[#3025] add ability to inherit env in ProcessSpawn

src/lib/asiolink/process_spawn.cc

@@ -9,10 +9,12 @@
 #include <asiolink/io_service_signal.h>
 #include <asiolink/process_spawn.h>
 #include <exceptions/exceptions.h>
-#include <cstring>
+
 #include <functional>
 #include <map>
 #include <mutex>
+
+#include <cstring>
 #include <signal.h>
 #include <stdlib.h>
 #include <errno.h>
@@ -25,6 +27,8 @@
 using namespace std;
 namespace ph = std::placeholders;
 
+extern char **environ;
+
 namespace isc {
 namespace asiolink {
 
@@ -77,10 +81,13 @@ public:
     /// @param executable A full path to the program to be executed.
     /// @param args Arguments for the program to be executed.
     /// @param vars Environment variables for the program to be executed.
+    /// @param inherit_env whether the spawned process will inherit the
+    ///        environment before adding 'vars' on top.
     ProcessSpawnImpl(IOServicePtr io_service,
                      const std::string& executable,
                      const ProcessArgs& args,
-                     const ProcessEnvVars& vars);
+                     const ProcessEnvVars& vars,
+                     const bool inherit_env);
 
     /// @brief Destructor.
     ~ProcessSpawnImpl();
@@ -238,9 +245,24 @@ void ProcessSpawnImpl::IOSignalSetInitializer::initIOSignalSet(IOServicePtr io_s
 ProcessSpawnImpl::ProcessSpawnImpl(IOServicePtr io_service,
                                    const std::string& executable,
                                    const ProcessArgs& args,
-                                   const ProcessEnvVars& vars)
+                                   const ProcessEnvVars& vars,
+                                   const bool inherit_env)
     : executable_(executable), args_(new char*[args.size() + 2]),
-      vars_(new char*[vars.size() + 1]), store_(false), io_service_(io_service) {
+      store_(false), io_service_(io_service) {
+
+    // Size of vars except the trailing null
+    size_t vars_size;
+    if (inherit_env) {
+        size_t i(0);
+        while (environ[i]) {
+            ++i;
+        }
+        vars_size = i + vars.size();
+    } else {
+        vars_size = vars.size();
+    }
+
+    vars_ = boost::shared_ptr<char*[]>(new char*[vars_size + 1]);
 
     struct stat st;
 
@@ -256,16 +278,23 @@ ProcessSpawnImpl::ProcessSpawnImpl(IOServicePtr io_service,
     // all pointers within an array to NULL to indicate that they haven't
     // been allocated yet.
     memset(args_.get(), 0, (args.size() + 2) * sizeof(char*));
-    memset(vars_.get(), 0, (vars.size() + 1) * sizeof(char*));
+    memset(vars_.get(), 0, (vars_size + 1) * sizeof(char*));
     // By convention, the first argument points to an executable name.
     args_[0] = allocateInternal(executable_);
     // Copy arguments to the array.
-    for (int i = 1; i <= args.size(); ++i) {
+    for (size_t i = 1; i <= args.size(); ++i) {
         args_[i] = allocateInternal(args[i - 1]);
     }
     // Copy environment variables to the array.
-    for (int i = 0; i < vars.size(); ++i) {
+    size_t i(0);
-        vars_[i] = allocateInternal(vars[i]);
+    if (inherit_env) {
+        while (environ[i]) {
+            vars_[i] = allocateInternal(environ[i]);
+            ++i;
+        }
+    }
+    for (size_t j = 0; j < vars.size(); ++j) {
+        vars_[i + j] = allocateInternal(vars[j]);
     }
 }
 
