syntax = "proto3";
package Etcd;


import "gogo.proto";
import "kv.proto";
import "auth.proto";

option (gogoproto.marshaler_all) = true;
option (gogoproto.unmarshaler_all) = true;

service KV {
  // Range gets the keys in the range from the key-value store.
  rpc Range(RangeRequest) returns (RangeResponse) {
  }

  // Put puts the given key into the key-value store.
  // A put request increments the revision of the key-value store
  // and generates one event in the event history.
  rpc Put(PutRequest) returns (PutResponse) {
  }

  // DeleteRange deletes the given range from the key-value store.
  // A delete request increments the revision of the key-value store
  // and generates a delete event in the event history for every deleted key.
  rpc DeleteRange(DeleteRangeRequest) returns (DeleteRangeResponse) {
  }

  // Txn processes multiple requests in a single transaction.
  // A txn request increments the revision of the key-value store
  // and generates events with the same revision for every completed request.
  // It is not allowed to modify the same key several times within one txn.
  rpc Txn(TxnRequest) returns (TxnResponse) {
  }

  // Compact compacts the event history in the etcd key-value store. The key-value
  // store should be periodically compacted or the event history will continue to grow
  // indefinitely.
  rpc Compact(CompactionRequest) returns (CompactionResponse) {
  }
}

service Watch {
  // Watch watches for events happening or that have happened. Both input and output
  // are streams; the input stream is for creating and canceling watchers and the output
  // stream sends events. One watch RPC can watch on multiple key ranges, streaming events
  // for several watches at once. The entire event history can be watched starting from the
  // last compaction revision.
  rpc Watch(stream WatchRequest) returns (stream WatchResponse) {
  }
}

service Lease {
  // LeaseGrant creates a lease which expires if the server does not receive a keepAlive
  // within a given time to live period. All keys attached to the lease will be expired and
  // deleted if the lease expires. Each expired key generates a delete event in the event history.
  rpc LeaseGrant (LeaseGrantRequest) returns (LeaseGrantResponse) {
  }

  // LeaseRevoke revokes a lease. All keys attached to the lease will expire and be deleted.
  rpc LeaseRevoke (LeaseRevokeRequest) returns (LeaseRevokeResponse) {
  }

  // LeaseKeepAlive keeps the lease alive by streaming keep alive requests from the client
  // to the server and streaming keep alive responses from the server to the client.
  rpc LeaseKeepAlive (stream LeaseKeepAliveRequest) returns (stream LeaseKeepAliveResponse) {
  }

  // LeaseTimeToLive retrieves lease information.
  rpc LeaseTimeToLive (LeaseTimeToLiveRequest) returns (LeaseTimeToLiveResponse) {
  }

  // LeaseLeases lists all existing leases.
  rpc LeaseLeases (LeaseLeasesRequest) returns (LeaseLeasesResponse) {
  }
}

service Cluster {
  // MemberAdd adds a member into the cluster.
  rpc MemberAdd(MemberAddRequest) returns (MemberAddResponse) {
  }

  // MemberRemove removes an existing member from the cluster.
  rpc MemberRemove(MemberRemoveRequest) returns (MemberRemoveResponse) {
  }

  // MemberUpdate updates the member configuration.
  rpc MemberUpdate(MemberUpdateRequest) returns (MemberUpdateResponse) {
  }

  // MemberList lists all the members in the cluster.
  rpc MemberList(MemberListRequest) returns (MemberListResponse) {
  }

  // MemberPromote promotes a member from raft learner (non-voting) to raft voting member.
  rpc MemberPromote(MemberPromoteRequest) returns (MemberPromoteResponse) {
  }
}

service Maintenance {
  // Alarm activates, deactivates, and queries alarms regarding cluster health.
  rpc Alarm(AlarmRequest) returns (AlarmResponse) {
  }

  // Status gets the status of the member.
  rpc Status(StatusRequest) returns (StatusResponse) {
  }

  // Defragment defragments a member's backend database to recover storage space.
  rpc Defragment(DefragmentRequest) returns (DefragmentResponse) {
  }

  // Hash computes the hash of whole backend keyspace,
  // including key, lease, and other buckets in storage.
  // This is designed for testing ONLY!
  // Do not rely on this in production with ongoing transactions,
  // since Hash operation does not hold MVCC locks.
  // Use "HashKV" API instead for "key" bucket consistency checks.
  rpc Hash(HashRequest) returns (HashResponse) {
  }

