Include Rust oak_loader in reproducibilty index

Fixes project-oak#862
Ref project-oak#861

cloudbuild.yaml

@@ -103,20 +103,18 @@ steps:
 
   # Rebuild the index file with hashes of reproducible artifacts. If this changed compared to the
   # checked-in version, it will be detected by the `git_check_diff` step below.
-  # TODO(#861): Re-enable this step (before git_check_diff) when artifacts are actually reproducibly
-  # built.
-  # - name: 'gcr.io/oak-ci/oak:latest'
-  #   id: build_reproducibility_index
-  #   waitFor: ['run_examples', 'build_server_rust']
-  #   timeout: 5m
-  #   entrypoint: 'bash'
-  #   args: ['./scripts/build_reproducibility_index']
+  - name: 'gcr.io/oak-ci/oak:latest'
+    id: build_reproducibility_index
+    waitFor: ['run_examples', 'build_server_rust']
+    timeout: 5m
+    entrypoint: 'bash'
+    args: ['./scripts/build_reproducibility_index']
 
   # Check whether any of the previous steps resulted in file diffs that were not checked in or
   # ignored by git.
   - name: 'gcr.io/oak-ci/oak:latest'
     id: git_check_diff
-    waitFor: ['git_init', 'run_clang_tidy', 'run_tests', 'run_examples']
+    waitFor: ['git_init', 'run_clang_tidy', 'run_tests', 'run_examples', 'build_reproducibility_index']
     timeout: 5m
     entrypoint: 'bash'
     args: ['./scripts/git_check_diff']

reproducibility_index

@@ -1,10 +1 @@
-61fdf25b4e2b4171a579dd9e4716b24348fb3f9f90ad936f9c91046618c93ed5  ./target/wasm32-unknown-unknown/release/abitest_0_frontend.wasm
-32a5f6aa9cbac2f71f40be10c52da32653a5b579810e5927af42df171a0f9dfc  ./target/wasm32-unknown-unknown/release/abitest_1_backend.wasm
-c697982360ea5d5a95b795889b4633ed27d3bc892f9bc9ac1df480c3759cb9b5  ./target/wasm32-unknown-unknown/release/aggregator.wasm
-2f5b176dbe8c9269d6bc2253c82d627d556db8a7214de8133ebfa185075a08dc  ./target/wasm32-unknown-unknown/release/chat.wasm
-c9a7fe26f4ad22af68ec375946a212c0356f5d90827f22884df540008dfc30dc  ./target/wasm32-unknown-unknown/release/hello_world.wasm
-874c832f9e16cc78e393b73e98ec08ee0c6b475ed67298e4094d31eaaf07f98c  ./target/wasm32-unknown-unknown/release/machine_learning.wasm
-97906ca9165f63281b03647ec55203e38a7acd2207f9518de52098a4c7c81bde  ./target/wasm32-unknown-unknown/release/running_average.wasm
-c6f59836ce3f0b2206134ee93215da39f37658cdabd5e90fb40c216ea0f1d694  ./target/wasm32-unknown-unknown/release/translator.wasm
-b2e0fe6e68f082564019b986128de56aad7eab08b791e3baacc66c784064dd04  ./bazel-clang-bin/oak/server/loader/oak_runner
-6fdb4a4a2c4ec7dab0581dbb5a179c9f66b28834de32c170a4bba74cd46b72e2  ./target/debug/oak_loader
+64e97f2701df8a8967f704a6c657d4fee0a92869d411fa1a512411ec9c0f6c4e  ./target/x86_64-unknown-linux-musl/release/oak_loader

scripts/build_reproducibility_index

@@ -12,14 +12,14 @@ source "$SCRIPTS_DIR/common"
 
 # List of artifacts that are expected to be reproducibly built.
 readonly REPRODUCIBLE_ARTIFACTS=(
-  ./target/wasm32-unknown-unknown/release/*.wasm
-  ./bazel-clang-bin/oak/server/loader/oak_runner
-  ./target/debug/oak_loader
+  # TODO(#865): Include wasm files when they are reproducibly buildable.
+  # ./target/wasm32-unknown-unknown/release/*.wasm
+  ./target/x86_64-unknown-linux-musl/release/oak_loader
 )
 
 # Index file containing hashes of the reproducible artifacts, alongside their file names.
 readonly REPRODUCIBILITY_INDEX='./reproducibility_index'
 
 # Generate the index file by computing the hashes of the artifacts.
 # The index file must be checked in, and
-sha256sum "${REPRODUCIBLE_ARTIFACTS[@]}" > "${REPRODUCIBILITY_INDEX}"
+sha256sum "${REPRODUCIBLE_ARTIFACTS[@]}" | tee "${REPRODUCIBILITY_INDEX}"