feat(ollama-bootstrap): support podman + brew autoinstall + fail loud

The first cut of the bootstrap script silently fell back to a no-op when
neither Docker nor a local 'ollama' CLI was available, leaving Langflow
running with OLLAMA_BASE_URL pointing at nothing. Tightens the script:

- Auto-detect docker OR podman (this repo defaults to podman in the
  Makefile, so podman support is required). Honour LANGFLOW_OLLAMA_ENGINE
  to force one. Pin the image to docker.io/ollama/ollama:latest so it
  resolves under podman's default registry policy.
- On macOS with Homebrew, install Ollama automatically via 'brew install
  ollama' when no engine and no CLI are present (gated by
  LANGFLOW_OLLAMA_NO_INSTALL=1).
- Fail loudly with concrete install instructions instead of warning and
  exiting 0. New LANGFLOW_OLLAMA_OPTIONAL=1 escape hatch for CI or
  contributors that don't need the bundled provider.
- Treat 'wait_for_server' timeouts as fatal so 'make run_cli' aborts
  instead of starting Langflow with a dead Ollama URL.
- ollama_down Make target now also detects podman.
- README mentions the podman compose path.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: Empreiteiro

Makefile

@@ -237,9 +237,14 @@ ollama_up: ## start a local Ollama with granite3.3:2b for the bundled model prov
 	@bash scripts/setup/ollama_bootstrap.sh
 
 ollama_down: ## stop and remove the bundled Ollama container (keeps the model volume)
-	@if docker ps -a --format '{{.Names}}' 2>/dev/null | grep -Fxq langflow-ollama; then \
-		echo 'Stopping langflow-ollama container...'; \
-		docker rm -f langflow-ollama >/dev/null; \
+	@engine=""; \
+	for c in docker podman; do \
+		if command -v $$c >/dev/null 2>&1 && $$c info >/dev/null 2>&1; then engine=$$c; break; fi; \
+	done; \
+	if [ -z "$$engine" ]; then echo 'No usable container engine (docker/podman) found.'; exit 0; fi; \
+	if $$engine ps -a --format '{{.Names}}' 2>/dev/null | grep -Fxq langflow-ollama; then \
+		echo "Stopping langflow-ollama container ($$engine)..."; \
+		$$engine rm -f langflow-ollama >/dev/null; \
 	else \
 		echo 'No langflow-ollama container found.'; \
 	fi

