refactor: Refactor downloadURL function of kubectl

Author: pratikjagrut

pkg/devspace/deploy/deployer/kubectl/builder.go

@@ -74,34 +74,49 @@ func NewKubectlBuilder(path string, config *latest.DeploymentConfig, context, na
 	}
 }
 
-func (k *kubectlBuilder) Build(manifest string, cmd RunCommand) ([]*unstructured.Unstructured, error) {
-	args := []string{"create"}
-	if k.context != "" && !k.isInCluster {
-		args = append(args, "--context", k.context)
-	}
-	if k.namespace != "" {
-		args = append(args, "--namespace", k.namespace)
-	}
-
+// this function is called in Build function
+// to decide the --dry-run value
+var useOldDryRun = func(path string) (bool, error) {
 	// compare kubectl version for --dry-run flag value
-	out, err := command.NewStreamCommand(k.path, []string{"version", "--client", "--short"}).Output()
+	out, err := command.NewStreamCommand(path, []string{"version", "--client", "--short"}).Output()
 	if err != nil {
-		return nil, err
+		return false, err
 	}
 
-	versionSlice := strings.Split(string(out), "v")
-	v1, err := version.NewVersion(strings.TrimSpace(versionSlice[1]))
+	v1, err := version.NewVersion(strings.TrimPrefix(strings.TrimSpace(string(out)), "Client Version: v"))
 	if err != nil {
 
-		return nil, err
+		return false, err
 	}
 
 	v2, err := version.NewVersion("1.18.0")
 	if err != nil {
-		return nil, err
+		return false, err
 	}
 
 	if v1.LessThan(v2) {
+		return true, nil
+	}
+
+	return false, nil
+}
+
+func (k *kubectlBuilder) Build(manifest string, cmd RunCommand) ([]*unstructured.Unstructured, error) {
+	args := []string{"create"}
+	if k.context != "" && !k.isInCluster {
+		args = append(args, "--context", k.context)
+	}
+	if k.namespace != "" {
+		args = append(args, "--namespace", k.namespace)
+	}
+
+	// decides which --dry-run value is to be used
+	uodr, err := useOldDryRun(k.path)
+	if err != nil {
+		return nil, err
+	}
+
+	if uodr {
 		args = append(args, "--dry-run", "--output", "yaml", "--validate=false")
 	} else {
 		args = append(args, "--dry-run=client", "--output", "yaml", "--validate=false")

pkg/devspace/deploy/deployer/kubectl/kubectl_test.go

@@ -192,6 +192,10 @@ func TestRender(t *testing.T) {
 			},
 		}
 
+		useOldDryRun = func(path string) (bool, error) {
+			return true, nil
+		}
+
 		reader, writer := io.Pipe()
 		defer reader.Close()
 
@@ -318,6 +322,9 @@ func TestDelete(t *testing.T) {
 			}
 		}
 
+		useOldDryRun = func(path string) (bool, error) {
+			return true, nil
+		}
 		err := deployer.Delete()
 		if testCase.expectedErr == "" {
 			assert.NilError(t, err, "Error in testCase %s", testCase.name)
@@ -402,6 +409,9 @@ func TestDeploy(t *testing.T) {
 			}
 		}
 
+		useOldDryRun = func(path string) (bool, error) {
+			return true, nil
+		}
 		deployed, err := deployer.Deploy(testCase.forceDeploy, testCase.builtImages)
 
 		if testCase.expectedErr == "" {
@@ -479,7 +489,9 @@ func TestGetReplacedManifest(t *testing.T) {
 				Images: testCase.imageConfigs,
 			}, cache, nil, constants.DefaultConfigPath),
 		}
-
+		useOldDryRun = func(path string) (bool, error) {
+			return true, nil
+		}
 		shouldRedeploy, replacedManifest, err := deployer.getReplacedManifest(testCase.manifest, testCase.builtImages)
 
 		if testCase.expectedErr == "" {

pkg/util/downloader/commands/kubectl.go

@@ -2,7 +2,6 @@ package commands
 
 import (
 	"io/ioutil"
-	"log"
 	"net/http"
 	"path/filepath"
 	"runtime"
@@ -14,22 +13,6 @@ import (
 	"github.com/otiai10/copy"
 )
 
-var (
-	kubectlVersion = func() string {
-		res, err := http.Get("https://storage.googleapis.com/kubernetes-release/release/stable.txt")
-		if err != nil {
-			log.Fatal(err)
-		}
-		content, err := ioutil.ReadAll(res.Body)
-		res.Body.Close()
-		if err != nil {
-			log.Fatal(err)
-		}
-		return string(content)
-	}
-	kubectlDownload = "https://storage.googleapis.com/kubernetes-release/release/" + kubectlVersion() + "/bin/" + runtime.GOOS + "/" + runtime.GOARCH + "/kubectl"
-)
-
 func NewKubectlCommand() Command {
 	return &kubectlCommand{}
 }
@@ -55,7 +38,21 @@ func (k *kubectlCommand) InstallPath() (string, error) {
 }
 
 func (k *kubectlCommand) DownloadURL() string {
-	url := kubectlDownload
+	// let the default kubectl version be 1.22.0
+	kubectlVersion := "v1.22.0"
+
+	// try to fetch latest kubectl version if it fails use default version
+	res, err := http.Get("https://storage.googleapis.com/kubernetes-release/release/stable.txt")
+	if err == nil {
+		content, err := ioutil.ReadAll(res.Body)
+		res.Body.Close()
+		if err == nil {
+			kubectlVersion = string(content)
+		}
+	}
+
+	url := "https://storage.googleapis.com/kubernetes-release/release/" + kubectlVersion + "/bin/" + runtime.GOOS + "/" + runtime.GOARCH + "/kubectl"
+
 	if runtime.GOOS == "windows" {
 		url += ".exe"
 	}

pkg/util/downloader/downloader.go

@@ -1,13 +1,14 @@
 package downloader
 
 import (
-	"github.com/loft-sh/devspace/pkg/util/downloader/commands"
 	"io"
 	"io/ioutil"
 	"net/http"
 	"os"
 	"path/filepath"
 
+	"github.com/loft-sh/devspace/pkg/util/downloader/commands"
+
 	logpkg "github.com/loft-sh/devspace/pkg/util/log"
 	"github.com/pkg/errors"
 )