icinga2/components/discovery/discoverycomponent.cpp

449 lines
14 KiB
C++

/******************************************************************************
* Icinga 2 *
* Copyright (C) 2012 Icinga Development Team (http://www.icinga.org/) *
* *
* This program is free software; you can redistribute it and/or *
* modify it under the terms of the GNU General Public License *
* as published by the Free Software Foundation; either version 2 *
* of the License, or (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, write to the Free Software Foundation *
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. *
******************************************************************************/
#include "i2-discovery.h"
using namespace icinga;
/**
* Starts the discovery component.
*/
void DiscoveryComponent::Start(void)
{
m_Endpoint = boost::make_shared<VirtualEndpoint>();
m_Endpoint->RegisterTopicHandler("discovery::RegisterComponent",
boost::bind(&DiscoveryComponent::RegisterComponentMessageHandler, this, _2, _3));
m_Endpoint->RegisterTopicHandler("discovery::NewComponent",
boost::bind(&DiscoveryComponent::NewComponentMessageHandler, this, _3));
m_Endpoint->RegisterTopicHandler("discovery::Welcome",
boost::bind(&DiscoveryComponent::WelcomeMessageHandler, this, _2, _3));
EndpointManager::GetInstance()->ForEachEndpoint(boost::bind(&DiscoveryComponent::NewEndpointHandler, this, _2));
EndpointManager::GetInstance()->OnNewEndpoint.connect(boost::bind(&DiscoveryComponent::NewEndpointHandler, this, _2));
EndpointManager::GetInstance()->RegisterEndpoint(m_Endpoint);
/* create the reconnect timer */
m_DiscoveryTimer = boost::make_shared<Timer>();
m_DiscoveryTimer->SetInterval(30);
m_DiscoveryTimer->OnTimerExpired.connect(boost::bind(&DiscoveryComponent::DiscoveryTimerHandler, this));
m_DiscoveryTimer->Start();
/* call the timer as soon as possible */
m_DiscoveryTimer->Reschedule(0);
}
/**
* Stops the discovery component.
*/
void DiscoveryComponent::Stop(void)
{
EndpointManager::Ptr mgr = EndpointManager::GetInstance();
if (mgr)
mgr->UnregisterEndpoint(m_Endpoint);
}
/**
* Checks whether the specified endpoint is already connected
* and disconnects older endpoints.
*
* @param self The endpoint that is to be checked.
* @param other The other endpoint.
*/
void DiscoveryComponent::CheckExistingEndpoint(const Endpoint::Ptr& self, const Endpoint::Ptr& other)
{
if (self == other)
return;
if (!other->IsConnected())
return;
if (self->GetIdentity() == other->GetIdentity()) {
Logger::Write(LogWarning, "discovery", "Detected duplicate identity:" + other->GetIdentity() + " - Disconnecting old endpoint.");
other->Stop();
EndpointManager::GetInstance()->UnregisterEndpoint(other);
}
}
/**
* Deals with a new endpoint.
*
* @param endpoint The endpoint.
*/
void DiscoveryComponent::NewEndpointHandler(const Endpoint::Ptr& endpoint)
{
/* immediately finish session setup for local endpoints */
if (endpoint->IsLocal()) {
endpoint->OnSessionEstablished(endpoint);
return;
}
String identity = endpoint->GetIdentity();
if (identity == EndpointManager::GetInstance()->GetIdentity()) {
Logger::Write(LogWarning, "discovery", "Detected loop-back connection - Disconnecting endpoint.");
endpoint->Stop();
EndpointManager::GetInstance()->UnregisterEndpoint(endpoint);
return;
}
EndpointManager::GetInstance()->ForEachEndpoint(boost::bind(&DiscoveryComponent::CheckExistingEndpoint, this, endpoint, _2));
// we assume the other component _always_ wants
// discovery::RegisterComponent messages from us
endpoint->RegisterSubscription("discovery::RegisterComponent");
// send a discovery::RegisterComponent message, if the
// other component is a broker this makes sure
// the broker knows about our message types
SendDiscoveryMessage("discovery::RegisterComponent", EndpointManager::GetInstance()->GetIdentity(), endpoint);
map<String, ComponentDiscoveryInfo::Ptr>::iterator ic;
// we assume the other component _always_ wants
// discovery::NewComponent messages from us
endpoint->RegisterSubscription("discovery::NewComponent");
// send discovery::NewComponent message for ourselves
SendDiscoveryMessage("discovery::NewComponent", EndpointManager::GetInstance()->GetIdentity(), endpoint);
// send discovery::NewComponent messages for all components
// we know about
for (ic = m_Components.begin(); ic != m_Components.end(); ic++) {
SendDiscoveryMessage("discovery::NewComponent", ic->first, endpoint);
}
// check if we already know the other component
ic = m_Components.find(endpoint->GetIdentity());
if (ic == m_Components.end()) {
// we don't know the other component yet, so
// wait until we get a discovery::NewComponent message
// from a broker
return;
}
// register published/subscribed topics for this endpoint
ComponentDiscoveryInfo::Ptr info = ic->second;
BOOST_FOREACH(String subscription, info->Subscriptions) {
endpoint->RegisterSubscription(subscription);
}
FinishDiscoverySetup(endpoint);
}
/**
* Registers message Subscriptions/sources in the specified component information object.