  // HashKV computes the hash of all MVCC keys up to a given revision.
  // It only iterates "key" bucket in backend storage.
  rpc HashKV(HashKVRequest) returns (HashKVResponse) {
  }

  // Snapshot sends a snapshot of the entire backend from a member over a stream to a client.
  rpc Snapshot(SnapshotRequest) returns (stream SnapshotResponse) {
  }

  // MoveLeader requests current leader node to transfer its leadership to transferee.
  rpc MoveLeader(MoveLeaderRequest) returns (MoveLeaderResponse) {
  }
}

service Auth {
  // AuthEnable enables authentication.
  rpc AuthEnable(AuthEnableRequest) returns (AuthEnableResponse) {
  }

  // AuthDisable disables authentication.
  rpc AuthDisable(AuthDisableRequest) returns (AuthDisableResponse) {
  }

  // Authenticate processes an authenticate request.
  rpc Authenticate(AuthenticateRequest) returns (AuthenticateResponse) {
  }

  // UserAdd adds a new user. User name cannot be empty.
  rpc UserAdd(AuthUserAddRequest) returns (AuthUserAddResponse) {
  }

  // UserGet gets detailed user information.
  rpc UserGet(AuthUserGetRequest) returns (AuthUserGetResponse) {
  }

  // UserList gets a list of all users.
  rpc UserList(AuthUserListRequest) returns (AuthUserListResponse) {
  }

  // UserDelete deletes a specified user.
  rpc UserDelete(AuthUserDeleteRequest) returns (AuthUserDeleteResponse) {
  }

  // UserChangePassword changes the password of a specified user.
  rpc UserChangePassword(AuthUserChangePasswordRequest) returns (AuthUserChangePasswordResponse) {
  }

  // UserGrant grants a role to a specified user.
  rpc UserGrantRole(AuthUserGrantRoleRequest) returns (AuthUserGrantRoleResponse) {
  }

  // UserRevokeRole revokes a role of specified user.
  rpc UserRevokeRole(AuthUserRevokeRoleRequest) returns (AuthUserRevokeRoleResponse) {
  }

  // RoleAdd adds a new role. Role name cannot be empty.
  rpc RoleAdd(AuthRoleAddRequest) returns (AuthRoleAddResponse) {
  }

  // RoleGet gets detailed role information.
  rpc RoleGet(AuthRoleGetRequest) returns (AuthRoleGetResponse) {
  }

  // RoleList gets lists of all roles.
  rpc RoleList(AuthRoleListRequest) returns (AuthRoleListResponse) {
  }

  // RoleDelete deletes a specified role.
  rpc RoleDelete(AuthRoleDeleteRequest) returns (AuthRoleDeleteResponse) {
  }

  // RoleGrantPermission grants a permission of a specified key or range to a specified role.
  rpc RoleGrantPermission(AuthRoleGrantPermissionRequest) returns (AuthRoleGrantPermissionResponse) {
  }

  // RoleRevokePermission revokes a key or range permission of a specified role.
  rpc RoleRevokePermission(AuthRoleRevokePermissionRequest) returns (AuthRoleRevokePermissionResponse) {
  }
}


message ResponseHeader {
  // cluster_id is the ID of the cluster which sent the response.
  uint64 cluster_id = 1;
  // member_id is the ID of the member which sent the response.
  uint64 member_id = 2;
  // revision is the key-value store revision when the request was applied.
  // For watch progress responses, the header.revision indicates progress. All future events
  // received in this stream are guaranteed to have a higher revision number than the
  // header.revision number.
  int64 revision = 3;
  // raft_term is the raft term when the request was applied.
  uint64 raft_term = 4;
}

message RangeRequest {
  enum SortOrder {
    NONE = 0; // default, no sorting
    ASCEND = 1; // lowest target value first
    DESCEND = 2; // highest target value first
  }
  enum SortTarget {
    KEY = 0;
    VERSION = 1;
    CREATE = 2;
    MOD = 3;
    VALUE = 4;
  }

  // key is the first key for the range. If range_end is not given, the request only looks up key.
  bytes key = 1;
  // range_end is the upper bound on the requested range [key, range_end).
  // If range_end is '\0', the range is all keys >= key.
  // If range_end is key plus one (e.g., "aa"+1 == "ab", "a\xff"+1 == "b"),
  // then the range request gets all keys prefixed with key.
  // If both key and range_end are '\0', then the range request returns all keys.
  bytes range_end = 2;
  // limit is a limit on the number of keys returned for the request. When limit is set to 0,
  // it is treated as no limit.
  int64 limit = 3;
  // revision is the point-in-time of the key-value store to use for the range.
  // If revision is less or equal to zero, the range is over the newest key-value store.
  // If the revision has been compacted, ErrCompacted is returned as a response.
  int64 revision = 4;

