app-template: allow apps to specify a name for help message

Right now the help message just say "App options" for the app-specific
options, while naming Core, SMP, Metrics, etc, by name.

It's a nice addition to allow the application to be named as well.

Signed-off-by: Glauber Costa <glauber@scylladb.com>
Message-Id: <1490277033-31971-1-git-send-email-glauber@scylladb.com>

core/app-template.cc

@@ -32,15 +32,16 @@
 
 namespace bpo = boost::program_options;
 
-app_template::app_template()
-        : _opts("App options") {
-    _opts.add_options()
-            ("help,h", "show help message")
-            ;
-    _opts.add(reactor::get_options_description());
-    _opts.add(seastar::metrics::get_options_description());
-    _opts.add(smp::get_options_description());
-    _opts.add(scollectd::get_options_description());
+app_template::app_template(app_template::config cfg)
+    : _cfg(std::move(cfg))
+    , _opts(_cfg.name + " options") {
+        _opts.add_options()
+                ("help,h", "show help message")
+                ;
+        _opts.add(reactor::get_options_description());
+        _opts.add(seastar::metrics::get_options_description());
+        _opts.add(smp::get_options_description());
+        _opts.add(scollectd::get_options_description());
 }
 
 boost::program_options::options_description_easy_init

core/app-template.hh

@@ -25,9 +25,15 @@
 #include <boost/optional.hpp>
 #include <functional>
 #include <core/future.hh>
+#include <core/sstring.hh>
 
 class app_template {
+public:
+    struct config {
+        sstring name;
+    };
 private:
+    config _cfg;
     boost::program_options::options_description _opts;
     boost::program_options::positional_options_description _pos_opts;
     boost::optional<boost::program_options::variables_map> _configuration;
@@ -39,7 +45,8 @@ public:
         int max_count;
     };
 public:
-    app_template();
+    explicit app_template(config cfg = config{"App"});
+
     boost::program_options::options_description_easy_init add_options();
     void add_positional_options(std::initializer_list<positional_option> options);
     boost::program_options::variables_map& configuration();