support for check latest Helm version

Tasks/Common/utility-common/downloadutility.ts

@@ -4,15 +4,22 @@ var https   = require('https');
 var fs      = require('fs');
 import * as tl from "vsts-task-lib/task";
 
-export async function download(url: string, downloadPath: string): Promise<void> {
+export async function download(url: any, downloadPath: string, printData: boolean = false): Promise<void> {
     var file = fs.createWriteStream(downloadPath);
+    var body = ''
     return new Promise<void>((resolve, reject) => {
         var req = https.request(url, res => {
             tl.debug("statusCode: " + res.statusCode);
             res.pipe(file);
             res.on("error", err => reject(err));
+            res.on('data', d => body += d);
+
             res.on("end", () => {
                 file.end(null, null, file.close);
+                if(printData) {
+                    tl.debug(body);
+                }
+
                 if(res.statusCode < 200 || res.statusCode >= 300) {
                     tl.debug("File download failed");
                     reject(new Error('Failed to download file status code: ' + res.statusCode));
@@ -23,12 +30,11 @@ export async function download(url: string, downloadPath: string): Promise<void>
                 }
             });
         });
-
         req.on("error", err => {
             tl.debug(err);
             reject(err);
         });
-
+    
         req.end();
     });
 }

Tasks/HelmInstaller/Strings/resources.resjson/en-US/resources.resjson

@@ -6,6 +6,8 @@
   "loc.group.displayName.prerequisite": "Prerequisite",
   "loc.input.label.helmVersion": "Helm Version Spec",
   "loc.input.help.helmVersion": "Specify the version of Helm to install",
+  "loc.input.label.checkLatestHelmVersion": "Check for latest version of Helm",
+  "loc.input.help.checkLatestHelmVersion": "Check for latest version of Helm.",
   "loc.input.label.installKubeCtl": "Install Kubectl",
   "loc.input.help.installKubeCtl": "Install Kubectl.",
   "loc.input.label.kubectlVersion": "Kubectl Version Spec",
@@ -16,5 +18,6 @@
   "loc.messages.DownloadKubectlFailedFromLocation": "Failed to download kubectl from location %s. Error %s",
   "loc.messages.NotAValidSemverVersion": "Version not specified in correct format. E.g: 1.8.2, v1.8.2, 2.8.2, v2.8.2.",
   "loc.messages.HelmNotFoundInFolder": "Helm executable not found in path %s",
-  "loc.messages.HelmDownloadFailed": "Failed to download helm from location %s. Error %s"
+  "loc.messages.HelmDownloadFailed": "Failed to download helm from location %s. Error %s",
+  "loc.messages.HelmLatestNotKnown": "Can not get lateast helm info from %s. Error %s. Using default helm version %s."
 }

Tasks/HelmInstaller/src/helminstaller.ts

@@ -8,9 +8,17 @@ import * as utils from './utils';
 import * as os from "os";
 import * as util from "util";
 const uuidV4 = require('uuid/v4');
+import downloadutility = require("utility-common/downloadutility");
 const helmToolName = "helm"
+const helmLatestReleaseUrl = "https://api.github.com/repos/kubernetes/helm/releases/latest";
+const stableHelmVersion = "v2.8.2"
 
 export async function getHelmVersion(): Promise<string> {
+    var checkLatestHelmVersion = tl.getBoolInput('checkLatestHelmVersion', false); 
+    if(checkLatestHelmVersion) {
+        return await getStableHelmVersion();
+    }
+
     return utils.sanitizeVersionString(tl.getInput("helmVersion", true));
 }
 
@@ -60,10 +68,50 @@ function getHelmDownloadURL(version: string) : string {
     }
 }
 
+async function getStableHelmVersion() : Promise<string>{
+    var downloadPath = path.join(getTempDirectory(), uuidV4() +".json");
+    var options = {
+        hostname: 'api.github.com',
+        port: 443,
+        path: '/repos/kubernetes/helm/releases/latest',
+        method: 'GET',
+        secureProtocol: "TLSv1_2_method",
+        headers: {
+            'User-Agent' : 'vsts'
+          }
+    }
+
+    try{
+        await downloadutility.download(options, downloadPath, true);
+        var version = await getReleaseVersion(downloadPath);
+        return version;
+    } catch(error) {
+        tl.warning(tl.loc("HelmLatestNotKnown", helmLatestReleaseUrl, error, stableHelmVersion));
+    }
+
+    return stableHelmVersion;
+}
+
 function getExecutableExtention(): string {
     if(os.type().match(/^Win/)){
         return ".exe";
     }
 
     return "";
+}
+
+function getTempDirectory(): string {
+    return tl.getVariable('agent.tempDirectory') || os.tmpdir();
+}
+
+function getReleaseVersion(jsonFilePath): Promise<string> {
+    return new Promise(function (fulfill, reject){
+        fs.readFile(jsonFilePath, {encoding: 'utf8'} ,function(err,data) {
+            if(err) {
+                reject(err);
+            }
+            var latestVersionInfo = JSON.parse(data);
+            fulfill(latestVersionInfo.tag_name);
+        })
+    });
 }

Tasks/HelmInstaller/task.json

@@ -13,7 +13,7 @@
     "version": {
         "Major": 0,
         "Minor": 1,
-        "Patch": 2
+        "Patch": 3
     },
     "demands": [],
     "satisfies": ["Helm"],
@@ -35,6 +35,13 @@
             "helpMarkDown": "Specify the version of Helm to install",
             "defaultValue": "2.8.2"
         },
+        {
+            "name": "checkLatestHelmVersion",
+            "type": "boolean",
+            "label": "Check for latest version of Helm",
+            "defaultValue": "true",
+            "helpMarkDown": "Check for latest version of Helm."
+        },
         {
             "name": "installKubeCtl",
             "aliases": ["installKubectl"],
@@ -76,6 +83,7 @@
         "DownloadKubectlFailedFromLocation": "Failed to download kubectl from location %s. Error %s",
         "NotAValidSemverVersion": "Version not specified in correct format. E.g: 1.8.2, v1.8.2, 2.8.2, v2.8.2.",
         "HelmNotFoundInFolder": "Helm executable not found in path %s",
-        "HelmDownloadFailed": "Failed to download helm from location %s. Error %s"
+        "HelmDownloadFailed": "Failed to download helm from location %s. Error %s",
+        "HelmLatestNotKnown": "Can not get lateast helm info from %s. Error %s. Using default helm version %s."
     }
 }

Tasks/HelmInstaller/task.loc.json

@@ -13,7 +13,7 @@
   "version": {
     "Major": 0,
     "Minor": 1,
-    "Patch": 2
+    "Patch": 3
   },
   "demands": [],
   "satisfies": [
@@ -37,6 +37,13 @@
       "helpMarkDown": "ms-resource:loc.input.help.helmVersion",
       "defaultValue": "2.8.2"
     },
+    {
+      "name": "checkLatestHelmVersion",
+      "type": "boolean",
+      "label": "ms-resource:loc.input.label.checkLatestHelmVersion",
+      "defaultValue": "true",
+      "helpMarkDown": "ms-resource:loc.input.help.checkLatestHelmVersion"
+    },
     {
       "name": "installKubeCtl",
       "aliases": [
@@ -82,6 +89,7 @@
     "DownloadKubectlFailedFromLocation": "ms-resource:loc.messages.DownloadKubectlFailedFromLocation",
     "NotAValidSemverVersion": "ms-resource:loc.messages.NotAValidSemverVersion",
     "HelmNotFoundInFolder": "ms-resource:loc.messages.HelmNotFoundInFolder",
-    "HelmDownloadFailed": "ms-resource:loc.messages.HelmDownloadFailed"
+    "HelmDownloadFailed": "ms-resource:loc.messages.HelmDownloadFailed",
+    "HelmLatestNotKnown": "ms-resource:loc.messages.HelmLatestNotKnown"
   }
 }