Code refactoring

Split versioning operations into smaller pieces
flavio · May 9, 2020 · 56e5114 · 56e5114
1 parent b4f9288
commit 56e5114
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Showing 3 changed files with 97 additions and 71 deletions.
diff --git a/cmd/kuberlr/main.go b/cmd/kuberlr/main.go
@@ -1,18 +1,15 @@
 package main
 
 import (
-	"net/url"
 	"os"
 	"path/filepath"
 	"strings"
 	"syscall"
 
-	"github.com/blang/semver"
 	"github.com/spf13/cobra"
 
 	"github.com/flavio/kuberlr/cmd/kuberlr/flags"
 	"github.com/flavio/kuberlr/internal/kubectl_versioner"
-	"github.com/flavio/kuberlr/internal/kubehelper"
 	"k8s.io/klog"
 )
 
@@ -48,7 +45,7 @@ func newRootCmd() *cobra.Command {
 }
 
 func kubectlWrapperMode() {
-	version, err := kubectlVersionToUse()
+	version, err := kubectl_versioner.KubectlVersionToUse()
 	if err != nil {
 		klog.Fatal(err)
 	}
@@ -62,28 +59,3 @@ func kubectlWrapperMode() {
 	err = syscall.Exec(kubectlBin, childArgs, os.Environ())
 	klog.Fatal(err)
 }
-
-func kubectlVersionToUse() (semver.Version, error) {
-	version, err := kubehelper.ApiVersion()
-	if err != nil && isTimeout(err) {
-		// the remote server is unreachable, let's get
-		// the latest version of kubectl that is available on the system
-		klog.Info("Remote kubernetes server unreachable")
-		version, err = kubectl_versioner.MostRecentKubectlDownloaded()
-		if err != nil && isNoVersionFound(err) {
-			klog.Info("No local kubectl binary found, fetching latest stable release version")
-			version, err = kubectl_versioner.UpstreamStableVersion()
-		}
-	}
-	return version, err
-}
-
-func isTimeout(err error) bool {
-	urlError, ok := err.(*url.Error)
-	return ok && urlError.Timeout()
-}
-
-func isNoVersionFound(err error) bool {
-	nvError, ok := err.(*kubectl_versioner.NoVersionFoundError)
-	return ok && nvError.NoVersionFound()
-}
diff --git a/internal/kubectl_versioner/filesystem.go b/internal/kubectl_versioner/filesystem.go
@@ -0,0 +1,73 @@
+package kubectl_versioner
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"runtime"
+
+	"github.com/flavio/kuberlr/internal/common"
+
+	"github.com/blang/semver"
+)
+
+const KUBECTL_LOCAL_NAMING_SCHEME = "kubectl-%d.%d.%d"
+
+func BuildKubectNameFromVersion(v semver.Version) string {
+	return fmt.Sprintf(KUBECTL_LOCAL_NAMING_SCHEME, v.Major, v.Minor, v.Patch)
+}
+
+func LocalDownloadDir() string {
+	platform := fmt.Sprintf("%s-%s", runtime.GOOS, runtime.GOARCH)
+
+	return filepath.Join(
+		common.HomeDir(),
+		".kuberlr",
+		platform,
+	)
+}
+
+func IsKubectlAvailable(filename string) bool {
+	if _, err := os.Stat(filename); os.IsNotExist(err) {
+		return false
+	}
+	return true
+}
+
+func SetupLocalDirs() error {
+	return os.MkdirAll(LocalDownloadDir(), os.ModePerm)
+}
+
+func LocalKubectlVersions() (semver.Versions, error) {
+	var versions semver.Versions
+
+	kubectlBins, err := ioutil.ReadDir(LocalDownloadDir())
+	if err != nil {
+		if os.IsNotExist(err) {
+			err = &NoVersionFoundError{}
+		}
+		return versions, err
+	}
+
+	for _, f := range kubectlBins {
+		var major, minor, patch uint64
+		n, err := fmt.Sscanf(
+			f.Name(),
+			KUBECTL_LOCAL_NAMING_SCHEME,
+			&major,
+			&minor,
+			&patch)
+
+		if n == 3 && err == nil {
+			sv := semver.Version{
+				Major: major,
+				Minor: minor,
+				Patch: patch,
+			}
+			versions = append(versions, sv)
+		}
+	}
+
+	return versions, nil
+}
diff --git a/internal/kubectl_versioner/versioner.go b/internal/kubectl_versioner/versioner.go
@@ -4,42 +4,41 @@ import (
 	"fmt"
 	"io/ioutil"
 	"net/http"
-	"os"
+	"net/url"
 	"path/filepath"
-	"runtime"
 