  // sort_order is the order for returned sorted results.
  SortOrder sort_order = 5;

  // sort_target is the key-value field to use for sorting.
  SortTarget sort_target = 6;

  // serializable sets the range request to use serializable member-local reads.
  // Range requests are linearizable by default; linearizable requests have higher
  // latency and lower throughput than serializable requests but reflect the current
  // consensus of the cluster. For better performance, in exchange for possible stale reads,
  // a serializable range request is served locally without needing to reach consensus
  // with other nodes in the cluster.
  bool serializable = 7;

  // keys_only when set returns only the keys and not the values.
  bool keys_only = 8;

  // count_only when set returns only the count of the keys in the range.
  bool count_only = 9;

  // min_mod_revision is the lower bound for returned key mod revisions; all keys with
  // lesser mod revisions will be filtered away.
  int64 min_mod_revision = 10;

  // max_mod_revision is the upper bound for returned key mod revisions; all keys with
  // greater mod revisions will be filtered away.
  int64 max_mod_revision = 11;

  // min_create_revision is the lower bound for returned key create revisions; all keys with
  // lesser create revisions will be filtered away.
  int64 min_create_revision = 12;

  // max_create_revision is the upper bound for returned key create revisions; all keys with
  // greater create revisions will be filtered away.
  int64 max_create_revision = 13;
}

message RangeResponse {
  ResponseHeader header = 1;
  // kvs is the list of key-value pairs matched by the range request.
  // kvs is empty when count is requested.
  repeated mvccpb.KeyValue kvs = 2;
  // more indicates if there are more keys to return in the requested range.
  bool more = 3;
  // count is set to the number of keys within the range when requested.
  int64 count = 4;
}

message PutRequest {
  // key is the key, in bytes, to put into the key-value store.
  bytes key = 1;
  // value is the value, in bytes, to associate with the key in the key-value store.
  bytes value = 2;
  // lease is the lease ID to associate with the key in the key-value store. A lease
  // value of 0 indicates no lease.
  int64 lease = 3;

  // If prev_kv is set, etcd gets the previous key-value pair before changing it.
  // The previous key-value pair will be returned in the put response.
  bool prev_kv = 4;

  // If ignore_value is set, etcd updates the key using its current value.
  // Returns an error if the key does not exist.
  bool ignore_value = 5;

  // If ignore_lease is set, etcd updates the key using its current lease.
  // Returns an error if the key does not exist.
  bool ignore_lease = 6;
}

message PutResponse {
  ResponseHeader header = 1;
  // if prev_kv is set in the request, the previous key-value pair will be returned.
  mvccpb.KeyValue prev_kv = 2;
}

message DeleteRangeRequest {
  // key is the first key to delete in the range.
  bytes key = 1;
  // range_end is the key following the last key to delete for the range [key, range_end).
  // If range_end is not given, the range is defined to contain only the key argument.
  // If range_end is one bit larger than the given key, then the range is all the keys
  // with the prefix (the given key).
  // If range_end is '\0', the range is all keys greater than or equal to the key argument.
  bytes range_end = 2;

  // If prev_kv is set, etcd gets the previous key-value pairs before deleting it.
  // The previous key-value pairs will be returned in the delete response.
  bool prev_kv = 3;
}

message DeleteRangeResponse {
  ResponseHeader header = 1;
  // deleted is the number of keys deleted by the delete range request.
  int64 deleted = 2;
  // if prev_kv is set in the request, the previous key-value pairs will be returned.
  repeated mvccpb.KeyValue prev_kvs = 3;
}

message RequestOp {
  // request is a union of request types accepted by a transaction.
  oneof request {
    RangeRequest request_range = 1;
    PutRequest request_put = 2;
    DeleteRangeRequest request_delete_range = 3;
    TxnRequest request_txn = 4;
  }
}

message ResponseOp {
  // response is a union of response types returned by a transaction.
  oneof response {
    RangeResponse response_range = 1;
    PutResponse response_put = 2;
    DeleteRangeResponse response_delete_range = 3;
    TxnResponse response_txn = 4;
  }
}

