WIP

monitor.go

@@ -0,0 +1,77 @@
+package main
+
+import (
+	"log"
+	"os/exec"
+	"time"
+)
+
+type Monitor struct {
+	// Config values
+	Name          string
+	Command       []string
+	CommandShell  string   `yaml:"command_shell`
+	AlertDown     []string `yaml:"alert_down"`
+	AlertUp       []string `yaml:"alert_up"`
+	CheckInterval float64  `yaml:"check_interval"`
+	AlertAfter    int16    `yaml:"alert_after"`
+	AlertEvey     int16    `yaml:"alert_every"`
+	// Other values
+	LastCheck  time.Time
+	LastOutput string
+}
+
+func (monitor Monitor) IsValid() bool {
+	atLeastOneCommand := (monitor.CommandShell != "" || monitor.Command != nil)
+	atMostOneCommand := (monitor.CommandShell == "" || monitor.Command == nil)
+	return atLeastOneCommand && atMostOneCommand
+}
+
+func (monitor Monitor) ShouldCheck() bool {
+	if monitor.LastCheck.IsZero() {
+		return true
+	}
+
+	sinceLastCheck := time.Now().Sub(monitor.LastCheck).Seconds()
+	return sinceLastCheck >= monitor.CheckInterval
+}
+
+func (monitor *Monitor) Check() bool {
+	// TODO: This should probably return a list of alerts since the `raise`
+	// pattern doesn't carry over from Python
+	var cmd *exec.Cmd
+
+	if monitor.Command != nil {
+		cmd = exec.Command(monitor.Command[0], monitor.Command[1:]...)
+	} else {
+		// TODO: Handle a command shell as well. This is untested
+		cmd = exec.Command(monitor.CommandShell)
+	}
+
+	output, err := cmd.CombinedOutput()
+	log.Printf("Check %s\n---\n%s\n---", monitor.Name, string(output))
+
+	is_success := (err == nil)
+	if err != nil {
+		log.Printf("error: %v", err)
+	}
+
+	monitor.LastCheck = time.Now()
+	monitor.LastOutput = string(output)
+
+	if is_success {
+		monitor.success()
+	} else {
+		monitor.failure()
+	}
+
+	return is_success
+}
+
+func (monitor Monitor) success() {
+	log.Printf("Great success!")
+}
+
+func (monitor *Monitor) failure() {
+	log.Printf("Devastating failure. :(")
+}