Fix Docker builds

Author: valeriansaliou

Dockerfile

@@ -1,14 +1,21 @@
-FROM rustlang/rust:nightly-buster-slim AS build
+FROM rust:slim-bullseye AS build
 
 RUN apt-get update
 RUN apt-get install -y build-essential clang
 
+RUN rustup --version
+RUN rustup component add rustfmt
+
+RUN rustc --version && \
+    rustup --version && \
+    cargo --version
+
 WORKDIR /app
 COPY . /app
 RUN cargo clean && cargo build --release --target x86_64-unknown-linux-gnu
 RUN strip ./target/x86_64-unknown-linux-gnu/release/sonic
 
-FROM debian:buster-slim
+FROM debian:bullseye-slim
 
 WORKDIR /usr/src/sonic