Fast and extensible multi-platform HTTP/1-2-3 web server with automatic HTTPS
Mirrored from https://github.com/Slazee/caddy.git
Synced Nov 11, 01:00 UTC
| 1 | // Copyright 2020 Matthew Holt and The Caddy Authors |
| 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 | package metrics |
| 16 | |
| 17 | import ( |
| 18 | "errors" |
| 19 | "net/http" |
| 20 | |
| 21 | "github.com/prometheus/client_golang/prometheus" |
| 22 | "github.com/prometheus/client_golang/prometheus/promhttp" |
| 23 | "go.uber.org/zap" |
| 24 | |
| 25 | "github.com/caddyserver/caddy/v2" |
| 26 | "github.com/caddyserver/caddy/v2/caddyconfig/caddyfile" |
| 27 | "github.com/caddyserver/caddy/v2/caddyconfig/httpcaddyfile" |
| 28 | "github.com/caddyserver/caddy/v2/modules/caddyhttp" |
| 29 | ) |
| 30 | |
| 31 | func init() { |
| 32 | caddy.RegisterModule(Metrics{}) |
| 33 | httpcaddyfile.RegisterHandlerDirective("metrics", parseCaddyfile) |
| 34 | } |
| 35 | |
| 36 | // Metrics is a module that serves a /metrics endpoint so that any gathered |
| 37 | // metrics can be exposed for scraping. This module is configurable by end-users |
| 38 | // unlike AdminMetrics. |
| 39 | type Metrics struct { |
| 40 | metricsHandler http.Handler |
| 41 | |
| 42 | // Disable OpenMetrics negotiation, enabled by default. May be necessary if |
| 43 | // the produced metrics cannot be parsed by the service scraping metrics. |
| 44 | DisableOpenMetrics bool `json:"disable_openmetrics,omitempty"` |
| 45 | } |
| 46 | |
| 47 | // CaddyModule returns the Caddy module information. |
| 48 | func (Metrics) CaddyModule() caddy.ModuleInfo { |
| 49 | return caddy.ModuleInfo{ |
| 50 | ID: "http.handlers.metrics", |
| 51 | New: func() caddy.Module { return new(Metrics) }, |
| 52 | } |
| 53 | } |
| 54 | |
| 55 | type zapLogger struct { |
| 56 | zl *zap.Logger |
| 57 | } |
| 58 | |
| 59 | func (l *zapLogger) Println(v ...any) { |
| 60 | l.zl.Sugar().Error(v...) |
| 61 | } |
| 62 | |
| 63 | // Provision sets up m. |
| 64 | func (m *Metrics) Provision(ctx caddy.Context) error { |
| 65 | log := ctx.Logger() |
| 66 | registry := ctx.GetMetricsRegistry() |
| 67 | if registry == nil { |
| 68 | return errors.New("no metrics registry found") |
| 69 | } |
| 70 | m.metricsHandler = createMetricsHandler(&zapLogger{log}, !m.DisableOpenMetrics, registry) |
| 71 | return nil |
| 72 | } |
| 73 | |
| 74 | func parseCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error) { |
| 75 | var m Metrics |
| 76 | err := m.UnmarshalCaddyfile(h.Dispenser) |
| 77 | return m, err |
| 78 | } |
| 79 | |
| 80 | // UnmarshalCaddyfile sets up the handler from Caddyfile tokens. Syntax: |
| 81 | // |
| 82 | // metrics [<matcher>] { |
| 83 | // disable_openmetrics |
| 84 | // } |
| 85 | func (m *Metrics) UnmarshalCaddyfile(d *caddyfile.Dispenser) error { |
| 86 | d.Next() // consume directive name |
| 87 | args := d.RemainingArgs() |
| 88 | if len(args) > 0 { |
| 89 | return d.ArgErr() |
| 90 | } |
| 91 | |
| 92 | for d.NextBlock(0) { |
| 93 | switch d.Val() { |
| 94 | case "disable_openmetrics": |
| 95 | m.DisableOpenMetrics = true |
| 96 | default: |
| 97 | return d.Errf("unrecognized subdirective %q", d.Val()) |
| 98 | } |
| 99 | } |
| 100 | return nil |
| 101 | } |
| 102 | |
| 103 | func (m Metrics) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyhttp.Handler) error { |
| 104 | m.metricsHandler.ServeHTTP(w, r) |
| 105 | return nil |
| 106 | } |
| 107 | |
| 108 | // Interface guards |
| 109 | var ( |
| 110 | _ caddy.Provisioner = (*Metrics)(nil) |
| 111 | _ caddyhttp.MiddlewareHandler = (*Metrics)(nil) |
| 112 | _ caddyfile.Unmarshaler = (*Metrics)(nil) |
| 113 | ) |
| 114 | |
| 115 | func createMetricsHandler(logger promhttp.Logger, enableOpenMetrics bool, registry *prometheus.Registry) http.Handler { |
| 116 | return promhttp.InstrumentMetricHandler(registry, |
| 117 | promhttp.HandlerFor(registry, promhttp.HandlerOpts{ |
| 118 | // will only log errors if logger is non-nil |
| 119 | ErrorLog: logger, |
| 120 | |
| 121 | // Allow OpenMetrics format to be negotiated - largely compatible, |
| 122 | // except quantile/le label values always have a decimal. |
| 123 | EnableOpenMetrics: enableOpenMetrics, |
| 124 | }), |
| 125 | ) |
| 126 | } |