Optionalize name resolvers

15 files changed, 66 insertions, 164 deletions

diff --git a/src/core/ext/resolver/dns/native/README.md b/src/core/ext/resolver/dns/native/README.md
new file mode 100644
index 0000000000..695de47b9f
--- /dev/null
+++ b/src/core/ext/resolver/dns/native/README.md
@@ -0,0 +1,2 @@
+dns: scheme name resolution, using getaddrbyname
+(or other OS specific implementation)
diff --git a/src/core/lib/client_config/resolvers/dns_resolver.c b/src/core/ext/resolver/dns/native/dns_resolver.c
index 62bccdd045..60028848bb 100644
--- a/src/core/lib/client_config/resolvers/dns_resolver.c
+++ b/src/core/ext/resolver/dns/native/dns_resolver.c
@@ -31,8 +31,6 @@
  *
  */
 
-#include "src/core/lib/client_config/resolvers/dns_resolver.h"
-
 #include <string.h>
 
 #include <grpc/support/alloc.h>
@@ -40,6 +38,7 @@
 #include <grpc/support/string_util.h>
 
 #include "src/core/lib/client_config/lb_policy_registry.h"
+#include "src/core/lib/client_config/resolver_registry.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/support/backoff.h"
@@ -277,8 +276,8 @@ static grpc_resolver *dns_factory_create_resolver(
   return dns_create(args, "https", "pick_first");
 }
 
-char *dns_factory_get_default_host_name(grpc_resolver_factory *factory,
-                                        grpc_uri *uri) {
+static char *dns_factory_get_default_host_name(grpc_resolver_factory *factory,
+                                               grpc_uri *uri) {
   const char *path = uri->path;
   if (path[0] == '/') ++path;
   return gpr_strdup(path);
@@ -289,6 +288,12 @@ static const grpc_resolver_factory_vtable dns_factory_vtable = {
     dns_factory_get_default_host_name, "dns"};
 static grpc_resolver_factory dns_resolver_factory = {&dns_factory_vtable};
 
-grpc_resolver_factory *grpc_dns_resolver_factory_create() {
+static grpc_resolver_factory *dns_resolver_factory_create() {
   return &dns_resolver_factory;
 }
+
+void grpc_resolver_dns_native_init(void) {
+  grpc_register_resolver_type(dns_resolver_factory_create());
+}
+
+void grpc_resolver_dns_native_shutdown(void) {}
diff --git a/src/core/ext/resolver/sockaddr/README.md b/src/core/ext/resolver/sockaddr/README.md
new file mode 100644
index 0000000000..e307ba88f5
--- /dev/null
+++ b/src/core/ext/resolver/sockaddr/README.md
@@ -0,0 +1 @@
+Support for resolving ipv4:, ipv6:, unix: schemes
diff --git a/src/core/lib/client_config/resolvers/sockaddr_resolver.c b/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
index c787bd57d6..a416f10dcb 100644
--- a/src/core/lib/client_config/resolvers/sockaddr_resolver.c
+++ b/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
@@ -33,8 +33,6 @@
 
 #include <grpc/support/port_platform.h>
 
-#include "src/core/lib/client_config/resolvers/sockaddr_resolver.h"
-
 #include <stdio.h>
 #include <string.h>
 
@@ -43,6 +41,7 @@
 #include <grpc/support/string_util.h>
 
 #include "src/core/lib/client_config/lb_policy_registry.h"
+#include "src/core/lib/client_config/resolver_registry.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/unix_sockets_posix.h"
 #include "src/core/lib/support/string.h"
@@ -343,12 +342,20 @@ static void sockaddr_factory_unref(grpc_resolver_factory *factory) {}
       name##_factory_create_resolver, prefix##name##_get_default_authority, \
       #name};                                                               \
   static grpc_resolver_factory name##_resolver_factory = {                  \
-      &name##_factory_vtable};                                              \
-  grpc_resolver_factory *grpc_##name##_resolver_factory_create() {          \
-    return &name##_resolver_factory;                                        \
-  }
+      &name##_factory_vtable}
 
