Optionalize name resolvers

6 files changed, 1178 insertions, 0 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/ext/resolver/dns/native/dns_resolver.c b/src/core/ext/resolver/dns/native/dns_resolver.c
new file mode 100644
index 0000000000..60028848bb
--- /dev/null
+++ b/src/core/ext/resolver/dns/native/dns_resolver.c
@@ -0,0 +1,299 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/host_port.h>
+#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"
+#include "src/core/lib/support/string.h"
+
+#define BACKOFF_MULTIPLIER 1.6
+#define BACKOFF_JITTER 0.2
+#define BACKOFF_MIN_SECONDS 1
+#define BACKOFF_MAX_SECONDS 120
+
+typedef struct {
+  /** base class: must be first */
+  grpc_resolver base;
+  /** refcount */
+  gpr_refcount refs;
+  /** name to resolve */
+  char *name;
+  /** default port to use */
+  char *default_port;
+  /** subchannel factory */
+  grpc_subchannel_factory *subchannel_factory;
+  /** load balancing policy name */
+  char *lb_policy_name;
+
+  /** mutex guarding the rest of the state */
+  gpr_mu mu;
+  /** are we currently resolving? */
+  int resolving;
+  /** which version of resolved_config have we published? */
+  int published_version;
+  /** which version of resolved_config is current? */
+  int resolved_version;
+  /** pending next completion, or NULL */
+  grpc_closure *next_completion;
+  /** target config address for next completion */
+  grpc_client_config **target_config;
+  /** current (fully resolved) config */
+  grpc_client_config *resolved_config;
+  /** retry timer */
+  bool have_retry_timer;
+  grpc_timer retry_timer;
+  /** retry backoff state */
+  gpr_backoff backoff_state;
+} dns_resolver;
+
+static void dns_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
+
+static void dns_start_resolving_locked(dns_resolver *r);
+static void dns_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
+                                         dns_resolver *r);
+
+static void dns_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
+static void dns_channel_saw_error(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
+static void dns_next(grpc_exec_ctx *exec_ctx, grpc_resolver *r,
+                     grpc_client_config **target_config,
+                     grpc_closure *on_complete);
+
+static const grpc_resolver_vtable dns_resolver_vtable = {
+    dns_destroy, dns_shutdown, dns_channel_saw_error, dns_next};
+
+static void dns_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver) {
+  dns_resolver *r = (dns_resolver *)resolver;
+  gpr_mu_lock(&r->mu);
+  if (r->have_retry_timer) {
+    grpc_timer_cancel(exec_ctx, &r->retry_timer);
+  }
+  if (r->next_completion != NULL) {
+    *r->target_config = NULL;
+    grpc_exec_ctx_enqueue(exec_ctx, r->next_completion, true, NULL);
+    r->next_completion = NULL;
+  }
+  gpr_mu_unlock(&r->mu);
+}
+
+static void dns_channel_saw_error(grpc_exec_ctx *exec_ctx,
+                                  grpc_resolver *resolver) {
+  dns_resolver *r = (dns_resolver *)resolver;
+  gpr_mu_lock(&r->mu);
+  if (!r->resolving) {
+    gpr_backoff_reset(&r->backoff_state);
+    dns_start_resolving_locked(r);
+  }
+  gpr_mu_unlock(&r->mu);
+}
+
+static void dns_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
+                     grpc_client_config **target_config,
+                     grpc_closure *on_complete) {
+  dns_resolver *r = (dns_resolver *)resolver;
+  gpr_mu_lock(&r->mu);
+  GPR_ASSERT(!r->next_completion);
+  r->next_completion = on_complete;
+  r->target_config = target_config;
+  if (r->resolved_version == 0 && !r->resolving) {
+    gpr_backoff_reset(&r->backoff_state);
+    dns_start_resolving_locked(r);
+  } else {
+    dns_maybe_finish_next_locked(exec_ctx, r);
+  }
+  gpr_mu_unlock(&r->mu);
+}
+
+static void dns_on_retry_timer(grpc_exec_ctx *exec_ctx, void *arg,
+                               bool success) {
+  dns_resolver *r = arg;
+
+  gpr_mu_lock(&r->mu);
+  r->have_retry_timer = false;
+  if (success) {
+    if (!r->resolving) {
+      dns_start_resolving_locked(r);
+    }
+  }
+  gpr_mu_unlock(&r->mu);
+
+  GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "retry-timer");
+}
+
+static void dns_on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
+                            grpc_resolved_addresses *addresses) {
+  dns_resolver *r = arg;
+  grpc_client_config *config = NULL;
+  grpc_lb_policy *lb_policy;
+  gpr_mu_lock(&r->mu);
+  GPR_ASSERT(r->resolving);
+  r->resolving = 0;
