#!/bin/sh
# Substitute environment variables in YAML config templates before starting the service.
# Usage: entrypoint.sh <binary> -f <config.yaml>
#
# The YAML file is treated as a template with ${VAR} placeholders.
# envsubst replaces them with actual environment variable values at container start time.
# The rendered config is written to /tmp to avoid read-only filesystem issues (e.g. ConfigMap mounts).

set -e

BINARY="$1"
shift

# Scan args for -f <config> and render to /tmp
ARGS=""
PREV=""
for arg in "$@"; do
    if [ "$PREV" = "-f" ] && [ -f "$arg" ]; then
        RENDERED="/tmp/$(basename "$arg")"
        envsubst < "$arg" > "$RENDERED"
        ARGS="$ARGS $RENDERED"
    else
        ARGS="$ARGS $arg"
    fi
    PREV="$arg"
done

exec "$BINARY" $ARGS