Partial fix for PRO-4872

This is a partial fix that makes self-update on Aktualizr work, although we
should build a proper solution soon.  It does at least work end-to-end, and
unblocks the remaining testing.

Change-Id: I03d8c1dd461fd21c244145f641d808e8bbdfd450

src/deb.cc

@@ -30,16 +30,25 @@ Json::Value DebianManager::getInstalledPackages() {
 
 data::InstallOutcome DebianManager::install(const Uptane::Target &target) const {
   LOG_INFO << "Installing " << target.filename() << " as Debian package...";
-  std::string cmd = "dpkg -i ";
-  std::string output;
-  TemporaryDirectory package_dir("deb_dir");
-  std::stringstream sstr;
-  sstr << *storage_->openTargetFile(target.filename());
-  boost::filesystem::path deb_path = package_dir / target.filename();
-  Utils::writeFile(deb_path, sstr.str());
 
-  int status = Utils::shell(cmd + deb_path.string(), &output, true);
+  // Install the new package. This is complicated by the fact that it needs to
+  // support self-update, where aktualizr installs a new aktualzr Debian
+  // package.  Removing the old package stops the Aktualizr systemd service,
+  // which causes Aktualizr to get killed. Therefore we perform the
+  // installation in a separate cgroup, using systemd-run.
+  // This is a temporary solution--in the future we should juggle things to
+  // report the installation status correctly.
+  const std::string tmp_deb_file("/tmp/incoming-package.deb", std::ofstream::trunc);  // TODO Make this secure
+  std::ofstream package(tmp_deb_file);
+  package << *storage_->openTargetFile(target.filename());
+  package.close();
+
+  std::string cmd = "systemd-run --no-ask-password dpkg -i " + tmp_deb_file;
+
+  std::string output;
+  int status = Utils::shell(cmd, &output, true);
   if (status == 0) {
+    // This is only checking the result of the systemd-run command
     LOG_INFO << "... Installation of Debian package successful";
     storage_->saveInstalledVersion(target);
     return data::InstallOutcome(data::OK, "Installing debian package was successful");

tests/packagemanager_deb_tests.cc

@@ -26,12 +26,12 @@ TEST(PackageManagerFactory, Debian_Install_Good) {
 
   Json::Value target_json_test;
   target_json_test["hashes"]["sha256"] = "hash_old";
-  target_json_test["length"] = 0;
+  target_json_test["length"] = 5;
   Uptane::Target target_test("test.deb", target_json_test);
   storage->saveInstalledVersion(target_test);
 
-  std::unique_ptr<StorageTargetWHandle> fhandle = storage->allocateTargetFile(false, "good.deb", 2);
-  std::stringstream("ab") >> *fhandle;
+  std::unique_ptr<StorageTargetWHandle> fhandle = storage->allocateTargetFile(false, "good.deb", 5);
+  std::stringstream("GOOD\n") >> *fhandle;
 
   EXPECT_EQ(pacman->install(target).first, data::OK);
   std::map<std::string, InstalledVersion> versions_loaded;

tests/test_data/fake_dpkg/dpkg → tests/test_data/fake_dpkg/systemd-run

@@ -1,8 +1,7 @@
 #!/usr/bin/env bash
 set -e
 
-if [[ "$2" == */good.deb ]]
-then
+if grep -q GOOD "${@: -1}"; then
     exit 0
 else
     echo -ne "Error installing"