Introduce EnvResolver

refs #6259

lib/icinga/CMakeLists.txt

@@ -41,6 +41,7 @@ set(icinga_SOURCES
   customvarobject.cpp customvarobject.hpp customvarobject-ti.hpp
   dependency.cpp dependency.hpp dependency-ti.hpp dependency-apply.cpp
   downtime.cpp downtime.hpp downtime-ti.hpp
+  envresolver.cpp envresolver.hpp
   eventcommand.cpp eventcommand.hpp eventcommand-ti.hpp
   externalcommandprocessor.cpp externalcommandprocessor.hpp
   host.cpp host.hpp host-ti.hpp

lib/icinga/envresolver.cpp

@@ -0,0 +1,20 @@
+/* Icinga 2 | (c) 2020 Icinga GmbH | GPLv2+ */
+
+#include "base/string.hpp"
+#include "base/value.hpp"
+#include "icinga/envresolver.hpp"
+#include "icinga/checkresult.hpp"
+#include <cstdlib>
+
+using namespace icinga;
+
+bool EnvResolver::ResolveMacro(const String& macro, const CheckResult::Ptr&, Value *result) const
+{
+	auto value (getenv(macro.CStr()));
+
+	if (value) {
+		*result = value;
+	}
+
+	return value;
+}

lib/icinga/envresolver.hpp

@@ -0,0 +1,30 @@
+/* Icinga 2 | (c) 2020 Icinga GmbH | GPLv2+ */
+
+#ifndef ENVRESOLVER_H
+#define ENVRESOLVER_H
+
+#include "base/object.hpp"
+#include "base/string.hpp"
+#include "base/value.hpp"
+#include "icinga/macroresolver.hpp"
+#include "icinga/checkresult.hpp"
+
+namespace icinga
+{
+
+/**
+ * Resolves env var names.
+ *
+ * @ingroup icinga
+ */
+class EnvResolver final : public Object, public MacroResolver
+{
+public:
+	DECLARE_PTR_TYPEDEFS(EnvResolver);
+
+	bool ResolveMacro(const String& macro, const CheckResult::Ptr&, Value *result) const override;
+};
+
+}
+
+#endif /* ENVRESOLVER_H */