+  if (addresses != NULL) {
+    grpc_lb_policy_args lb_policy_args;
+    config = grpc_client_config_create();
+    memset(&lb_policy_args, 0, sizeof(lb_policy_args));
+    lb_policy_args.addresses = addresses;
+    lb_policy_args.subchannel_factory = r->subchannel_factory;
+    lb_policy =
+        grpc_lb_policy_create(exec_ctx, r->lb_policy_name, &lb_policy_args);
+    if (lb_policy != NULL) {
+      grpc_client_config_set_lb_policy(config, lb_policy);
+      GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "construction");
+    }
+    grpc_resolved_addresses_destroy(addresses);
+  } else {
+    gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
+    gpr_timespec next_try = gpr_backoff_step(&r->backoff_state, now);
+    gpr_timespec timeout = gpr_time_sub(next_try, now);
+    gpr_log(GPR_DEBUG, "dns resolution failed: retrying in %d.%09d seconds",
+            timeout.tv_sec, timeout.tv_nsec);
+    GPR_ASSERT(!r->have_retry_timer);
+    r->have_retry_timer = true;
+    GRPC_RESOLVER_REF(&r->base, "retry-timer");
+    grpc_timer_init(exec_ctx, &r->retry_timer, next_try, dns_on_retry_timer, r,
+                    now);
+  }
+  if (r->resolved_config) {
+    grpc_client_config_unref(exec_ctx, r->resolved_config);
+  }
+  r->resolved_config = config;
+  r->resolved_version++;
+  dns_maybe_finish_next_locked(exec_ctx, r);
+  gpr_mu_unlock(&r->mu);
+
+  GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "dns-resolving");
+}
+
+static void dns_start_resolving_locked(dns_resolver *r) {
+  GRPC_RESOLVER_REF(&r->base, "dns-resolving");
+  GPR_ASSERT(!r->resolving);
+  r->resolving = 1;
+  grpc_resolve_address(r->name, r->default_port, dns_on_resolved, r);
+}
+
+static void dns_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
+                                         dns_resolver *r) {
+  if (r->next_completion != NULL &&
+      r->resolved_version != r->published_version) {
+    *r->target_config = r->resolved_config;
+    if (r->resolved_config) {
+      grpc_client_config_ref(r->resolved_config);
+    }
+    grpc_exec_ctx_enqueue(exec_ctx, r->next_completion, true, NULL);
+    r->next_completion = NULL;
+    r->published_version = r->resolved_version;
+  }
+}
+
+static void dns_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *gr) {
+  dns_resolver *r = (dns_resolver *)gr;
+  gpr_mu_destroy(&r->mu);
+  if (r->resolved_config) {
+    grpc_client_config_unref(exec_ctx, r->resolved_config);
+  }
+  grpc_subchannel_factory_unref(exec_ctx, r->subchannel_factory);
+  gpr_free(r->name);
+  gpr_free(r->default_port);
+  gpr_free(r->lb_policy_name);
+  gpr_free(r);
+}
+
+static grpc_resolver *dns_create(grpc_resolver_args *args,
+                                 const char *default_port,
+                                 const char *lb_policy_name) {
+  dns_resolver *r;
+  const char *path = args->uri->path;
+
+  if (0 != strcmp(args->uri->authority, "")) {
+    gpr_log(GPR_ERROR, "authority based dns uri's not supported");
+    return NULL;
+  }
+
+  if (path[0] == '/') ++path;
+
+  r = gpr_malloc(sizeof(dns_resolver));
+  memset(r, 0, sizeof(*r));
+  gpr_ref_init(&r->refs, 1);
+  gpr_mu_init(&r->mu);
+  grpc_resolver_init(&r->base, &dns_resolver_vtable);
+  r->name = gpr_strdup(path);
+  r->default_port = gpr_strdup(default_port);
+  r->subchannel_factory = args->subchannel_factory;
+  gpr_backoff_init(&r->backoff_state, BACKOFF_MULTIPLIER, BACKOFF_JITTER,
+                   BACKOFF_MIN_SECONDS * 1000, BACKOFF_MAX_SECONDS * 1000);
+  grpc_subchannel_factory_ref(r->subchannel_factory);
+  r->lb_policy_name = gpr_strdup(lb_policy_name);
+  return &r->base;
+}
+
+/*
+ * FACTORY
+ */
+
+static void dns_factory_ref(grpc_resolver_factory *factory) {}
+
+static void dns_factory_unref(grpc_resolver_factory *factory) {}
+
+static grpc_resolver *dns_factory_create_resolver(
+    grpc_resolver_factory *factory, grpc_resolver_args *args) {
+  return dns_create(args, "https", "pick_first");
+}
+
+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);
+}
+
+static const grpc_resolver_factory_vtable dns_factory_vtable = {
+    dns_factory_ref, dns_factory_unref, dns_factory_create_resolver,
+    dns_factory_get_default_host_name, "dns"};
+static grpc_resolver_factory dns_resolver_factory = {&dns_factory_vtable};
+
+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/ext/resolver/sockaddr/sockaddr_resolver.c b/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
new file mode 100644
index 0000000000..a416f10dcb
