chore: rename templates to distributions (#3035)

As the title says. Distributions is in, Templates is out.

`llama stack build --template` --> `llama stack build --distro`. For
backward compatibility, the previous option is kept but results in a
warning.

Updated `server.py` to remove the "config_or_template" backward
compatibility since it has been a couple releases since that change.

llama_stack/distributions/postgres-demo/postgres_demo.py

@@ -0,0 +1,144 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+
+from llama_stack.apis.models import ModelType
+from llama_stack.core.datatypes import (
+    BuildProvider,
+    ModelInput,
+    Provider,
+    ShieldInput,
+    ToolGroupInput,
+)
+from llama_stack.distributions.template import (
+    DistributionTemplate,
+    RunConfigSettings,
+)
+from llama_stack.providers.inline.inference.sentence_transformers import SentenceTransformersInferenceConfig
+from llama_stack.providers.remote.inference.vllm import VLLMInferenceAdapterConfig
+from llama_stack.providers.remote.vector_io.chroma.config import ChromaVectorIOConfig
+from llama_stack.providers.utils.kvstore.config import PostgresKVStoreConfig
+from llama_stack.providers.utils.sqlstore.sqlstore import PostgresSqlStoreConfig
+
+
+def get_distribution_template() -> DistributionTemplate:
+    inference_providers = [
+        Provider(
+            provider_id="vllm-inference",
+            provider_type="remote::vllm",
+            config=VLLMInferenceAdapterConfig.sample_run_config(
+                url="${env.VLLM_URL:=http://localhost:8000/v1}",
+            ),
+        ),
+    ]
+    providers = {
+        "inference": [
+            BuildProvider(provider_type="remote::vllm"),
+            BuildProvider(provider_type="inline::sentence-transformers"),
+        ],
+        "vector_io": [BuildProvider(provider_type="remote::chromadb")],
+        "safety": [BuildProvider(provider_type="inline::llama-guard")],
+        "agents": [BuildProvider(provider_type="inline::meta-reference")],
+        "telemetry": [BuildProvider(provider_type="inline::meta-reference")],
+        "tool_runtime": [
+            BuildProvider(provider_type="remote::brave-search"),
+            BuildProvider(provider_type="remote::tavily-search"),
+            BuildProvider(provider_type="inline::rag-runtime"),
+            BuildProvider(provider_type="remote::model-context-protocol"),
+        ],
+    }
+    name = "postgres-demo"
+
+    vector_io_providers = [
+        Provider(
+            provider_id="${env.ENABLE_CHROMADB:+chromadb}",
+            provider_type="remote::chromadb",
+            config=ChromaVectorIOConfig.sample_run_config(
+                f"~/.llama/distributions/{name}",
+                url="${env.CHROMADB_URL:=}",
+            ),
+        ),
+    ]
+    default_tool_groups = [
+        ToolGroupInput(
+            toolgroup_id="builtin::websearch",
+            provider_id="tavily-search",
+        ),
+        ToolGroupInput(
+            toolgroup_id="builtin::rag",
+            provider_id="rag-runtime",
+        ),
+    ]
+
+    default_models = [
+        ModelInput(
+            model_id="${env.INFERENCE_MODEL}",
+            provider_id="vllm-inference",
+        )
+    ]
+    embedding_provider = Provider(
+        provider_id="sentence-transformers",
+        provider_type="inline::sentence-transformers",
+        config=SentenceTransformersInferenceConfig.sample_run_config(),
+    )
+    embedding_model = ModelInput(
+        model_id="all-MiniLM-L6-v2",
+        provider_id=embedding_provider.provider_id,
+        model_type=ModelType.embedding,
+        metadata={
+            "embedding_dimension": 384,
+        },
+    )
+    postgres_config = PostgresSqlStoreConfig.sample_run_config()
+    return DistributionTemplate(
+        name=name,
+        distro_type="self_hosted",
+        description="Quick start template for running Llama Stack with several popular providers",
+        container_image=None,
+        template_path=None,
+        providers=providers,
+        available_models_by_provider={},
+        run_configs={
+            "run.yaml": RunConfigSettings(
+                provider_overrides={
+                    "inference": inference_providers + [embedding_provider],
+                    "vector_io": vector_io_providers,
+                    "agents": [
+                        Provider(
+                            provider_id="meta-reference",
+                            provider_type="inline::meta-reference",
+                            config=dict(
+                                persistence_store=postgres_config,
+                                responses_store=postgres_config,
+                            ),
+                        )
+                    ],
+                    "telemetry": [
+                        Provider(
+                            provider_id="meta-reference",
+                            provider_type="inline::meta-reference",
+                            config=dict(
+                                service_name="${env.OTEL_SERVICE_NAME:=\u200b}",
+                                sinks="${env.TELEMETRY_SINKS:=console,otel_trace}",
+                                otel_trace_endpoint="${env.OTEL_TRACE_ENDPOINT:=http://localhost:4318/v1/traces}",
+                            ),
+                        )
+                    ],
+                },
+                default_models=default_models + [embedding_model],
+                default_tool_groups=default_tool_groups,
+                default_shields=[ShieldInput(shield_id="meta-llama/Llama-Guard-3-8B")],
+                metadata_store=PostgresKVStoreConfig.sample_run_config(),
+                inference_store=postgres_config,
+            ),
+        },
+        run_config_env_vars={
+            "LLAMA_STACK_PORT": (
+                "8321",
+                "Port for the Llama Stack distribution server",
+            ),
+        },
+    )