-	"github.com/flavio/kuberlr/internal/common"
 	"github.com/flavio/kuberlr/internal/downloader"
+	"github.com/flavio/kuberlr/internal/kubehelper"
 
 	"github.com/blang/semver"
 	"k8s.io/klog"
 )
 
 const KUBECTL_STABLE_URL = "https://storage.googleapis.com/kubernetes-release/release/stable.txt"
 
-func BuildKubectNameFromVersion(v semver.Version) string {
-	return fmt.Sprintf("kubectl-%d.%d.%d", v.Major, v.Minor, v.Patch)
-}
-
-func LocalDownloadDir() string {
-	platform := fmt.Sprintf("%s-%s", runtime.GOOS, runtime.GOARCH)
-
-	return filepath.Join(
-		common.HomeDir(),
-		".kuberlr",
-		platform,
-	)
+func KubectlVersionToUse() (semver.Version, error) {
+	version, err := kubehelper.ApiVersion()
+	if err != nil && isTimeout(err) {
+		// the remote server is unreachable, let's get
+		// the latest version of kubectl that is available on the system
+		klog.Info("Remote kubernetes server unreachable")
+		version, err = MostRecentKubectlDownloaded()
+		if err != nil && isNoVersionFound(err) {
+			klog.Info("No local kubectl binary found, fetching latest stable release version")
+			version, err = UpstreamStableVersion()
+		}
+	}
+	return version, err
 }
 
-func IsKubectlAvailable(filename string) bool {
-	if _, err := os.Stat(filename); os.IsNotExist(err) {
-		return false
-	}
-	return true
+func isTimeout(err error) bool {
+	urlError, ok := err.(*url.Error)
+	return ok && urlError.Timeout()
 }
 
-func SetupLocalDirs() error {
-	return os.MkdirAll(LocalDownloadDir(), os.ModePerm)
+func isNoVersionFound(err error) bool {
+	nvError, ok := err.(*NoVersionFoundError)
+	return ok && nvError.NoVersionFound()
 }
 
 func EnsureKubectlIsAvailable(v semver.Version) (string, error) {
@@ -61,7 +60,7 @@ func EnsureKubectlIsAvailable(v semver.Version) (string, error) {
 		return "", err
 	}
 
-	klog.Info("Correct kubectl version missing, downloading...")
+	klog.Infof("Right kubectl missing, downloading version %s", v.String())
 	err = downloader.Download(downloadUrl, filename, 0755)
 	if err != nil {
 		return "", err
@@ -70,29 +69,11 @@ func EnsureKubectlIsAvailable(v semver.Version) (string, error) {
 }
 
 func MostRecentKubectlDownloaded() (semver.Version, error) {
-	var versions []semver.Version
-
-	kubectlBins, err := ioutil.ReadDir(LocalDownloadDir())
+	versions, err := LocalKubectlVersions()
 	if err != nil {
-		if os.IsNotExist(err) {
-			err = &NoVersionFoundError{}
-		}
 		return semver.Version{}, err
 	}
 
-	for _, f := range kubectlBins {
-		var major, minor, patch uint64
-		n, err := fmt.Sscanf(f.Name(), "kubectl-%d.%d.%d", &major, &minor, &patch)
-		if n == 3 && err == nil {
-			sv := semver.Version{
-				Major: major,
-				Minor: minor,
-				Patch: patch,
-			}
-			versions = append(versions, sv)
-		}
-	}
-
 	if len(versions) == 0 {
 		return semver.Version{}, &NoVersionFoundError{}
 	}