docker_example/ollama-granite/README.md

@@ -8,6 +8,12 @@ Turnkey stack: Langflow, Postgres, and an Ollama server with `granite3.3:2b` pre
 docker compose up
 ```
 
+Or, with Podman:
+
+```bash
+podman compose up        # podman-compose / podman compose plugin
+```
+
 Open http://localhost:7860. The first start downloads the model (~1.5 GB), so allow a few minutes.
 
 ## Services

scripts/setup/ollama_bootstrap.sh

@@ -2,16 +2,27 @@
 # Bootstrap a local Ollama server with the granite3.3:2b model so that
 # `make run_cli` exposes a pre-configured Ollama provider in Langflow.
 #
-# Behavior:
-#   - If something is already responding on $OLLAMA_PORT, do nothing.
-#   - Else if `docker` is available, start (or restart) a container named
-#     `langflow-ollama` and pull granite3.3:2b on it.
-#   - Else if the `ollama` CLI is installed locally, start `ollama serve`
-#     in the background and pull the model.
-#   - Else print a warning and exit 0 (Langflow still starts; Ollama provider
-#     just won't be reachable).
+# Resolution order:
+#   1. If something already responds on $OLLAMA_PORT, use it.
+#   2. Else if a container engine (docker or podman) is available with a
+#      running daemon, start (or restart) a container named `langflow-ollama`
+#      and pull the model.
+#   3. Else if the `ollama` CLI is installed, start `ollama serve` in the
+#      background and pull the model.
+#   4. Else, on macOS with Homebrew, install Ollama via `brew install ollama`,
+#      then go to step 3. Skip this with LANGFLOW_OLLAMA_NO_INSTALL=1.
+#   5. Else, fail with explicit installation instructions.
 #
-# Exits non-zero only when an explicit step fails (docker run/exec, ollama pull).
+# Environment variables:
+#   OLLAMA_PORT                 default 11434
+#   OLLAMA_HOST                 default 127.0.0.1
+#   LANGFLOW_OLLAMA_MODEL       default granite3.3:2b
+#   LANGFLOW_OLLAMA_ENGINE      override container engine: docker | podman
+#                               (auto-detected when unset)
+#   LANGFLOW_OLLAMA_NO_INSTALL  set to 1 to disable brew autoinstall
+#   LANGFLOW_OLLAMA_OPTIONAL    set to 1 to make this script never exit non-zero
+#                               (useful for CI / contributors who do not need
+#                                the bundled provider)
 
 set -euo pipefail
 
@@ -22,10 +33,22 @@ CONTAINER_NAME="langflow-ollama"
 VOLUME_NAME="langflow-ollama-data"
 HEALTH_TIMEOUT_S=60
 
+# Resolved container engine (docker | podman). Empty means "no engine usable".
+ENGINE=""
+
 log()  { printf '\033[1;36m[ollama-bootstrap]\033[0m %s\n' "$*"; }
 warn() { printf '\033[1;33m[ollama-bootstrap]\033[0m %s\n' "$*" >&2; }
 err()  { printf '\033[1;31m[ollama-bootstrap]\033[0m %s\n' "$*" >&2; }
 
+abort() {
+  err "$*"
+  if [ "${LANGFLOW_OLLAMA_OPTIONAL:-0}" = "1" ]; then
+    warn "LANGFLOW_OLLAMA_OPTIONAL=1 — continuing without Ollama (provider will be unreachable)."
+    exit 0
+  fi
+  exit 1
+}
+
 is_server_up() {
   curl -fsS --max-time 2 "http://${OLLAMA_HOST}:${OLLAMA_PORT}/api/tags" >/dev/null 2>&1
 }
@@ -34,21 +57,43 @@ wait_for_server() {
   local elapsed=0
   while ! is_server_up; do
     if [ "$elapsed" -ge "$HEALTH_TIMEOUT_S" ]; then
-      err "Ollama did not become healthy within ${HEALTH_TIMEOUT_S}s"
       return 1
     fi
     sleep 2
     elapsed=$((elapsed + 2))
   done
 }
 
-ensure_model_docker() {
-  log "Ensuring model '${OLLAMA_MODEL}' is pulled (docker exec)..."
-  if docker exec "$CONTAINER_NAME" ollama list 2>/dev/null | awk 'NR>1 {print $1}' | grep -Fxq "$OLLAMA_MODEL"; then
+engine_is_usable() {
+  local cmd="$1"
+  command -v "$cmd" >/dev/null 2>&1 && "$cmd" info >/dev/null 2>&1
+}
+
+resolve_engine() {
+  if [ -n "${LANGFLOW_OLLAMA_ENGINE:-}" ]; then
+    if engine_is_usable "$LANGFLOW_OLLAMA_ENGINE"; then
+      ENGINE="$LANGFLOW_OLLAMA_ENGINE"
+      return 0
+    fi
+    warn "LANGFLOW_OLLAMA_ENGINE='${LANGFLOW_OLLAMA_ENGINE}' is not usable — falling back to auto-detect."
+  fi
+  for candidate in docker podman; do
+    if engine_is_usable "$candidate"; then
+      ENGINE="$candidate"
+      return 0
+    fi
+  done
+  return 1
+}
+
+ensure_model_engine() {
+  log "Ensuring model '${OLLAMA_MODEL}' is pulled (${ENGINE} exec)..."
