# Build stage
FROM golang:1.25.3-alpine AS builder

WORKDIR /app

# Copy go mod files and download dependencies
COPY go.mod go.sum ./
RUN go mod download

# Copy source code
COPY . .

# Build binary
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o keenetic-exporter main.go

# Runtime stage
FROM alpine:latest

# Install ca-certificates for HTTPS requests
RUN apk --no-cache add ca-certificates tzdata

# Create non-root user
RUN addgroup -S appgroup && adduser -S appuser -G appgroup

WORKDIR /app

# Copy binary from builder
COPY --from=builder /app/keenetic-exporter .

# Copy default config
COPY config.default.yaml .

# Change ownership to non-root user
RUN chown -R appuser:appgroup /app

# Switch to non-root user
USER appuser

# Expose prometheus metrics port
EXPOSE 9090

# Run the exporter
CMD ["./keenetic-exporter"]