simple check option

common/common.go

@@ -1,8 +1,13 @@
 package common
 
 import (
+	"bytes"
+	"encoding/json"
 	"fmt"
 	"os"
+	"os/exec"
+
+	resource "github.com/cioplenu/concourse-nomad-resource"
 )
 
 func Check(err error, msg string) {
@@ -11,3 +16,24 @@ func Check(err error, msg string) {
 		os.Exit(1)
 	}
 }
+
+func GetHistory(source resource.Source) []resource.JobVersion {
+	cmd := exec.Command(
+		"nomad",
+		"job",
+		"history",
+		"-json",
+		"-address="+source.URL,
+		"-token="+source.Token,
+		source.Name,
+	)
+	var histResp bytes.Buffer
+	cmd.Stdout = &histResp
+	err := cmd.Run()
+	Check(err, "Error checking versions")
+
+	var history []resource.JobVersion
+	json.Unmarshal(histResp.Bytes(), &history)
+
+	return history
+}