--- /dev/null
+++ b/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
@@ -0,0 +1,361 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#include <stdio.h>
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/host_port.h>
+#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"
+
+typedef struct {
+  /** base class: must be first */
+  grpc_resolver base;
+  /** refcount */
+  gpr_refcount refs;
+  /** subchannel factory */
+  grpc_subchannel_factory *subchannel_factory;
+  /** load balancing policy name */
+  char *lb_policy_name;
+
+  /** the addresses that we've 'resolved' */
+  grpc_resolved_addresses *addresses;
+
+  /** mutex guarding the rest of the state */
+  gpr_mu mu;
+  /** have we published? */
+  int published;
+  /** pending next completion, or NULL */
+  grpc_closure *next_completion;
+  /** target config address for next completion */
+  grpc_client_config **target_config;
+} sockaddr_resolver;
+
+static void sockaddr_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
+
+static void sockaddr_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
+                                              sockaddr_resolver *r);
+
+static void sockaddr_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
+static void sockaddr_channel_saw_error(grpc_exec_ctx *exec_ctx,
+                                       grpc_resolver *r);
+static void sockaddr_next(grpc_exec_ctx *exec_ctx, grpc_resolver *r,
+                          grpc_client_config **target_config,
+                          grpc_closure *on_complete);
+
+static const grpc_resolver_vtable sockaddr_resolver_vtable = {
+    sockaddr_destroy, sockaddr_shutdown, sockaddr_channel_saw_error,
+    sockaddr_next};
+
+static void sockaddr_shutdown(grpc_exec_ctx *exec_ctx,
+                              grpc_resolver *resolver) {
+  sockaddr_resolver *r = (sockaddr_resolver *)resolver;
+  gpr_mu_lock(&r->mu);
+  if (r->next_completion != NULL) {
+    *r->target_config = NULL;
+    grpc_exec_ctx_enqueue(exec_ctx, r->next_completion, true, NULL);
+    r->next_completion = NULL;
+  }
+  gpr_mu_unlock(&r->mu);
+}
+
+static void sockaddr_channel_saw_error(grpc_exec_ctx *exec_ctx,
+                                       grpc_resolver *resolver) {
+  sockaddr_resolver *r = (sockaddr_resolver *)resolver;
+  gpr_mu_lock(&r->mu);
+  r->published = 0;
+  sockaddr_maybe_finish_next_locked(exec_ctx, r);
+  gpr_mu_unlock(&r->mu);
+}
+
+static void sockaddr_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
+                          grpc_client_config **target_config,
+                          grpc_closure *on_complete) {
+  sockaddr_resolver *r = (sockaddr_resolver *)resolver;
+  gpr_mu_lock(&r->mu);
+  GPR_ASSERT(!r->next_completion);
+  r->next_completion = on_complete;
+  r->target_config = target_config;
+  sockaddr_maybe_finish_next_locked(exec_ctx, r);
+  gpr_mu_unlock(&r->mu);
+}
+
+static void sockaddr_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
+                                              sockaddr_resolver *r) {
+  if (r->next_completion != NULL && !r->published) {
+    grpc_client_config *cfg = grpc_client_config_create();
+    grpc_lb_policy_args lb_policy_args;
+    memset(&lb_policy_args, 0, sizeof(lb_policy_args));
+    lb_policy_args.addresses = r->addresses;
+    lb_policy_args.subchannel_factory = r->subchannel_factory;
+    grpc_lb_policy *lb_policy =
+        grpc_lb_policy_create(exec_ctx, r->lb_policy_name, &lb_policy_args);
+    grpc_client_config_set_lb_policy(cfg, lb_policy);
+    GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "sockaddr");
+    r->published = 1;
+    *r->target_config = cfg;
+    grpc_exec_ctx_enqueue(exec_ctx, r->next_completion, true, NULL);
+    r->next_completion = NULL;
+  }
+}
+
+static void sockaddr_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *gr) {
+  sockaddr_resolver *r = (sockaddr_resolver *)gr;
+  gpr_mu_destroy(&r->mu);
+  grpc_subchannel_factory_unref(exec_ctx, r->subchannel_factory);
+  grpc_resolved_addresses_destroy(r->addresses);
+  gpr_free(r->lb_policy_name);
+  gpr_free(r);
+}
+
+static char *ip_get_default_authority(grpc_uri *uri) {
+  const char *path = uri->path;
+  if (path[0] == '/') ++path;
+  return gpr_strdup(path);
+}
+
+static char *ipv4_get_default_authority(grpc_resolver_factory *factory,
+                                        grpc_uri *uri) {
+  return ip_get_default_authority(uri);
+}
+
+static char *ipv6_get_default_authority(grpc_resolver_factory *factory,
