Dockerfile

FROM golang:1.25.9-alpine3.23 AS builder

WORKDIR /app

# Copy go mod files first for better caching
COPY go.mod go.sum ./
RUN go mod download

# Copy source code
COPY . .

# Build the binary with security flags
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -ldflags '-extldflags "-static"' -o secrets-management-proxy

FROM alpine:3.23.4

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

# Create non-root user for security
RUN addgroup -g 1001 -S appgroup && \
    adduser -u 1001 -S appuser -G appgroup

WORKDIR /app

# Copy binary from builder stage
COPY --from=builder /app/secrets-management-proxy /app/secrets-management-proxy

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

# Switch to non-root user
USER appuser

CMD ["/app/secrets-management-proxy", "--bind-addr=127.0.0.1:5353"]