message Compare {
  enum CompareResult {
    EQUAL = 0;
    GREATER = 1;
    LESS = 2;
    NOT_EQUAL = 3;
  }
  enum CompareTarget {
    VERSION = 0;
    CREATE = 1;
    MOD = 2;
    VALUE = 3;
    LEASE = 4;
  }
  // result is logical comparison operation for this comparison.
  CompareResult result = 1;
  // target is the key-value field to inspect for the comparison.
  CompareTarget target = 2;
  // key is the subject key for the comparison operation.
  bytes key = 3;
  oneof target_union {
    // version is the version of the given key
    int64 version = 4;
    // create_revision is the creation revision of the given key
    int64 create_revision = 5;
    // mod_revision is the last modified revision of the given key.
    int64 mod_revision = 6;
    // value is the value of the given key, in bytes.
    bytes value = 7;
    // lease is the lease id of the given key.
    int64 lease = 8;
    // leave room for more target_union field tags, jump to 64
  }

  // range_end compares the given target to all keys in the range [key, range_end).
  // See RangeRequest for more details on key ranges.
  bytes range_end = 64;
  // TODO: fill out with most of the rest of RangeRequest fields when needed.
}

// From google paxosdb paper:
// Our implementation hinges around a powerful primitive which we call MultiOp. All other database
// operations except for iteration are implemented as a single call to MultiOp. A MultiOp is applied atomically
// and consists of three components:
// 1. A list of tests called guard. Each test in guard checks a single entry in the database. It may check
// for the absence or presence of a value, or compare with a given value. Two different tests in the guard
// may apply to the same or different entries in the database. All tests in the guard are applied and
// MultiOp returns the results. If all tests are true, MultiOp executes t op (see item 2 below), otherwise
// it executes f op (see item 3 below).
// 2. A list of database operations called t op. Each operation in the list is either an insert, delete, or
// lookup operation, and applies to a single database entry. Two different operations in the list may apply
// to the same or different entries in the database. These operations are executed
// if guard evaluates to
// true.
// 3. A list of database operations called f op. Like t op, but executed if guard evaluates to false.
message TxnRequest {
  // compare is a list of predicates representing a conjunction of terms.
  // If the comparisons succeed, then the success requests will be processed in order,
  // and the response will contain their respective responses in order.
  // If the comparisons fail, then the failure requests will be processed in order,
  // and the response will contain their respective responses in order.
  repeated Compare compare = 1;
  // success is a list of requests which will be applied when compare evaluates to true.
  repeated RequestOp success = 2;
  // failure is a list of requests which will be applied when compare evaluates to false.
  repeated RequestOp failure = 3;
}

message TxnResponse {
  ResponseHeader header = 1;
  // succeeded is set to true if the compare evaluated to true or false otherwise.
  bool succeeded = 2;
  // responses is a list of responses corresponding to the results from applying
  // success if succeeded is true or failure if succeeded is false.
  repeated ResponseOp responses = 3;
}

// CompactionRequest compacts the key-value store up to a given revision. All superseded keys
// with a revision less than the compaction revision will be removed.
message CompactionRequest {
  // revision is the key-value store revision for the compaction operation.
  int64 revision = 1;
  // physical is set so the RPC will wait until the compaction is physically
  // applied to the local database such that compacted entries are totally
  // removed from the backend database.
  bool physical = 2;
}

message CompactionResponse {
  ResponseHeader header = 1;
}

message HashRequest {
}

message HashKVRequest {
  // revision is the key-value store revision for the hash operation.
  int64 revision = 1;
}

message HashKVResponse {
  ResponseHeader header = 1;
  // hash is the hash value computed from the responding member's MVCC keys up to a given revision.
  uint32 hash = 2;
  // compact_revision is the compacted revision of key-value store when hash begins.
  int64 compact_revision = 3;
}

message HashResponse {
  ResponseHeader header = 1;
  // hash is the hash value computed from the responding member's KV's backend.
  uint32 hash = 2;
}

message SnapshotRequest {
}

message SnapshotResponse {
  // header has the current key-value store information. The first header in the snapshot
  // stream indicates the point in time of the snapshot.
  ResponseHeader header = 1;

  // remaining_bytes is the number of blob bytes to be sent after this message
  uint64 remaining_bytes = 2;

  // blob contains the next chunk of the snapshot in the snapshot stream.
  bytes blob = 3;
}

message WatchRequest {
  // request_union is a request to either create a new watcher or cancel an existing watcher.
  oneof request_union {
    WatchCreateRequest create_request = 1;
    WatchCancelRequest cancel_request = 2;
    WatchProgressRequest progress_request = 3;
  }
}

message WatchCreateRequest {
  // key is the key to register for watching.
  bytes key = 1;

