Portable / Embeddable lighweight version of the sensu client
You can use this project by two different ways.
-
The first is use the project as a standalone program and use external checks/metrics.
-
The second is to use the project as an external golang package and write a project with another main method and add some checks / metrics inside.
The easiest way to get started is to download the binary from your command line:
- Linux
$ curl -sL https://github.com/upfluence/sensu-client-go/releases/download/v0.0.1/sensu-client-go-linux-amd64-0.0.1 \
> sensu-client
$ chmod +x sensu-client- OSX
$ curl -sL
https://github.com/upfluence/sensu-client-go/releases/download/v0.0.1/sensu-client-go-darwin-amd64-0.0.1 \
> sensu-client
$ chmod +x sensu-clientThen you just have to run the program as ./sensu-client -c /etc/sensu/config.json. EASY!
If you want to write a simple check you just have to write a function
with zero argument and which returns a check.ExtensionCheckResult. Wrap
this function pointer into an check.ExtensionCheck and add it into the
check.Store map with check name as key, such as:
package main
package main
import (
"net/http"
"github.com/upfluence/goutils/log"
"github.com/upfluence/sensu-go/sensu/transport/rabbitmq"
"github.com/upfluence/sensu-client-go/sensu"
"github.com/upfluence/sensu-client-go/sensu/check"
"github.com/upfluence/sensu-client-go/sensu/handler"
)
func HTTPCheck() check.ExtensionCheckResult {
resp, err := http.Get("http://example.com/")
if err != nil {
return handler.Error(err.Error())
}
if resp.StatusCode >= 200 && resp.StatusCode < 300 {
return handler.Ok("Example.com is alive!")
} else if resp.StatusCode >= 500 {
return handler.Error("Example.com return an 5XX status code")
} else {
return handler.Warning("Example.com is not responding as expected")
}
}
func main() {
cfg, err := sensu.NewConfigFromFlagSet(sensu.ExtractFlags())
if err != nil {
log.Fatal(err.Error())
}
t, err := rabbitmq.NewRabbitMQTransport(cfg.RabbitMQURI())
if err != nil {
log.Fatal(err.Error())
}
client := sensu.NewClient(t, cfg)
check.Store["http_check"] = &check.ExtensionCheck{HTTPCheck}
client.Start()
}If you want to write a check and a metric which inspect the same value
you can use the StandardCheck struct from the github.com/upfluence/sensu-client-go/sensu/handler
package. Such as:
package main
import (
"fmt"
"net/http"
"time"
"github.com/upfluence/goutils/log"
"github.com/upfluence/sensu-go/sensu/transport/rabbitmq"
"github.com/upfluence/sensu-client-go/sensu"
"github.com/upfluence/sensu-client-go/sensu/check"
"github.com/upfluence/sensu-client-go/sensu/utils"
)
func HTTPCallDuration() (float64, error) {
t0 := time.Now().Unix()
_, err := http.Get("http://example.com/")
return float64(time.Now().Unix() - t0), err
}
func main() {
c := &utils.StandardCheck{
ErrorThreshold: 20.0,
WarningThreshold: 10.0,
MetricName: "http_call.duration",
Value: HTTPCallDuration,
CheckMessage: func(v float64) string {
return fmt.Sprintf("Duration: %.2fs", v)
},
Comp: func(x, y float64) bool { return x > y },
}
cfg, err := sensu.NewConfigFromFlagSet(sensu.ExtractFlags())
if err != nil {
log.Fatal(err.Error())
}
t, err := rabbitmq.NewRabbitMQTransport(cfg.RabbitMQURI())
if err != nil {
log.Fatal(err.Error())
}
client := sensu.NewClient(t, cfg)
check.Store["http_duration_check"] = &check.ExtensionCheck{c.Check}
check.Store["http_duration_metric"] = &check.ExtensionCheck{c.Metric}
client.Start()
}If the duration exceed 20s the http_duration_check will return an
Error, if the duration exceed 10s the check will return a warning
otherwise it will returns an "OK" code.
The http_duration_metric will return http_call_duration 5.000000 1438125085
with 5.0 as the duration of the HTTP call and 1438125085 the timestamp
You just have to compile it and execute it, such as:
$ ls
my_awesome_main.go sensu-config.json
$ go build -o sensu-client .
$ ./sensu-client -c sensu-config.json
In the both cases, you can use the -c flag to use a specific
configuration file, the configuration is pretty similar to the ruby
client check out the doc. The
difference is about the configuration of the RabbitMQ client. You have
to provide an RabbitMQ URI through the RABBITMQ_URI environment
variable or by adding the rabbit_uri key into the root of the JSON
configuration file.
By the way you can also specify some options through environment variables:
| variable | explanation | example |
|---|---|---|
| SENSU_CLIENT_SUBSCRIPTIONS | Comma separated subscriptions | email,slack |
| SENSU_CLIENT_NAME | The name of the client | node-01 |
| SENSU_CLIENT_ADDRESS | The ip addres of the client | 127.0.0.1 |
| RABBITMQ_URI | RabbitMQ URI | amqp://guest:guest@localhost:5672/%2f |
- Implement the keep-alives specific configurations (thresholds and hanlder)