+                                        grpc_uri *uri) {
+  return ip_get_default_authority(uri);
+}
+
+static int parse_ipv4(grpc_uri *uri, struct sockaddr_storage *addr,
+                      size_t *len) {
+  const char *host_port = uri->path;
+  char *host;
+  char *port;
+  int port_num;
+  int result = 0;
+  struct sockaddr_in *in = (struct sockaddr_in *)addr;
+
+  if (*host_port == '/') ++host_port;
+  if (!gpr_split_host_port(host_port, &host, &port)) {
+    return 0;
+  }
+
+  memset(in, 0, sizeof(*in));
+  *len = sizeof(*in);
+  in->sin_family = AF_INET;
+  if (inet_pton(AF_INET, host, &in->sin_addr) == 0) {
+    gpr_log(GPR_ERROR, "invalid ipv4 address: '%s'", host);
+    goto done;
+  }
+
+  if (port != NULL) {
+    if (sscanf(port, "%d", &port_num) != 1 || port_num < 0 ||
+        port_num > 65535) {
+      gpr_log(GPR_ERROR, "invalid ipv4 port: '%s'", port);
+      goto done;
+    }
+    in->sin_port = htons((uint16_t)port_num);
+  } else {
+    gpr_log(GPR_ERROR, "no port given for ipv4 scheme");
+    goto done;
+  }
+
+  result = 1;
+done:
+  gpr_free(host);
+  gpr_free(port);
+  return result;
+}
+
+static int parse_ipv6(grpc_uri *uri, struct sockaddr_storage *addr,
+                      size_t *len) {
+  const char *host_port = uri->path;
+  char *host;
+  char *port;
+  int port_num;
+  int result = 0;
+  struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)addr;
+
+  if (*host_port == '/') ++host_port;
+  if (!gpr_split_host_port(host_port, &host, &port)) {
+    return 0;
+  }
+
+  memset(in6, 0, sizeof(*in6));
+  *len = sizeof(*in6);
+  in6->sin6_family = AF_INET6;
+  if (inet_pton(AF_INET6, host, &in6->sin6_addr) == 0) {
+    gpr_log(GPR_ERROR, "invalid ipv6 address: '%s'", host);
+    goto done;
+  }
+
+  if (port != NULL) {
+    if (sscanf(port, "%d", &port_num) != 1 || port_num < 0 ||
+        port_num > 65535) {
+      gpr_log(GPR_ERROR, "invalid ipv6 port: '%s'", port);
+      goto done;
+    }
+    in6->sin6_port = htons((uint16_t)port_num);
+  } else {
+    gpr_log(GPR_ERROR, "no port given for ipv6 scheme");
+    goto done;
+  }
+
+  result = 1;
+done:
+  gpr_free(host);
+  gpr_free(port);
+  return result;
+}
+
+static void do_nothing(void *ignored) {}
+
+static grpc_resolver *sockaddr_create(
+    grpc_resolver_args *args, const char *default_lb_policy_name,
+    int parse(grpc_uri *uri, struct sockaddr_storage *dst, size_t *len)) {
+  int errors_found = 0; /* GPR_FALSE */
+  sockaddr_resolver *r;
+  gpr_slice path_slice;
+  gpr_slice_buffer path_parts;
+
+  if (0 != strcmp(args->uri->authority, "")) {
+    gpr_log(GPR_ERROR, "authority based uri's not supported by the %s scheme",
+            args->uri->scheme);
+    return NULL;
+  }
+
+  r = gpr_malloc(sizeof(sockaddr_resolver));
+  memset(r, 0, sizeof(*r));
+
+  r->lb_policy_name = NULL;
+  if (0 != strcmp(args->uri->query, "")) {
+    gpr_slice query_slice;
+    gpr_slice_buffer query_parts;
+
+    query_slice =
+        gpr_slice_new(args->uri->query, strlen(args->uri->query), do_nothing);
+    gpr_slice_buffer_init(&query_parts);
+    gpr_slice_split(query_slice, "=", &query_parts);
+    GPR_ASSERT(query_parts.count == 2);
+    if (0 == gpr_slice_str_cmp(query_parts.slices[0], "lb_policy")) {
+      r->lb_policy_name = gpr_dump_slice(query_parts.slices[1], GPR_DUMP_ASCII);
+    }
+    gpr_slice_buffer_destroy(&query_parts);
+    gpr_slice_unref(query_slice);
+  }
+  if (r->lb_policy_name == NULL) {
+    r->lb_policy_name = gpr_strdup(default_lb_policy_name);
+  }
+
+  path_slice =
+      gpr_slice_new(args->uri->path, strlen(args->uri->path), do_nothing);
+  gpr_slice_buffer_init(&path_parts);
+
+  gpr_slice_split(path_slice, ",", &path_parts);
+  r->addresses = gpr_malloc(sizeof(grpc_resolved_addresses));
+  r->addresses->naddrs = path_parts.count;
+  r->addresses->addrs =
+      gpr_malloc(sizeof(grpc_resolved_address) * r->addresses->naddrs);
+
+  for (size_t i = 0; i < r->addresses->naddrs; i++) {
+    grpc_uri ith_uri = *args->uri;
+    char *part_str = gpr_dump_slice(path_parts.slices[i], GPR_DUMP_ASCII);
+    ith_uri.path = part_str;
+    if (!parse(&ith_uri,
+               (struct sockaddr_storage *)(&r->addresses->addrs[i].addr),
+               &r->addresses->addrs[i].len)) {
+      errors_found = 1; /* GPR_TRUE */
+    }
+    gpr_free(part_str);
+    if (errors_found) break;
+  }
+
+  gpr_slice_buffer_destroy(&path_parts);
+  gpr_slice_unref(path_slice);
