Merge pull request #219 from codecrafters-io/fix-rust

Use repository-aware caching for Redis/Rust

Author: rohitpaulk

dockerfiles/rust-1.77.Dockerfile

@@ -1,17 +1,17 @@
+# syntax=docker/dockerfile:1.7-labs
 FROM rust:1.77-buster
 
-COPY Cargo.toml /app/Cargo.toml
-COPY Cargo.lock /app/Cargo.lock
+WORKDIR /app
 
-RUN mkdir /app/src
-RUN echo 'fn main() { println!("Hello World!"); }' > /app/src/main.rs
+# .git & README.md are unique per-repository. We ignore them on first copy to prevent cache misses
+COPY --exclude=.git --exclude=README.md . /app
 
-WORKDIR /app
 RUN cargo build --release --target-dir=/tmp/codecrafters-redis-target
 
 RUN rm /tmp/codecrafters-redis-target/release/redis-starter-rust
 RUN rm /tmp/codecrafters-redis-target/release/redis-starter-rust.d
 
+# Build caching schenanigans, see if this can be simplified
 RUN find /tmp/codecrafters-redis-target/release -type f -maxdepth 1 -delete
 RUN rm -f /tmp/codecrafters-redis-target/release/deps/*redis_starter_rust*
 RUN rm -f /tmp/codecrafters-redis-target/release/deps/redis_starter_rust*
@@ -25,3 +25,5 @@ RUN chmod +x /codecrafters-precompile.sh
 
 ENV CODECRAFTERS_DEPENDENCY_FILE_PATHS="Cargo.toml,Cargo.lock"
 
+# Once the heavy steps are done, we can copy all files back
+COPY . /app

dockerfiles/zig-0.12.Dockerfile

@@ -1,4 +1,5 @@
-FROM alpine:3.19
+# syntax=docker/dockerfile:1.7-labs
+FROM alpine:3.20
 
 # Add the testing repository
 RUN echo "@community http://dl-cdn.alpinelinux.org/alpine/edge/community" >> /etc/apk/repositories
@@ -17,5 +18,15 @@ RUN echo "@community http://dl-cdn.alpinelinux.org/alpine/edge/community" >> /et
 # Update the package list and install Zig
 RUN apk add --no-cache zig@community=0.12.0-r0
 
+WORKDIR /app
+
+# .git & README.md are unique per-repository. We ignore them on first copy to prevent cache misses
+COPY --exclude=.git --exclude=README.md . /app
+
+RUN zig build
+
 RUN printf "set -e \ncd \${CODECRAFTERS_SUBMISSION_DIR} \necho 'Running zig build' \nzig build \necho 'zig build completed.' \n" > /codecrafters-precompile.sh
 RUN chmod +x /codecrafters-precompile.sh
+
+# Once the heavy steps are done, we can copy all files back
+COPY . /app