Added Open Policy Agent Installer Task

.github/CODEOWNERS

@@ -263,6 +263,8 @@ Tasks/NuGetPublisherV0/*    @zjrunner
 
 Tasks/NuGetToolInstallerV0/*    @zjrunner
 
+Tasks/OpenPolicyAgentInstallerV0/*    @Anumita
+
 Tasks/PackerBuildV0/*   @bishal-pdmsft
 
 Tasks/PackerBuildV1/*   @bishal-pdmsft

Tasks/OpenPolicyAgentInstallerV0/Strings/resources.resjson/en-US/resources.resjson

@@ -0,0 +1,12 @@
+{
+  "loc.friendlyName": "Open Policy Agent Installer",
+  "loc.helpMarkDown": "[Learn more about this task](https://go.microsoft.com/fwlink/?linkid=851275)",
+  "loc.description": "Install Open Policy Agent on agent machine",
+  "loc.instanceNameFormat": "Install opa $(opaVersion)",
+  "loc.input.label.opaVersion": "OPA Version Spec",
+  "loc.input.help.opaVersion": "Specify the version of open policy agent to install",
+  "loc.messages.DownloadOpaFailedFromLocation": "Failed to download opa from location %s. Error %s",
+  "loc.messages.OpaLatestNotKnown": "Cannot get the latest OpenPolicyAgent info from %s. Error %s. Using default OpenPolicyAgent version %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.VerifyOpaInstallation": "Verifying opa installation..."
+}

Tasks/OpenPolicyAgentInstallerV0/make.json

@@ -0,0 +1,2 @@
+{
+}

Tasks/OpenPolicyAgentInstallerV0/package.json

@@ -0,0 +1,8 @@
+{
+  "dependencies": {
+    "@types/node": "^6.0.101",
+    "@types/q": "^1.5.0",
+    "azure-pipelines-task-lib": "2.8.0",
+    "azure-pipelines-tool-lib": "0.12.0"
+  }
+}

Tasks/OpenPolicyAgentInstallerV0/src/opatoolinstaller.ts

@@ -0,0 +1,33 @@
+'use strict';
+import * as tl from 'azure-pipelines-task-lib/task';
+import * as path from 'path';
+import * as toolLib from 'azure-pipelines-tool-lib/tool';
+import utils = require("./utils");
+
+tl.setResourcePath(path.join(__dirname, '..', 'task.json'));
+
+async function configureOpa() {
+    var version = await utils.getOpaVersion();
+    var opaPath = await utils.downloadOpa(version);
+
+    // prepend the tools path. instructs the agent to prepend for future tasks
+    if (!process.env['PATH'].startsWith(path.dirname(opaPath))) {
+        toolLib.prependPath(path.dirname(opaPath));
+    }
+}
+
+async function verifyOpa() {
+    console.log(tl.loc("VerifyOpaInstallation"));
+    var opaToolPath = tl.which("opa", true);
+    var opaTool = tl.tool(opaToolPath);
+    opaTool.arg("version");
+    return opaTool.exec();
+}
+
+configureOpa()
+    .then(() => verifyOpa())
+    .then(() => {
+        tl.setResult(tl.TaskResult.Succeeded, "");
+    }).catch((error) => {
+        tl.setResult(tl.TaskResult.Failed, error);
+    });