+  if (errors_found) {
+    gpr_free(r->lb_policy_name);
+    grpc_resolved_addresses_destroy(r->addresses);
+    gpr_free(r);
+    return NULL;
+  }
+
+  gpr_ref_init(&r->refs, 1);
+  gpr_mu_init(&r->mu);
+  grpc_resolver_init(&r->base, &sockaddr_resolver_vtable);
+  r->subchannel_factory = args->subchannel_factory;
+  grpc_subchannel_factory_ref(r->subchannel_factory);
+
+  return &r->base;
+}
+
+/*
+ * FACTORY
+ */
+
+static void sockaddr_factory_ref(grpc_resolver_factory *factory) {}
+
+static void sockaddr_factory_unref(grpc_resolver_factory *factory) {}
+
+#define DECL_FACTORY(name, prefix)                                          \
+  static grpc_resolver *name##_factory_create_resolver(                     \
+      grpc_resolver_factory *factory, grpc_resolver_args *args) {           \
+    return sockaddr_create(args, "pick_first", prefix##parse_##name);       \
+  }                                                                         \
+  static const grpc_resolver_factory_vtable name##_factory_vtable = {       \
+      sockaddr_factory_ref, sockaddr_factory_unref,                         \
+      name##_factory_create_resolver, prefix##name##_get_default_authority, \
+      #name};                                                               \
+  static grpc_resolver_factory name##_resolver_factory = {                  \
+      &name##_factory_vtable}
+
+#ifdef GPR_HAVE_UNIX_SOCKET
+DECL_FACTORY(unix, grpc_);
+#endif
+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/ext/resolver/zookeeper/zookeeper_resolver.c b/src/core/ext/resolver/zookeeper/zookeeper_resolver.c
new file mode 100644
index 0000000000..404dfcd423
--- /dev/null
+++ b/src/core/ext/resolver/zookeeper/zookeeper_resolver.c
@@ -0,0 +1,514 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+#include "src/core/lib/client_config/resolvers/zookeeper_resolver.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/string_util.h>
+
+#include <grpc/grpc_zookeeper.h>
+#include <zookeeper/zookeeper.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/json/json.h"
+#include "src/core/lib/support/string.h"
+#include "src/core/lib/surface/api_trace.h"
+
+/** Zookeeper session expiration time in milliseconds */
+#define GRPC_ZOOKEEPER_SESSION_TIMEOUT 15000
+
+typedef struct {
+  /** base class: must be first */
+  grpc_resolver base;
+  /** refcount */
+  gpr_refcount refs;
+  /** name to resolve */
+  char *name;
+  /** subchannel factory */
+  grpc_subchannel_factory *subchannel_factory;
+  /** load balancing policy name */
+  char *lb_policy_name;
+
+  /** mutex guarding the rest of the state */
+  gpr_mu mu;
+  /** are we currently resolving? */
+  int resolving;
+  /** which version of resolved_config have we published? */
+  int published_version;
+  /** which version of resolved_config is current? */
+  int resolved_version;
+  /** pending next completion, or NULL */
+  grpc_closure *next_completion;
+  /** target config address for next completion */
+  grpc_client_config **target_config;
+  /** current (fully resolved) config */
+  grpc_client_config *resolved_config;
+
+  /** zookeeper handle */
+  zhandle_t *zookeeper_handle;
+  /** zookeeper resolved addresses */
+  grpc_resolved_addresses *resolved_addrs;
+  /** total number of addresses to be resolved */
+  int resolved_total;
+  /** number of addresses resolved */
+  int resolved_num;
+} zookeeper_resolver;
+
+static void zookeeper_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
+
+static void zookeeper_start_resolving_locked(zookeeper_resolver *r);
+static void zookeeper_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
+                                               zookeeper_resolver *r);
+
+static void zookeeper_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *r);
+static void zookeeper_channel_saw_error(grpc_exec_ctx *exec_ctx,
+                                        grpc_resolver *r);
+static void zookeeper_next(grpc_exec_ctx *exec_ctx, grpc_resolver *r,
+                           grpc_client_config **target_config,
+                           grpc_closure *on_complete);
+
+static const grpc_resolver_vtable zookeeper_resolver_vtable = {
+    zookeeper_destroy, zookeeper_shutdown, zookeeper_channel_saw_error,
+    zookeeper_next};
+
+static void zookeeper_shutdown(grpc_exec_ctx *exec_ctx,
+                               grpc_resolver *resolver) {
+  zookeeper_resolver *r = (zookeeper_resolver *)resolver;
+  grpc_closure *call = NULL;
