Adding API key support

Summary:

Test Plan:

Config client:
```
llama-stack-client configure --endpoint=https://api.hostname.com --api-key='_API_KEY_'

Done! You can now use the Llama Stack Client CLI with endpoint https://api.hostname.com
```

Try listing the models
```
llama-stack-client models list

┏━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━┳━━━━━━━━━━━━┓
┃ identifier            ┃ provider_id ┃ provider_resource_id  ┃ metadata ┃ model_type ┃
┡━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━╇━━━━━━━━━━━━┩
│ llama3.1-8b-instruct  │ meta-llama  │ llama3.1-8b-instruct  │ {}       │ llm        │
│ llama3.3-70b-instruct │ meta-llama  │ llama3.3-70b-instruct │ {}       │ llm        │
│ llama3.4-17b-instruct │ meta-llama  │ llama3.4-17b-instruct │ {}       │ llm        │
└───────────────────────┴─────────────┴───────────────────────┴──────────┴────────────┘
```

Author: vladimirivic

src/llama_stack_client/lib/cli/configure.py

@@ -24,42 +24,42 @@ def get_config():
 
 
 @click.command()
-@click.option("--host", type=str, help="Llama Stack distribution host")
-@click.option("--port", type=str, help="Llama Stack distribution port number")
-@click.option("--endpoint", type=str, help="Llama Stack distribution endpoint")
-def configure(host: str | None, port: str | None, endpoint: str | None):
+@click.option("--endpoint", type=str, help="Llama Stack distribution endpoint", default="")
+@click.option("--api-key", type=str, help="Llama Stack distribution API key", default="")
+def configure(endpoint: str | None, api_key: str | None):
     """Configure Llama Stack Client CLI"""
     os.makedirs(LLAMA_STACK_CLIENT_CONFIG_DIR, exist_ok=True)
     config_path = get_config_file_path()
 
-    if endpoint:
+    if endpoint != "":
         final_endpoint = endpoint
     else:
-        if host and port:
-            final_endpoint = f"http://{host}:{port}"
-        else:
-            host = prompt(
-                "> Enter the host name of the Llama Stack distribution server: ",
-                validator=Validator.from_callable(
-                    lambda x: len(x) > 0,
-                    error_message="Host cannot be empty, please enter a valid host",
-                ),
-            )
-            port = prompt(
-                "> Enter the port number of the Llama Stack distribution server: ",
-                validator=Validator.from_callable(
-                    lambda x: x.isdigit(),
-                    error_message="Please enter a valid port number",
-                ),
-            )
-            final_endpoint = f"http://{host}:{port}"
+        final_endpoint = prompt(
+            "> Enter the endpoint of the Llama Stack distribution server: ",
+            validator=Validator.from_callable(
+                lambda x: len(x) > 0,
+                error_message="Endpoint cannot be empty, please enter a valid endpoint",
+            ),
+        )
+
+    if api_key != "":
+        final_api_key = api_key
+    else:
+        final_api_key = prompt(
+            "> Enter the API key (leave empty if no key is needed): ",
+        )
+
+    # Prepare config dict before writing it
+    config_dict = {
+        "endpoint": final_endpoint,
+    }
+    if final_api_key != "":
+        config_dict["api_key"] = final_api_key
 
     with open(config_path, "w") as f:
         f.write(
             yaml.dump(
-                {
-                    "endpoint": final_endpoint,
-                },
+                config_dict,
                 sort_keys=True,
             )
         )

src/llama_stack_client/lib/cli/llama_stack_client.py

@@ -35,9 +35,12 @@
 @click.option(
     "--endpoint", type=str, help="Llama Stack distribution endpoint", default=""
 )
+@click.option(
+    "--api-key", type=str, help="Llama Stack distribution API key", default=""
+)
 @click.option("--config", type=str, help="Path to config file", default=None)
 @click.pass_context
-def cli(ctx, endpoint: str, config: str | None):
+def cli(ctx, endpoint: str, api_key: str, config: str | None):
     """Welcome to the LlamaStackClient CLI"""
     ctx.ensure_object(dict)
 
@@ -55,20 +58,28 @@ def cli(ctx, endpoint: str, config: str | None):
             with open(config, "r") as f:
                 config_dict = yaml.safe_load(f)
                 endpoint = config_dict.get("endpoint", endpoint)
+                api_key = config_dict.get("api_key", "")
         except Exception as e:
             click.echo(f"Error loading config from {config}: {str(e)}", err=True)
             click.echo("Falling back to HTTP client with endpoint", err=True)
 
     if endpoint == "":
         endpoint = "http://localhost:8321"
 
+    default_headers = {}
+    if api_key != "":
+        default_headers = {
+            "Authorization": f"Bearer {api_key}",
+        }
+
     client = LlamaStackClient(
         base_url=endpoint,
         provider_data={
             "fireworks_api_key": os.environ.get("FIREWORKS_API_KEY", ""),
             "together_api_key": os.environ.get("TOGETHER_API_KEY", ""),
             "openai_api_key": os.environ.get("OPENAI_API_KEY", ""),
         },
+        default_headers=default_headers,
     )
     ctx.obj = {"client": client}