@@ -410,8 +439,9 @@ ProcessSpawnImpl::clearState(const pid_t pid) {
 ProcessSpawn::ProcessSpawn(IOServicePtr io_service,
                            const std::string& executable,
                            const ProcessArgs& args,
-                           const ProcessEnvVars& vars)
+                           const ProcessEnvVars& vars,
-    : impl_(new ProcessSpawnImpl(io_service, executable, args, vars)) {
+                           const bool inherit_env /* = false */)
+    : impl_(new ProcessSpawnImpl(io_service, executable, args, vars, inherit_env)) {
 }
 
 std::string

src/lib/asiolink/process_spawn.h

@@ -67,10 +67,13 @@ public:
     /// @param executable A full path to the program to be executed.
     /// @param args Arguments for the program to be executed.
     /// @param vars Environment variables for the program to be executed.
+    /// @param inherit_env whether the spawned process will inherit the
+    ///        environment before adding 'vars' on top.
     ProcessSpawn(isc::asiolink::IOServicePtr io_service,
                  const std::string& executable,
                  const ProcessArgs& args = ProcessArgs(),
-                 const ProcessEnvVars& vars = ProcessEnvVars());
+                 const ProcessEnvVars& vars = ProcessEnvVars(),
+                 const bool inherit_env = false);
 
     /// @brief Destructor.
     ~ProcessSpawn() = default;

src/lib/asiolink/tests/process_spawn_app.sh.in

@@ -28,48 +28,45 @@
 # used.
 set -eu
 
-exit_code=
+exit_code=0
 
-while test "${#}" -gt 0
+# The exit code of 32 is returned when no args specified.
-do
+if test "${#}" = 0; then
+    exit_code=32
+fi
+
+while test "${#}" -gt 0; do
     option=${1}
+    shift
     case ${option} in
         -p)
             exit_code=${$}
             ;;
         -e)
-            shift
             exit_code=${1-}
+            shift
             ;;
         -s)
+            sleep "${1-0}"
+            exit_code=12
             shift
-            sleep "${1}"
             ;;
         -v)
-            shift
             VAR_NAME=${1}
             shift
             VAR_VALUE=${1}
-            EXPECTED=$(env | grep -E "^${VAR_NAME}=")
+            shift
+            EXPECTED=$(env | grep -E "^${VAR_NAME}=" || true)
             if ! test "${VAR_NAME}=${VAR_VALUE}" = "${EXPECTED}"; then
-                exit 123
+                exit_code=34
+            else
+                exit_code=56
             fi
             ;;
         *)
-            exit 123
+            exit_code=78
             ;;
     esac
-    # We've shifted in the loop so we may have run out of parameters in the
-    # meantime. Check again.
-    if test "${#}" -gt 0; then
-      shift
-    fi
 done
 
-# The exit code of 32 is returned when no args specified or
-# when only the -s arg has been specified.
-if [ -z "${exit_code}" ]; then
-    exit 32
-fi
-
 exit "${exit_code}"

src/lib/asiolink/tests/process_spawn_unittest.cc

@@ -128,6 +128,7 @@ TEST_F(ProcessSpawnTest, spawnWithArgs) {
     ASSERT_EQ(1, processed_signals_.size());
     ASSERT_EQ(SIGCHLD, processed_signals_[0]);
 
+    // Exit code 64 as requested.
     EXPECT_EQ(64, process.getExitStatus(pid));
 }
 
@@ -161,7 +162,8 @@ TEST_F(ProcessSpawnTest, spawnWithArgsAndEnvVars) {
     ASSERT_EQ(1, processed_signals_.size());
     ASSERT_EQ(SIGCHLD, processed_signals_[0]);
 
-    EXPECT_EQ(32, process.getExitStatus(pid));
+    // 56 means successful comparison of env vars.
+    EXPECT_EQ(56, process.getExitStatus(pid));
 }
 
 // This test verifies that the single ProcessSpawn object can be used
@@ -245,6 +247,7 @@ TEST_F(ProcessSpawnTest, spawnNoArgs) {
     ASSERT_EQ(1, processed_signals_.size());
     ASSERT_EQ(SIGCHLD, processed_signals_[0]);
 
+    // 32 means no args.
     EXPECT_EQ(32, process.getExitStatus(pid));
 
     ASSERT_NO_THROW(pid = process.spawn(true));
@@ -347,4 +350,71 @@ TEST_F(ProcessSpawnTest, isRunning) {
     ASSERT_EQ(SIGCHLD, processed_signals_[0]);
 }
 