  // range_end is the end of the range [key, range_end) to watch. If range_end is not given,
  // only the key argument is watched. If range_end is equal to '\0', all keys greater than
  // or equal to the key argument are watched.
  // If the range_end is one bit larger than the given key,
  // then all keys with the prefix (the given key) will be watched.
  bytes range_end = 2;

  // start_revision is an optional revision to watch from (inclusive). No start_revision is "now".
  int64 start_revision = 3;

  // progress_notify is set so that the etcd server will periodically send a WatchResponse with
  // no events to the new watcher if there are no recent events. It is useful when clients
  // wish to recover a disconnected watcher starting from a recent known revision.
  // The etcd server may decide how often it will send notifications based on current load.
  bool progress_notify = 4;

  enum FilterType {
    // filter out put event.
    NOPUT = 0;
    // filter out delete event.
    NODELETE = 1;
  }

  // filters filter the events at server side before it sends back to the watcher.
  repeated FilterType filters = 5;

  // If prev_kv is set, created watcher gets the previous KV before the event happens.
  // If the previous KV is already compacted, nothing will be returned.
  bool prev_kv = 6;

  // If watch_id is provided and non-zero, it will be assigned to this watcher.
  // Since creating a watcher in etcd is not a synchronous operation,
  // this can be used ensure that ordering is correct when creating multiple
  // watchers on the same stream. Creating a watcher with an ID already in
  // use on the stream will cause an error to be returned.
  int64 watch_id = 7;

  // fragment enables splitting large revisions into multiple watch responses.
  bool fragment = 8;
}

message WatchCancelRequest {
  // watch_id is the watcher id to cancel so that no more events are transmitted.
  int64 watch_id = 1;
}

// Requests the a watch stream progress status be sent in the watch response stream as soon as
// possible.
message WatchProgressRequest {
}

message WatchResponse {
  ResponseHeader header = 1;
  // watch_id is the ID of the watcher that corresponds to the response.
  int64 watch_id = 2;

  // created is set to true if the response is for a create watch request.
  // The client should record the watch_id and expect to receive events for
  // the created watcher from the same stream.
  // All events sent to the created watcher will attach with the same watch_id.
  bool created = 3;

  // canceled is set to true if the response is for a cancel watch request.
  // No further events will be sent to the canceled watcher.
  bool canceled = 4;

  // compact_revision is set to the minimum index if a watcher tries to watch
  // at a compacted index.
  //
  // This happens when creating a watcher at a compacted revision or the watcher cannot
  // catch up with the progress of the key-value store.
  //
  // The client should treat the watcher as canceled and should not try to create any
  // watcher with the same start_revision again.
  int64 compact_revision = 5;

  // cancel_reason indicates the reason for canceling the watcher.
  string cancel_reason = 6;

  // framgment is true if large watch response was split over multiple responses.
  bool fragment = 7;

  repeated mvccpb.Event events = 11;
}

message LeaseGrantRequest {
  // TTL is the advisory time-to-live in seconds. Expired lease will return -1.
  int64 TTL = 1;
  // ID is the requested ID for the lease. If ID is set to 0, the lessor chooses an ID.
  int64 ID = 2;
}

message LeaseGrantResponse {
  ResponseHeader header = 1;
  // ID is the lease ID for the granted lease.
  int64 ID = 2;
  // TTL is the server chosen lease time-to-live in seconds.
  int64 TTL = 3;
  string error = 4;
}

message LeaseRevokeRequest {
  // ID is the lease ID to revoke. When the ID is revoked, all associated keys will be deleted.
  int64 ID = 1;
}

message LeaseRevokeResponse {
  ResponseHeader header = 1;
}

message LeaseCheckpoint {
  // ID is the lease ID to checkpoint.
  int64 ID = 1;

  // Remaining_TTL is the remaining time until expiry of the lease.
  int64 remaining_TTL = 2;
}

message LeaseCheckpointRequest {
  repeated LeaseCheckpoint checkpoints = 1;
}

message LeaseCheckpointResponse {
  ResponseHeader header = 1;
}

message LeaseKeepAliveRequest {
  // ID is the lease ID for the lease to keep alive.
  int64 ID = 1;
}

message LeaseKeepAliveResponse {
  ResponseHeader header = 1;
  // ID is the lease ID from the keep alive request.
  int64 ID = 2;
  // TTL is the new time-to-live for the lease.
  int64 TTL = 3;
}

message LeaseTimeToLiveRequest {
  // ID is the lease ID for the lease.
  int64 ID = 1;
  // keys is true to query all the keys attached to this lease.
  bool keys = 2;
}

