1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161

// Copyright (c) The Diem Core Contributors
// SPDX-License-Identifier: Apache-2.0

use crate::{
    gather_metrics, json_encoder::JsonEncoder, json_metrics::get_json_metrics,
    public_metrics::PUBLIC_METRICS, NUM_METRICS,
};
use futures::future;
use hyper::{
    service::{make_service_fn, service_fn},
    Body, Method, Request, Response, Server, StatusCode,
};
use prometheus::{proto::MetricFamily, Encoder, TextEncoder};
use std::{
    collections::HashMap,
    net::{SocketAddr, ToSocketAddrs},
    thread,
};
use tokio::runtime;

fn encode_metrics(encoder: impl Encoder, whitelist: &'static [&'static str]) -> Vec<u8> {
    let mut metric_families = gather_metrics();
    if !whitelist.is_empty() {
        metric_families = whitelist_metrics(metric_families, whitelist);
    }
    let mut buffer = vec![];
    encoder.encode(&metric_families, &mut buffer).unwrap();

    NUM_METRICS
        .with_label_values(&["total_bytes"])
        .inc_by(buffer.len() as u64);
    buffer
}

// filtering metrics from the prometheus collections
// only return the whitelisted metrics
fn whitelist_metrics(
    metric_families: Vec<MetricFamily>,
    whitelist: &'static [&'static str],
) -> Vec<MetricFamily> {
    let mut whitelist_metrics = Vec::new();
    for mf in metric_families {
        let name = mf.get_name();
        if whitelist.contains(&name) {
            whitelist_metrics.push(mf.clone());
        }
    }
    whitelist_metrics
}

// filtering metrics from the Json format metrics
// only return the whitelisted metrics
fn whitelist_json_metrics(
    json_metrics: HashMap<String, String>,
    whitelist: &'static [&'static str],
) -> HashMap<&'static str, String> {
    let mut whitelist_metrics: HashMap<&'static str, String> = HashMap::new();
    for key in whitelist {
        if let Some(metric) = json_metrics.get(*key) {
            whitelist_metrics.insert(key, metric.clone());
        }
    }
    whitelist_metrics
}

async fn serve_metrics(req: Request<Body>) -> Result<Response<Body>, hyper::Error> {
    let mut resp = Response::new(Body::empty());
    match (req.method(), req.uri().path()) {
        (&Method::GET, "/-/healthy") => {
            *resp.body_mut() = Body::from("diem-node:ok");
        }
        (&Method::GET, "/metrics") => {
            //Prometheus server expects metrics to be on host:port/metrics
            let encoder = TextEncoder::new();
            let buffer = encode_metrics(encoder, &[]);
            *resp.body_mut() = Body::from(buffer);
        }
        // expose non-numeric metrics to host:port/json_metrics
        (&Method::GET, "/json_metrics") => {
            let json_metrics = get_json_metrics();
            let encoded_metrics = serde_json::to_string(&json_metrics).unwrap();
            *resp.body_mut() = Body::from(encoded_metrics);
        }
        (&Method::GET, "/counters") => {
            // Json encoded diem_metrics;
            let encoder = JsonEncoder;
            let buffer = encode_metrics(encoder, &[]);
            *resp.body_mut() = Body::from(buffer);
        }
        _ => {
            *resp.status_mut() = StatusCode::NOT_FOUND;
        }
    };

    Ok(resp)
}

async fn serve_public_metrics(req: Request<Body>) -> Result<Response<Body>, hyper::Error> {
    let mut resp = Response::new(Body::empty());
    match (req.method(), req.uri().path()) {
        (&Method::GET, "/metrics") => {
            let encoder = TextEncoder::new();
            // encode public metrics defined in common/metrics/src/public_metrics.rs
            let buffer = encode_metrics(encoder, PUBLIC_METRICS);
            *resp.body_mut() = Body::from(buffer);
        }
        (&Method::GET, "/json_metrics") => {
            let json_metrics = get_json_metrics();
            let whitelist_json_metrics = whitelist_json_metrics(json_metrics, PUBLIC_METRICS);
            let encoded_metrics = serde_json::to_string(&whitelist_json_metrics).unwrap();
            *resp.body_mut() = Body::from(encoded_metrics);
        }
        _ => {
            *resp.status_mut() = StatusCode::NOT_FOUND;
        }
    };

    Ok(resp)
}

pub fn start_server(host: String, port: u16, public_metric: bool) {
    // Only called from places that guarantee that host is parsable, but this must be assumed.
    let addr: SocketAddr = (host.as_str(), port)
        .to_socket_addrs()
        .unwrap_or_else(|_| unreachable!("Failed to parse {}:{} as address", host, port))
        .next()
        .unwrap();

    if public_metric {
        thread::spawn(move || {
            let make_service = make_service_fn(|_| {
                future::ok::<_, hyper::Error>(service_fn(serve_public_metrics))
            });

            let rt = runtime::Builder::new_current_thread()
                .enable_io()
                .build()
                .unwrap();
            rt.block_on(async {
                let server = Server::bind(&addr).serve(make_service);
                server.await
            })
            .unwrap();
        });
    } else {
        thread::spawn(move || {
            let make_service =
                make_service_fn(|_| future::ok::<_, hyper::Error>(service_fn(serve_metrics)));

            let rt = runtime::Builder::new_current_thread()
                .enable_io()
                .build()
                .unwrap();
            rt.block_on(async {
                let server = Server::bind(&addr).serve(make_service);
                server.await
            })
            .unwrap();
        });
    }
}