Merge pull request #7741 from rjfd/wip-14527

Lookup monitors through DNS, feature #7741 

verified in teuthology (we had 8 failures that appear unrelated to this change)

PendingReleaseNotes

@@ -1,3 +1,11 @@
+>= 11.0.0
+------
+
+* The list of monitor hosts/addresses for building the monmap can now be
+  obtained from DNS SRV records. The service name used in when querying the DNS 
+  is defined in the "mon_dns_srv_name" config option, which defaults to
+  "ceph-mon".
+
 11.0.0
 ------
 

src/CMakeLists.txt

@@ -452,6 +452,7 @@ set(libcommon_files
   osdc/Objecter.cc
   common/Graylog.cc
   common/fs_types.cc
+  common/dns_resolve.cc
   ${arch_files}
   ${auth_files}
   $<TARGET_OBJECTS:compressor_objs>
@@ -504,7 +505,7 @@ endif(${HAVE_ARMV8_CRC})
 
 add_library(common_utf8 STATIC common/utf8.c)
 
-target_link_libraries(common json_spirit common_utf8 erasure_code rt uuid ${CRYPTO_LIBS} ${Boost_LIBRARIES} ${BLKID_LIBRARIES} ${EXECINFO_LIBRARIES})
+target_link_libraries(common json_spirit common_utf8 erasure_code rt uuid resolv ${CRYPTO_LIBS} ${Boost_LIBRARIES} ${BLKID_LIBRARIES} ${EXECINFO_LIBRARIES})
 
 if(${WITH_LTTNG})
   add_subdirectory(tracing)
@@ -704,7 +705,6 @@ if(${WITH_RADOSGW})
     curl
     expat
     fcgi
-    resolv
   )
 endif(${WITH_RADOSGW})
 if(${WITH_RBD})

src/common/Makefile.am

@@ -77,7 +77,8 @@ libcommon_internal_la_SOURCES = \
 	common/TracepointProvider.cc \
 	common/PluginRegistry.cc \
 	common/scrub_types.cc \
-	common/blkdev.cc
+	common/blkdev.cc \
+	common/dns_resolve.cc
 
 common/PluginRegistry.cc: ./ceph_ver.h
 
@@ -168,6 +169,7 @@ LIBCOMMON_DEPS += \
 	$(LIBMSG) $(LIBAUTH) \
 	$(LIBCRUSH) $(LIBJSON_SPIRIT) $(LIBLOG) $(LIBARCH) \
 	$(BOOST_RANDOM_LIBS) \
+	$(RESOLV_LIBS) \
 	-luuid
 
 if LINUX
@@ -284,7 +286,8 @@ noinst_HEADERS += \
 	common/ceph_timer.h \
 	common/align.h \
 	common/mutex_debug.h \
-	common/shunique_lock.h
+	common/shunique_lock.h \
+	common/dns_resolve.h
 
 if ENABLE_XIO
 noinst_HEADERS += \

src/common/config_opts.h

@@ -22,6 +22,7 @@ OPTION(cluster_network, OPT_STR, "")
 OPTION(num_client, OPT_INT, 1)
 OPTION(monmap, OPT_STR, "")
 OPTION(mon_host, OPT_STR, "")
+OPTION(mon_dns_srv_name, OPT_STR, "ceph-mon")
 OPTION(lockdep, OPT_BOOL, false)
 OPTION(lockdep_force_backtrace, OPT_BOOL, false) // always gather current backtrace at every lock
 OPTION(run_dir, OPT_STR, "/var/run/ceph")       // the "/var/run/ceph" dir, created on daemon startup