tests: Improve test-elf-detection.sh robustness and diagnostics

Author: euanh

scripts/test-elf-detection.sh

@@ -1,23 +1,70 @@
 #!/usr/bin/env bash
+##===----------------------------------------------------------------------===##
+##
+## This source file is part of the SwiftContainerPlugin open source project
+##
+## Copyright (c) 2025 Apple Inc. and the SwiftContainerPlugin project authors
+## Licensed under Apache License v2.0
+##
+## See LICENSE.txt for license information
+## See CONTRIBUTORS.txt for the list of SwiftContainerPlugin project authors
+##
+## SPDX-License-Identifier: Apache-2.0
+##
+##===----------------------------------------------------------------------===##
 
-set -ex -o pipefail
+#
+# This script assumes that the Static Linux SDK has already been installed
+#
 
+log() { printf -- "** %s\n" "$*" >&2; }
+error() { printf -- "** ERROR: %s\n" "$*" >&2; }
+fatal() { error "$@"; exit 1; }
+
+set -euo pipefail
+
+RUNTIME=${RUNTIME-"docker"}
+
+#
+# Create a test package
+#
 PKGPATH=$(mktemp -d)
 swift package --package-path "$PKGPATH" init --type executable --name hello
 
+cleanup() {
+  log "Deleting temporary package $PKGPATH"
+  rm -rf "$PKGPATH"
+}
+trap cleanup EXIT
+
+#
 # Build and package an x86_64 binary
+#
 swift build --package-path "$PKGPATH" --swift-sdk x86_64-swift-linux-musl
-file "$PKGPATH/.build/x86_64-swift-linux-musl/debug/hello"
+FILETYPE=$(file "$PKGPATH/.build/x86_64-swift-linux-musl/debug/hello")
+log "Executable type: $FILETYPE"
+
 IMGREF=$(swift run containertool --repository localhost:5000/elf_test "$PKGPATH/.build/x86_64-swift-linux-musl/debug/hello" --from scratch)
-docker pull "$IMGREF"
-docker inspect "$IMGREF" --format "{{.Architecture}}" | grep amd64
-echo x86_64 detection: PASSED
+$RUNTIME pull "$IMGREF"
+IMGARCH=$($RUNTIME inspect "$IMGREF" --format "{{.Architecture}}")
+if [ "$IMGARCH" = "amd64" ] ; then
+  log "x86_64 detection: PASSED"
+else
+  fatal "x86_64 detection: FAILED - image architecture was $IMGARCH; expected amd64"
+fi
 
+#
 # Build and package an aarch64 binary
+#
 swift build --package-path "$PKGPATH" --swift-sdk aarch64-swift-linux-musl
-file "$PKGPATH/.build/aarch64-swift-linux-musl/debug/hello"
-IMGREF=$(swift run containertool --repository localhost:5000/elf_test "$PKGPATH/.build/aarch64-swift-linux-musl/debug/hello" --from scratch)
-docker pull "$IMGREF"
-docker inspect "$IMGREF" --format "{{.Architecture}}" | grep arm64
+FILETYPE=$(file "$PKGPATH/.build/x86_64-swift-linux-musl/debug/hello")
+log "Executable type: $FILETYPE"
 
-echo aarch64 detection: PASSED
+IMGREF=$(swift run containertool --repository localhost:5000/elf_test "$PKGPATH/.build/aarch64-swift-linux-musl/debug/hello" --from scratch)
+$RUNTIME pull "$IMGREF"
+IMGARCH=$($RUNTIME inspect "$IMGREF" --format "{{.Architecture}}")
+if [ "$IMGARCH" = "arm64" ] ; then
+  log "aarch64 detection: PASSED"
+else
+  fatal "aarch64 detection: FAILED - image architecture was $IMGARCH; expected arm64"
+fi