Dockerfile

# ── Devil Studio — TTS API ──────────────────────────────────────────────────
# Multi-stage build: keeps the final image lean while pre-downloading all
# KittenTTS models so the container starts instantly with no cold-download lag.
# ---------------------------------------------------------------------------

# ── Stage 1: dependency builder ─────────────────────────────────────────────
FROM python:3.11-slim AS builder

WORKDIR /build

# System deps needed to compile some Python packages (e.g. soundfile → libsndfile)
RUN apt-get update && apt-get install -y --no-install-recommends \
        build-essential \
        libsndfile1-dev \
    && rm -rf /var/lib/apt/lists/*

COPY requirements.txt .

RUN pip install --upgrade pip \
 && pip install --prefix=/install --no-cache-dir -r requirements.txt


# ── Stage 2: model pre-downloader ───────────────────────────────────────────
# Runs a tiny Python snippet that imports KittenTTS and downloads/caches all
# three models so the runtime image has them baked in.
FROM python:3.11-slim AS model-fetcher

WORKDIR /fetch

RUN apt-get update && apt-get install -y --no-install-recommends \
        libsndfile1 \
    && rm -rf /var/lib/apt/lists/*

COPY --from=builder /install /usr/local

# Download all three models into the default HuggingFace cache directory.
# They will be copied into the final image, so the running container never
# needs outbound internet access to fetch weights.
ENV HF_HOME=/model-cache
RUN python - <<'EOF'
from kittentts import KittenTTS
import os

models = [
    "KittenML/kitten-tts-nano-0.8-fp32",
    "KittenML/kitten-tts-micro-0.8",
    "KittenML/kitten-tts-mini-0.8",
]

for m in models:
    print(f"Fetching {m} …", flush=True)
    KittenTTS(m)
    print(f"  ✓ {m}", flush=True)

print("All models cached.", flush=True)
EOF


# ── Stage 3: final runtime image ────────────────────────────────────────────
FROM python:3.11-slim

LABEL maintainer="Devil Studio"
LABEL description="OpenAI-compatible TTS API powered by KittenTTS"

# Runtime system libraries only (no build tools)
RUN apt-get update && apt-get install -y --no-install-recommends \
        libsndfile1 \
        # tini for proper PID-1 signal handling inside Docker
        tini \
    && rm -rf /var/lib/apt/lists/*

# Copy installed Python packages from builder
COPY --from=builder /install /usr/local

# Copy pre-downloaded model weights
ENV HF_HOME=/model-cache
COPY --from=model-fetcher /model-cache /model-cache

# Create a non-root user for security
RUN useradd --system --create-home --uid 1001 devilstudio
WORKDIR /app
RUN chown devilstudio:devilstudio /app

# Copy application source
COPY --chown=devilstudio:devilstudio main.py .

# Expose the API port (override with -e PORT=xxxx if needed)
ENV PORT=7860
EXPOSE 7860

# Tini as PID 1 — ensures clean signal forwarding and zombie reaping
ENTRYPOINT ["/usr/bin/tini", "--"]

# Single uvicorn worker so all three models share the same process memory.
# --no-access-log keeps logs clean; structured request logging is done in app.
CMD ["python", "-m", "uvicorn", "main:app", \
     "--host", "0.0.0.0", \
     "--port", "7860", \
     "--workers", "1", \
     "--log-level", "info", \
     "--no-access-log"]