DSL: introduce on_config_committed

refs #3520

lib/cli/daemonutility.cpp

@@ -7,6 +7,7 @@
 #include "base/logger.hpp"
 #include "base/application.hpp"
 #include "base/scriptglobal.hpp"
+#include "config/commitcontext.hpp"
 #include "config/configcompiler.hpp"
 #include "config/configcompilercontext.hpp"
 #include "config/configitembuilder.hpp"
@@ -240,6 +241,7 @@ bool DaemonUtility::LoadConfigFiles(const std::vector<std::string>& configs,
 	std::vector<ConfigItem::Ptr>& newItems,
 	const String& objectsFile, const String& varsfile)
 {
+	CommitContext cc;
 	ActivationScope ascope;
 
 	if (!DaemonUtility::ValidateConfigFiles(configs, objectsFile)) {
@@ -254,7 +256,7 @@ bool DaemonUtility::LoadConfigFiles(const std::vector<std::string>& configs,
 
 	WorkQueue upq(25000, Configuration::Concurrency);
 	upq.SetName("DaemonUtility::LoadConfigFiles");
-	bool result = ConfigItem::CommitItems(ascope.GetContext(), upq, newItems);
+	bool result = ConfigItem::CommitItems(ascope.GetContext(), upq, newItems) && cc.RunOnConfigCommitted();
 
 	if (!result) {
 		ConfigCompilerContext::GetInstance()->CancelObjectsFile();

lib/config/CMakeLists.txt

@@ -22,6 +22,7 @@ set(config_SOURCES
   i2-config.hpp
   activationcontext.cpp activationcontext.hpp
   applyrule.cpp applyrule-targeted.cpp applyrule.hpp
+  commitcontext.cpp commitcontext.hpp
   configcompiler.cpp configcompiler.hpp
   configcompilercontext.cpp configcompilercontext.hpp
   configfragment.hpp

lib/config/commitcontext.cpp

@@ -0,0 +1,7 @@
+/* Icinga 2 | (c) 2019 Icinga GmbH | GPLv2+ */
+
+#include "config/commitcontext.hpp"
+
+using namespace icinga;
+
+thread_local CommitContext* CommitContext::m_Current = nullptr;

lib/config/commitcontext.hpp

@@ -0,0 +1,86 @@
+/* Icinga 2 | (c) 2019 Icinga GmbH | GPLv2+ */
+
+#ifndef COMMITCONTEXT_H
+#define COMMITCONTEXT_H
+
+#include "base/debug.hpp"
+#include "base/exception.hpp"
+#include "base/logger.hpp"
+#include "base/scriptframe.hpp"
+#include "config/expression.hpp"
+#include <exception>
+#include <memory>
+#include <utility>
+#include <vector>
+
+namespace icinga
+{
+
+class CommitContext
+{
+public:
+	static inline
+	CommitContext* GetCurrent()
+	{
+		return m_Current;
+	}
+
+	inline CommitContext() : m_Started(false)
+	{
+		VERIFY(!m_Current);
+
+		m_Current = this;
+	}
+
+	CommitContext(const CommitContext&) = delete;
+	CommitContext(CommitContext&&) = delete;
+	CommitContext& operator=(const CommitContext&) = delete;
+	CommitContext& operator=(CommitContext&&) = delete;
+
+	inline ~CommitContext()
+	{
+		VERIFY(m_Current);
+
+		m_Current = nullptr;
+	}
+
+	inline void RegisterOnConfigCommitted(std::shared_ptr<Expression> expr)
+	{
+		m_OnConfigCommitted.emplace_back(std::move(expr));
+	}
+
+	inline bool RunOnConfigCommitted()
+	{
+		m_Started = true;
+
+		for (auto& expr : m_OnConfigCommitted) {
+			if (!expr)
+				return false;
+
+			try {
+				ScriptFrame frame(false);
+				expr->Evaluate(frame);
+			} catch (const std::exception& ex) {
+				Log(LogCritical, "config", DiagnosticInformation(ex));
+				return false;
+			}
+		}
+
+		return true;
+	}
+
+	inline bool HasStarted()
+	{
+		return m_Started;
+	}
+
+private:
+	static thread_local CommitContext* m_Current;
+
+	std::vector<std::shared_ptr<Expression>> m_OnConfigCommitted;
+	bool m_Started;
+};
+
+}
+
+#endif /* COMMITCONTEXT_H */

