[#25,!14] Moved daemon.cc|h, unittests to process

1 files changed, 255 insertions, 0 deletions

diff --git a/src/lib/process/daemon.h b/src/lib/process/daemon.h
new file mode 100644
index 0000000000..df895ddd42
--- /dev/null
+++ b/src/lib/process/daemon.h
@@ -0,0 +1,255 @@
+// Copyright (C) 2014-2015,2017 Internet Systems Consortium, Inc. ("ISC")
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#ifndef DAEMON_H
+#define DAEMON_H
+
+#include <cc/data.h>
+#include <dhcpsrv/srv_config.h>
+#include <util/pid_file.h>
+#include <util/signal_set.h>
+#include <boost/noncopyable.hpp>
+#include <string>
+
+namespace isc {
+namespace dhcp {
+
+/// @brief Exception thrown when a the PID file points to a live PID
+class DaemonPIDExists : public Exception {
+public:
+    DaemonPIDExists(const char* file, size_t line, const char* what) :
+        isc::Exception(file, line, what) { };
+};
+
+/// @brief Base class for all services
+///
+/// This is the base class that all daemons (DHCPv4, DHCPv6, D2 and possibly
+/// others) are derived from. It provides a standard interface for starting up,
+/// reconfiguring, shutting down and several other operations. It also covers
+/// some common operations.
+///
+/// This class is not expected to be instantiated directly, but rather daemon
+/// implementations should derive from it.
+///
+/// Methods are not pure virtual, as we need to instantiate basic daemons (e.g.
+/// Dhcpv6Srv) in tests, without going through the hassles of implementing stub
+/// methods.
+///
+/// Classes derived from @c Daemon may install custom signal handlers using
+/// @c isc::util::SignalSet class. This base class provides a declaration
+/// of the @c SignalSet object that should be initialized in the derived
+/// classes to install the custom exception handlers.
+///
+/// @note Only one instance of this class is instantiated as it encompasses
+///       the whole operation of the server.  Nothing, however, enforces the
+///       singleton status of the object.
+class Daemon : public boost::noncopyable {
+
+public:
+    /// @brief Default constructor
+    ///
+    /// Initializes the object installing custom signal handlers for the
+    /// process to NULL.
+    Daemon();
+
+    /// @brief Destructor
+    ///
+    /// Having virtual destructor ensures that all derived classes will have
+    /// virtual destructor as well.
+    virtual ~Daemon();
+
+    /// @brief Performs final deconfiguration.
+    ///
+    /// Performs configuration backend specific final clean-up. This is called
+    /// shortly before the daemon terminates. Depending on backend, it may
+    /// terminat existing msgq session, close LDAP connection or similar.
+    ///
+    /// The daemon is not expected to receive any further commands or
+    /// configuration updates as it is in final stages of shutdown.
+    virtual void cleanup();
+
+    /// @brief Initiates shutdown procedure for the whole DHCPv6 server.
+    virtual void shutdown();
+
+    /// @brief Initializes logger
+    ///
+    /// This method initializes logging system. It also sets the default
+    /// output to stdout. This is used in early stages of the startup
+    /// phase before config file and parsed and proper logging details
+    /// are known.
+    ///
+    /// @param log_name name used in logger initialization
+    /// @param verbose verbose mode (true usually enables DEBUG messages)
+    static void loggerInit(const char* log_name, bool verbose);
+
+    /// @brief Configures logger
+    ///
+    /// Applies configuration stored in "Logging" structure in the
+    /// configuration file. This structure has a "loggers" array that
+    /// contains 0 or more entries, each configuring one logging source
+    /// (name, severity, debuglevel), each with zero or more outputs (file,
+    /// maxsize, maximum number of files).
+    ///
+    /// @param log_config JSON structures that describe logging
+    /// @param storage configuration will be stored here
+    static void configureLogger(const isc::data::ConstElementPtr& log_config,
+                                const isc::dhcp::SrvConfigPtr& storage);
+
+    /// @brief Sets or clears verbose mode
+    ///
+    /// Verbose mode (-v in command-line) triggers loggers to log everything
+    /// (sets severity to DEBUG and debuglevel to 99). Values specified in the
+    /// config file are ignored.
+    ///
+    /// @param verbose specifies if verbose should be set or not
+    void setVerbose(const bool verbose);
+
+    /// @brief Returns if running in verbose mode
+    ///
+    /// @return verbose mode
+    bool getVerbose() const;
+
+    /// @brief returns Kea version on stdout and exits.
+    ///
+    /// With extended == false, this method returns a simple string
+    /// containing version number. With extended == true, it returns
+    /// also additional information about sources. It is expected to
+    /// return extra information about dependencies and used DB backends.
