Pass verbosity flag to subprocesses as environment variable

Author: jemoreira

base/cvd/cuttlefish/common/libs/utils/tee_logging.cpp

@@ -290,8 +290,8 @@ Result<LogSeverity> ToSeverity(const std::string& value) {
   }
   int value_int;
   CF_EXPECT(android::base::ParseInt(value, &value_int),
-      "Unable to determine severity from \"" << value << "\"");
-  for (const auto& [name, value]: string_to_severity) {
+            "Unable to determine severity from \"" << value << "\"");
+  for (const auto& [name, value] : string_to_severity) {
     if (static_cast<int>(value) == value_int) {
       return value;
     }
@@ -306,11 +306,16 @@ static LogSeverity GuessSeverity(const std::string& env_var,
 }
 
 LogSeverity ConsoleSeverity() {
-  return GuessSeverity("CF_CONSOLE_SEVERITY", LogSeverity::Info);
+  return GuessSeverity(kConsoleSeverityEnvVar, LogSeverity::Info);
 }
 
 LogSeverity LogFileSeverity() {
-  return GuessSeverity("CF_FILE_SEVERITY", LogSeverity::Debug);
+  LogSeverity severity = GuessSeverity(kFileSeverityEnvVar, LogSeverity::Debug);
+  if (severity > LogSeverity::Debug) {
+    // Debug or higher severity logs must always be written to files.
+    return LogSeverity::Debug;
+  }
+  return severity;
 }
 
 void SetLoggers(std::vector<SeverityTarget> destinations,

base/cvd/cuttlefish/common/libs/utils/tee_logging.h

@@ -25,6 +25,9 @@
 
 namespace cuttlefish {
 
+constexpr const char* kConsoleSeverityEnvVar = "CF_CONSOLE_SEVERITY";
+constexpr const char* kFileSeverityEnvVar = "CF_FILE_SEVERITY";
+
 enum class LogSeverity : int {
   Verbose = 0,
   Debug,

base/cvd/cuttlefish/host/commands/cvd/main.cc

@@ -70,6 +70,16 @@ LogSeverity CvdVerbosityOption(cvd_common::Args& all_args) {
     return LogSeverity::Info;
   }
   LogSeverity verbosity = *to_severity_res;
+  // Set environment variables to the requested verbosity for subcommands and
+  // subprocesses to use.
+  if (int res = setenv(kConsoleSeverityEnvVar, verbosity_flag_value.c_str(), 1);
+      res) {
+    PLOG(ERROR) << "Failed to set console log severity environment variable";
+  }
+  if (int res = setenv(kFileSeverityEnvVar, verbosity_flag_value.c_str(), 1);
+      res) {
+    PLOG(ERROR) << "Failed to set file log severity environment variable";
+  }
   return verbosity;
 }