Files
cachet-monitor/http.go
Matej Kramny 0dc54e4e6e - customisable time format
- custom messages
- configure threshold count instead of uptime %
2017-02-05 23:43:38 -08:00

129 lines
3.0 KiB
Go

package cachet
import (
"crypto/tls"
"io/ioutil"
"net/http"
"regexp"
"strconv"
"strings"
"time"
"github.com/Sirupsen/logrus"
)
// Investigating template
var defaultHTTPInvestigatingTpl = MessageTemplate{
Subject: `{{ .Monitor.Name }} - {{ .SystemName }}`,
Message: `{{ .Name }} check **failed** - {{ .now }}
{{ .lastFailReason }}`,
}
// Fixed template
var defaultHTTPFixedTpl = MessageTemplate{
Subject: `{{ .Name }} - {{ .config.SystemName }}`,
Message: `**Resolved** - {{ .now }}
- - -
{{ .incident.Message }}`,
}
type HTTPMonitor struct {
AbstractMonitor `mapstructure:",squash"`
Method string
ExpectedStatusCode int `mapstructure:"expected_status_code"`
Headers map[string]string
// compiled to Regexp
ExpectedBody string `mapstructure:"expected_body"`
bodyRegexp *regexp.Regexp
}
func (monitor *HTTPMonitor) test() bool {
req, err := http.NewRequest(monitor.Method, monitor.Target, nil)
for k, v := range monitor.Headers {
req.Header.Add(k, v)
}
transport := http.DefaultTransport.(*http.Transport)
transport.TLSClientConfig = &tls.Config{InsecureSkipVerify: monitor.Strict == false}
client := &http.Client{
Timeout: time.Duration(monitor.Timeout * time.Second),
Transport: transport,
}
resp, err := client.Do(req)
if err != nil {
monitor.lastFailReason = err.Error()
return false
}
defer resp.Body.Close()
if monitor.ExpectedStatusCode > 0 && resp.StatusCode != monitor.ExpectedStatusCode {
monitor.lastFailReason = "Unexpected response code: " + strconv.Itoa(resp.StatusCode) + ". Expected " + strconv.Itoa(monitor.ExpectedStatusCode)
return false
}
if monitor.bodyRegexp != nil {
// check body
responseBody, err := ioutil.ReadAll(resp.Body)
if err != nil {
monitor.lastFailReason = err.Error()
return false
}
match := monitor.bodyRegexp.Match(responseBody)
if !match {
monitor.lastFailReason = "Unexpected body: " + string(responseBody) + ". Expected to match " + monitor.ExpectedBody
}
return match
}
return true
}
func (mon *HTTPMonitor) Validate() []string {
mon.Template.Investigating.SetDefault(defaultHTTPInvestigatingTpl)
mon.Template.Fixed.SetDefault(defaultHTTPFixedTpl)
errs := mon.AbstractMonitor.Validate()
logrus.Warnf("%#v", mon.Template.Investigating)
if len(mon.ExpectedBody) > 0 {
exp, err := regexp.Compile(mon.ExpectedBody)
if err != nil {
errs = append(errs, "Regexp compilation failure: "+err.Error())
} else {
mon.bodyRegexp = exp
}
}
if len(mon.ExpectedBody) == 0 && mon.ExpectedStatusCode == 0 {
errs = append(errs, "Both 'expected_body' and 'expected_status_code' fields empty")
}
mon.Method = strings.ToUpper(mon.Method)
switch mon.Method {
case "GET", "POST", "PUT", "PATCH", "DELETE", "OPTIONS", "HEAD":
break
case "":
mon.Method = "GET"
default:
errs = append(errs, "Unsupported HTTP method: "+mon.Method)
}
return errs
}
func (mon *HTTPMonitor) Describe() []string {
features := mon.AbstractMonitor.Describe()
features = append(features, "Method: "+mon.Method)
return features
}