added config file for infoLogger clients

Author: sy-c

doc/README.md

@@ -237,7 +237,10 @@ The InfoLogger library allows to inject messages directly from programs, as show
 ## Configuration
 
 * Description and example of parameters for each InfoLogger component can be found in /opt/o2-InfoLogger/etc/*.cfg.
-  The parameters can usually be mixed in a single configuration file, as they are grouped in sections ([infoLoggerServer], [infoLoggerD], [infoBrowser], ...).
+  The parameters can usually be mixed in a single configuration file, as they are grouped in sections ([infoLoggerServer], [infoLoggerD], [infoBrowser], [client] ...).
+
+* Path to configuration file can be defined as startup parameter for the infoLoggerServer and infoLoggerD daemons. Processes using the client library can also be
+  configured by defining the INFOLOGGER_CONFIG environment variable, pointing to the selected config file. The path should be in the form: "file:/etc/infoLogger.cfg"
 
 * On multiple-hosts systems, the serverHost configuration key should be set for infoLoggerD and infoBrowser, so that they are able to connect infoLoggerServer
   if not running locally.
@@ -265,3 +268,12 @@ achieved on CentOS 7 with e.g. (as root):
   During development phase, it can be useful to set mode to "stdout", to allow using the infoLogger interface
   and printing messages without infoLoggerD/infoLoggerServer.
   When "infoLoggerD" mode is selected and no infoLoggerD connection can be established, the mode falls back to "stdout".
+
+* infoLoggerD local socket
+  
+  The connection between a client process using infoLogger API and the local infoLoggerD is done through a UNIX named socket.
+  By default, it uses a Linux abstract socket name.
+  On systems where such sockets are not available, one can configure it to a named socket associated with the filesystem.
+  This can be done by specifying in infoLoggerD configuration the rxSocketPath parameter, and name it with a path starting with '/', e.g. '/tmp/infoLoggerD.socket'.
+  The same value has to be set for the client configuration, in the txSocketPath key.
+  User is responsible to ensure that file access permissions are configured properly.

infoLoggerClient.cfg

@@ -0,0 +1,21 @@
+# Example configuration file for infoLogger clients
+# i.e. processes using the infoLogger library.
+# Lines starting with # are comments
+
+# On standard systems, this is usually not necessary to create this file,
+# the default values usually work without need to redefine them
+# and the infoLogger clients find their way to infoLoggerD alone.
+
+# When defined, path to this file should usually be provided by setting the environment variable
+# INFOLOGGER_CONFIG=file:/etc/infoLogger.cfg
+
+
+[client]
+# see ConfigInfoLoggerClient::ConfigInfoLoggerClient() definition
+# for exhaustive list of config parameters accepted
+
+# specify communication channel to infoLoggerD
+# it should be the same value as rxSocketPath parameter in infoLoggerD configuration
+# defining this value might be needed e.g. on Mac OS, which does not support the default abstract named socket used by infologgerD
+#txSocketPath=/tmp/infoLoggerD.socket
+

src/InfoLoggerClient.cxx

@@ -18,8 +18,10 @@
 #include <string.h>
 
 #include <Common/SimpleLog.h>
+#include <Common/Configuration.h>
 
 #include "InfoLoggerClient.h"
+#include "infoLoggerDefaults.h"
 
 
 
@@ -32,19 +34,35 @@ ConfigInfoLoggerClient::ConfigInfoLoggerClient(const char*configPath) {
   // setup default configuration
   resetConfig();
   // load configuration, if defined
+  if (configPath==nullptr) {
+    // when not specified directly, check environment to get path to config file
+    configPath=getenv(INFOLOGGER_ENV_CONFIG_PATH);
+  }
   if (configPath!=nullptr) {
+    //printf("Using infoLogger configuration %s\n",configPath);
+    // get configuration information from file
+    ConfigFile config;
+    try {
+      config.load(configPath);
+    }
+    catch(std::string err) {
+      printf("Error reading configuration file %s : %s",configPath,err.c_str());
+      return;
+    }
+    config.getOptionalValue<std::string>(INFOLOGGER_CONFIG_SECTION_NAME_CLIENT ".txSocketPath", txSocketPath);
+    config.getOptionalValue<int>(INFOLOGGER_CONFIG_SECTION_NAME_CLIENT ".txSocketOutBufferSize", txSocketOutBufferSize);
+    config.getOptionalValue<std::string>(INFOLOGGER_CONFIG_SECTION_NAME_CLIENT ".logFile", logFile);
   }
 }
 