Tasks/OpenPolicyAgentInstallerV0/src/utils.ts

@@ -0,0 +1,102 @@
+"use strict";
+
+var fs = require('fs');
+import * as path from "path";
+import * as tl from "azure-pipelines-task-lib/task";
+import * as os from "os";
+import * as toolLib from 'azure-pipelines-tool-lib/tool';
+import * as util from "util";
+
+const opaToolName = 'opa';
+const opaLatestReleaseUrl = 'https://api.github.com/repos/open-policy-agent/opa/releases/latest';
+const stableOpaVersion = 'v0.13.5';
+
+export function getTempDirectory(): string {
+    return tl.getVariable('agent.tempDirectory') || os.tmpdir();
+}
+
+export async function getOpaVersion(): Promise<string> {
+    let opaVersion = tl.getInput("opaVersion");
+    if(opaVersion && opaVersion != "latest") {
+        return sanitizeVersionString(opaVersion.trim());
+    }
+
+    return await getStableOpaVersion();
+}
+
+function getOpaDownloadURL(version: string): string {
+    switch (os.type()) {
+        case 'Linux':
+            return util.format('https://github.com/open-policy-agent/opa/releases/download/%s/opa_linux_amd64', version);
+
+        case 'Darwin':
+            return util.format('https://github.com/open-policy-agent/opa/releases/download/%s/opa_darwin_amd64', version);
+
+        case 'Windows_NT':
+            return util.format('https://github.com/open-policy-agent/opa/releases/download/%s/opa_windows_amd64.exe', version);
+
+        default:
+            throw Error('Unknown OS type');
+    }
+}
+
+export async function getStableOpaVersion(): Promise<string> {
+    try {
+        const downloadPath = await toolLib.downloadTool(opaLatestReleaseUrl);
+        const response = JSON.parse(fs.readFileSync(downloadPath, 'utf8').toString().trim());
+        if (!response.tag_name)
+        {
+            return stableOpaVersion;
+        }
+
+        return response.tag_name;
+    } catch (error) {
+        tl.warning(tl.loc('OpaLatestNotKnown', opaLatestReleaseUrl, error, stableOpaVersion));
+    }
+
+    return stableOpaVersion;
+}
+
+export function getExecutableExtension(): string {
+    if (os.type().match(/^Win/)) {
+        return '.exe';
+    }
+
+    return '';
+}
+
+export async function downloadOpa(version: string): Promise<string> {
+    let cachedToolpath = toolLib.findLocalTool(opaToolName, version);
+    let opaDownloadPath = '';
+    if (!cachedToolpath) {
+        try {
+            opaDownloadPath = await toolLib.downloadTool(getOpaDownloadURL(version));
+        } catch (exception) {
+            throw new Error(tl.loc('DownloadOpaFailedFromLocation', getOpaDownloadURL(version), exception));
+        }
+
+        cachedToolpath = await toolLib.cacheFile(opaDownloadPath, opaToolName + getExecutableExtension(), opaToolName, version);
+    }
+
+    const opaPath = path.join(cachedToolpath, opaToolName + getExecutableExtension());
+
+    if (!cachedToolpath || !fs.existsSync(opaPath)) {
+        const opaPathTmp = path.join(getTempDirectory(), opaToolName + getExecutableExtension());
+        tl.cp(opaDownloadPath, opaPathTmp, '-f');
+        fs.chmodSync(opaPathTmp, '777');
+        return opaPathTmp;
+    }
+
+    fs.chmodSync(opaPath, '777');
+    return opaPath;
+}
+
+// handle user input scenerios
+export function sanitizeVersionString(inputVersion: string) : string{
+    var version = toolLib.cleanVersion(inputVersion);
+    if(!version) {
+        throw new Error(tl.loc("NotAValidSemverVersion"));
+    }
+
+    return "v"+version;
+}

Tasks/OpenPolicyAgentInstallerV0/task.json

@@ -0,0 +1,43 @@
+{
+    "id": "50817E39-E160-45E1-A825-1C746B7D2EB2",
+    "name": "OpenPolicyAgentInstaller",
+    "friendlyName": "Open Policy Agent Installer",
+    "description": "Install Open Policy Agent on agent machine",
+    "helpUrl": "https://docs.microsoft.com/azure/devops/pipelines/tasks",
+    "helpMarkDown": "[Learn more about this task](https://go.microsoft.com/fwlink/?linkid=851275)",
+    "category": "Utility",
+    "visibility": [
+        "Build",
+        "Release"
+    ],
+    "author": "Microsoft Corporation",
+    "version": {
+        "Major": 0,
+        "Minor": 157,
+        "Patch": 0
+    },
+    "demands": [],
+    "groups": [],
+    "inputs": [
+        {
+            "name": "opaVersion",
+            "label": "OPA Version Spec",
+            "type": "string",
+            "helpMarkDown": "Specify the version of open policy agent to install",
+            "defaultValue": "latest"
+        }   
+    ],
+
+    "instanceNameFormat": "Install opa $(opaVersion)",
+    "execution": {
+        "Node": {
+            "target": "src//opatoolinstaller.js"
+        }
+    },
+    "messages": {
+        "DownloadOpaFailedFromLocation": "Failed to download opa from location %s. Error %s",
+        "OpaLatestNotKnown": "Cannot get the latest OpenPolicyAgent info from %s. Error %s. Using default OpenPolicyAgent version %s.",
+        "NotAValidSemverVersion": "Version not specified in correct format. E.g: 1.8.2, v1.8.2, 2.8.2, v2.8.2.",
+        "VerifyOpaInstallation": "Verifying opa installation..."
+    }
+}