From 1dcba640957b14d02d97f54e9e1488ac25468b12 Mon Sep 17 00:00:00 2001
From: "Brian J. Tarricone" <brian@tarricone.org>
Date: Sat, 16 Sep 2023 00:06:13 -0700
Subject: [PATCH] Speed up docker rebuilds

This should keep all the dependency build artifacts in a cached layer
below the layer that builds our app and links the final binary.
---
 Dockerfile | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/Dockerfile b/Dockerfile
index 94e5c89..76dfbc4 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -2,7 +2,15 @@ FROM rust:1.72-slim-bullseye AS builder
 
 WORKDIR /bebot-build
 
-COPY . ./
+# Build and cache dependencies
+COPY Cargo.toml Cargo.lock ./
+RUN mkdir -p src && echo 'fn main() {}' > src/main.rs
+RUN cargo build --release
+
+# Build and link our app
+RUN rm -rf src
+COPY src ./src
+RUN touch src/main.rs
 RUN cargo build --release
 
 FROM debian:bookworm-slim