Develop (#3)

* Update command added
* Ensure that the upgraded version is really greater
* Update command should not update prerelease
* Minor presentation changes
* Fix command generation in containers from docker-compose file
- Refactored service creation
* Place the full command to the "cmd" package
* Update cobra to v1.4.0
* Updated build and release creation
* Created an install script
* Add more doc
* Add some tests...
* Add a test directive in Makefile

update/main.go

@@ -0,0 +1,140 @@
+package update
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"runtime"
+	"time"
+
+	"golang.org/x/mod/semver"
+)
+
+var exe, _ = os.Executable()
+var Version = "master" // reset by cmd/main.go
+
+// Asset is a github asset from release url.
+type Asset struct {
+	Name string `json:"name"`
+	URL  string `json:"browser_download_url"`
+}
+
+// CheckLatestVersion check katenary latest version from release and propose to download it
+func CheckLatestVersion() (string, []Asset, error) {
+
+	githuburl := "https://api.github.com/repos/metal3d/katenary/releases/latest"
+	// Create a HTTP client with 1s timeout
+	client := &http.Client{
+		Timeout: time.Second * 1,
+	}
+	// Create a request
+	req, err := http.NewRequest("GET", githuburl, nil)
+	if err != nil {
+		return "", nil, err
+	}
+
+	// Send the request via a client
+	resp, err := client.Do(req)
+	if err != nil {
+		return "", nil, err
+	}
+	defer resp.Body.Close()
+
+	// Get tag_name from the json response
+	var release = struct {
+		TagName    string  `json:"tag_name"`
+		Assets     []Asset `json:"assets"`
+		PreRelease bool    `json:"prerelease"`
+	}{}
+	err = json.NewDecoder(resp.Body).Decode(&release)
+	if err != nil {
+		return "", nil, err
+	}
+
+	// if it's a prerelease, don't update
+	if release.PreRelease {
+		return "", nil, errors.New("Prerelease detected, not updating")
+	}
+
+	// no tag, don't update
+	if release.TagName == "" {
+		return "", nil, errors.New("No release found")
+	}
+
+	// compare the current version, if the current version is the same or lower than the latest version, don't update
+	versions := []string{Version, release.TagName}
+	semver.Sort(versions)
+	if versions[1] == Version {
+		return "", nil, errors.New("Current version is the latest version")
+	}
+
+	return release.TagName, release.Assets, nil
+}
+
+// DownloadLatestVersion will download the latest version of katenary.
+func DownloadLatestVersion(assets []Asset) error {
+	// Download the latest version
+	fmt.Println("Downloading the latest version...")
+
+	// ok, replace this from the current version to the latest version
+	err := os.Rename(exe, exe+".old")
+	if err != nil {
+		return err
+	}
+
+	// Download the latest version for the current OS
+	for _, asset := range assets {
+		switch runtime.GOOS {
+		case "windows":
+			if asset.Name == "katenary.exe" {
+				err = DownloadFile(asset.URL, exe)
+			}
+		case "linux":
+			switch runtime.GOARCH {
+			case "amd64":
+				if asset.Name == "katenary-linux-amd64" {
+					err = DownloadFile(asset.URL, exe)
+				}
+			case "arm64":
+				if asset.Name == "katenary-linux-arm64" {
+					err = DownloadFile(asset.URL, exe)
+				}
+			}
+		case "darwin":
+			if asset.Name == "katenary-darwin" {
+				err = DownloadFile(asset.URL, exe)
+			}
+		default:
+			fmt.Println("Unsupported OS")
+			err = errors.New("Unsupported OS")
+		}
+	}
+	if err == nil {
+		// remove the old version
+		os.Remove(exe + ".old")
+	} else {
+		// restore the old version
+		os.Rename(exe+".old", exe)
+	}
+	return err
+}
+
+// DownloadFile will download a url to a local file. It also ensure that the file is executable.
+func DownloadFile(url, exe string) error {
+	// Download the url binary to exe path
+	resp, err := http.Get(url)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	fp, err := os.OpenFile(exe, os.O_WRONLY|os.O_CREATE, 0755)
+	if err != nil {
+		return err
+	}
+	defer fp.Close()
+	_, err = io.Copy(fp, resp.Body)
+	return err
+}

update/update_test.go

@@ -0,0 +1,52 @@
+package update
+
+import (
+	"fmt"
+	"os"
+	"testing"
+)
+
+func TestDownloadLatestRelease(t *testing.T) {
+
+	// Reset the version to test the latest release
+	Version = "0.0.0"
+
+	// change "exe" to /tmp/test-katenary
+	exe = "/tmp/test-katenary"
+	defer os.Remove(exe)
+
+	// Now call the CheckLatestVersion function
+	version, assets, err := CheckLatestVersion()
+
+	if err != nil {
+		t.Errorf("Error: %s", err)
+	}
+
+	fmt.Println("Version found", version)
+
+	// Touch exe binary
+	f, _ := os.OpenFile(exe, os.O_RDONLY|os.O_CREATE, 0755)
+	f.Write(nil)
+	f.Close()
+
+	err = DownloadLatestVersion(assets)
+	if err != nil {
+		t.Errorf("Error: %s", err)
+	}
+}
+
+func TestAlreadyUpToDate(t *testing.T) {
+	Version = "99999.999.99"
+	exe = "/tmp/test-katenary"
+	defer os.Remove(exe)
+
+	// Call the version check
+	version, _, err := CheckLatestVersion()
+
+	if err == nil {
+		t.Errorf("Error: %s", err)
+	}
+
+	t.Log("Version is already the most recent", version)
+
+}