The blog post by Sherry Ger provides a comprehensive guide on setting up a three-node Elasticsearch cluster on Google Cloud using the Google Compute Engine (GCE) discovery plugin, which utilizes GCE APIs for automatic unicast discovery of nodes. It outlines the necessary prerequisites, such as having a Google Cloud Platform project ID and installing the Google Cloud SDK, before detailing the steps to configure firewall rules, create GCE instances, and install required software like the Java Development Kit (JDK) and Elasticsearch. The post further explains the process of configuring Elasticsearch with the GCE discovery plugin and setting up necessary configurations in the elasticsearch.yml file. Additionally, it covers creating a custom GCE image from an instance to facilitate the deployment of additional instances across different projects, elaborating on steps to snapshot the disk, create a compressed tar file, and store it in a Google Cloud Storage bucket. Finally, the post provides instructions on creating new instances from the custom image and verifying the successful setup of the Elasticsearch cluster, while hinting at future enhancements such as installing X-Pack for security and using the Google Cloud Storage repository plugin for snapshot capabilities.