 #ifdef GPR_HAVE_UNIX_SOCKET
-DECL_FACTORY(unix, grpc_)
+DECL_FACTORY(unix, grpc_);
 #endif
-DECL_FACTORY(ipv4, ) DECL_FACTORY(ipv6, )
+DECL_FACTORY(ipv4, );
+DECL_FACTORY(ipv6, );
+
+void grpc_resolver_sockaddr_init(void) {
+  grpc_register_resolver_type(&ipv4_resolver_factory);
+  grpc_register_resolver_type(&ipv6_resolver_factory);
+#ifdef GPR_HAVE_UNIX_SOCKET
+  grpc_register_resolver_type(&unix_resolver_factory);
+#endif
+}
+
+void grpc_resolver_sockaddr_shutdown(void) {}
diff --git a/src/core/ext/resolver/zookeeper/README.md b/src/core/ext/resolver/zookeeper/README.md
new file mode 100644
index 0000000000..ce6f39683b
--- /dev/null
+++ b/src/core/ext/resolver/zookeeper/README.md
@@ -0,0 +1 @@
+Zookeeper based name resolver: WIP
diff --git a/src/core/lib/client_config/resolvers/zookeeper_resolver.c b/src/core/ext/resolver/zookeeper/zookeeper_resolver.c
index 404dfcd423..404dfcd423 100644
--- a/src/core/lib/client_config/resolvers/zookeeper_resolver.c
+++ b/src/core/ext/resolver/zookeeper/zookeeper_resolver.c
diff --git a/src/core/lib/client_config/resolver_registry.c b/src/core/lib/client_config/resolver_registry.c
index 29bd00c284..fd49d49abc 100644
--- a/src/core/lib/client_config/resolver_registry.c
+++ b/src/core/lib/client_config/resolver_registry.c
@@ -70,14 +70,11 @@ void grpc_register_resolver_type(grpc_resolver_factory *factory) {
   g_all_of_the_resolvers[g_number_of_resolvers++] = factory;
 }
 
-static grpc_resolver_factory *lookup_factory(grpc_uri *uri) {
+static grpc_resolver_factory *lookup_factory(const char *name) {
   int i;
 
-  /* handling NULL uri's here simplifies grpc_resolver_create */
-  if (!uri) return NULL;
-
   for (i = 0; i < g_number_of_resolvers; i++) {
-    if (0 == strcmp(uri->scheme, g_all_of_the_resolvers[i]->vtable->scheme)) {
+    if (0 == strcmp(name, g_all_of_the_resolvers[i]->vtable->scheme)) {
       return g_all_of_the_resolvers[i];
     }
   }
@@ -85,6 +82,17 @@ static grpc_resolver_factory *lookup_factory(grpc_uri *uri) {
   return NULL;
 }
 
+grpc_resolver_factory *grpc_resolver_factory_lookup(const char *name) {
+  grpc_resolver_factory *f = lookup_factory(name);
+  if (f) grpc_resolver_factory_ref(f);
+  return f;
+}
+
+static grpc_resolver_factory *lookup_factory_by_uri(grpc_uri *uri) {
+  if (!uri) return NULL;
+  return lookup_factory(uri->scheme);
+}
+
 static grpc_resolver_factory *resolve_factory(const char *target,
                                               grpc_uri **uri) {
   char *tmp;
@@ -92,13 +100,13 @@ static grpc_resolver_factory *resolve_factory(const char *target,
 
   GPR_ASSERT(uri != NULL);
   *uri = grpc_uri_parse(target, 1);
-  factory = lookup_factory(*uri);
+  factory = lookup_factory_by_uri(*uri);
   if (factory == NULL) {
     if (g_default_resolver_prefix != NULL) {
       grpc_uri_destroy(*uri);
       gpr_asprintf(&tmp, "%s%s", g_default_resolver_prefix, target);
       *uri = grpc_uri_parse(tmp, 1);
-      factory = lookup_factory(*uri);
+      factory = lookup_factory_by_uri(*uri);
       if (factory == NULL) {
         grpc_uri_destroy(grpc_uri_parse(target, 0));
         grpc_uri_destroy(grpc_uri_parse(tmp, 0));
diff --git a/src/core/lib/client_config/resolver_registry.h b/src/core/lib/client_config/resolver_registry.h
index 22289ca6bd..7d7009b9cd 100644
--- a/src/core/lib/client_config/resolver_registry.h
+++ b/src/core/lib/client_config/resolver_registry.h
@@ -58,6 +58,10 @@ void grpc_register_resolver_type(grpc_resolver_factory *factory);
 grpc_resolver *grpc_resolver_create(
     const char *target, grpc_subchannel_factory *subchannel_factory);
 
