Using google cloud endpoints on AppEngine

Question

I normally use Google Cloud Endpoints on the AppEngine (Java) , as described in :

https://cloud.google.com/appengine/docs/java/endpoints/helloendpoints-java-maven

The dependency for the endpoints library I use is :

<plugin>
   <groupId>com.google.appengine</groupId>
   <artifactId>appengine-endpoints</artifactId>
   <version>1.9.48</version>
</plugin>

Using this, I can start a local development server using the command: mvn clean package appengine:devserver

However, there seems to be a new version of cloud endpoints. https://cloud.google.com/endpoints/docs/frameworks/java/quickstart-frameworks-java .

The new framework is found here

<dependency>
<groupId>com.google.endpoints</groupId>
<artifactId>endpoints-framework</artifactId>
<version>${endpoints.framework.version}</version>
</dependency>

The same maven commands do not work here. I am unable to start a local dev server, open the API explorer or use a local datastore (all of which was possible earlier) . Could someone please guide me on how to work with the new framework.

Also, is the former framework likely to be deprecated ?

Answer 1

To answer my own question partially : I could finally get the "Echo application" (mentioned in https://cloud.google.com/endpoints/docs/frameworks/java/quickstart-frameworks-java ) to work

But I had to make 2 changes: a) Comment out the block in appengine-web.xml . ie,

<!--
<basic-scaling>
  <max-instances>2</max-instances>
</basic-scaling>
-->

After doing this, I got a different error, "failed endpoints-api-configuration: com.google.api.config.ServiceConfigException: Failed to fetch default config version for service" To get around this :

b) Comment out the ServiceManagementConfigFilter from web.xml , ie,

<!--
    <filter>
      <filter-name>endpoints-api-configuration</filter-name>
      <filter-class>com.google.api.control.ServiceManagementConfigFilter</filter-class>
   </filter>
-->
<!--    
<filter-mapping>
    <filter-name>endpoints-api-configuration</filter-name>
    <servlet-name>EndpointsServlet</servlet-name>
</filter-mapping>
-->

After this,

1. To build : mvn clean package

2. To run locally : appengine-java-sdk/1.9.44/appengine-java-sdk/appengine-java-sdk-1.9.44/bin/dev_appserver.sh /path/to/war/directory

It would be great if someone could shed more light on implication of these changes, and on how we could get it to work out of the box

Answer 2

There are a few problems you are running into and this stuff is overly sensitive to configuration issues:

To solve the problems follow the instructions in: https://cloud.google.com/endpoints/docs/frameworks/java/quickstart-frameworks-java

1. Use the correct Google project id when you replace the YOUR_PROJECT_ID in pom.xml. It needs to be a valid project id for all the steps to work.
2. Same when replacing the YOUR-PROJECT-ID in echo.java

If the project id is not valid (actually exists in AppEngine) the next steps won't work

3. execute: mvn exec:java -DGetSwaggerDoc
4. execute: gcloud service-management deploy openapi.json
5. execute: export ENDPOINTS_SERVICE_NAME=echo-api.endpoints.<your project id>.cloud.goog

The quickstart guide is not very helpful for step 5. Step 4 needs to end with a success message.

Finally the sample comes with a Maven plugin that does not seem to work with the new Endpoints. Instead of using:

    <plugin>
        <groupId>com.google.cloud.tools</groupId>
        <artifactId>appengine-maven-plugin</artifactId>
        <version>${appengine.maven.plugin.version}</version>
    </plugin>

use:

    <plugin>
        <groupId>com.google.appengine</groupId>
        <artifactId>appengine-maven-plugin</artifactId>
        <version>1.9.44</version>
    </plugin>

The answer to the question why mvn appengine:devserver doesn't work is that the devserver target doesn't exist in the new plugin. The old Maven plugin allows you to execute: mvn appengine:devserver