*
* @param neea Event arguments for the endpoint.
* @param info Component information object.
* @return 0
*/
void DiscoveryComponent::DiscoveryEndpointHandler(const Endpoint::Ptr& endpoint, const ComponentDiscoveryInfo::Ptr& info) const
{
Endpoint::ConstTopicIterator i;
for (i = endpoint->BeginSubscriptions(); i != endpoint->EndSubscriptions(); i++)
info->Subscriptions.insert(*i);
}
/**
* Retrieves the component information object for the specified component.
*
* @param component The identity of the component.
* @param info Pointer to the information object.
* @returns true if the info object was successfully retrieved, false otherwise.
*/
bool DiscoveryComponent::GetComponentDiscoveryInfo(String component, ComponentDiscoveryInfo::Ptr *info) const
{
if (component == EndpointManager::GetInstance()->GetIdentity()) {
/* Build fake discovery info for ourselves */
*info = boost::make_shared<ComponentDiscoveryInfo>();
EndpointManager::GetInstance()->ForEachEndpoint(boost::bind(&DiscoveryComponent::DiscoveryEndpointHandler, this, _2, *info));
(*info)->LastSeen = 0;
(*info)->Node = IcingaApplication::GetInstance()->GetNode();
(*info)->Service = IcingaApplication::GetInstance()->GetService();
return true;
}
map<String, ComponentDiscoveryInfo::Ptr>::const_iterator i;
i = m_Components.find(component);
if (i == m_Components.end())
return false;
*info = i->second;
return true;
}
/**
* Processes discovery::Welcome messages.
*
* @param nrea Event arguments for the request.
* @returns 0
*/
void DiscoveryComponent::WelcomeMessageHandler(const Endpoint::Ptr& sender, const RequestMessage& request)
{
if (sender->HasReceivedWelcome())
return;
sender->SetReceivedWelcome(true);
if (sender->HasSentWelcome())
sender->OnSessionEstablished(sender);
}
/**
* Finishes the welcome handshake for a new component
* by registering message Subscriptions/sources for the component
* and sending a welcome message if necessary.
*
* @param endpoint The endpoint to set up.
*/
void DiscoveryComponent::FinishDiscoverySetup(const Endpoint::Ptr& endpoint)
{
if (endpoint->HasSentWelcome())
return;
// we assume the other component _always_ wants
// discovery::Welcome messages from us
endpoint->RegisterSubscription("discovery::Welcome");
RequestMessage request;
request.SetMethod("discovery::Welcome");
EndpointManager::GetInstance()->SendUnicastMessage(m_Endpoint, endpoint, request);
endpoint->SetSentWelcome(true);
if (endpoint->HasReceivedWelcome())
endpoint->OnSessionEstablished(endpoint);
}
/**
* Sends a discovery message for the specified identity using the
* specified message type.
*
* @param method The method to use for the message ("discovery::NewComponent" or "discovery::RegisterComponent").
* @param identity The identity of the component for which a message should be sent.
* @param recipient The recipient of the message. A multicast message is sent if this parameter is empty.
*/
void DiscoveryComponent::SendDiscoveryMessage(const String& method, const String& identity, const Endpoint::Ptr& recipient)
{
RequestMessage request;
request.SetMethod(method);
DiscoveryMessage params;
request.SetParams(params);
params.SetIdentity(identity);
ComponentDiscoveryInfo::Ptr info;
if (!GetComponentDiscoveryInfo(identity, &info))
return;
if (!info->Node.IsEmpty() && !info->Service.IsEmpty()) {
params.SetNode(info->Node);
params.SetService(info->Service);
}
set<String>::iterator i;
Dictionary::Ptr subscriptions = boost::make_shared<Dictionary>();
BOOST_FOREACH(String subscription, info->Subscriptions) {
subscriptions->Add(subscription);
}
params.SetSubscriptions(subscriptions);
if (recipient)
EndpointManager::GetInstance()->SendUnicastMessage(m_Endpoint, recipient, request);
else
EndpointManager::GetInstance()->SendMulticastMessage(m_Endpoint, request);
}
/**
* Processes a discovery message by registering the component in the
* discovery component registry.
*
* @param identity The authorative identity of the component.
* @param message The discovery message.
* @param trusted Whether the message comes from a trusted source (i.e. a broker).