+/** Find a resolver factory given a name and return an (owned-by-the-caller)
+ *  reference to it */
+grpc_resolver_factory *grpc_resolver_factory_lookup(const char *name);
+
 /** Given a target, return a (freshly allocated with gpr_malloc) string
     representing the default authority to pass from a client. */
 char *grpc_get_default_authority(const char *target);
diff --git a/src/core/lib/client_config/resolvers/dns_resolver.h b/src/core/lib/client_config/resolvers/dns_resolver.h
deleted file mode 100644
index eb46e41c77..0000000000
--- a/src/core/lib/client_config/resolvers/dns_resolver.h
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
- *
- * Copyright 2015-2016, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVERS_DNS_RESOLVER_H
-#define GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVERS_DNS_RESOLVER_H
-
-#include "src/core/lib/client_config/resolver_factory.h"
-
-/** Create a dns resolver factory */
-grpc_resolver_factory *grpc_dns_resolver_factory_create(void);
-
-#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVERS_DNS_RESOLVER_H */
diff --git a/src/core/lib/client_config/resolvers/sockaddr_resolver.h b/src/core/lib/client_config/resolvers/sockaddr_resolver.h
deleted file mode 100644
index 45c55bd160..0000000000
--- a/src/core/lib/client_config/resolvers/sockaddr_resolver.h
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- *
- * Copyright 2015-2016, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVERS_SOCKADDR_RESOLVER_H
-#define GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVERS_SOCKADDR_RESOLVER_H
-
-#include <grpc/support/port_platform.h>
-
-#include "src/core/lib/client_config/resolver_factory.h"
-
-grpc_resolver_factory *grpc_ipv4_resolver_factory_create(void);
-
-grpc_resolver_factory *grpc_ipv6_resolver_factory_create(void);
-
-#ifdef GPR_POSIX_SOCKET
-/** Create a unix resolver factory */
-grpc_resolver_factory *grpc_unix_resolver_factory_create(void);
-#endif
-
-#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVERS_SOCKADDR_RESOLVER_H */
diff --git a/src/core/lib/client_config/resolvers/zookeeper_resolver.h b/src/core/lib/client_config/resolvers/zookeeper_resolver.h
deleted file mode 100644
index 7ee7604360..0000000000
--- a/src/core/lib/client_config/resolvers/zookeeper_resolver.h
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
- *
- * Copyright 2015-2016, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#ifndef GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVERS_ZOOKEEPER_RESOLVER_H
-#define GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVERS_ZOOKEEPER_RESOLVER_H
-
-#include "src/core/lib/client_config/resolver_factory.h"
-
-/** Create a zookeeper resolver factory */
-grpc_resolver_factory *grpc_zookeeper_resolver_factory_create(void);
-
-#endif /* GRPC_CORE_LIB_CLIENT_CONFIG_RESOLVERS_ZOOKEEPER_RESOLVER_H */
diff --git a/src/core/lib/surface/init.c b/src/core/lib/surface/init.c
index 786bf1d5da..51d9625e2a 100644
--- a/src/core/lib/surface/init.c
+++ b/src/core/lib/surface/init.c
@@ -48,8 +48,6 @@
 #include "src/core/lib/channel/http_server_filter.h"
 #include "src/core/lib/client_config/lb_policy_registry.h"
 #include "src/core/lib/client_config/resolver_registry.h"
-#include "src/core/lib/client_config/resolvers/dns_resolver.h"
-#include "src/core/lib/client_config/resolvers/sockaddr_resolver.h"
 #include "src/core/lib/client_config/subchannel.h"
 #include "src/core/lib/client_config/subchannel_index.h"
 #include "src/core/lib/debug/trace.h"
@@ -165,12 +163,6 @@ void grpc_init(void) {
     grpc_channel_init_init();
     grpc_lb_policy_registry_init();
     grpc_resolver_registry_init(GRPC_DEFAULT_NAME_PREFIX);
-    grpc_register_resolver_type(grpc_dns_resolver_factory_create());
-    grpc_register_resolver_type(grpc_ipv4_resolver_factory_create());
-    grpc_register_resolver_type(grpc_ipv6_resolver_factory_create());
-#ifdef GPR_HAVE_UNIX_SOCKET
-    grpc_register_resolver_type(grpc_unix_resolver_factory_create());
-#endif
     grpc_register_tracer("api", &grpc_api_trace);
     grpc_register_tracer("channel", &grpc_trace_channel);
     grpc_register_tracer("http", &grpc_http_trace);
diff --git a/src/core/plugin_registry/grpc_plugin_registry.c b/src/core/plugin_registry/grpc_plugin_registry.c
index 422d3c92b8..79df85516e 100644
--- a/src/core/plugin_registry/grpc_plugin_registry.c
+++ b/src/core/plugin_registry/grpc_plugin_registry.c
@@ -37,6 +37,10 @@ extern void grpc_lb_policy_pick_first_init(void);
 extern void grpc_lb_policy_pick_first_shutdown(void);
 extern void grpc_lb_policy_round_robin_init(void);
 extern void grpc_lb_policy_round_robin_shutdown(void);
+extern void grpc_resolver_dns_native_init(void);
+extern void grpc_resolver_dns_native_shutdown(void);
+extern void grpc_resolver_sockaddr_init(void);
+extern void grpc_resolver_sockaddr_shutdown(void);
 extern void census_grpc_plugin_init(void);
 extern void census_grpc_plugin_shutdown(void);
 
