add build params and co update

docs/source/distributions/building_distro.md

@@ -20,6 +20,7 @@ llama stack build -h
 We will start build our distribution (in the form of a Conda environment, or Docker image). In this step, we will specify:
 - `name`: the name for our distribution (e.g. `my-stack`)
 - `image_type`: our build image type (`conda | docker`)
+- `platform`: the platform for docker image (e.g. `linux/arm64`)
 - `distribution_spec`: our distribution specs for specifying API providers
   - `description`: a short description of the configurations for the distribution
   - `providers`: specifies the underlying implementation for serving each API endpoint
@@ -36,6 +37,7 @@ llama stack build
 
 > Enter a name for your Llama Stack (e.g. my-local-stack): my-stack
 > Enter the image type you want your Llama Stack to be built as (docker or conda): conda
+> Enter the target platform you want your Llama Stack to be built for: linux/arm64
 
 Llama Stack is composed of several APIs working together. Let's select
 the provider types (implementations) you want to use for these APIs.

llama_stack/distribution/build_container.sh

@@ -11,9 +11,9 @@ LLAMA_STACK_DIR=${LLAMA_STACK_DIR:-}
 TEST_PYPI_VERSION=${TEST_PYPI_VERSION:-}
 BUILD_PLATFORM=${BUILD_PLATFORM:-}
 
-if [ "$#" -lt 4 ]; then
-  echo "Usage: $0 <build_name> <docker_base> <pip_dependencies> [<special_pip_deps>]" >&2
-  echo "Example: $0 my-fastapi-app python:3.9-slim 'fastapi uvicorn' " >&2
+if [ "$#" -lt 5 ]; then
+  echo "Usage: $0 <build_name> <docker_base> <platform> <pip_dependencies> [<special_pip_deps>]" >&2
+  echo "Example: $0 my-fastapi-app python:3.9-slim linux/arm64 'fastapi uvicorn' " >&2
   exit 1
 fi
 
@@ -24,9 +24,10 @@ set -euo pipefail
 build_name="$1"
 image_name="distribution-$build_name"
 docker_base=$2
-build_file_path=$3
-host_build_dir=$4
-pip_dependencies=$5
+platform=$3
+build_file_path=$4
+host_build_dir=$5
+pip_dependencies=$6
 
 # Define color codes
 RED='\033[0;31m'