import json
+import os
 from typing import Any
 
 import click
 
 __all__ = [
     "Union",
     "format_list_arg",
+    "list_set_env",
     "parse_json",
     "parse_list",
     "parse_list_floats",
     "set_if_not_default",
 ]
 
 
+def list_set_env(prefix: str = "GUIDELLM_") -> list[str]:
+    """
+    List all set environment variables prefixed with the given prefix.
+
+    :param prefix: The prefix to filter environment variables.
+    :return: List of environment variable names that are set with the given prefix.
+    """
+    return [key for key in os.environ if key.startswith(prefix)]
+
+
 def parse_list(ctx, param, value) -> list[str] | None:
     """
     Click callback to parse the input value into a list of strings.