binary-update: Do not fetch update info for minio binary compiled from source.

fixes #2494

cmd/main.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"os"
 	"sort"
+	"strings"
 
 	"github.com/minio/cli"
 	"github.com/minio/mc/pkg/console"
@@ -180,14 +181,16 @@ func Main() {
 
 		// Do not print update messages, if quiet flag is set.
 		if !globalQuiet {
-			// Do not print any errors in release update function.
-			noError := true
-			updateMsg := getReleaseUpdate(minioUpdateStableURL, noError)
-			if updateMsg.Update {
+			if strings.HasPrefix(Version, "RELEASE.") {
+				updateMsg, _, err := getReleaseUpdate(minioUpdateStableURL)
+				if err != nil {
+					// Ignore any errors during getReleaseUpdate() because
+					// the internet might not be available.
+					return nil
+				}
 				console.Println(updateMsg)
 			}
 		}
-
 		return nil
 	}
 

cmd/update-main.go

@@ -129,7 +129,7 @@ func parseReleaseData(data string) (time.Time, error) {
 }
 
 // verify updates for releases.
-func getReleaseUpdate(updateURL string, noError bool) updateMessage {
+func getReleaseUpdate(updateURL string) (updateMsg updateMessage, errMsg string, err error) {
 	// Construct a new update url.
 	newUpdateURLPrefix := updateURL + "/" + runtime.GOOS + "-" + runtime.GOARCH
 	newUpdateURL := newUpdateURLPrefix + "/minio.shasum"
@@ -146,7 +146,7 @@ func getReleaseUpdate(updateURL string, noError bool) updateMessage {
 	}
 
 	// Initialize update message.
-	updateMsg := updateMessage{
+	updateMsg = updateMessage{
 		Download: downloadURL,
 		Version:  Version,
 	}
@@ -156,61 +156,54 @@ func getReleaseUpdate(updateURL string, noError bool) updateMessage {
 		Timeout: 3 * time.Second,
 	}
 
-	// Fetch new update.
-	data, err := client.Get(newUpdateURL)
-	if err != nil && noError {
-		return updateMsg
-	}
-	fatalIf((err), "Unable to read from update URL ‘"+newUpdateURL+"’.")
-
-	// Error out if 'update' command is issued for development based builds.
-	if Version == "DEVELOPMENT.GOGET" && !noError {
-		fatalIf((errors.New("")),
-			"Update mechanism is not supported for ‘go get’ based binary builds. Please download official releases from https://minio.io/#minio")
-	}
-
 	// Parse current minio version into RFC3339.
 	current, err := time.Parse(time.RFC3339, Version)
-	if err != nil && noError {
-		return updateMsg
+	if err != nil {
+		errMsg = "Unable to parse version string as time."
+		return
 	}
-	fatalIf((err), "Unable to parse version string as time.")
 
 	// Verify if current minio version is zero.
-	if current.IsZero() && !noError {
-		fatalIf((errors.New("")),
-			"Updates mechanism is not supported for custom builds. Please download official releases from https://minio.io/#minio")
+	if current.IsZero() {
+		err = errors.New("date should not be zero")
+		errMsg = "Updates mechanism is not supported for custom builds. Please download official releases from https://minio.io/#minio"
+		return
+	}
+
+	// Fetch new update.
+	data, err := client.Get(newUpdateURL)
+	if err != nil {
+		return
 	}
 
 	// Verify if we have a valid http response i.e http.StatusOK.
 	if data != nil {
 		if data.StatusCode != http.StatusOK {
-			// Return quickly if noError is set.
-			if noError {
-				return updateMsg
-			}
-			fatalIf((errors.New("")), "Failed to retrieve update notice. "+data.Status)
+			errMsg = "Failed to retrieve update notice."
+			err = errors.New("http status : " + data.Status)
+			return
 		}
 	}
 
 	// Read the response body.
 	updateBody, err := ioutil.ReadAll(data.Body)
-	if err != nil && noError {
-		return updateMsg
+	if err != nil {
+		errMsg = "Failed to retrieve update notice. Please try again later."
+		return
 	}
-	fatalIf((err), "Failed to retrieve update notice. Please try again later.")
+
+	errMsg = "Failed to retrieve update notice. Please try again later. Please report this issue at https://github.com/minio/minio/issues"
 
 	// Parse the date if its valid.
 	latest, err := parseReleaseData(string(updateBody))
-	if err != nil && noError {
-		return updateMsg
+	if err != nil {
+		return
 	}
-	errMsg := "Failed to retrieve update notice. Please try again later. Please report this issue at https://github.com/minio/minio/issues"
-	fatalIf(err, errMsg)
 
 	// Verify if the date is not zero.
-	if latest.IsZero() && !noError {
-		fatalIf((errors.New("")), errMsg)
+	if latest.IsZero() {
+		err = errors.New("date should not be zero")
+		return
 	}
 
 	// Is the update latest?.
@@ -219,18 +212,25 @@ func getReleaseUpdate(updateURL string, noError bool) updateMessage {
 	}
 
 	// Return update message.
-	return updateMsg
+	return updateMsg, "", nil
 }
 
 // main entry point for update command.
 func mainUpdate(ctx *cli.Context) {
-	// Print all errors as they occur.
-	noError := false
+	// Error out if 'update' command is issued for development based builds.
+	if Version == "DEVELOPMENT.GOGET" {
+		fatalIf(errors.New(""), "Update mechanism is not supported for ‘go get’ based binary builds. Please download official releases from https://minio.io/#minio")
+	}
 
 	// Check for update.
+	var updateMsg updateMessage
+	var errMsg string
+	var err error
 	if ctx.Bool("experimental") {
-		console.Println(getReleaseUpdate(minioUpdateExperimentalURL, noError))
+		updateMsg, errMsg, err = getReleaseUpdate(minioUpdateExperimentalURL)
 	} else {
-		console.Println(getReleaseUpdate(minioUpdateStableURL, noError))
+		updateMsg, errMsg, err = getReleaseUpdate(minioUpdateStableURL)
 	}
+	fatalIf(err, errMsg)
+	console.Println(updateMsg)
 }