+    ///
+    /// As there is no static virtual methods in C++ this class method
+    /// has to be redefined in derived classes and called with the
+    /// derived class name or a child name.
+    ///
+    /// @param extended print additional information?
+    /// @return text string
+    static std::string getVersion(bool extended);
+
+    /// @brief Returns config file name.
+    /// @return text string
+    std::string getConfigFile() const;
+
+    /// @brief Sets the configuration file name
+    ///
+    /// @param config_file pathname of the configuration file
+    void setConfigFile(const std::string& config_file);
+
+    /// @brief Writes current configuration to specified file
+    ///
+    /// This method writes the current configuration to specified file.
+    /// @todo: this logically more belongs to CPL process file. Once
+    /// Daemon is merged with CPL architecture, it will be a better
+    /// fit.
+    ///
+    /// If cfg is not specified, the current config (as returned by
+    /// CfgMgr::instance().getCurrentCfg() will be returned.
+    ///
+    /// @param config_file name of the file to write the configuration to
+    /// @param cfg configuration to write (optional)
+    /// @return number of files written
+    /// @throw Unexpected if CfgMgr can't retrieve configuration or file cannot
+    ///                   be written
+    virtual size_t
+    writeConfigFile(const std::string& config_file,
+                    isc::data::ConstElementPtr cfg = isc::data::ConstElementPtr()) const;
+
+    /// @brief returns the process name
+    /// This value is used as when forming the default PID file name
+    /// @return text string
+    std::string getProcName() const;
+
+    /// @brief Sets the process name
+    /// @param proc_name name the process by which the process is recognized
+    void setProcName(const std::string& proc_name);
+
+    /// @brief Returns the directory used when forming default PID file name
+    /// @return text string
+    std::string getPIDFileDir() const;
+
+    /// @brief Sets the PID file directory
+    /// @param pid_file_dir path into which the PID file should be written
+    /// Note the value should not include a trailing slash, '/'
+    void setPIDFileDir(const std::string& pid_file_dir);
+
+    /// @brief Returns the current PID file name
+    /// @return text string
+    std::string getPIDFileName() const;
+
+    /// @brief Sets PID file name
+    ///
+    /// If this method is called prior to calling createPIDFile,
+    /// the value passed in will be treated as the full file name
+    /// for the PID file.  This provides a means to override the
+    /// default file name with an explicit value.
+    ///
+    /// @param pid_file_name file name to be used as the PID file
+    void setPIDFileName(const std::string& pid_file_name);
+
+    /// @brief Creates the PID file
+    ///
+    /// If the PID file name has not been previously set, the method
+    /// uses manufacturePIDFileName() to set it.  If the PID file
+    /// name refers to an existing file whose contents are a PID whose
+    /// process is still alive, the method will throw a DaemonPIDExists
+    /// exception.  Otherwise, the file created (or truncated) and
+    /// the given pid (if not zero) is written to the file.
+    ///
+    /// @param pid PID to write to the file if not zero, otherwise the
+    /// PID of the current process is used.
+    void createPIDFile(int pid = 0);
+
+protected:
+
+    /// @brief Invokes handler for the next received signal.
+    ///
+    /// This function provides a default implementation for the function
+    /// handling next signal received by the process. It checks if a pointer
+    /// to @c isc::util::SignalSet object and the signal handler function
+    /// have been set. If they have been set, the signal handler is invoked for
+    /// the the next signal registered in the @c SignalSet object.
+    ///
+    /// This function should be received in the main loop of the process.
+    virtual void handleSignal();
+
+    /// @brief A pointer to the object installing custom signal handlers.
+    ///
+    /// This pointer needs to be initialized to point to the @c SignalSet
+    /// object in the derived classes which need to handle signals received
+    /// by the process.
+    isc::util::SignalSetPtr signal_set_;
+
+    /// @brief Pointer to the common signal handler invoked by the handleSignal
+    /// function.
+    ///
+    /// This pointer needs to be initialized to point to the signal handler
+    /// function for signals being handled by the process. If signal handler
+    /// it not initialized, the signals will not be handled.
+    isc::util::SignalHandler signal_handler_;
+
+    /// @brief Manufacture the pid file name
+    std::string makePIDFileName() const;
+
+private:
+    /// @brief Config file name or empty if config file not used.
+    std::string config_file_;
+
+    /// @brief Name of this process, used when creating its pid file
+    std::string proc_name_;
+
+    /// @brief Pointer to the directory where PID file(s) are written
+    /// It defaults to --localstatedir
+    std::string pid_file_dir_;
+
+    /// @brief Pointer to the PID file for this process
+    isc::util::PIDFilePtr pid_file_;
+
+    /// @brief Flag indicating if this instance created the file
+    bool am_file_author_;
+};
+
+}; // end of isc::dhcp namespace
+}; // end of isc namespace
+
+#endif