lib/config/config_lexer.ll

@@ -156,6 +156,7 @@ template			return T_TEMPLATE;
 include				return T_INCLUDE;
 include_recursive		return T_INCLUDE_RECURSIVE;
 include_zones			return T_INCLUDE_ZONES;
+on_config_committed		return T_ON_CONFIG_COMMITTED;
 library				return T_LIBRARY;
 null				return T_NULL;
 true				{ yylval->boolean = 1; return T_BOOLEAN; }

lib/config/config_parser.yy

@@ -140,6 +140,7 @@ static void MakeRBinaryOp(Expression** result, Expression *left, Expression *rig
 %token T_INCLUDE "include (T_INCLUDE)"
 %token T_INCLUDE_RECURSIVE "include_recursive (T_INCLUDE_RECURSIVE)"
 %token T_INCLUDE_ZONES "include_zones (T_INCLUDE_ZONES)"
+%token T_ON_CONFIG_COMMITTED "on_config_committed (T_ON_CONFIG_COMMITTED)"
 %token T_LIBRARY "library (T_LIBRARY)"
 %token T_APPLY "apply (T_APPLY)"
 %token T_TO "to (T_TO)"
@@ -195,6 +196,7 @@ static void MakeRBinaryOp(Expression** result, Expression *left, Expression *rig
 
 %right T_FOLLOWS
 %right T_INCLUDE T_INCLUDE_RECURSIVE T_INCLUDE_ZONES T_OBJECT T_TEMPLATE T_APPLY T_IMPORT T_ASSIGN T_IGNORE T_WHERE
+%right T_ON_CONFIG_COMMITTED
 %right T_FUNCTION T_FOR
 %left T_SET T_SET_ADD T_SET_SUBTRACT T_SET_MULTIPLY T_SET_DIVIDE T_SET_MODULO T_SET_XOR T_SET_BINARY_AND T_SET_BINARY_OR
 %right '?' ':'
@@ -563,6 +565,10 @@ lterm: T_LIBRARY rterm
 
 		$$ = MakeLiteralRaw();
 	}
+	| T_ON_CONFIG_COMMITTED rterm
+	{
+		$$ = new OnConfigCommittedExpression(std::shared_ptr<Expression>($2), @$);
+	}
 	| T_RETURN optional_rterm
 	{
 		UseFlowControl(context, FlowControlReturn, @$);

lib/config/expression.cpp

@@ -1,6 +1,7 @@
 /* Icinga 2 | (c) 2012 Icinga GmbH | GPLv2+ */
 
 #include "config/expression.hpp"
+#include "config/commitcontext.hpp"
 #include "config/configitem.hpp"
 #include "config/configcompiler.hpp"
 #include "config/vmops.hpp"
@@ -1046,6 +1047,22 @@ ExpressionResult IncludeExpression::DoEvaluate(ScriptFrame& frame, DebugHint *dh
 	return res;
 }
 
+ExpressionResult OnConfigCommittedExpression::DoEvaluate(ScriptFrame& frame, DebugHint *dhint) const
+{
+	if (frame.Sandboxed)
+		BOOST_THROW_EXCEPTION(ScriptError("on_config_committed is not allowed in sandbox mode.", m_DebugInfo));
+
+	auto cc (CommitContext::GetCurrent());
+
+	if (!cc || cc->HasStarted()) {
+		BOOST_THROW_EXCEPTION(ScriptError("on_config_committed is not allowed after the config has been committed.", m_DebugInfo));
+	}
+
+	cc->RegisterOnConfigCommitted(m_Expr);
+
+	return Empty;
+}
+
 ExpressionResult BreakpointExpression::DoEvaluate(ScriptFrame& frame, DebugHint *dhint) const
 {
 	ScriptBreakpoint(frame, nullptr, GetDebugInfo());

lib/config/expression.hpp

@@ -955,6 +955,20 @@ private:
 	String m_Package;
 };
 
+class OnConfigCommittedExpression final : public DebuggableExpression
+{
+public:
+	OnConfigCommittedExpression(std::shared_ptr<Expression> expr, const DebugInfo& debugInfo = DebugInfo())
+		: DebuggableExpression(debugInfo), m_Expr(std::move(expr))
+	{ }
+
+protected:
+	ExpressionResult DoEvaluate(ScriptFrame& frame, DebugHint *dhint) const override;
+
+private:
+	std::shared_ptr<Expression> m_Expr;
+};
+
 class BreakpointExpression final : public DebuggableExpression
 {
 public: