add feature to checksum files if they already exist

this prevents re-downloading when unnecessary

cmd/download.go

@@ -17,7 +17,9 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
 package cmd
 
 import (
+	"crypto/md5"
 	"fmt"
+	"io"
 	"os"
 	"path/filepath"
 
@@ -33,6 +35,7 @@ var(
 	fileName string
 	acceptEula bool
 	outputDir string
+	forceDownload bool
 )
 
 
@@ -99,11 +102,46 @@ func downloadFiles(downloadPayloads []sdk.DownloadPayload) {
 			authorizedDownload, err := api.FetchDownloadLink(downloadPayload, username, password)
 			handleErrors(err)
 			authorizedDownload.FileName = filepath.Join(outputDir, authorizedDownload.FileName)
-			err = downloader.TriggerDownload(authorizedDownload)
-			handleErrors(err)
+			if forceDownload || checkToDownload(authorizedDownload.FileName, downloadPayload.Md5checksum){	
+				err = downloader.TriggerDownload(authorizedDownload)
+				handleErrors(err)
+			}
 		}
 }
 
+func checkToDownload(fileName string, expectedMD5 string) bool{
+	if fileExists(fileName){
+		fmt.Printf("Found file %s, calculating MD5 checksum to validate\n", fileName)
+		file, err := os.Open(fileName)
+		handleErrors(err)
+		defer file.Close()
+
+		// Create a hash instance and pass the file through it
+		hash := md5.New()
+		_, err = io.Copy(hash, file)
+		handleErrors(err)
+		// Usage for Sprintf needed as a standard string conversation broke some strings
+		calculatedMD5 := fmt.Sprintf("%x", hash.Sum(nil))
+
+		if expectedMD5 != calculatedMD5{
+			fmt.Printf("Expected checksum of [%s], but found [%s].\nAttempting to re-download.\n", expectedMD5, calculatedMD5)
+			return true
+		} else {
+			fmt.Println("Checksum validate completed successfully. No need to re-download.")
+			return false
+		}
+	}
+	return true
+}
+
+func fileExists(filename string) bool {
+	info, err := os.Stat(filename)
+	if os.IsNotExist(err) {
+			return false
+	}
+	return !info.IsDir()
+}
+
 func init() {
 	rootCmd.AddCommand(downloadCmd)
 	downloadCmd.Flags().StringVarP(&slug, "product", "p", "", "Product code")
@@ -113,4 +151,5 @@ func init() {
 	downloadCmd.Flags().StringVarP(&manifestFile, "manifest", "m", "", "Filename of the manifest containing details of what to download")
 	downloadCmd.Flags().StringVarP(&outputDir, "output", "o", "", "Directory to download files to")
 	downloadCmd.Flags().BoolVarP(&acceptEula, "accepteula", "a", false, "Filename string")
+	downloadCmd.Flags().BoolVarP(&forceDownload, "forcedownload", "d", false, "(optional) Force a file to be re-downloaded even if it already exists")
 }

cmd/root.go

@@ -27,7 +27,7 @@ var password string
 
 // rootCmd represents the base command when called without any subcommands
 var rootCmd = &cobra.Command{
-	Version: "0.2.1",
+	Version: "0.2.0",
 	Use:   "vmd",
 	Short: "Download binaries from customerconnect.vmware.com",
 	Long: "vmd downloads binaries from customerconnect.vmware.com",

test/bats/download.bats

@@ -21,7 +21,7 @@ teardown() {
   local cmd="$VMD_CMD download -p vmware_horizon_clients -s cart+andrd_x8632 -v 2106 -f VMware-Horizon-Client-AndroidOS-x86-*-store.apk --accepteula -o $TEMP_DIR"
   echo $cmd
   run $cmd
-  echo $output
+  echo "$output"
   [[ "$output" != *"No output directory set."* ]]
   [[ "$output" == *"Collecting download payload"* ]]
   [[ "$output" == *"Download started to"* ]]
@@ -30,12 +30,37 @@ teardown() {
   [ -f $TEMP_DIR/VMware-Horizon-Client-*.apk ]
 }
 
+@test "re-download single file successfully to temp" {
+  $VMD_CMD logout
+  rm -f $TEMP_DIR/*
+  local cmd="$VMD_CMD download -p vmware_tools -s vmtools -v 11.3.0 -f VMware-Tools-darwin-*.gz --accepteula -o $TEMP_DIR"
+  echo "$cmd"
+  run $cmd
+  run $cmd
+  echo "$output"
+  [[ "$output" != *"No output directory set."* ]]
+  [[ "$output" == *"Collecting download payload"* ]]
+  [[ "$output" == *"Checksum validate completed successfully. No need to re-download."* ]]
+  [ "$status" -eq 0 ]
+  [ -f $TEMP_DIR/VMware-Tools-darwin-*.gz ]
+  local cmd="$VMD_CMD download -p vmware_tools -s vmtools -v 11.3.0 -f VMware-Tools-darwin-*.gz --accepteula -o $TEMP_DIR --forcedownload"
+  echo "$cmd"
+  run $cmd
+  echo "$output"
+  [[ "$output" != *"No output directory set."* ]]
+  [[ "$output" == *"Collecting download payload"* ]]
+  [[ "$output" == *"Download started to"* ]]
+  [[ "$output" == *"Download finished"* ]]
+  [ "$status" -eq 0 ]
+  [ -f $TEMP_DIR/VMware-Tools-darwin-*.gz ]
+}
+
 @test "download single file successfully to user vmd-downloads" {
   rm -f $TEMP_DIR/*
   local cmd="$VMD_CMD download -p vmware_tools -s vmtools -v 11.3.0 -f VMware-Tools-darwin-*.zip --accepteula"
   echo $cmd
   run $cmd
-  echo $output
+  echo "$output"
   [[ "$output" == *"No output directory set."* ]]
   [[ "$output" == *"Collecting download payload"* ]]
   [[ "$output" == *"Download started to"* ]]
@@ -47,7 +72,7 @@ teardown() {
 @test "download multiple files successfully to temp" {
   rm -f $TEMP_DIR/*
   run $VMD_CMD download -p vmware_tools -s vmtools -v 11.3.0 -f VMware-Tools-darwin-* --accepteula -o $TEMP_DIR
-  echo $output
+  echo "$output"
   [[ "$output" != *"No output directory set."* ]]
   [[ "$output" == *"Collecting download payload"* ]]
   [[ "$output" == *"Download started to"* ]]
@@ -60,7 +85,7 @@ teardown() {
 @test "download from manifest" {
   rm -f $TEMP_DIR/*
   run $VMD_CMD download -m <(echo "$VALID_YAML") --accepteula -o $TEMP_DIR
-  echo $output
+  echo "$output"
   [[ "$output" == *"Opening manifest file:"* ]]
   [[ "$output" == *"Collecting download payload"* ]]
   [[ "$output" == *"Download started to"* ]]
@@ -74,7 +99,7 @@ teardown() {
 
 @test "download from manifest missing field" {
   run $VMD_CMD download -m <(echo "$INVALID_YAML_MISSING_FIELD") --accepteula -o $TEMP_DIR
-  echo $output
+  echo "$output"
   [[ "$output" == *"Opening manifest file:"* ]]
   [[ "$output" == *"Manifest entry 0 does not have the 4 required keys!"* ]]
   [[ "$output" != *"Collecting download payload"* ]]
@@ -85,7 +110,7 @@ teardown() {
 
 @test "download from manifest invalid type" {
   run $VMD_CMD download -m <(echo "$INVALID_YAML_INVALID_TYPE") --accepteula -o $TEMP_DIR
-  echo $output
+  echo "$output"
   [[ "$output" == *"Opening manifest file:"* ]]
   [[ "$output" == *"Parsing file failed with error:"* ]]
   [[ "$output" != *"Collecting download payload"* ]]
@@ -96,44 +121,44 @@ teardown() {
 
 @test "download with invalid product" {
   run $VMD_CMD download -p INVALID -s vmtools -v 11.3.0 -f VMware-Tools-darwin-*.zip --accepteula
-  echo $output
+  echo "$output"
   [[ "$output" == *"$ERRORINVALIDSLUG"* ]]
   [ "$status" -eq 1 ]
 }
 
 @test "download with invalid subproduct" {
   run $VMD_CMD download -p vmware_tools -s INVALID -v 11.3.0 -f VMware-Tools-darwin-*.zip --accepteula
-  echo $output
+  echo "$output"
   [[ "$output" == *"$ERRORINVALIDSUBPRODUCT"* ]]
   [ "$status" -eq 1 ]
 }
 
 @test "download with invalid version" {
   run $VMD_CMD download -p vmware_tools -s vmtools -v INVALID -f VMware-Tools-darwin-*.zip --accepteula
-  echo $output
+  echo "$output"
   [[ "$output" == *"$ERRORINVALIDVERSION"* ]]
   [ "$status" -eq 1 ]
 }
 
 @test "download with invalid credentials" {
   $VMD_CMD logout
   run $VMD_CMD download -p vmware_tools -s vmtools -v 11.3.0 -f VMware-Tools-darwin-*.zip --accepteula --user invalid --pass invalid
-  echo $output
+  echo "$output"
   [[ "$output" == *"$ERRORAUTHENTICATIONFAILURE"* ]]
   [ "$status" -eq 1 ]
 }
 
 @test "download when not entitled" {
   $VMD_CMD logout
   run $VMD_CMD download -p vmware_vsan -s esxi -v 7.* -f VMware-VMvisor-Installer-*.iso --accepteula
-  echo $output
+  echo "$output"
   [[ "$output" == *"$ERRORNOTENTITLED"* ]]
   [ "$status" -eq 1 ]
 }
 
 @test "download with invalid output directory" {
   run $VMD_CMD download -p vmware_tools -s vmtools -v 11.3.0 -f VMware-Tools-darwin-*.zip --accepteula -o /tmp/stilton/on/toast
-  echo $output
+  echo "$output"
   [[ "$output" == *"ERROR: Output directory"* ]]
   [ "$status" -eq 1 ]
 }

test/test_tanzu.yml

@@ -0,0 +1,14 @@
+---
+product: vmware_tanzu_kubernetes_grid
+subproduct: tkg
+version: "1.3.1"
+filename_globs:
+  - "ubuntu-*-kube-v1.2*.ova" # Files can be globbed in any way to select files
+  - "tanzu-cli-bundle-linux-amd64.tar" # Or just called out explicitly
+---
+product: vmware_tanzu_kubernetes_grid
+subproduct: tkg
+version: "*" # Globbing of version is also supported
+filename_globs:
+  - "tanzu-cli-bundle*linux-amd64.tar"
+---