add class for config ownership

4 files changed, 90 insertions, 0 deletions

diff --git a/configd/src/apps/sentinel/CMakeLists.txt b/configd/src/apps/sentinel/CMakeLists.txt
index 765988fa2ef..b20aa4e190a 100644
--- a/configd/src/apps/sentinel/CMakeLists.txt
+++ b/configd/src/apps/sentinel/CMakeLists.txt
@@ -1,6 +1,7 @@
 # Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 vespa_add_executable(configd_config-sentinel_app
     SOURCES
+    config-owner.cpp
     sentinel.cpp
     service.cpp
     manager.cpp
diff --git a/configd/src/apps/sentinel/config-owner.cpp b/configd/src/apps/sentinel/config-owner.cpp
new file mode 100644
index 00000000000..f4ea76855f6
--- /dev/null
+++ b/configd/src/apps/sentinel/config-owner.cpp
@@ -0,0 +1,44 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+#include "config-owner.h"
+#include <vespa/vespalib/util/exceptions.h>
+#include <string>
+
+#include <vespa/log/log.h>
+LOG_SETUP(".config-owner");
+
+namespace config::sentinel {
+
+ConfigOwner::ConfigOwner() : _subscriber() {}
+
+ConfigOwner::~ConfigOwner() = default;
+
+void
+ConfigOwner::subscribe(const std::string & configId, std::chrono::milliseconds timeout) {
+    _sentinelHandle = _subscriber.subscribe<SentinelConfig>(configId, timeout);
+}
+
+void
+ConfigOwner::doConfigure()
+{
+    _currConfig = _sentinelHandle->getConfig();
+    LOG_ASSERT(_currConfig);
+    _currGeneration = _subscriber.getGeneration();
+    const SentinelConfig& config(*_currConfig);
+    const auto & app = config.application;
+    LOG(info, "ConfigOwner got %zd service elements [tenant(%s), application(%s), instance(%s)] for config generation %zd",
+        config.service.size(), app.tenant.c_str(), app.name.c_str(), app.instance.c_str(), _currGeneration);
+}
+
+
+// Return true if there was a config generation change
+bool
+ConfigOwner::checkForConfigUpdate() {
+    if (_subscriber.nextGenerationNow()) {
+        doConfigure();
+        return true;
+    }
+    return false;
+}
+
+}
diff --git a/configd/src/apps/sentinel/config-owner.h b/configd/src/apps/sentinel/config-owner.h
new file mode 100644
index 00000000000..612db7fe9a1
--- /dev/null
+++ b/configd/src/apps/sentinel/config-owner.h
@@ -0,0 +1,40 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+#pragma once
+
+#include <vespa/config-sentinel.h>
+#include <vespa/config/config.h>
+
+using cloud::config::SentinelConfig;
+
+using config::ConfigSubscriber;
+using config::ConfigHandle;
+
+namespace config::sentinel {
+
+/**
+ * Handles config subscription and has a snapshot of current config.
+ **/
+class ConfigOwner {
+private:
+    ConfigSubscriber _subscriber;
+    ConfigHandle<SentinelConfig>::UP _sentinelHandle;
+
+    int64_t _currGeneration = -1;
+    std::unique_ptr<SentinelConfig> _currConfig;
+
+    ConfigOwner(const ConfigOwner&) = delete;
+    ConfigOwner& operator =(const ConfigOwner&) = delete;
+
+    void doConfigure();
+public:
+    ConfigOwner();
+    virtual ~ConfigOwner();
+    void subscribe(const std::string & configId, std::chrono::milliseconds timeout);
+    bool checkForConfigUpdate();
+    bool hasConfig() const { return _currConfig.get() != nullptr; }
+    const SentinelConfig& getConfig() const { return *_currConfig; }
+    int64_t getGeneration() const { return _currGeneration; }
+};
+
+}
diff --git a/configd/src/apps/sentinel/manager.h b/configd/src/apps/sentinel/manager.h
index 4eaff7a2ef3..e157d5e003d 100644
--- a/configd/src/apps/sentinel/manager.h
+++ b/configd/src/apps/sentinel/manager.h
@@ -22,6 +22,11 @@ namespace config::sentinel {
 
 class OutputConnection;
 
+/**
+ *  Management of services.
+ *  Handles requests from RPC, service events,
+ *  and service configuration updates.
+ **/
 class Manager {
 private:
     typedef std::map<vespalib::string, Service::UP> ServiceMap;