Use logrus for logging messages

.drone.yml

@@ -9,7 +9,7 @@ pipeline:
       - CGO_ENABLED=0
     commands:
       - go test -cover -coverprofile=coverage.out
-      - go build -ldflags "-s -w -X main.build=$DRONE_BUILD_NUMBER" -a
+      - go build -ldflags "-s -w -X main.revision=$(git rev-parse HEAD)" -a
 
   coverage:
     image: coverage

main.go

@@ -9,14 +9,14 @@ import (
 	"github.com/urfave/cli"
 )
 
-var version string // build number set at compile-time
+var revision string // build number set at compile-time
 
 func main() {
 	app := cli.NewApp()
 	app.Name = "terraform plugin"
 	app.Usage = "terraform plugin"
 	app.Action = run
-	app.Version = version
+	app.Version = revision
 	app.Flags = []cli.Flag{
 
 		//
@@ -81,6 +81,10 @@ func main() {
 }
 
 func run(c *cli.Context) error {
+	logrus.WithFields(logrus.Fields{
+		"Revision": revision,
+	}).Info("Drone Terraform Plugin Version")
+
 	if c.String("env-file") != "" {
 		_ = godotenv.Load(c.String("env-file"))
 	}

plugin.go

@@ -6,6 +6,7 @@ import (
 	"github.com/aws/aws-sdk-go/aws/credentials/stscreds"
 	"github.com/aws/aws-sdk-go/aws/session"
 	"github.com/aws/aws-sdk-go/service/sts"
+	"github.com/Sirupsen/logrus"
 	"io/ioutil"
 	"os"
 	"os/exec"
@@ -13,10 +14,6 @@ import (
 	"time"
 )
 
-var (
-	buildCommit string
-)
-
 type (
 	Config struct {
 		Remote      Remote
@@ -41,8 +38,6 @@ type (
 )
 
 func (p Plugin) Exec() error {
-	fmt.Printf("Drone Terraform Plugin built from %s\n", buildCommit)
-
 	if p.Config.RoleARN != "" {
 		assumeRole(p.Config.RoleARN)
 	}
@@ -81,11 +76,11 @@ func (p Plugin) Exec() error {
 
 		err := c.Run()
 		if err != nil {
-			fmt.Println("Error!")
-			fmt.Println(err)
-			os.Exit(1)
+			logrus.WithFields(logrus.Fields{
+				"error": err,
+			}).Fatal("Failed to execute a command")
 		}
-		fmt.Println("Command completed successfully")
+		logrus.Debug("Command completed successfully")
 	}
 
 	return nil
@@ -176,9 +171,9 @@ func assumeRole(roleArn string) {
 
 	value, err := credentials.NewCredentials(stsProvider).Get()
 	if err != nil {
-		fmt.Println("Error assuming role!")
-		fmt.Println(err)
-		os.Exit(1)
+		logrus.WithFields(logrus.Fields{
+			"error": err,
+		}).Fatal("Error assuming role!")
 	}
 	os.Setenv("AWS_ACCESS_KEY_ID", value.AccessKeyID)
 	os.Setenv("AWS_SECRET_ACCESS_KEY", value.SecretAccessKey)