commit e2cac6148b9e1357596e545900b40acd9509749c
author Jae Hoon Kim <kimjae@chromium.org> Mon Nov 02 18:30:29 2020 -0800
committer Commit Bot <commit-bot@chromium.org> Tue Nov 10 00:17:27 2020 +0000
tree d55f650c01477bae990e21fdf50f15a905b19389
parent 5611cd3e418bc1e7451d4247daef836077efa9a0

update_engine: Support DLC Cohorts

UE at the moment doesn't send the correct cohorts to Omaha for DLCs. In
fact, the platform cohorts that are persisted are used for all DLCs.
This is incorrect and this CL fixes it.

```
Example DLC Response:
... cohort="1:7:" cohortname="eve_dlc_pita_canary"...

localhost ~ # ls /var/lib/update_engine/prefs/dlc/pita/omaha-cohort*
/var/lib/update_engine/prefs/dlc/pita/omaha-cohort
/var/lib/update_engine/prefs/dlc/pita/omaha-cohort-name
localhost ~ # cat /var/lib/update_engine/prefs/dlc/pita/omaha-cohort
1:7:
localhost ~ # cat
/var/lib/update_engine/prefs/dlc/pita/omaha-cohort-name
eve_dlc_pita_canary
```

BUG=b:162463872
TEST=FEATURES=test emerge-$B update_engine
TEST=# cros deploy + comment above

Change-Id: Ie503f0a63d3b19a51abb88379cb2e8f85919858b
Reviewed-on: https://chromium-review.googlesource.com/c/aosp/platform/system/update_engine/+/2515072
Tested-by: Jae Hoon Kim <kimjae@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
Commit-Queue: Jae Hoon Kim <kimjae@chromium.org>

cros/omaha_request_action.cc

diff --git a/cros/omaha_request_action.cc b/cros/omaha_request_action.cc
index 0916f9d..51c0ac9 100644
--- a/cros/omaha_request_action.cc
+++ b/cros/omaha_request_action.cc
@@ -763,17 +763,7 @@
   }
 
   // We persist the cohorts sent by omaha even if the status is "noupdate".
-  for (const auto& app : parser_data->apps) {
-    if (app.id == params_->GetAppId()) {
-      if (app.cohort)
-        PersistCohortData(kPrefsOmahaCohort, app.cohort.value());
-      if (app.cohorthint)
-        PersistCohortData(kPrefsOmahaCohortHint, app.cohorthint.value());
-      if (app.cohortname)
-        PersistCohortData(kPrefsOmahaCohortName, app.cohortname.value());
-      break;
-    }
-  }
+  PersistCohorts(*parser_data);
 
   PersistEolInfo(parser_data->updatecheck_attrs);
 
@@ -1398,16 +1388,53 @@
   return true;
 }
 
-bool OmahaRequestAction::PersistCohortData(const string& prefs_key,
-                                           const string& new_value) {
-  if (new_value.empty() && system_state_->prefs()->Exists(prefs_key)) {
-    LOG(INFO) << "Removing stored " << prefs_key << " value.";
-    return system_state_->prefs()->Delete(prefs_key);
-  } else if (!new_value.empty()) {
-    LOG(INFO) << "Storing new setting " << prefs_key << " as " << new_value;
-    return system_state_->prefs()->SetString(prefs_key, new_value);
+void OmahaRequestAction::PersistCohortData(const string& prefs_key,
+                                           const Optional<string>& new_value) {
+  if (!new_value)
+    return;
+  const string& value = new_value.value();
+  if (value.empty() && system_state_->prefs()->Exists(prefs_key)) {
+    if (!system_state_->prefs()->Delete(prefs_key))
+      LOG(ERROR) << "Failed to remove stored " << prefs_key << "value.";
+    else
+      LOG(INFO) << "Removed stored " << prefs_key << " value.";
+  } else if (!value.empty()) {
+    if (!system_state_->prefs()->SetString(prefs_key, value))
+      LOG(INFO) << "Failed to store new setting " << prefs_key << " as "
+                << value;
+    else
+      LOG(INFO) << "Stored cohort setting " << prefs_key << " as " << value;
   }
-  return true;
+}
+
+void OmahaRequestAction::PersistCohorts(const OmahaParserData& parser_data) {
+  for (const auto& app : parser_data.apps) {
+    // For platform App ID.
+    if (app.id == params_->GetAppId()) {
+      PersistCohortData(kPrefsOmahaCohort, app.cohort);
+      PersistCohortData(kPrefsOmahaCohortName, app.cohortname);
+      PersistCohortData(kPrefsOmahaCohortHint, app.cohorthint);
+    } else if (params_->IsDlcAppId(app.id)) {
+      string dlc_id;
+      if (!params_->GetDlcId(app.id, &dlc_id)) {
+        LOG(WARNING) << "Skip persisting cohorts for DLC App ID=" << app.id
+                     << " as it is not in the request params.";
+        continue;
+      }
+      PrefsInterface* prefs = system_state_->prefs();
+      PersistCohortData(
+          prefs->CreateSubKey({kDlcPrefsSubDir, dlc_id, kPrefsOmahaCohort}),
+          app.cohort);
+      PersistCohortData(
+          prefs->CreateSubKey({kDlcPrefsSubDir, dlc_id, kPrefsOmahaCohortName}),
+          app.cohortname);
+      PersistCohortData(
+          prefs->CreateSubKey({kDlcPrefsSubDir, dlc_id, kPrefsOmahaCohortHint}),
+          app.cohorthint);
+    } else {
+      LOG(WARNING) << "Skip persisting cohorts for unknown App ID=" << app.id;
+    }
+  }
 }
 
 bool OmahaRequestAction::PersistEolInfo(const map<string, string>& attrs) {