*/
void DiscoveryComponent::ProcessDiscoveryMessage(const String& identity, const DiscoveryMessage& message, bool trusted)
{
/* ignore discovery messages that are about ourselves */
if (identity == EndpointManager::GetInstance()->GetIdentity())
return;
ComponentDiscoveryInfo::Ptr info = boost::make_shared<ComponentDiscoveryInfo>();
info->LastSeen = Utility::GetTime();
String node;
if (message.GetNode(&node) && !node.IsEmpty())
info->Node = node;
String service;
if (message.GetService(&service) && !service.IsEmpty())
info->Service = service;
DynamicObject::Ptr endpointConfig = DynamicObject::GetObject("Endpoint", identity);
Dictionary::Ptr roles;
if (endpointConfig)
roles = endpointConfig->Get("roles");
Endpoint::Ptr endpoint = EndpointManager::GetInstance()->GetEndpointByIdentity(identity);
Dictionary::Ptr subscriptions;
if (message.GetSubscriptions(&subscriptions)) {
Value subscription;
BOOST_FOREACH(tie(tuples::ignore, subscription), subscriptions) {
info->Subscriptions.insert(subscription);
if (endpoint)
endpoint->RegisterSubscription(subscription);
}
}
map<String, ComponentDiscoveryInfo::Ptr>::iterator i;
i = m_Components.find(identity);
if (i != m_Components.end())
m_Components.erase(i);
m_Components[identity] = info;
SendDiscoveryMessage("discovery::NewComponent", identity, Endpoint::Ptr());
/* don't send a welcome message for discovery::NewComponent messages */
if (endpoint && !trusted)
FinishDiscoverySetup(endpoint);
}
/**
* Processes "discovery::NewComponent" messages.
*
* @param nrea Event arguments for the request.
*/
void DiscoveryComponent::NewComponentMessageHandler(const RequestMessage& request)
{
DiscoveryMessage message;
request.GetParams(&message);
String identity;
if (!message.GetIdentity(&identity))
return;
ProcessDiscoveryMessage(identity, message, true);
}
/**
* Processes "discovery::RegisterComponent" messages.
*
* @param nrea Event arguments for the request.
*/
void DiscoveryComponent::RegisterComponentMessageHandler(const Endpoint::Ptr& sender, const RequestMessage& request)
{
DiscoveryMessage message;
request.GetParams(&message);
ProcessDiscoveryMessage(sender->GetIdentity(), message, false);
}
/**
* Checks whether we have to reconnect to other components and removes stale
* components from the registry.
*/
void DiscoveryComponent::DiscoveryTimerHandler(void)
{
EndpointManager::Ptr endpointManager = EndpointManager::GetInstance();
double now = Utility::GetTime();
/* check whether we have to reconnect to one of our upstream endpoints */
DynamicObject::Ptr object;
BOOST_FOREACH(tie(tuples::ignore, object), DynamicObject::GetObjects("Endpoint")) {
/* Check if we're already connected to this endpoint. */
if (endpointManager->GetEndpointByIdentity(object->GetName()))
continue;
String node = object->Get("node");
String service = object->Get("service");
if (!node.IsEmpty() && !service.IsEmpty()) {
/* reconnect to this endpoint */
endpointManager->AddConnection(node, service);
}
}
map<String, ComponentDiscoveryInfo::Ptr>::iterator curr, i;
for (i = m_Components.begin(); i != m_Components.end(); ) {
const String& identity = i->first;
const ComponentDiscoveryInfo::Ptr& info = i->second;
curr = i;
i++;
/* there's no need to reconnect to ourself */
if (identity == EndpointManager::GetInstance()->GetIdentity())
continue;
/* for explicitly-configured upstream endpoints
* we prefer to use the node/service from the
* config object - which is what the for loop above does */
if (DynamicObject::GetObject("endpoint", identity))
continue;
if (info->LastSeen < now - DiscoveryComponent::RegistrationTTL) {
/* unregister this component if its registration has expired */
m_Components.erase(curr);
continue;
}
/* send discovery message to all connected components to
refresh their TTL for this component */
SendDiscoveryMessage("discovery::NewComponent", identity, Endpoint::Ptr());
Endpoint::Ptr endpoint = endpointManager->GetEndpointByIdentity(identity);
if (endpoint && endpoint->IsConnected()) {
/* update LastSeen if we're still connected to this endpoint */
info->LastSeen = now;
} else {
/* try and reconnect to this component */
try {
if (!info->Node.IsEmpty() && !info->Service.IsEmpty())
endpointManager->AddConnection(info->Node, info->Service);
} catch (const exception& ex) {
stringstream msgbuf;
msgbuf << "Exception while trying to reconnect to endpoint '" << endpoint->GetIdentity() << "': " << ex.what();;
Logger::Write(LogInformation, "discovery", msgbuf.str());
}
}
}
}
EXPORT_COMPONENT(discovery, DiscoveryComponent);