@@ -45,6 +49,10 @@ void grpc_register_built_in_plugins(void) {
                        grpc_lb_policy_pick_first_shutdown);
   grpc_register_plugin(grpc_lb_policy_round_robin_init,
                        grpc_lb_policy_round_robin_shutdown);
+  grpc_register_plugin(grpc_resolver_dns_native_init,
+                       grpc_resolver_dns_native_shutdown);
+  grpc_register_plugin(grpc_resolver_sockaddr_init,
+                       grpc_resolver_sockaddr_shutdown);
   grpc_register_plugin(census_grpc_plugin_init,
                        census_grpc_plugin_shutdown);
 }
diff --git a/src/core/plugin_registry/grpc_unsecure_plugin_registry.c b/src/core/plugin_registry/grpc_unsecure_plugin_registry.c
index 422d3c92b8..b3786c927d 100644
--- a/src/core/plugin_registry/grpc_unsecure_plugin_registry.c
+++ b/src/core/plugin_registry/grpc_unsecure_plugin_registry.c
@@ -33,6 +33,10 @@
 
 #include <grpc/grpc.h>
 
+extern void grpc_resolver_dns_native_init(void);
+extern void grpc_resolver_dns_native_shutdown(void);
+extern void grpc_resolver_sockaddr_init(void);
+extern void grpc_resolver_sockaddr_shutdown(void);
 extern void grpc_lb_policy_pick_first_init(void);
 extern void grpc_lb_policy_pick_first_shutdown(void);
 extern void grpc_lb_policy_round_robin_init(void);
@@ -41,6 +45,10 @@ extern void census_grpc_plugin_init(void);
 extern void census_grpc_plugin_shutdown(void);
 
 void grpc_register_built_in_plugins(void) {
+  grpc_register_plugin(grpc_resolver_dns_native_init,
+                       grpc_resolver_dns_native_shutdown);
+  grpc_register_plugin(grpc_resolver_sockaddr_init,
+                       grpc_resolver_sockaddr_shutdown);
   grpc_register_plugin(grpc_lb_policy_pick_first_init,
                        grpc_lb_policy_pick_first_shutdown);
   grpc_register_plugin(grpc_lb_policy_round_robin_init,
diff --git a/src/python/grpcio/grpc_core_dependencies.py b/src/python/grpcio/grpc_core_dependencies.py
index 0a516ed534..882ce0bb03 100644
--- a/src/python/grpcio/grpc_core_dependencies.py
+++ b/src/python/grpcio/grpc_core_dependencies.py
@@ -87,6 +87,8 @@ CORE_SOURCE_FILES = [
   'src/core/ext/lb_policy/grpclb/proto/grpc/lb/v0/load_balancer.pb.c',
   'src/core/ext/lb_policy/pick_first/pick_first.c',
   'src/core/ext/lb_policy/round_robin/round_robin.c',
+  'src/core/ext/resolver/dns/native/dns_resolver.c',
+  'src/core/ext/resolver/sockaddr/sockaddr_resolver.c',
   'src/core/ext/transport/chttp2/client/insecure/channel_create.c',
   'src/core/ext/transport/chttp2/client/secure/secure_channel_create.c',
   'src/core/ext/transport/chttp2/server/insecure/server_chttp2.c',
@@ -131,8 +133,6 @@ CORE_SOURCE_FILES = [
   'src/core/lib/client_config/resolver.c',
   'src/core/lib/client_config/resolver_factory.c',
   'src/core/lib/client_config/resolver_registry.c',
-  'src/core/lib/client_config/resolvers/dns_resolver.c',
-  'src/core/lib/client_config/resolvers/sockaddr_resolver.c',
   'src/core/lib/client_config/subchannel.c',
   'src/core/lib/client_config/subchannel_factory.c',
   'src/core/lib/client_config/subchannel_index.c',