Migrate to MUSL

Dockerfile

@@ -1,19 +1,28 @@
-FROM rust:latest AS builder
+# --- Builder stage ---
+FROM rust:1-bookworm AS builder
+
+# Install musl target and musl-tools
+RUN rustup target add x86_64-unknown-linux-musl \
+    && apt-get update \
+    && apt-get install -y musl-tools build-essential
 
 WORKDIR /app
 
 COPY Cargo.toml Cargo.lock ./
-
 COPY . .
 
-RUN cargo build --release
+# Build fully static binary
+RUN cargo build --release --target x86_64-unknown-linux-musl
 
+# --- Final stage ---
 FROM debian:bookworm
 
-COPY --from=builder /app/target/release/payphone /usr/local/bin/payphone
+# Copy static binary
+COPY --from=builder /app/target/x86_64-unknown-linux-musl/release/payphone /usr/local/bin/payphone
 
-RUN apt-get update && apt-get install -y ca-certificates
-RUN update-ca-certificates
+RUN apt-get update && apt-get install -y ca-certificates \
+    && update-ca-certificates \
+    && rm -rf /var/lib/apt/lists/*
 
-ENTRYPOINT [ "/usr/local/bin/payphone" ]
-CMD [ "start" ]
+ENTRYPOINT ["/usr/local/bin/payphone"]
+CMD ["start"]