+  gpr_mu_lock(&r->mu);
+  if (r->next_completion != NULL) {
+    *r->target_config = NULL;
+    call = r->next_completion;
+    r->next_completion = NULL;
+  }
+  zookeeper_close(r->zookeeper_handle);
+  gpr_mu_unlock(&r->mu);
+  if (call != NULL) {
+    call->cb(exec_ctx, call->cb_arg, 1);
+  }
+}
+
+static void zookeeper_channel_saw_error(grpc_exec_ctx *exec_ctx,
+                                        grpc_resolver *resolver) {
+  zookeeper_resolver *r = (zookeeper_resolver *)resolver;
+  gpr_mu_lock(&r->mu);
+  if (r->resolving == 0) {
+    zookeeper_start_resolving_locked(r);
+  }
+  gpr_mu_unlock(&r->mu);
+}
+
+static void zookeeper_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
+                           grpc_client_config **target_config,
+                           grpc_closure *on_complete) {
+  zookeeper_resolver *r = (zookeeper_resolver *)resolver;
+  gpr_mu_lock(&r->mu);
+  GPR_ASSERT(r->next_completion == NULL);
+  r->next_completion = on_complete;
+  r->target_config = target_config;
+  if (r->resolved_version == 0 && r->resolving == 0) {
+    zookeeper_start_resolving_locked(r);
+  } else {
+    zookeeper_maybe_finish_next_locked(exec_ctx, r);
+  }
+  gpr_mu_unlock(&r->mu);
+}
+
+/** Zookeeper global watcher for connection management
+    TODO: better connection management besides logs */
+static void zookeeper_global_watcher(zhandle_t *zookeeper_handle, int type,
+                                     int state, const char *path,
+                                     void *watcher_ctx) {
+  if (type == ZOO_SESSION_EVENT) {
+    if (state == ZOO_EXPIRED_SESSION_STATE) {
+      gpr_log(GPR_ERROR, "Zookeeper session expired");
+    } else if (state == ZOO_AUTH_FAILED_STATE) {
+      gpr_log(GPR_ERROR, "Zookeeper authentication failed");
+    }
+  }
+}
+
+/** Zookeeper watcher triggered by changes to watched nodes
+    Once triggered, it tries to resolve again to get updated addresses */
+static void zookeeper_watcher(zhandle_t *zookeeper_handle, int type, int state,
+                              const char *path, void *watcher_ctx) {
+  if (watcher_ctx != NULL) {
+    zookeeper_resolver *r = (zookeeper_resolver *)watcher_ctx;
+    if (state == ZOO_CONNECTED_STATE) {
+      gpr_mu_lock(&r->mu);
+      if (r->resolving == 0) {
+        zookeeper_start_resolving_locked(r);
+      }
+      gpr_mu_unlock(&r->mu);
+    }
+  }
+}
+
+/** Callback function after getting all resolved addresses
+    Creates a subchannel for each address */
+static void zookeeper_on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
+                                  grpc_resolved_addresses *addresses) {
+  zookeeper_resolver *r = arg;
+  grpc_client_config *config = NULL;
+  grpc_lb_policy *lb_policy;
+
+  if (addresses != NULL) {
+    grpc_lb_policy_args lb_policy_args;
+    config = grpc_client_config_create();
+
+    lb_policy_args.addresses = addresses;
+    lb_policy_args.subchannel_factory = r->subchannel_factory;
+    lb_policy =
+        grpc_lb_policy_create(exec_ctx, r->lb_policy_name, &lb_policy_args);
+
+    if (lb_policy != NULL) {
+      grpc_client_config_set_lb_policy(config, lb_policy);
+      GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "construction");
+    }
+    grpc_resolved_addresses_destroy(addresses);
+  }
+  gpr_mu_lock(&r->mu);
+  GPR_ASSERT(r->resolving == 1);
+  r->resolving = 0;
+  if (r->resolved_config != NULL) {
+    grpc_client_config_unref(exec_ctx, r->resolved_config);
+  }
+  r->resolved_config = config;
+  r->resolved_version++;
+  zookeeper_maybe_finish_next_locked(exec_ctx, r);
+  gpr_mu_unlock(&r->mu);
+
+  GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "zookeeper-resolving");
+}
+
+/** Callback function for each DNS resolved address */
+static void zookeeper_dns_resolved(grpc_exec_ctx *exec_ctx, void *arg,
+                                   grpc_resolved_addresses *addresses) {
+  size_t i;
+  zookeeper_resolver *r = arg;
+  int resolve_done = 0;
+
+  gpr_mu_lock(&r->mu);
+  r->resolved_num++;
+  r->resolved_addrs->addrs =
+      gpr_realloc(r->resolved_addrs->addrs,
+                  sizeof(grpc_resolved_address) *
+                      (r->resolved_addrs->naddrs + addresses->naddrs));
+  for (i = 0; i < addresses->naddrs; i++) {
+    memcpy(r->resolved_addrs->addrs[i + r->resolved_addrs->naddrs].addr,
+           addresses->addrs[i].addr, addresses->addrs[i].len);
+    r->resolved_addrs->addrs[i + r->resolved_addrs->naddrs].len =
