build: update dependencies and fix Dockerfile

Dockerfile

@@ -1,18 +1,43 @@
-FROM golang:1.24-alpine AS builder
+# 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 . .
-RUN CGO_ENABLED=0 GOOS=linux go build -o exporter ./cmd/exporter
 
+# Build binary
+RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o keenetic-exporter main.go
+
+# Runtime stage
 FROM alpine:latest
-RUN apk --no-cache add ca-certificates
-WORKDIR /root/
 
-COPY --from=builder /app/exporter .
-COPY --from=builder /app/configs ./configs
+# 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
-CMD ["./exporter"]
+
+# Run the exporter
+CMD ["./keenetic-exporter"]