message LeaseTimeToLiveResponse {
  ResponseHeader header = 1;
  // ID is the lease ID from the keep alive request.
  int64 ID = 2;
  // TTL is the remaining TTL in seconds for the lease; the lease will expire in under TTL+1 seconds.
  int64 TTL = 3;
  // GrantedTTL is the initial granted time in seconds upon lease creation/renewal.
  int64 grantedTTL = 4;
  // Keys is the list of keys attached to this lease.
  repeated bytes keys = 5;
}

message LeaseLeasesRequest {
}

message LeaseStatus {
  int64 ID = 1;
  // TODO: int64 TTL = 2;
}

message LeaseLeasesResponse {
  ResponseHeader header = 1;
  repeated LeaseStatus leases = 2;
}

message Member {
  // ID is the member ID for this member.
  uint64 ID = 1;
  // name is the human-readable name of the member. If the member is not started, the name will be an empty string.
  string name = 2;
  // peerURLs is the list of URLs the member exposes to the cluster for communication.
  repeated string peerURLs = 3;
  // clientURLs is the list of URLs the member exposes to clients for communication. If the member is not started, clientURLs will be empty.
  repeated string clientURLs = 4;
  // isLearner indicates if the member is raft learner.
  bool isLearner = 5;
}

message MemberAddRequest {
  // peerURLs is the list of URLs the added member will use to communicate with the cluster.
  repeated string peerURLs = 1;
  // isLearner indicates if the added member is raft learner.
  bool isLearner = 2;
}

message MemberAddResponse {
  ResponseHeader header = 1;
  // member is the member information for the added member.
  Member member = 2;
  // members is a list of all members after adding the new member.
  repeated Member members = 3;
}

message MemberRemoveRequest {
  // ID is the member ID of the member to remove.
  uint64 ID = 1;
}

message MemberRemoveResponse {
  ResponseHeader header = 1;
  // members is a list of all members after removing the member.
  repeated Member members = 2;
}

message MemberUpdateRequest {
  // ID is the member ID of the member to update.
  uint64 ID = 1;
  // peerURLs is the new list of URLs the member will use to communicate with the cluster.
  repeated string peerURLs = 2;
}

message MemberUpdateResponse{
  ResponseHeader header = 1;
  // members is a list of all members after updating the member.
  repeated Member members = 2;
}

message MemberListRequest {
}

message MemberListResponse {
  ResponseHeader header = 1;
  // members is a list of all members associated with the cluster.
  repeated Member members = 2;
}

message MemberPromoteRequest {
  // ID is the member ID of the member to promote.
  uint64 ID = 1;
}

message MemberPromoteResponse {
  ResponseHeader header = 1;
  // members is a list of all members after promoting the member.
  repeated Member members = 2;
}

message DefragmentRequest {
}

message DefragmentResponse {
  ResponseHeader header = 1;
}

message MoveLeaderRequest {
  // targetID is the node ID for the new leader.
  uint64 targetID = 1;
}

message MoveLeaderResponse {
  ResponseHeader header = 1;
}

enum AlarmType {
  NONE = 0; // default, used to query if any alarm is active
  NOSPACE = 1; // space quota is exhausted
  CORRUPT = 2; // kv store corruption detected
}

message AlarmRequest {
  enum AlarmAction {
    GET = 0;
    ACTIVATE = 1;
    DEACTIVATE = 2;
  }
  // action is the kind of alarm request to issue. The action
  // may GET alarm statuses, ACTIVATE an alarm, or DEACTIVATE a
  // raised alarm.
  AlarmAction action = 1;
  // memberID is the ID of the member associated with the alarm. If memberID is 0, the
  // alarm request covers all members.
  uint64 memberID = 2;
  // alarm is the type of alarm to consider for this request.
  AlarmType alarm = 3;
}

message AlarmMember {
  // memberID is the ID of the member associated with the raised alarm.
  uint64 memberID = 1;
  // alarm is the type of alarm which has been raised.
  AlarmType alarm = 2;
}

message AlarmResponse {
  ResponseHeader header = 1;
  // alarms is a list of alarms associated with the alarm request.
  repeated AlarmMember alarms = 2;
}