+        addresses->addrs[i].len;
+  }
+
+  r->resolved_addrs->naddrs += addresses->naddrs;
+  grpc_resolved_addresses_destroy(addresses);
+
+  /** Wait for all addresses to be resolved */
+  resolve_done = (r->resolved_num == r->resolved_total);
+  gpr_mu_unlock(&r->mu);
+  if (resolve_done) {
+    zookeeper_on_resolved(exec_ctx, r, r->resolved_addrs);
+  }
+}
+
+/** Parses JSON format address of a zookeeper node */
+static char *zookeeper_parse_address(const char *value, size_t value_len) {
+  grpc_json *json;
+  grpc_json *cur;
+  const char *host;
+  const char *port;
+  char *buffer;
+  char *address = NULL;
+
+  buffer = gpr_malloc(value_len);
+  memcpy(buffer, value, value_len);
+  json = grpc_json_parse_string_with_len(buffer, value_len);
+  if (json != NULL) {
+    host = NULL;
+    port = NULL;
+    for (cur = json->child; cur != NULL; cur = cur->next) {
+      if (!strcmp(cur->key, "host")) {
+        host = cur->value;
+        if (port != NULL) {
+          break;
+        }
+      } else if (!strcmp(cur->key, "port")) {
+        port = cur->value;
+        if (host != NULL) {
+          break;
+        }
+      }
+    }
+    if (host != NULL && port != NULL) {
+      gpr_asprintf(&address, "%s:%s", host, port);
+    }
+    grpc_json_destroy(json);
+  }
+  gpr_free(buffer);
+
+  return address;
+}
+
+static void zookeeper_get_children_node_completion(int rc, const char *value,
+                                                   int value_len,
+                                                   const struct Stat *stat,
+                                                   const void *arg) {
+  char *address = NULL;
+  zookeeper_resolver *r = (zookeeper_resolver *)arg;
+  int resolve_done = 0;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+
+  if (rc != 0) {
+    gpr_log(GPR_ERROR, "Error in getting a child node of %s", r->name);
+    grpc_exec_ctx_finish(&exec_ctx);
+    return;
+  }
+
+  address = zookeeper_parse_address(value, (size_t)value_len);
+  if (address != NULL) {
+    /** Further resolves address by DNS */
+    grpc_resolve_address(address, NULL, zookeeper_dns_resolved, r);
+    gpr_free(address);
+  } else {
+    gpr_log(GPR_ERROR, "Error in resolving a child node of %s", r->name);
+    gpr_mu_lock(&r->mu);
+    r->resolved_total--;
+    resolve_done = (r->resolved_num == r->resolved_total);
+    gpr_mu_unlock(&r->mu);
+    if (resolve_done) {
+      zookeeper_on_resolved(&exec_ctx, r, r->resolved_addrs);
+    }
+  }
+
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
+static void zookeeper_get_children_completion(
+    int rc, const struct String_vector *children, const void *arg) {
+  char *path;
+  int status;
+  int i;
+  zookeeper_resolver *r = (zookeeper_resolver *)arg;
+
+  if (rc != 0) {
+    gpr_log(GPR_ERROR, "Error in getting zookeeper children of %s", r->name);
+    return;
+  }
+
+  if (children->count == 0) {
+    gpr_log(GPR_ERROR, "Error in resolving zookeeper address %s", r->name);
+    return;
+  }
+
+  r->resolved_addrs = gpr_malloc(sizeof(grpc_resolved_addresses));
+  r->resolved_addrs->addrs = NULL;
+  r->resolved_addrs->naddrs = 0;
+  r->resolved_total = children->count;
+
+  /** TODO: Replace expensive heap allocation with stack
+      if we can get maximum length of zookeeper path */
+  for (i = 0; i < children->count; i++) {
+    gpr_asprintf(&path, "%s/%s", r->name, children->data[i]);
+    status = zoo_awget(r->zookeeper_handle, path, zookeeper_watcher, r,
+                       zookeeper_get_children_node_completion, r);
+    gpr_free(path);
+    if (status != 0) {
+      gpr_log(GPR_ERROR, "Error in getting zookeeper node %s", path);
+    }
+  }
+}
+
+static void zookeeper_get_node_completion(int rc, const char *value,
+                                          int value_len,
+                                          const struct Stat *stat,
+                                          const void *arg) {
+  int status;
+  char *address = NULL;
+  zookeeper_resolver *r = (zookeeper_resolver *)arg;
+  r->resolved_addrs = NULL;
+  r->resolved_total = 0;
+  r->resolved_num = 0;
+
+  if (rc != 0) {
+    gpr_log(GPR_ERROR, "Error in getting zookeeper node %s", r->name);
+    return;
+  }
+
+  /** If zookeeper node of path r->name does not have address
+      (i.e. service node), get its children */
+  address = zookeeper_parse_address(value, (size_t)value_len);
+  if (address != NULL) {
+    r->resolved_addrs = gpr_malloc(sizeof(grpc_resolved_addresses));