 ConfigInfoLoggerClient::~ConfigInfoLoggerClient(){
-  // release resources
- delete txSocketPath;
 }
 
 void ConfigInfoLoggerClient::resetConfig() {
   // assign default values to all config parameters
-  txSocketPath=new std::string("infoLoggerD");
+  txSocketPath=INFOLOGGER_DEFAULT_LOCAL_SOCKET;
   txSocketOutBufferSize=-1;
+  logFile="/dev/null";
 }
 
 //////////////////////////////////////////////////////
@@ -63,12 +81,12 @@ InfoLoggerClient::InfoLoggerClient() {
   txSocket=-1;
 
   isInitialized=0;
-  log.setLogFile("/dev/null");
+  log.setLogFile(cfg.logFile.c_str());
 
   try {
 
      // create receiving socket for incoming messages
-    log.info("Creating transmission socket named %s",cfg.txSocketPath->c_str());
+    log.info("Creating transmission socket named %s",cfg.txSocketPath.c_str());
     txSocket=socket(PF_LOCAL,SOCK_STREAM,0);
     if (txSocket==-1) {
       log.error("Could not create socket: %s",strerror(errno));
@@ -110,17 +128,17 @@ InfoLoggerClient::InfoLoggerClient() {
     struct sockaddr_un socketAddrr;
     bzero(&socketAddrr, sizeof(socketAddrr));      
     socketAddrr.sun_family = PF_LOCAL;
-    if (cfg.txSocketPath->length()+2>sizeof(socketAddrr.sun_path)) {
+    if (cfg.txSocketPath.length()+2>sizeof(socketAddrr.sun_path)) {
       log.error("Socket name too long: max allowed is %d",(int)sizeof(socketAddrr.sun_path)-2);
       throw __LINE__;
     }
     // if name starts with '/', use normal socket name. if not, use an abstract socket name
     // this is to allow non-abstract sockets on systems not supporting them.
-    if (cfg.txSocketPath->c_str()[0]=='/')  {
-      strncpy(&socketAddrr.sun_path[0], cfg.txSocketPath->c_str(), cfg.txSocketPath->length());
+    if (cfg.txSocketPath.c_str()[0]=='/')  {
+      strncpy(&socketAddrr.sun_path[0], cfg.txSocketPath.c_str(), cfg.txSocketPath.length());
     } else {
       // leave first char 0, to get abstract socket name - see man 7 unix
-      strncpy(&socketAddrr.sun_path[1], cfg.txSocketPath->c_str(), cfg.txSocketPath->length());
+      strncpy(&socketAddrr.sun_path[1], cfg.txSocketPath.c_str(), cfg.txSocketPath.length());
     }
     if (connect(txSocket, (struct sockaddr *)&socketAddrr, sizeof(socketAddrr))) {
       log.error("Failed to connect to infoLoggerD: %s",strerror(errno));

src/InfoLoggerClient.h

@@ -11,8 +11,9 @@ class ConfigInfoLoggerClient {
 
   void resetConfig(); // set default configuration parameters
 
-  std::string *txSocketPath;       // name of socket used to receive log messages from clients
+  std::string txSocketPath;       // name of socket used to receive log messages from clients
   int txSocketOutBufferSize;
+  std::string logFile;  // log file for internal library logs
 };
 
 

src/infoLoggerDefaults.h

@@ -1,9 +1,11 @@
 #define INFOLOGGER_DEFAULT_CONFIG_PATH "/etc/infoLogger.cfg"
+#define INFOLOGGER_ENV_CONFIG_PATH "INFOLOGGER_CONFIG"
 
 // name of the section where to find parameters
 #define INFOLOGGER_CONFIG_SECTION_NAME_ADMIN "admin"
 #define INFOLOGGER_CONFIG_SECTION_NAME_SERVER "infoLoggerServer"
 #define INFOLOGGER_CONFIG_SECTION_NAME_INFOLOGGERD "infoLoggerD"
+#define INFOLOGGER_CONFIG_SECTION_NAME_CLIENT "client"
 
 
 // Infologger DB: name of the main message table
@@ -15,7 +17,6 @@
 // default infoLoggerServer listening port for infoBrowser
 #define INFOLOGGER_DEFAULT_SERVER_TX_PORT 6102
 
-
 // default listening socket name for infoLoggerD
 #define INFOLOGGER_DEFAULT_LOCAL_SOCKET "infoLoggerD"