chore: harden hotpath profiling artifact collection (#5848)

Co-authored-by: heihutu <heihutu@gmail.com>

scripts/test_collect_remote_samply_artifacts.sh

@@ -0,0 +1,80 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+repo_root=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
+tmp_dir=$(mktemp -d)
+trap 'rm -rf "$tmp_dir"' EXIT
+
+mock_bin="$tmp_dir/bin"
+mkdir -p "$mock_bin"
+
+cat >"$mock_bin/ssh" <<'EOF'
+#!/usr/bin/env bash
+set -euo pipefail
+printf 'ssh:%s\n' "$*" >>"$CALL_LOG"
+echo "profile.json.gz 128 bytes"
+echo "profile.syms.json 64 bytes"
+EOF
+
+cat >"$mock_bin/scp" <<'EOF'
+#!/usr/bin/env bash
+set -euo pipefail
+if read -r consumed; then
+  printf 'scp-consumed-stdin:%s\n' "$consumed" >>"$CALL_LOG"
+  exit 23
+fi
+printf 'scp:%s\n' "$*" >>"$CALL_LOG"
+dest="${@: -1}"
+mkdir -p "$dest"
+touch "$dest/copied-profile.json.gz"
+EOF
+
+chmod +x "$mock_bin/ssh" "$mock_bin/scp"
+
+mapping="$tmp_dir/nodes.txt"
+cat >"$mapping" <<'EOF'
+vm004 /data/rustfs/hotpath/put-1m
+vm005 /data/rustfs/hotpath/get-1m
+EOF
+
+export CALL_LOG="$tmp_dir/calls.log"
+output=$("$repo_root/scripts/collect_remote_samply_artifacts.sh" \
+  --mapping "$mapping" \
+  --out-dir "$tmp_dir/out" \
+  --ssh-bin "$mock_bin/ssh" \
+  --scp-bin "$mock_bin/scp")
+
+[[ "$output" == "collected_nodes=2" ]]
+[[ -f "$tmp_dir/out/vm004/copied-profile.json.gz" ]]
+[[ -f "$tmp_dir/out/vm005/copied-profile.json.gz" ]]
+[[ "$(grep -c '^scp:' "$CALL_LOG")" -eq 2 ]]
+if grep -q '^scp-consumed-stdin:' "$CALL_LOG"; then
+  echo "scp consumed the mapping loop stdin" >&2
+  exit 1
+fi
+
+bad_mapping="$tmp_dir/bad-nodes.txt"
+printf 'vm004 /\n' >"$bad_mapping"
+if "$repo_root/scripts/collect_remote_samply_artifacts.sh" \
+  --mapping "$bad_mapping" \
+  --out-dir "$tmp_dir/bad-out" \
+  --ssh-bin "$mock_bin/ssh" \
+  --scp-bin "$mock_bin/scp" >"$tmp_dir/bad.stdout" 2>"$tmp_dir/bad.stderr"; then
+  echo "unsafe remote directory was accepted" >&2
+  exit 1
+fi
+grep -q 'path contains unsafe characters' "$tmp_dir/bad.stderr"
+
+unsafe_mapping="$tmp_dir/unsafe-nodes.txt"
+printf 'vm004 /data/rustfs/hotpath/put;rm\n' >"$unsafe_mapping"
+if "$repo_root/scripts/collect_remote_samply_artifacts.sh" \
+  --mapping "$unsafe_mapping" \
+  --out-dir "$tmp_dir/unsafe-out" \
+  --ssh-bin "$mock_bin/ssh" \
+  --scp-bin "$mock_bin/scp" >"$tmp_dir/unsafe.stdout" 2>"$tmp_dir/unsafe.stderr"; then
+  echo "unsafe remote path was accepted" >&2
+  exit 1
+fi
+grep -q 'path contains unsafe characters' "$tmp_dir/unsafe.stderr"
+
+echo "test_collect_remote_samply_artifacts: ok"