servers/grpc/
prom_query_gateway.rs

1// Copyright 2023 Greptime Team
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15//! PrometheusGateway provides a gRPC interface to query Prometheus metrics
16//! by PromQL. The behavior is similar to the Prometheus HTTP API.
17
18use std::sync::Arc;
19
20use api::v1::prometheus_gateway_server::PrometheusGateway;
21use api::v1::promql_request::Promql;
22use api::v1::{PromqlRequest, PromqlResponse, ResponseHeader};
23use async_trait::async_trait;
24use auth::UserProviderRef;
25use common_error::ext::ErrorExt;
26use common_error::status_code::StatusCode;
27use common_time::util::current_time_rfc3339;
28use promql_parser::parser::value::ValueType;
29use query::parser::PromQuery;
30use session::context::{Channel, QueryContext};
31use snafu::OptionExt;
32use tonic::{Request, Response};
33
34use crate::error::InvalidQuerySnafu;
35use crate::grpc::TonicResult;
36use crate::grpc::context_auth::auth;
37use crate::grpc::greptime_handler::create_query_context;
38use crate::http::prometheus::{PrometheusJsonResponse, retrieve_metric_name_and_result_type};
39use crate::prometheus_handler::PrometheusHandlerRef;
40
41pub struct PrometheusGatewayService {
42    handler: PrometheusHandlerRef,
43    user_provider: Option<UserProviderRef>,
44}
45
46#[async_trait]
47impl PrometheusGateway for PrometheusGatewayService {
48    async fn handle(&self, req: Request<PromqlRequest>) -> TonicResult<Response<PromqlResponse>> {
49        let mut is_range_query = false;
50        let inner = req.into_inner();
51        let prom_query = match inner.promql.context(InvalidQuerySnafu {
52            reason: "Expecting non-empty PromqlRequest.",
53        })? {
54            Promql::RangeQuery(range_query) => {
55                is_range_query = true;
56                PromQuery {
57                    query: range_query.query,
58                    start: range_query.start,
59                    end: range_query.end,
60                    step: range_query.step,
61                    lookback: range_query.lookback,
62                }
63            }
64            Promql::InstantQuery(instant_query) => {
65                let time = if instant_query.time.is_empty() {
66                    current_time_rfc3339()
67                } else {
68                    instant_query.time
69                };
70                PromQuery {
71                    query: instant_query.query,
72                    start: time.clone(),
73                    end: time,
74                    step: String::from("1s"),
75                    lookback: instant_query.lookback,
76                }
77            }
78        };
79
80        let header = inner.header.as_ref();
81        let query_ctx = create_query_context(Channel::Promql, header, Default::default())?;
82
83        let user_info = auth(self.user_provider.clone(), header, &query_ctx).await?;
84        query_ctx.set_current_user(user_info);
85
86        let json_response = self
87            .handle_inner(prom_query, query_ctx, is_range_query)
88            .await;
89        let json_bytes = serde_json::to_string(&json_response).unwrap().into_bytes();
90
91        let response = Response::new(PromqlResponse {
92            header: Some(ResponseHeader {
93                status: Some(api::v1::Status {
94                    status_code: StatusCode::Success as _,
95                    ..Default::default()
96                }),
97            }),
98            body: json_bytes,
99        });
100        Ok(response)
101    }
102}
103
104impl PrometheusGatewayService {
105    pub fn new(handler: PrometheusHandlerRef, user_provider: Option<UserProviderRef>) -> Self {
106        Self {
107            handler,
108            user_provider,
109        }
110    }
111
112    async fn handle_inner(
113        &self,
114        query: PromQuery,
115        ctx: Arc<QueryContext>,
116        is_range_query: bool,
117    ) -> PrometheusJsonResponse {
118        let db = ctx.get_db_string();
119        let _timer = crate::metrics::METRIC_SERVER_GRPC_PROM_REQUEST_TIMER
120            .with_label_values(&[db.as_str()])
121            .start_timer();
122
123        let result = self.handler.do_query(&query, ctx).await;
124        let (metric_name, mut result_type) =
125            match retrieve_metric_name_and_result_type(&query.query) {
126                Ok((metric_name, result_type)) => (metric_name, result_type),
127                Err(err) => {
128                    return PrometheusJsonResponse::error(err.status_code(), err.output_msg());
129                }
130            };
131        // range query only returns matrix
132        if is_range_query {
133            result_type = ValueType::Matrix;
134        };
135
136        PrometheusJsonResponse::from_query_result(result, metric_name, result_type).await
137    }
138}
servers/grpc/prom_query_gateway.rs

servers/grpc/
prom_query_gateway.rs
