Add old Dockerfile as Dockerfile.alpine

Dockerfile.apline

@@ -0,0 +1,29 @@
+# Build stage
+FROM rust:1.72-alpine3.18 AS cargo-build
+
+RUN apk add --no-cache musl-dev pkgconfig openssl-dev
+
+WORKDIR /src/websocat
+ENV RUSTFLAGS='-Ctarget-feature=-crt-static'
+
+COPY Cargo.toml Cargo.toml
+ARG CARGO_OPTS="--features=workaround1,seqpacket,prometheus_peer,prometheus/process,crypto_peer"
+
+RUN mkdir src/ &&\
+    echo "fn main() {println!(\"if you see this, the build broke\")}" > src/main.rs && \
+    cargo build --release $CARGO_OPTS && \
+    rm -f target/release/deps/websocat*
+
+COPY src src
+RUN cargo build --release $CARGO_OPTS && \
+    strip target/release/websocat
+
+# Final stage
+FROM alpine:3.18
+
+RUN apk add --no-cache libgcc
+
+WORKDIR /
+COPY --from=cargo-build /src/websocat/target/release/websocat /usr/local/bin/
+
+ENTRYPOINT ["/usr/local/bin/websocat"]