common: implement "config help" to output schema

Signed-off-by: John Spray <john.spray@redhat.com>

3 files changed, 102 insertions, 1 deletions

diff --git a/src/common/ceph_context.cc b/src/common/ceph_context.cc
index be83c442b87..1d5c6facade 100644
--- a/src/common/ceph_context.cc
+++ b/src/common/ceph_context.cc
@@ -448,6 +448,27 @@ void CephContext::do_command(std::string command, cmdmap_t& cmdmap,
 	    f->dump_string(var.c_str(), buf);
 	}
       }
+    } else if (command == "config help") {
+      std::string var;
+      if (cmd_getval(this, cmdmap, "var", var)) {
+        // Output a single one
+        std::string key = ConfFile::normalize_key_name(var);
+        const auto &i = _conf->schema.find(key);
+        if (i == _conf->schema.end()) {
+          std::ostringstream msg;
+          msg << "Setting not found: '" << key << "'";
+          f->dump_string("error", msg.str());
+        } else {
+          i->second.dump(f);
+        }
+      } else {
+        // Output all
+        f->open_array_section("options");
+        for (const auto &option : ceph_options) {
+          option.dump(f);
+        }
+        f->close_section();
+      }
     } else if (command == "config diff") {
       md_config_t def_conf;
       def_conf.set_val("cluster", _conf->cluster);
@@ -601,6 +622,7 @@ CephContext::CephContext(uint32_t module_type_, int init_flags_)
   _admin_socket->register_command("perf histogram schema", "perf histogram schema", _admin_hook, "dump perf histogram schema");
   _admin_socket->register_command("perf reset", "perf reset name=var,type=CephString", _admin_hook, "perf reset <name>: perf reset all or one perfcounter name");
   _admin_socket->register_command("config show", "config show", _admin_hook, "dump current config settings");
+  _admin_socket->register_command("config help", "config help name=var,type=CephString,req=false", _admin_hook, "get config setting schema and descriptions");
   _admin_socket->register_command("config set", "config set name=var,type=CephString name=val,type=CephString,n=N",  _admin_hook, "config set <field> <val> [<val> ...]: set a config variable");
   _admin_socket->register_command("config get", "config get name=var,type=CephString", _admin_hook, "config get <field>: get the config value");
   _admin_socket->register_command("config diff",
@@ -648,6 +670,7 @@ CephContext::~CephContext()
   _admin_socket->unregister_command("config show");
   _admin_socket->unregister_command("config set");
   _admin_socket->unregister_command("config get");
+  _admin_socket->unregister_command("config help");
   _admin_socket->unregister_command("config diff");
   _admin_socket->unregister_command("config diff get");
   _admin_socket->unregister_command("log flush");
diff --git a/src/common/options.cc b/src/common/options.cc
index ad1b231477d..c8c20908843 100644
--- a/src/common/options.cc
+++ b/src/common/options.cc
@@ -3,6 +3,7 @@
 
 #include "acconfig.h"
 #include "options.h"
+#include "common/Formatter.h"
 
 // Helpers for validators
 #include "include/stringify.h"
@@ -10,6 +11,70 @@
 #include <boost/lexical_cast.hpp>
 #include <boost/regex.hpp>
 
+
+void Option::dump_value(const char *field_name,
+    const Option::value_t &v, Formatter *f) const
+{
+  if (boost::get<boost::blank>(&v)) {
+    // This should be nil but Formatter doesn't allow it.
+    f->dump_string(field_name, "");
+  } else if (type == TYPE_UINT) {
+    f->dump_unsigned(field_name, boost::get<uint64_t>(v));
+  } else if (type == TYPE_INT) {
+    f->dump_int(field_name, boost::get<int64_t>(v));
+  } else if (type == TYPE_STR) {
+    f->dump_string(field_name, boost::get<std::string>(v));
+  } else if (type == TYPE_FLOAT) {
+    f->dump_float(field_name, boost::get<double>(v));
+  } else if (type == TYPE_BOOL) {
+    f->dump_bool(field_name, boost::get<bool>(v));
+  } else {
+    f->dump_stream(field_name) << v;
+  }
+}
+
+void Option::dump(Formatter *f) const
+{
+  f->open_object_section("option");
+  f->dump_string("name", name);
+
+  f->dump_string("type", type_to_str(type));
+  std::string level_str;
+
+  f->dump_string("level", level_to_str(level));
+
+  f->dump_string("desc", desc);
+  f->dump_string("long_desc", long_desc);
+
+  dump_value("default", value, f);
+  dump_value("daemon_default", daemon_value, f);
+
+  f->open_array_section("tags");
+  for (const auto t : tags) {
+    f->dump_string("tag", t);
+  }
+  f->close_section();
+
+  f->open_array_section("see_also");
+  for (const auto sa : see_also) {
+    f->dump_string("see_also", sa);
+  }
+  f->close_section();
+
+  if (type == TYPE_STR) {
+    f->open_array_section("enum_values");
+    for (const auto &ea : enum_allowed) {
+      f->dump_string("enum_value", ea);
+    }
+    f->close_section();
+  }
+
+  dump_value("min", min, f);
+  dump_value("max", max, f);
+
+  f->close_section();
+}
+
 const std::vector<Option> ceph_options = {
 
   // ** global basics **
diff --git a/src/common/options.h b/src/common/options.h
index c8ff3f86ce4..95fc2ad94cf 100644
--- a/src/common/options.h
+++ b/src/common/options.h
@@ -20,7 +20,7 @@ struct Option {
     TYPE_UUID,
   };
 
-  const char *type_to_str(type_t t) {
+  const char *type_to_str(type_t t) const {
     switch (t) {
     case TYPE_UINT: return "uint64_t";
     case TYPE_INT: return "int64_t";
@@ -39,6 +39,15 @@ struct Option {
     LEVEL_DEV,
   };
 
+  const char *level_to_str(level_t l) const {
+    switch(l) {
+      case LEVEL_BASIC: return "basic";
+      case LEVEL_ADVANCED: return "advanced";
+      case LEVEL_DEV: return "developer";
+      default: return "unknown";
+    }
+  }
+
   using value_t = boost::variant<
     boost::blank,
     std::string,
@@ -101,6 +110,8 @@ struct Option {
     }
   }
 
+  void dump_value(const char *field_name, const value_t &v, Formatter *f) const;
+
   // const char * must be explicit to avoid it being treated as an int
   Option& set_value(value_t& v, const char *new_value) {
     v = std::string(new_value);
@@ -184,6 +195,8 @@ struct Option {
     return *this;
   }
 
+  void dump(Formatter *f) const;
+
   /**
    * A crude indicator of whether the value may be
    * modified safely at runtime -- should be replaced