chore: use sccache (#26376)

* chore: remove CARGO_TARGET_CACHE

* chore: prepare sccache env for docker container

* chore: use s3 as sccache backend

.buildkite/hooks/post-command

@@ -1,22 +1,5 @@
 #!/bin/bash -e
 
-#
-# Save target/ for the next CI build on this machine
-#
-if [[ -z $CARGO_TARGET_CACHE ]]; then
-  echo "+++ CARGO_TARGET_CACHE not defined" # pre-command should have defined it
-else
-  (
-    set -x
-    mkdir -p "$CARGO_TARGET_CACHE"
-    set -x
-    rsync -a --delete --link-dest="$PWD" target "$CARGO_TARGET_CACHE"
-    du -hs "$CARGO_TARGET_CACHE"
-    read -r cacheSizeInGB _ < <(du -s --block-size=1800000000 "$CARGO_TARGET_CACHE")
-    echo "--- ${cacheSizeInGB}GB: $CARGO_TARGET_CACHE"
-  )
-fi
-
 #
 # Add job_stats data point
 #

.buildkite/hooks/pre-command

@@ -18,32 +18,4 @@ HOST_RUST_VERSION="$rust_stable"
 pattern='^[0-9]+\.[0-9]+\.[0-9]+$'
 if [[ ${HOST_RUST_VERSION} =~ ${pattern} ]]; then
     HOST_RUST_VERSION="${rust_stable%.*}"
-fi
-export CARGO_TARGET_CACHE=$HOME/cargo-target-cache/"$CHANNEL"-"$BUILDKITE_LABEL"-"$SBF_TOOLS_VERSION"-"$HOST_RUST_VERSION"
-(
-  set -x
-  MAX_CACHE_SIZE=18 # gigabytes
-
-  if [[ -d $CARGO_TARGET_CACHE ]]; then
-    du -hs "$CARGO_TARGET_CACHE"
-    read -r cacheSizeInGB _ < <(du -s --block-size=1800000000 "$CARGO_TARGET_CACHE")
-    echo "--- ${cacheSizeInGB}GB: $CARGO_TARGET_CACHE"
-    if [[ $cacheSizeInGB -gt $MAX_CACHE_SIZE ]]; then
-      echo "--- $CARGO_TARGET_CACHE is too large, removing it"
-      rm -rf "$CARGO_TARGET_CACHE"
-    fi
-  else
-    echo "--- $CARGO_TARGET_CACHE not present"
-  fi
-
-  mkdir -p "$CARGO_TARGET_CACHE"/target
-  rsync -a --delete --link-dest="$CARGO_TARGET_CACHE" "$CARGO_TARGET_CACHE"/target .
-
-  # Don't reuse BPF target build artifacts due to incremental build issues with
-  # `std:
-  #    "found possibly newer version of crate `std` which `xyz` depends on
-  rm -rf target/bpfel-unknown-unknown
-  if [[ $BUILDKITE_LABEL = "stable-perf" ]]; then
-    rm -rf target/release
-  fi
-)
+fi

ci/docker-run.sh

@@ -83,6 +83,15 @@ ARGS+=(
   --env CRATES_IO_TOKEN
 )
 
+# sccache
+ARGS+=(
+  --env "RUSTC_WRAPPER=/home/.cargo/bin/sccache"
+  --env AWS_ACCESS_KEY_ID
+  --env AWS_SECRET_ACCESS_KEY
+  --env SCCACHE_BUCKET
+  --env SCCACHE_REGION
+)
+
 # Also propagate environment variables needed for codecov
 # https://docs.codecov.io/docs/testing-with-docker#section-codecov-inside-docker
 # We normalize CI to `1`; but codecov expects it to be `true` to detect Buildkite...