message StatusRequest {
}

message StatusResponse {
  ResponseHeader header = 1;
  // version is the cluster protocol version used by the responding member.
  string version = 2;
  // dbSize is the size of the backend database physically allocated, in bytes, of the responding member.
  int64 dbSize = 3;
  // leader is the member ID which the responding member believes is the current leader.
  uint64 leader = 4;
  // raftIndex is the current raft committed index of the responding member.
  uint64 raftIndex = 5;
  // raftTerm is the current raft term of the responding member.
  uint64 raftTerm = 6;
  // raftAppliedIndex is the current raft applied index of the responding member.
  uint64 raftAppliedIndex = 7;
  // errors contains alarm/health information and status.
  repeated string errors = 8;
  // dbSizeInUse is the size of the backend database logically in use, in bytes, of the responding member.
  int64 dbSizeInUse = 9;
  // isLearner indicates if the member is raft learner.
  bool isLearner = 10;
}

message AuthEnableRequest {
}

message AuthDisableRequest {
}

message AuthenticateRequest {
  string name = 1;
  string password = 2;
}

message AuthUserAddRequest {
  string name = 1;
  string password = 2;
  authpb.UserAddOptions options = 3;
}

message AuthUserGetRequest {
  string name = 1;
}

message AuthUserDeleteRequest {
  // name is the name of the user to delete.
  string name = 1;
}

message AuthUserChangePasswordRequest {
  // name is the name of the user whose password is being changed.
  string name = 1;
  // password is the new password for the user.
  string password = 2;
}

message AuthUserGrantRoleRequest {
  // user is the name of the user which should be granted a given role.
  string user = 1;
  // role is the name of the role to grant to the user.
  string role = 2;
}

message AuthUserRevokeRoleRequest {
  string name = 1;
  string role = 2;
}

message AuthRoleAddRequest {
  // name is the name of the role to add to the authentication system.
  string name = 1;
}

message AuthRoleGetRequest {
  string role = 1;
}

message AuthUserListRequest {
}

message AuthRoleListRequest {
}

message AuthRoleDeleteRequest {
  string role = 1;
}

message AuthRoleGrantPermissionRequest {
  // name is the name of the role which will be granted the permission.
  string name = 1;
  // perm is the permission to grant to the role.
  authpb.Permission perm = 2;
}

message AuthRoleRevokePermissionRequest {
  string role = 1;
  bytes key = 2;
  bytes range_end = 3;
}

message AuthEnableResponse {
  ResponseHeader header = 1;
}

message AuthDisableResponse {
  ResponseHeader header = 1;
}

message AuthenticateResponse {
  ResponseHeader header = 1;
  // token is an authorized token that can be used in succeeding RPCs
  string token = 2;
}

message AuthUserAddResponse {
  ResponseHeader header = 1;
}

message AuthUserGetResponse {
  ResponseHeader header = 1;

  repeated string roles = 2;
}

message AuthUserDeleteResponse {
  ResponseHeader header = 1;
}

message AuthUserChangePasswordResponse {
  ResponseHeader header = 1;
}

message AuthUserGrantRoleResponse {
  ResponseHeader header = 1;
}

message AuthUserRevokeRoleResponse {
  ResponseHeader header = 1;
}

message AuthRoleAddResponse {
  ResponseHeader header = 1;
}

message AuthRoleGetResponse {
  ResponseHeader header = 1;

  repeated authpb.Permission perm = 2;
}

message AuthRoleListResponse {
  ResponseHeader header = 1;

  repeated string roles = 2;
}

message AuthUserListResponse {
  ResponseHeader header = 1;

  repeated string users = 2;
}

message AuthRoleDeleteResponse {
  ResponseHeader header = 1;
}

message AuthRoleGrantPermissionResponse {
  ResponseHeader header = 1;
}

message AuthRoleRevokePermissionResponse {
  ResponseHeader header = 1;
}

message HealthCheckRequest {
  string service = 1;
}

message HealthCheckResponse {
  enum ServingStatus {
    UNKNOWN = 0;
    SERVING = 1;
    NOT_SERVING = 2;
    SERVICE_UNKNOWN = 3;  // Used only by the Watch method.
  }
  ServingStatus status = 1;
}

service Health {
  // If the requested service is unknown, the call will fail with status
  // NOT_FOUND.
  rpc Check(HealthCheckRequest) returns (HealthCheckResponse);

