feat: More detailed error message upon ARM deployment failure (#306)

Logs a more detailed error message when an ARM template deployment fails

Author: tbarlow12

src/models/azureProvider.ts

@@ -18,3 +18,9 @@ export interface FunctionMetadata {
   handler: string;
   events: FunctionEvent[];
 }
+
+export interface DeploymentExtendedError {
+  code: string;
+  message: string;
+  details?: DeploymentExtendedError[];
+}

src/services/armService.test.ts

@@ -8,6 +8,7 @@ import jsonpath from "jsonpath";
 import { Deployments } from "@azure/arm-resources";
 import { Deployment, DeploymentExtended } from "@azure/arm-resources/esm/models";
 import { ResourceService } from "./resourceService";
+import { DeploymentExtendedError } from "../models/azureProvider";
 
 describe("Arm Service", () => {
   let sls: Serverless
@@ -311,5 +312,47 @@ describe("Arm Service", () => {
       expect(call[1]).toMatch(expectedDeploymentNameRegex);
       expect(call[2]).toEqual(expectedDeployment);
     });
+
+    it("Throws more detailed error message upon failed ARM deployment", async () => {
+      Deployments.prototype.createOrUpdate = jest.fn(() => Promise.reject(null));
+      const lastDeploymentError: DeploymentExtendedError = {
+        code: "DeploymentFailed",
+        message: "At least one resource deployment operation failed. Please list deployment operations for details. Please see https://aka.ms/arm-debug for usage details.",
+        details: [
+          {
+            code: "ServiceAlreadyExists",
+            message: "Api service already exists: abc-123-apim"
+          },
+          {
+            code: "StorageAccountAlreadyTaken",
+            message: "The storage account named ABC123 is already taken."
+          }
+        ]
+      }
+      ResourceService.prototype.getLastDeployment = jest.fn(() => Promise.resolve({
+        properties: {
+          error: lastDeploymentError
+        }
+      })) as any;
+      const deployment: ArmDeployment = {
+        parameters: MockFactory.createTestParameters(false),
+        template: MockFactory.createTestArmTemplate()
+      };
+      deployment.parameters.param1 = "3"
+      const { code, message, details } = lastDeploymentError;
+      let errorPattern = [
+        code,
+        message,
+        details[0].code,
+        details[0].message,
+        details[1].code,
+        details[1].message
+      ].join(".*")
+      await expect(service.deployTemplate(deployment))
+        .rejects
+        .toThrowError(
+          new RegExp(`.*${errorPattern}.*`,"s")
+        );
+    });
   });
 });

src/services/armService.ts

@@ -10,6 +10,7 @@ import { Guard } from "../shared/guard";
 import { BaseService } from "./baseService";
 import { ResourceService } from "./resourceService"
 import deepEqual from "deep-equal";
+import { DeploymentExtendedError } from "../models/azureProvider";
 
 export class ArmService extends BaseService {
   private resourceClient: ResourceManagementClient;
@@ -130,14 +131,39 @@ export class ArmService extends BaseService {
     this.log(`---> Resource Group: ${this.resourceGroup}`)
     this.log(`---> Deployment Name: ${this.deploymentName}`)
 
-    const result = await this.resourceClient.deployments.createOrUpdate(
-      this.resourceGroup,
-      this.deploymentName,
-      armDeployment
-    );
-    this.log("-> ARM deployment complete");
+    try {
+      const result = await this.resourceClient.deployments.createOrUpdate(
+        this.resourceGroup,
+        this.deploymentName,
+        armDeployment
+      );
+      this.log("-> ARM deployment complete");
+      return result;
+    } catch (err) {
+      const lastDeployment = await resourceService.getLastDeployment();
+      const errorDetails: DeploymentExtendedError = lastDeployment.properties["error"];
+      if (errorDetails) {
+        throw new Error(this.deploymentErrorToString(errorDetails));
+      }
+    }
+  }
 
-    return result;
+  private deploymentErrorToString(deploymentError: DeploymentExtendedError) {
+    if (!deploymentError.code || !deploymentError.message) {
+      return JSON.stringify(deploymentError);
+    }
+    let errorString = `${deploymentError.code} - ${deploymentError.message}`;
+    if (deploymentError.details) {
+
+      errorString += `
+      ------------------------
+      DEPLOYMENT ERROR DETAILS
+      ------------------------\n`
+      deploymentError.details.forEach((childError) => {
+        errorString += `\n${this.deploymentErrorToString(childError)}`
+      })
+    }
+    return errorString;
   }
 
   /**