swap Dockerfile to prevent DO out-of-memory error

<LukeMathWalker/zero-to-production#71>

Dockerfile

@@ -1,38 +1,26 @@
-# Builder stage
-## Use the latest Rust stable release as base image
-FROM lukemathwalker/cargo-chef:latest-rust-1.53.0 AS planner
+FROM lukemathwalker/cargo-chef:latest-rust-1.53.0 as chef
 WORKDIR /app
+
+FROM chef as planner
 COPY . .
-# Generate a 'lock' file for our project
-RUN cargo chef prepare --recipe-path recipe.json
+RUN cargo chef prepare  --recipe-path recipe.json
 
-FROM lukemathwalker/cargo-chef:latest-rust-1.53.0 AS cacher
-WORKDIR /app
+FROM chef as builder
 COPY --from=planner /app/recipe.json recipe.json
 RUN cargo chef cook --release --recipe-path recipe.json
-
-FROM rust:1.53.0 AS builder
-WORKDIR /app
-# Cpopy over the cached dependencies
-COPY --from=cacher /app/target target
-COPY --from=cacher /usr/local/cargo /usr/local/cargo
 COPY . .
 ENV SQLX_OFFLINE true
-# Build application, with deps already cached :)
-RUN cargo build --release --bin zerotoprod
+RUN cargo build --release --bin zero2prod
 
-# Runtime stage
 FROM debian:buster-slim AS runtime
 WORKDIR /app
-# Install OpenSSL - it is dynamically linked by some of our dependencies
 RUN apt-get update -y \
     && apt-get install -y --no-install-recommends openssl \
     # Clean up
     && apt-get autoremove -y \
     && apt-get clean -y \
     && rm -rf /var/lib/apt/lists/*
-COPY --from=builder /app/target/release/zerotoprod zerotoprod
+COPY --from=builder /app/target/release/zero2prod zero2prod
 COPY configuration configuration
 ENV APP_ENVIRONMENT production
-# Launch binary on execute of `docker run`
-ENTRYPOINT ["./zerotoprod"]
+ENTRYPOINT ["./zero2prod"]