  // Performs a watch for the serving status of the requested service.
  // The server will immediately send back a message indicating the current
  // serving status.  It will then subsequently send a new message whenever
  // the service's serving status changes.
  //
  // If the requested service is unknown when the call is received, the
  // server will send a message setting the serving status to
  // SERVICE_UNKNOWN but will *not* terminate the call.  If at some
  // future point, the serving status of the service becomes known, the
  // server will send a new message with the service's serving status.
  //
  // If the call terminates with status UNIMPLEMENTED, then clients
  // should assume this method is not supported and should not retry the
  // call.  If the call terminates with any other status (including OK),
  // clients should retry the call with appropriate exponential backoff.
  rpc Watch(HealthCheckRequest) returns (stream HealthCheckResponse);
}

message LockRequest {
  // name is the identifier for the distributed shared lock to be acquired.
  bytes name = 1;
  // lease is the ID of the lease that will be attached to ownership of the
  // lock. If the lease expires or is revoked and currently holds the lock,
  // the lock is automatically released. Calls to Lock with the same lease will
  // be treated as a single acquisition; locking twice with the same lease is a
  // no-op.
  int64 lease = 2;
}

message LockResponse {
  ResponseHeader header = 1;
  // key is a key that will exist on etcd for the duration that the Lock caller
  // owns the lock. Users should not modify this key or the lock may exhibit
  // undefined behavior.
  bytes key = 2;
}

message UnlockRequest {
  // key is the lock ownership key granted by Lock.
  bytes key = 1;
}

message UnlockResponse {
  ResponseHeader header = 1;
}

// The lock service exposes client-side locking facilities as a gRPC interface.
service Lock {
  // Lock acquires a distributed shared lock on a given named lock.
  // On success, it will return a unique key that exists so long as the
  // lock is held by the caller. This key can be used in conjunction with
  // transactions to safely ensure updates to etcd only occur while holding
  // lock ownership. The lock is held until Unlock is called on the key or the
  // lease associate with the owner expires.
  rpc Lock(LockRequest) returns (LockResponse) {
  }

  // Unlock takes a key returned by Lock and releases the hold on lock. The
  // next Lock caller waiting for the lock will then be woken up and given
  // ownership of the lock.
  rpc Unlock(UnlockRequest) returns (UnlockResponse) {
  }
}

// The election service exposes client-side election facilities as a gRPC interface.
service Election {
  // Campaign waits to acquire leadership in an election, returning a LeaderKey
  // representing the leadership if successful. The LeaderKey can then be used
  // to issue new values on the election, transactionally guard API requests on
  // leadership still being held, and resign from the election.
  rpc Campaign(CampaignRequest) returns (CampaignResponse) {
  }
  // Proclaim updates the leader's posted value with a new value.
  rpc Proclaim(ProclaimRequest) returns (ProclaimResponse) {
  }
  // Leader returns the current election proclamation, if any.
  rpc Leader(LeaderRequest) returns (LeaderResponse) {
  }
  // Observe streams election proclamations in-order as made by the election's
  // elected leaders.
  rpc Observe(stream LeaderRequest) returns (stream LeaderResponse) {
  }
  // Resign releases election leadership so other campaigners may acquire
  // leadership on the election.
  rpc Resign(ResignRequest) returns (ResignResponse) {
  }
}

message CampaignRequest {
  // name is the election's identifier for the campaign.
  bytes name = 1;
  // lease is the ID of the lease attached to leadership of the election. If the
  // lease expires or is revoked before resigning leadership, then the
  // leadership is transferred to the next campaigner, if any.
  int64 lease = 2;
  // value is the initial proclaimed value set when the campaigner wins the
  // election.
  bytes value = 3;
}

message CampaignResponse {
  ResponseHeader header = 1;
  // leader describes the resources used for holding leadership of the election.
  LeaderKey leader = 2;
}

message LeaderKey {
  // name is the election identifier that corresponds to the leadership key.
  bytes name = 1;
  // key is an opaque key representing the ownership of the election. If the key
  // is deleted, then leadership is lost.
  bytes key = 2;
  // rev is the creation revision of the key. It can be used to test for ownership
  // of an election during transactions by testing the key's creation revision
  // matches rev.
  int64 rev = 3;
  // lease is the lease ID of the election leader.
  int64 lease = 4;
}

message LeaderRequest {
  // name is the election identifier for the leadership information.
  bytes name = 1;
}

message LeaderResponse {
  ResponseHeader header = 1;
  // kv is the key-value pair representing the latest leader update.
  mvccpb.KeyValue kv = 2;
}

message ResignRequest {
  // leader is the leadership to relinquish by resignation.
  LeaderKey leader = 1;
}

message ResignResponse {
  ResponseHeader header = 1;
}

message ProclaimRequest {
  // leader is the leadership hold on the election.
  LeaderKey leader = 1;
  // value is an update meant to overwrite the leader's current value.
  bytes value = 2;
}

message ProclaimResponse {
  ResponseHeader header = 1;
}