Dockerfile

# Build stage
FROM golang:1.21-alpine AS builder

# Install build dependencies
RUN apk add --no-cache gcc musl-dev sqlite-dev git

WORKDIR /app

# Explicitly enable Go modules
ENV GO111MODULE=on

# Copy go.mod and go.sum first for better caching
COPY go.mod go.sum* ./

# Download dependencies
RUN go mod download

# Copy all source files
COPY . .

# Verify module structure (debug)
RUN echo "=== Go mod contents ===" && cat go.mod && echo "=== Files ===" && ls -la

# Tidy and build
RUN go mod tidy
RUN CGO_ENABLED=1 GOOS=linux go build -o main .

# Runtime stage
FROM alpine:3.19

# Install runtime dependencies
RUN apk add --no-cache ca-certificates tzdata sqlite-libs

WORKDIR /app

# Create data directory
RUN mkdir -p /app/data

# Copy binary from builder
COPY --from=builder /app/main .

# Copy templates and static files
COPY --from=builder /app/templates ./templates
COPY --from=builder /app/static ./static

# Set environment variables
ENV PORT=7860
ENV DATABASE_PATH=/app/data/tempmail.db
ENV GIN_MODE=release

# Create non-root user
RUN adduser -D -g '' appuser && chown -R appuser:appuser /app
USER appuser

EXPOSE 7860

HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
    CMD wget --no-verbose --tries=1 --spider http://localhost:7860/ || exit 1

CMD ["./main"]