render-docs-update

#!/usr/bin/env sh

# render-docs-update: regenerate README.md from README.md.j2.
#
# Renders the template in place using the CONTAINER_VERSION derived from
# src/version.txt.  Equivalent to `make README.md` without requiring make;
# used by Renovate's postUpgradeTasks so the rendered README.md lands in
# the same commit as the version bump.

set -eu

TEMPLATE="README.md.j2"
VERSION_FILE="src/version.txt"
OUTPUT="README.md"

if [ ! -s "$TEMPLATE" ]; then
  echo "ERROR: ${TEMPLATE} is missing or empty." >&2
  exit 1
fi
if ! command -v uv > /dev/null 2>&1; then
  echo "ERROR: uv is required but not on the PATH.  Renovate must run the" >&2
  echo "full image variant (renovate-version: NN-full), which ships uv." >&2
  exit 1
fi

if [ ! -s "$VERSION_FILE" ]; then
  echo "ERROR: ${VERSION_FILE} is missing or empty." >&2
  exit 1
fi

# Derive CONTAINER_VERSION from the single source of truth (whitespace trimmed).
CONTAINER_VERSION=$(tr -d '[:space:]' < "$VERSION_FILE")

# Render to a sibling temp file so a failed render leaves README.md
# untouched and the final mv is an atomic same-directory rename.
tmpfile=$(mktemp "${OUTPUT}.XXXXXX")
trap 'rm -f "$tmpfile"' EXIT INT TERM

if ! uv run --group dev python tools/render_docs.py "$TEMPLATE" "$tmpfile" "$CONTAINER_VERSION"; then
  echo "ERROR: render-docs-update failed to render ${TEMPLATE}; ${OUTPUT} left unmodified." >&2
  exit 1
fi

mv "$tmpfile" "$OUTPUT"