// Copyright 2020 The LUCI Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

syntax = "proto3";

package statsd_to_tsmon.config;

option go_package = "config";


enum Kind {
  KIND_UNSPECIFIED = 0;
  GAUGE = 1;
  COUNTER = 2;
  CUMULATIVE_DISTRIBUTION = 3;
}


enum Unit {
  UNIT_UNSPECIFIED = 0;
  MILLISECONDS = 1;
  BYTES = 2;
}


message Config {
  // A collection of tsmon metrics and rules for how to extract them from statsd
  // metrics.
  repeated Metric metrics = 1;
}


message Metric {
  // Name of the tsmon metric to produce, required.
  string metric = 1;
  // A kind of the metric, required.
  Kind kind = 2;
  // Metric description. Optional, but recommended.
  string desc = 3;
  // Units of the metric value. Optional, but recommended.
  Unit units = 4;
  // A set of fields of this metric.
  repeated string fields = 5;

  // A list of rules that map statds metrics to fields of this metric.
  //
  // Each rule is represented by a statsd metric name pattern (that looks like
  // e.g. "something.*.${var}.*.sfx") and a recipe of how to get tsmon field
  // name of metrics matching the pattern.
  //
  // In the current implementation the last component of each pattern must be
  // some static string (i.e. not `*` and not a var) and all such suffixes must
  // be unique across the entire configuration file.
  repeated Rule rules = 6;
}


message Rule {
  // A pattern to match statsd metric name against.
  //
  // Also used to "extract" interesting portions of the metric name to use them
  // in `fields`.
  //
  // For example, if the pattern is "something.*.${var}.*.sfx", statds metric
  // "something.foo.val.bar.sfx" matches it, and `var` value is set to "val".
  string pattern = 1;

  // A map "field name => its value".
  //
  // The set of field names should be equal to the set of fields specified
  // in the metric definition.
  //
  // Each field value is either a static string ("foo"), or a reference to
  // some variable ("${var}") parsed from the statsd metric name according to
  // the pattern.
  map<string, string> fields = 2;
}