ginprom
Gin Prometheus metrics exporter inspired by github.com/zsais/go-gin-prometheus
Install
Simply run:
go get -u github.com/Depado/ginprom
Differences with go-gin-prometheus
- No support for Prometheus' Push Gateway
- Options on constructor
- Adds a
path
label to get the matched route - Ability to ignore routes
Usage
package main
import (
"github.com/Depado/ginprom"
"github.com/gin-gonic/gin"
)
func main() {
r := gin.Default()
p := ginprom.New(
ginprom.Engine(r),
ginprom.Subsystem("gin"),
ginprom.Path("/metrics"),
)
r.Use(p.Instrument())
r.GET("/hello/:id", func(c *gin.Context) {})
r.GET("/world/:id", func(c *gin.Context) {})
r.Run("127.0.0.1:8080")
}
Options
Path
Override the default path (/metrics
) on which the metrics can be accessed:
r := gin.New()
p := ginprom.New(
ginprom.Engine(r),
ginprom.Path("/custom/metrics"),
)
r.Use(p.Instrument())
Namespace
Override the default namespace (gin
):
r := gin.New()
p := ginprom.New(
ginprom.Engine(r),
ginprom.Namespace("custom_ns"),
)
r.Use(p.Instrument())
Subsystem
Override the default (gonic
) subsystem:
r := gin.New()
p := ginprom.New(
ginprom.Engine(r),
ginprom.Subsystem("your_subsystem"),
)
r.Use(p.Instrument())
Engine
The preferred way to pass the router to ginprom:
r := gin.New()
p := ginprom.New(
ginprom.Engine(r),
)
r.Use(p.Instrument())
The alternative being to call the Use
method after initialization:
p := ginprom.New()
// ...
r := gin.New()
p.Use(r)
r.Use(p.Instrument())
Ignore
Ignore allows to completely ignore some routes. Even though you can apply the middleware to the only groups you're interested in, it is sometimes useful to have routes not instrumented.
r := gin.New()
p := ginprom.New(
ginprom.Engine(r),
ginprom.Ignore("/api/no/no/no", "/api/super/secret/route")
)
r.Use(p.Instrument())
Note that most of the time this can be solved by gin groups:
r := gin.New()
p := ginprom.New(ginprom.Engine(r))
// Add the routes that do not need instrumentation
g := r.Group("/api/")
g.Use(p.Instrument())
{
// Instrumented routes
}
Token
Specify a secret token which Prometheus will use to access the endpoint. If the token is invalid, the endpoint will return an error.
r := gin.New()
p := ginprom.New(
ginprom.Engine(r),
ginprom.Token("supersecrettoken")
)
r.Use(p.Instrument())
Troubleshooting
The instrumentation doesn't seem to work
Make sure you have set the gin.Engine
in the ginprom
middleware, either when
initializing it using ginprom.New(ginprom.Engine(r))
or using the Use
function after the initialization like this :
p := ginprom.New(
ginprom.Namespace("gin"),
ginprom.Subsystem("gonic"),
ginprom.Path("/metrics"),
)
p.Use(r)
r.Use(p.Instrument())
By design, if the middleware was to panic, it would do so when a route is called. That's why it just silently fails when no engine has been set.