+// This test verifies inheritance of environment.
+TEST_F(ProcessSpawnTest, inheritEnv) {
+    // Run the process which sleeps for 10 seconds, so as we have
+    // enough time to check if it is running.
+    vector<string> args{"-v", "VAR", "value"};
+
+    ProcessEnvVars vars{"VAR=value"};
+
+    ProcessSpawn process(io_service_, TEST_SCRIPT_SH, args, vars,
+                         /* inherit_env = */ true);
+    pid_t pid = 0;
+    ASSERT_NO_THROW(pid = process.spawn());
+
+    // Set test fail safe.
+    setTestTime(1000);
+
+    // The next handler executed is IOSignal's handler.
+    io_service_->runOne();
+
+    // The first handler executed is the IOSignal's internal timer expire
+    // callback.
+    io_service_->runOne();
+
+    // Polling once to be sure.
+    io_service_->poll();
+
+    ASSERT_EQ(1, processed_signals_.size());
+    ASSERT_EQ(SIGCHLD, processed_signals_[0]);
+
+    // 56 means successful comparison of env vars.
+    EXPECT_EQ(56, process.getExitStatus(pid));
+}
+
+// This test verifies inheritance of environment when a variable is inherited
+// from parent. It assumes PATH is set.
+TEST_F(ProcessSpawnTest, inheritEnvWithParentVar) {
+    // Run the process which sleeps for 10 seconds, so as we have
+    // enough time to check if it is running.
+    vector<string> args{"-v", "PATH", "value"};
+
+    ProcessEnvVars vars{"VAR=value"};
+
+    ProcessSpawn process(io_service_, TEST_SCRIPT_SH, args, vars,
+                         /* inherit_env = */ true);
+    pid_t pid = 0;
+    ASSERT_NO_THROW(pid = process.spawn());
+
+    // Set test fail safe.
+    setTestTime(1000);
+
+    // The next handler executed is IOSignal's handler.
+    io_service_->runOne();
+
+    // The first handler executed is the IOSignal's internal timer expire
+    // callback.
+    io_service_->runOne();
+
+    // Polling once to be sure.
+    io_service_->poll();
+
+    ASSERT_EQ(1, processed_signals_.size());
+    ASSERT_EQ(SIGCHLD, processed_signals_[0]);
+
+    // 34 means failed comparison of env vars.
+    EXPECT_EQ(34, process.getExitStatus(pid));
+}
+
 } // end of anonymous namespace

src/lib/mysql/mysql_connection.cc

@@ -415,11 +415,13 @@ MySqlConnection::initializeSchema(const ParameterMap& parameters) {
 
     // Convert parameters.
     vector<string> kea_admin_parameters(toKeaAdminParameters(parameters));
+    ProcessEnvVars const vars;
     kea_admin_parameters.insert(kea_admin_parameters.begin(), "db-init");
 
     // Run.
     IOServicePtr io_service(new IOService());
-    ProcessSpawn kea_admin(io_service, KEA_ADMIN, kea_admin_parameters);
+    ProcessSpawn kea_admin(io_service, KEA_ADMIN, kea_admin_parameters, vars,
+                           /* inherit_env = */ true);
     DB_LOG_INFO(MYSQL_INITIALIZE_SCHEMA).arg(kea_admin.getCommandLine());
     pid_t const pid(kea_admin.spawn());
     io_service->runOne();

src/lib/pgsql/pgsql_connection.cc

@@ -220,7 +220,8 @@ PgSqlConnection::initializeSchema(const ParameterMap& parameters) {
 
     // Run.
     IOServicePtr io_service(new IOService());
-    ProcessSpawn kea_admin(io_service, KEA_ADMIN, kea_admin_parameters, vars);
+    ProcessSpawn kea_admin(io_service, KEA_ADMIN, kea_admin_parameters, vars,
+                           /* inherit_env = */ true);
     DB_LOG_INFO(PGSQL_INITIALIZE_SCHEMA).arg(kea_admin.getCommandLine());
     pid_t const pid(kea_admin.spawn());
     io_service->runOne();