Merge pull request #101164 from MikeDodaro/logStreaming

Draft log streaming doc

Author: American-Dipper

articles/spring-cloud/spring-cloud-howto-log-streaming.md

@@ -0,0 +1,76 @@
+---
+title:  Azure Spring Cloud log streaming for instant availability
+description: How to use log streaming to view application logs instantly 
+author:  MikeDodaro
+ms.author: barbkess
+ms.service: spring-cloud
+ms.topic: how-to
+ms.date: 01/14/2019
+---
+
+# Azure Spring Cloud log streaming for instant availability
+
+The log streaming feature makes application logs available instantly using CLI with limited range. To view logs out of range, see [Analyze logs and metrics with diagnostics settings](./diagnostic-services.md).
+
+## Prerequisites
+
+* Install minimum version 0.2.0 of the [Azure CLI extension](https://docs.microsoft.com/azure/spring-cloud/spring-cloud-quickstart-launch-app-cli#install-the-azure-cli-extension)
+* An instance of **Azure Spring Cloud** with a running application, for example [Spring Cloud app](./spring-cloud-quickstart-launch-app-cli.md)
+
+## Use CLI to tail logs
+
+To avoid repeatedly specifying your resource group and service instance name, set your default resource group name and cluster name.
+```
+az configure --defaults group=<service group name>
+az configure --defaults spring-cloud=<service instance name>
+```
+In following examples, the resource group and service name will be omitted in the commands.
+
+### Tail log for app with single instance
+If an app named auth-service has only one instance, you can view the instance log with following command:
+```
+az spring-cloud app log tail -n  auth-service
+```
+This will return logs:
+```
+...
+2020-01-15 01:54:40.481  INFO [auth-service,,,] 1 --- [main] o.apache.catalina.core.StandardService  : Starting service [Tomcat]
+2020-01-15 01:54:40.482  INFO [auth-service,,,] 1 --- [main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.22]
+2020-01-15 01:54:40.760  INFO [auth-service,,,] 1 --- [main] o.a.c.c.C.[Tomcat].[localhost].[/uaa]  : Initializing Spring embedded WebApplicationContext
+2020-01-15 01:54:40.760  INFO [auth-service,,,] 1 --- [main] o.s.web.context.ContextLoader  : Root WebApplicationContext: initialization completed in 7203 ms
+
+...
+```
+
+### Tail log for app with multiple instances
+If multiple instances exist for the app named `auth-service`, you can view the instance log by using the `-i/--instance` option. If the service auth-service has an instance named with auth-service-default-12-75cc4577fc-pw7hb, you can query with the following command.
+```
+az spring-cloud app log tail -n  auth-service -i auth-service-default-12-75cc4577fc-pw7hb
+```
+You can also get the app instances from the Azure portal. 
+1. Navigate to your Resource Group and select your Spring Cloud service.
+1. From the Spring Cloud service overview select **Apps** in the left navigation pane.
+1. Select your app, and then click **App Instances** in the left navigation pane. 
+1. App instances will be displayed.
+
+### Follow switch to track new logs
+By default, CLI will only print the existing log to console without following new logs. If you need to track the new logs, use `-f(--follow)` to track the new logs:
+```
+az spring-cloud app log tail -n  auth-service -f
+``` 
+### More options
+To see all the logging options supported:
+``` 
+az spring-cloud app log tail -h 
+```
+
+## Next steps
+
+* [Analyze logs and metrics with diagnostics settings](./diagnostic-services.md)
+
+ 
+
+
+
+
+

articles/spring-cloud/toc.yml

@@ -54,6 +54,8 @@
       href: spring-cloud-service-registration.md
     - name: Analyze application logs and Metrics
       href: diagnostic-services.md
+    - name: Azure Spring Cloud log streaming for instant availability
+      href: spring-cloud-howto-log-streaming.md  
     - name: Automate your CI/CD pipeline in Azure Spring Cloud
       href: spring-cloud-howto-cicd.md
     - name: Use persistent storage in Azure Spring Cloud