fix: make Linux installation permissions deterministic

scripts/test-update-fixture.sh

@@ -11,6 +11,10 @@ fail() {
   exit 1
 }
 
+mode_of() {
+  stat -c '%a' "$1" 2>/dev/null || stat -f '%Lp' "$1"
+}
+
 sed -n '/^is_semver()/,/^}/p' "$ROOT/deploy/update.sh" > "$WORK/update-semver.sh"
 # shellcheck disable=SC1090,SC1091
 source "$WORK/update-semver.sh"
@@ -21,6 +25,20 @@ for version in 01.2.3 1.02.3 1.2.03 1.2.3-01 1.2.3-alpha..1; do
   ! is_semver "$version" || fail "updater accepted invalid SemVer $version"
 done
 
+missing_service_user="kaidi-fixture-missing-$$"
+if KAIDI_APP_ROOT="$WORK/bootstrap/app" \
+  KAIDI_UPDATE_STATE_ROOT="$WORK/bootstrap/state" \
+  KAIDI_LOG_ROOT="$WORK/bootstrap/log" \
+  KAIDI_SERVICE_USER="$missing_service_user" \
+  KAIDI_SERVICE_GROUP="$missing_service_user" \
+  sh "$ROOT/deploy/update.sh" > "$WORK/bootstrap.log" 2>&1; then
+  fail 'updater accepted a missing service identity during bootstrap'
+fi
+grep -Fq "Service user $missing_service_user is missing" "$WORK/bootstrap.log" \
+  || fail 'updater bootstrap failure did not preserve its diagnostic'
+! grep -Eq 'No such file|nonexistent directory|cannot create' "$WORK/bootstrap.log" \
+  || fail 'updater bootstrap failure was masked by an unavailable status directory'
+
 write_mock_commands() {
   local mock_bin=$1
   mkdir -p "$mock_bin"
@@ -99,6 +117,33 @@ SH
   cat > "$mock_bin/chown" <<'SH'
 #!/bin/sh
 exit 0
+SH
+
+  cat > "$mock_bin/runuser" <<'SH'
+#!/bin/sh
+[ "${1:-}" = -u ] || exit 2
+shift 2
+[ "${1:-}" = -- ] && shift
+exec "$@"
+SH
+
+  cat > "$mock_bin/install" <<'SH'
+#!/usr/bin/env bash
+if [[ " $* " != *" -d "* ]]; then
+  exec /usr/bin/install "$@"
+fi
+mode=0755
+paths=()
+while [ "$#" -gt 0 ]; do
+  case "$1" in
+    -d) shift ;;
+    -o|-g) shift 2 ;;
+    -m) mode=$2; shift 2 ;;
+    *) paths+=("$1"); shift ;;
+  esac
+done
+mkdir -p "${paths[@]}"
+chmod "$mode" "${paths[@]}"
 SH
 
   cat > "$mock_bin/mv" <<'SH'
@@ -170,13 +215,18 @@ prepare_installation() {
   local fixture=$1
   local version=$2
   mkdir -p "$fixture/app/releases/1.0.0-preview.1/public" "$fixture/app/bin" \
-    "$fixture/state/inbox" "$fixture/systemd" "$fixture/log"
+    "$fixture/app/runtime/java/bin" "$fixture/state/inbox" "$fixture/systemd" "$fixture/log"
   printf 'old application\n' > "$fixture/app/releases/1.0.0-preview.1/app.jar"
   printf '<!doctype html><title>old</title>\n' > "$fixture/app/releases/1.0.0-preview.1/public/index.html"
   printf '1.0.0-preview.1\n' > "$fixture/app/releases/1.0.0-preview.1/VERSION"
   ln -s "$fixture/app/releases/1.0.0-preview.1" "$fixture/app/current"
   printf 'old update.sh\n' > "$fixture/app/bin/update.sh"
   chmod 0755 "$fixture/app/bin/update.sh"
+  cat > "$fixture/app/runtime/java/bin/java" <<'SH'
+#!/bin/sh
+exit 0
+SH
+  chmod 0755 "$fixture/app/runtime/java/bin/java"
   for name in kaidi-finance.service kaidi-update.service kaidi-update.path; do
     printf 'old %s\n' "$name" > "$fixture/systemd/$name"
   done
@@ -222,6 +272,8 @@ run_update() {
     MOCK_RELEASE_ORIGIN="${FIXTURE_RELEASE_ORIGIN:-https://release.fixture.invalid}" \
     MOCK_EXPECT_RELEASE_TOKEN="${FIXTURE_RELEASE_TOKEN-}" \
     MOCK_SYSTEMCTL_LOG="$fixture/systemctl.log" \
+    KAIDI_SERVICE_USER="$(id -un)" \
+    KAIDI_SERVICE_GROUP="$(id -gn)" \
     KAIDI_APP_ROOT="$fixture/app" \
     KAIDI_UPDATE_STATE_ROOT="$fixture/state" \
     KAIDI_LOG_ROOT="$fixture/log" \
@@ -310,6 +362,10 @@ assert_success_case() {
     || fail 'success case left a claimed request behind'
   grep -qx 'daemon-reload' "$fixture/systemctl.log" || fail 'systemd units were not reloaded'
   ! grep -qi nginx "$fixture/systemctl.log" || fail 'updater unexpectedly managed Nginx'
+  [ "$(mode_of "$fixture/app")" = 750 ] || fail 'application root is not traversable by the service group'
+  [ "$(mode_of "$fixture/app/releases/$version")" = 750 ] || fail 'release root mode is not 0750'
+  [ "$(mode_of "$fixture/app/current/app.jar")" = 640 ] || fail 'release file mode is not 0640'
+  [ "$(mode_of "$fixture/app/current/ops/update.sh")" = 750 ] || fail 'release updater mode is not 0750'
 }
 
 assert_rollback_case() {