How to Use the Command 'gcloud' (with examples)
The gcloud command-line tool is the official way to interact with Google Cloud Platform (GCP). It provides a comprehensive interface for managing various services and resources on GCP. With gcloud, users can manage their cloud infrastructure, set up and configure applications, administer virtual machines, and perform a broad range of cloud operations through the command line. This flexibility makes gcloud an invaluable tool for developers and system administrators working within the Google Cloud ecosystem. Below, we’ll explore several specific use cases for the gcloud command to illustrate its versatility and practicality.
Use case 1: List all properties in one’s active configuration
Code:
gcloud config list
Motivation: Understanding your current gcloud setup is crucial for effective cloud management. By listing all properties in your active configuration, you can review your current settings, such as the active project, default compute region, and zone. This insight helps ensure that you are interacting with the intended Google Cloud environment and can prevent accidental modifications to the wrong configurations.
Explanation: The gcloud config list command provides details of the current configurations, including project ID, access components, and settings for various environment configurations. This command does not require any additional arguments and provides a simple way to view existing configurations.
Example Output:
[compute]
region = us-central1
zone = us-central1-a
[core]
account = user@example.com
project = my-sample-project
Use case 2: Login to a Google account
Code:
gcloud auth login
Motivation: Before you can start using Google Cloud services, you must authenticate with a Google Account. The gcloud auth login command initiates this authentication process by opening a web browser window for you to log in. This step is fundamental because it grants you the necessary permissions to access and manage your Google Cloud resources.
Explanation: The gcloud auth login command uses the default web browser to prompt you to log into your Google account. No additional arguments are needed, and this step ensures your local gcloud setup is connected with the correct user’s credentials.
Example Output:
Your browser has been opened to visit: https://accounts.google.com/o/oauth2/auth?.....
You are now logged in as [user@example.com].
Your current project is [my-sample-project]. You can change it by running [gcloud config set project PROJECT_ID].
Use case 3: Set the active project
Code:
gcloud config set project project_name
Motivation: Google Cloud operations are organized around projects. Setting the correct active project ensures that your gcloud commands are applied to the appropriate context. This avoids confusion and potential misallocation of resources, which could result from actions being executed in the wrong project.
Explanation: This command sets the project’s configuration to project_name. You need to replace project_name with the actual project ID you wish to set as active. The command updates your local gcloud configuration to focus on this specified project, streamlining resource management and operations specific to that project context.
Example Output:
Updated property [core/project].
Use case 4: SSH into a virtual machine instance
Code:
gcloud compute ssh user@instance
Motivation: Securely accessing a virtual machine (VM) instance via SSH is a common requirement for developers and system administrators. This capability is essential for maintenance, troubleshooting, and configuration of applications hosted on Google Compute Engine.
Explanation: Here, user represents the username for SSH, and instance is the name of your VM instance. The command facilitates a secure shell connection directly from your local environment to the specified VM instance on Google Cloud, allowing you to manage and control its operations directly.
Example Output:
Warning: Permanently added 'compute-instance-ip' (ECDSA) to the list of known hosts.
Welcome to Ubuntu 20.04.2 LTS (GNU/Linux 5.4.0-1041-gcp x86_64)
Use case 5: Display all Google Compute Engine instances in a project
Code:
gcloud compute instances list
Motivation: Being able to view all virtual machine instances provides a snapshot of your compute resources in Google Cloud. This command is useful for auditing and managing your instances, ensuring that all resources are accounted for and allowing you to verify their status and configuration.
Explanation: gcloud compute instances list does not require additional arguments by default and will list instances across all zones within your active project. This command provides a comprehensive view of all running and stopped instances as well as crucial metadata about each, such as zone, machine type, and internal and external IP addresses.
Example Output:
NAME ZONE MACHINE_TYPE PREEMPTIBLE INTERNAL_IP EXTERNAL_IP STATUS
instance-1 us-central1-a n1-standard-1 10.128.0.2 35.202.123.456 RUNNING
instance-2 us-central1-b n1-standard-1 10.128.0.3 TERMINATED
Use case 6: Update a kubeconfig file with the appropriate credentials to point kubectl to a specific cluster in Google Kubernetes Engine (GKE)
Code:
gcloud container clusters get-credentials cluster_name
Motivation: Developers working with Kubernetes need to connect to their GKE clusters to deploy and manage applications. The gcloud container clusters get-credentials command updates your local kubeconfig, allowing kubectl to interact with the GKE cluster by authenticating with the necessary credentials.
Explanation: You must replace cluster_name with the name of the Kubernetes cluster. The command retrieves authentication credentials for the cluster, effectively configuring your local kubectl client to interact with it. This step is essential for managing Kubernetes resources within the specified GKE cluster.
Example Output:
Fetching cluster endpoint and auth data.
kubeconfig entry generated for cluster_name.
Use case 7: Update all gcloud components
Code:
gcloud components update
Motivation: Keeping gcloud components up to date ensures access to the latest features, enhancements, and security patches. Regular updates are critical for maintaining smooth and reliable command line interactions with your Google Cloud resources.
Explanation: This command checks for and installs updates for all gcloud components. No additional arguments are needed. Upon execution, the command verifies version status and proceeds to download and apply updates as necessary, ensuring that the gcloud tool remains current.
Example Output:
All components are up to date.
Use case 8: Display help for a given command
Code:
gcloud help command
Motivation: With the complexity and breadth of Google Cloud operations, users often need guidance on the usage of specific gcloud commands. Accessing command-specific help content directly via the command line facilitates learning and ensures accurate command execution.
Explanation: Replace command with the specific gcloud command you need help with. The result provides detailed syntax, usage examples, and explanations for various command options, aiding in the effective and accurate use of the gcloud tool.
Example Output:
NAME
gcloud help - display detailed help information
SYNOPSIS
gcloud help COMMAND [--help) [-h]
...
Conclusion
The gcloud command-line tool offers a powerful interface for managing Google Cloud resources. Each use case highlighted demonstrates how gcloud facilitates various tasks—from configuration management and authentication to virtual machine interaction and Kubernetes cluster management. Understanding these commands is essential for maximizing efficiency and control over cloud-based infrastructure on Google Cloud Platform.