+  if "$ENGINE" exec "$CONTAINER_NAME" ollama list 2>/dev/null \
+      | awk 'NR>1 {print $1}' | grep -Fxq "$OLLAMA_MODEL"; then
     log "Model '${OLLAMA_MODEL}' already present."
     return 0
   fi
-  docker exec "$CONTAINER_NAME" ollama pull "$OLLAMA_MODEL"
+  "$ENGINE" exec "$CONTAINER_NAME" ollama pull "$OLLAMA_MODEL"
 }
 
 ensure_model_local() {
@@ -60,49 +105,74 @@ ensure_model_local() {
   ollama pull "$OLLAMA_MODEL"
 }
 
-start_with_docker() {
-  log "Starting Ollama container '${CONTAINER_NAME}' on port ${OLLAMA_PORT}..."
-  if docker ps --format '{{.Names}}' | grep -Fxq "$CONTAINER_NAME"; then
+start_with_engine() {
+  log "Starting Ollama container '${CONTAINER_NAME}' on port ${OLLAMA_PORT} (engine: ${ENGINE})..."
+  if "$ENGINE" ps --format '{{.Names}}' | grep -Fxq "$CONTAINER_NAME"; then
     log "Container already running."
-  elif docker ps -a --format '{{.Names}}' | grep -Fxq "$CONTAINER_NAME"; then
+  elif "$ENGINE" ps -a --format '{{.Names}}' | grep -Fxq "$CONTAINER_NAME"; then
     log "Container exists but is stopped — restarting."
-    docker start "$CONTAINER_NAME" >/dev/null
+    "$ENGINE" start "$CONTAINER_NAME" >/dev/null
   else
-    docker volume create "$VOLUME_NAME" >/dev/null
-    docker run -d \
+    "$ENGINE" volume create "$VOLUME_NAME" >/dev/null 2>&1 || true
+    "$ENGINE" run -d \
       --name "$CONTAINER_NAME" \
       --restart unless-stopped \
       -p "${OLLAMA_PORT}:11434" \
       -v "${VOLUME_NAME}:/root/.ollama" \
-      ollama/ollama >/dev/null
+      docker.io/ollama/ollama:latest >/dev/null
+  fi
+  if ! wait_for_server; then
+    abort "Ollama container did not become healthy within ${HEALTH_TIMEOUT_S}s. Inspect with: ${ENGINE} logs ${CONTAINER_NAME}"
   fi
-  wait_for_server
-  ensure_model_docker
+  ensure_model_engine
 }
 
 start_with_local_cli() {
-  log "Starting local 'ollama serve' on port ${OLLAMA_PORT}..."
+  log "Starting local 'ollama serve' on port ${OLLAMA_PORT} (logs: /tmp/langflow-ollama.log)..."
   OLLAMA_HOST="${OLLAMA_HOST}:${OLLAMA_PORT}" nohup ollama serve >/tmp/langflow-ollama.log 2>&1 &
-  wait_for_server
+  if ! wait_for_server; then
+    abort "Local 'ollama serve' did not become healthy within ${HEALTH_TIMEOUT_S}s. Tail /tmp/langflow-ollama.log for details."
+  fi
   ensure_model_local
 }
 
+try_install_ollama() {
+  if [ "${LANGFLOW_OLLAMA_NO_INSTALL:-0}" = "1" ]; then
+    return 1
+  fi
+  case "$(uname -s)" in
+    Darwin)
+      if command -v brew >/dev/null 2>&1; then
+        log "Ollama not found — installing via Homebrew (brew install ollama)..."
+        brew install ollama
+        return 0
+      fi
+      ;;
+  esac
+  return 1
+}
+
 main() {
   if is_server_up; then
     log "Ollama already responding at http://${OLLAMA_HOST}:${OLLAMA_PORT} — skipping bootstrap."
-    log "(If granite3.3:2b is not installed, run: ollama pull ${OLLAMA_MODEL})"
+    log "(If '${OLLAMA_MODEL}' is not installed, run: ollama pull ${OLLAMA_MODEL})"
     return 0
   fi
 
-  if command -v docker >/dev/null 2>&1 && docker info >/dev/null 2>&1; then
-    start_with_docker
+  if resolve_engine; then
+    start_with_engine
   elif command -v ollama >/dev/null 2>&1; then
     start_with_local_cli
+  elif try_install_ollama && command -v ollama >/dev/null 2>&1; then
+    start_with_local_cli
   else
-    warn "Neither Docker nor the 'ollama' CLI is available."
-    warn "Langflow will start, but the Ollama provider won't be reachable."
-    warn "Install Docker (https://docs.docker.com/get-docker/) or Ollama (https://ollama.com/download) and re-run."
-    return 0
+    abort "Cannot start Ollama: no usable container engine (docker / podman) and no 'ollama' CLI.
+       Install one of:
+         - Podman:          https://podman.io/docs/installation  (then 'podman machine start')
+         - Docker Desktop:  https://docs.docker.com/get-docker/
+         - Ollama:          https://ollama.com/download           (or 'brew install ollama')
+       Then re-run 'make run_cli'.
+       To skip this bootstrap on this machine, run:  LANGFLOW_OLLAMA_OPTIONAL=1 make run_cli"
   fi
 
   log "Ollama is up at http://${OLLAMA_HOST}:${OLLAMA_PORT} with model '${OLLAMA_MODEL}'."