fix: remove fe from backend image build (#11579)

* asdf

* build langflow-backend image correctly with no frontend

* Update docker/build_and_push_backend.Dockerfile

Co-authored-by: Adam-Aghili <149833988+Adam-Aghili@users.noreply.github.com>

* Fix version check for backend image

* Add data dir

* Add npm back for mcp support

---------

Co-authored-by: Adam-Aghili <149833988+Adam-Aghili@users.noreply.github.com>

.github/workflows/docker_test.yml

@@ -78,7 +78,7 @@ jobs:
             .
       - name: Test backend image
         run: |
-          expected_version=$(cat pyproject.toml | grep version | head -n 1 | cut -d '"' -f 2)
+          expected_version=$(cat src/backend/base/pyproject.toml | grep version | head -n 1 | cut -d '"' -f 2)
           version=$(${{ env.CONTAINER_RUNTIME }} run --rm --entrypoint bash langflowai/langflow-backend:latest-dev -c "python -c 'from langflow.utils.version import get_version_info; print(get_version_info()[\"version\"])'")
           if [ "$expected_version" != "$version" ]; then
               echo "Expected version: $expected_version"

docker/build_and_push_backend.Dockerfile

@@ -1,9 +1,95 @@
 # syntax=docker/dockerfile:1
 # Keep this syntax directive! It's used to enable Docker BuildKit
+#
+# Backend-only Langflow image
+# - No frontend code or assets
+# - No Playwright
 
-ARG LANGFLOW_IMAGE
-FROM ${LANGFLOW_IMAGE}
+################################
+# BUILDER
+################################
+FROM ghcr.io/astral-sh/uv:python3.12-bookworm-slim AS builder
 
-RUN rm -rf /app/.venv/langflow/frontend
+WORKDIR /app
 
-CMD ["python", "-m", "langflow", "run", "--host", "0.0.0.0", "--port", "7860", "--backend-only"]
+# Required for apify-client
+ENV RUSTFLAGS='--cfg reqwest_unstable'
+
+# Install build dependencies
+RUN apt-get update \
+    && apt-get upgrade -y \
+    && apt-get install --no-install-recommends -y \
+        build-essential \
+        gcc \
+        git \
+        curl \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*
+
+# Copy only backend source (excludes frontend)
+COPY ./src/backend ./src/backend
+COPY ./src/lfx ./src/lfx
+
+# Create venv and install langflow-base with dependencies
+# Using uv pip instead of uv sync to avoid workspace complexities
+RUN uv venv /app/.venv
+ENV PATH="/app/.venv/bin:$PATH"
+ENV VIRTUAL_ENV="/app/.venv"
+
+RUN --mount=type=cache,target=/root/.cache/uv \
+    uv pip install ./src/lfx "./src/backend/base[complete,postgresql]"
+
+################################
+# RUNTIME
+################################
+FROM python:3.12.12-slim-trixie AS runtime
+
+# Install minimal runtime dependencies
+RUN apt-get update \
+    && apt-get upgrade -y \
+    && apt-get install --no-install-recommends -y \
+        curl \
+        git \
+        libpq5 \
+        gnupg \
+        xz-utils \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*
+
+# Install Node.js (required for npx-based MCP stdio servers)
+RUN ARCH=$(dpkg --print-architecture) \
+    && if [ "$ARCH" = "amd64" ]; then NODE_ARCH="x64"; \
+       elif [ "$ARCH" = "arm64" ]; then NODE_ARCH="arm64"; \
+       else NODE_ARCH="$ARCH"; fi \
+    && NODE_VERSION=$(curl -fsSL https://nodejs.org/dist/latest-v22.x/ \
+                    | grep -oP "node-v\K[0-9]+\.[0-9]+\.[0-9]+(?=-linux-${NODE_ARCH}\.tar\.xz)" \
+                    | head -1) \
+    && curl -fsSL "https://nodejs.org/dist/v${NODE_VERSION}/node-v${NODE_VERSION}-linux-${NODE_ARCH}.tar.xz" \
+    | tar -xJ -C /usr/local --strip-components=1 \
+    && npm install -g npm@latest \
+    && npm cache clean --force
+
+# Create non-root user
+RUN useradd --uid 1000 --gid 0 --no-create-home --home-dir /app/data user
+
+# Copy only the virtual environment
+COPY --from=builder --chown=1000:0 /app/.venv /app/.venv
+ENV PATH="/app/.venv/bin:$PATH"
+
+# Create home directory and ensure proper ownership
+# The user needs write access to /app/data (home) and /app (workdir)
+RUN mkdir -p /app/data && chown -R 1000:0 /app/data && chown -R 1000:0 /app
+
+LABEL org.opencontainers.image.title=langflow-backend
+LABEL org.opencontainers.image.authors=['Langflow']
+LABEL org.opencontainers.image.licenses=MIT
+LABEL org.opencontainers.image.url=https://github.com/langflow-ai/langflow
+LABEL org.opencontainers.image.source=https://github.com/langflow-ai/langflow
+
+USER user
+WORKDIR /app
+
+ENV LANGFLOW_HOST=0.0.0.0
+ENV LANGFLOW_PORT=7860
+
+CMD ["python", "-m", "langflow", "run", "--backend-only"]

src/backend/base/pyproject.toml

@@ -480,4 +480,4 @@ all = [
 ]
 
 [project.scripts]
-langflow-base = "langflow.__main__:main"
+langflow-base = "langflow.langflow_launcher:main"