+    r->resolved_addrs->addrs = NULL;
+    r->resolved_addrs->naddrs = 0;
+    r->resolved_total = 1;
+    /** Further resolves address by DNS */
+    grpc_resolve_address(address, NULL, zookeeper_dns_resolved, r);
+    gpr_free(address);
+    return;
+  }
+
+  status = zoo_awget_children(r->zookeeper_handle, r->name, zookeeper_watcher,
+                              r, zookeeper_get_children_completion, r);
+  if (status != 0) {
+    gpr_log(GPR_ERROR, "Error in getting zookeeper children of %s", r->name);
+  }
+}
+
+static void zookeeper_resolve_address(zookeeper_resolver *r) {
+  int status;
+  status = zoo_awget(r->zookeeper_handle, r->name, zookeeper_watcher, r,
+                     zookeeper_get_node_completion, r);
+  if (status != 0) {
+    gpr_log(GPR_ERROR, "Error in getting zookeeper node %s", r->name);
+  }
+}
+
+static void zookeeper_start_resolving_locked(zookeeper_resolver *r) {
+  GRPC_RESOLVER_REF(&r->base, "zookeeper-resolving");
+  GPR_ASSERT(r->resolving == 0);
+  r->resolving = 1;
+  zookeeper_resolve_address(r);
+}
+
+static void zookeeper_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
+                                               zookeeper_resolver *r) {
+  if (r->next_completion != NULL &&
+      r->resolved_version != r->published_version) {
+    *r->target_config = r->resolved_config;
+    if (r->resolved_config != NULL) {
+      grpc_client_config_ref(r->resolved_config);
+    }
+    grpc_exec_ctx_enqueue(exec_ctx, r->next_completion, true, NULL);
+    r->next_completion = NULL;
+    r->published_version = r->resolved_version;
+  }
+}
+
+static void zookeeper_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *gr) {
+  zookeeper_resolver *r = (zookeeper_resolver *)gr;
+  gpr_mu_destroy(&r->mu);
+  if (r->resolved_config != NULL) {
+    grpc_client_config_unref(exec_ctx, r->resolved_config);
+  }
+  grpc_subchannel_factory_unref(exec_ctx, r->subchannel_factory);
+  gpr_free(r->name);
+  gpr_free(r->lb_policy_name);
+  gpr_free(r);
+}
+
+static grpc_resolver *zookeeper_create(grpc_resolver_args *args,
+                                       const char *lb_policy_name) {
+  zookeeper_resolver *r;
+  size_t length;
+  char *path = args->uri->path;
+
+  if (0 == strcmp(args->uri->authority, "")) {
+    gpr_log(GPR_ERROR, "No authority specified in zookeeper uri");
+    return NULL;
+  }
+
+  /** Removes the trailing slash if exists */
+  length = strlen(path);
+  if (length > 1 && path[length - 1] == '/') {
+    path[length - 1] = 0;
+  }
+
+  r = gpr_malloc(sizeof(zookeeper_resolver));
+  memset(r, 0, sizeof(*r));
+  gpr_ref_init(&r->refs, 1);
+  gpr_mu_init(&r->mu);
+  grpc_resolver_init(&r->base, &zookeeper_resolver_vtable);
+  r->name = gpr_strdup(path);
+
+  r->subchannel_factory = args->subchannel_factory;
+  grpc_subchannel_factory_ref(r->subchannel_factory);
+
+  r->lb_policy_name = gpr_strdup(lb_policy_name);
+
+  /** Initializes zookeeper client */
+  zoo_set_debug_level(ZOO_LOG_LEVEL_WARN);
+  r->zookeeper_handle =
+      zookeeper_init(args->uri->authority, zookeeper_global_watcher,
+                     GRPC_ZOOKEEPER_SESSION_TIMEOUT, 0, 0, 0);
+  if (r->zookeeper_handle == NULL) {
+    gpr_log(GPR_ERROR, "Unable to connect to zookeeper server");
+    return NULL;
+  }
+
+  return &r->base;
+}
+
+static void zookeeper_plugin_init() {
+  grpc_register_resolver_type(grpc_zookeeper_resolver_factory_create());
+}
+
+void grpc_zookeeper_register() {
+  GRPC_API_TRACE("grpc_zookeeper_register(void)", 0, ());
+  grpc_register_plugin(zookeeper_plugin_init, NULL);
+}
+
+/*
+ * FACTORY
+ */
+
+static void zookeeper_factory_ref(grpc_resolver_factory *factory) {}
+
+static void zookeeper_factory_unref(grpc_resolver_factory *factory) {}
+
+static char *zookeeper_factory_get_default_hostname(
+    grpc_resolver_factory *factory, grpc_uri *uri) {
+  return NULL;
+}
+
+static grpc_resolver *zookeeper_factory_create_resolver(
+    grpc_resolver_factory *factory, grpc_resolver_args *args) {
+  return zookeeper_create(args, "pick_first");
+}
+
+static const grpc_resolver_factory_vtable zookeeper_factory_vtable = {
+    zookeeper_factory_ref, zookeeper_factory_unref,
+    zookeeper_factory_create_resolver, zookeeper_factory_get_default_hostname,
+    "zookeeper"};
+
+static grpc_resolver_factory zookeeper_resolver_factory = {
+    &zookeeper_factory_vtable};
+
+grpc_resolver_factory *grpc_zookeeper_resolver_factory_create() {
+  return &zookeeper_resolver_factory;
+}