gcloud environment variables – host discount code

Setting up environment variables in Google Cloud (gcloud) is an essential task for many developers and system administrators. It helps you manage configuration settings, credentials, and other important data without hardcoding them into your application. Below is a detailed guide on how to use environment variables in Google Cloud, particularly in Compute Engine, App Engine, and Cloud Functions.

What Are Environment Variables?

Environment variables are key-value pairs used to store configuration settings that your application can access during runtime. They allow you to change the behavior of your applications without modifying the code itself. In cloud environments like Google Cloud, they help manage secrets like API keys, database URLs, and credentials securely.

How to Set Environment Variables in Google Cloud

1. Using Environment Variables in Google Cloud Compute Engine

If you are running your applications on Google Cloud Compute Engine, you can set environment variables when you create or update your virtual machine instance.

Steps to set environment variables on Compute Engine:

1. Connect to Your Instance

   • First, connect to your VM instance using SSH.

   • Open Google Cloud Console, navigate to Compute Engine, and click on your instance.

   • Click on SSH to connect to your VM.

2. Set Environment Variables
   Once connected to the instance, you can set environment variables either temporarily or permanently.

   • Temporarily (for the current session):

     bash
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     export MY_VARIABLE="value"
     

   • Permanently (for all sessions):
     Add the export command to your ~/.bashrc or ~/.bash_profile file:

     bash
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     echo 'export MY_VARIABLE="value"' >> ~/.bashrc
     source ~/.bashrc
     

3. Accessing Environment Variables in Your Application
   Your application code can now access these variables using the respective method depending on the language:

   • In Python:

     python
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     import os
     my_variable = os.getenv('MY_VARIABLE')
     

   • In Node.js:

     javascript
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     const myVariable = process.env.MY_VARIABLE;
     

2. Setting Environment Variables in Google Cloud App Engine

Google Cloud App Engine allows you to set environment variables in your application’s configuration file.

Steps to set environment variables in App Engine:

1. Edit your app.yaml file
   The app.yaml file is where you define environment-specific settings for your App Engine application.

   In your app.yaml, you can add the env_variables block:

   yaml
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   env_variables:
     MY_VARIABLE: "value"
   

2. Deploy your app
   After updating the app.yaml file, deploy your application using the following command:

   bash
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   gcloud app deploy
   

   Now, your app can access the environment variable using the same method as described for Compute Engine.

3. Using Environment Variables in Google Cloud Functions

Google Cloud Functions allow you to set environment variables when you deploy the function. These variables can be accessed at runtime.

Steps to set environment variables in Cloud Functions:

1. Deploy with Environment Variables
   You can specify environment variables when deploying a Cloud Function using the --set-env-vars flag:

   bash
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   gcloud functions deploy YOUR_FUNCTION_NAME 
     --runtime NODE_JS_14 
     --trigger-http 
     --set-env-vars MY_VARIABLE="value"
   

2. Accessing the Environment Variables
   In your Cloud Function code, you can access these variables like this:

   • In Node.js:

     javascript
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     const myVariable = process.env.MY_VARIABLE;
     

   • In Python:

     python
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     import os
     my_variable = os.getenv('MY_VARIABLE')
     

4. Setting Environment Variables in Google Cloud Storage

If you’re storing sensitive information like API keys in Google Cloud Storage, ensure that these keys are set as environment variables rather than hardcoding them.

To retrieve secrets from Cloud Storage and use them as environment variables:

1. Store Secrets in Cloud Storage or Secret Manager

2. Access them in your VM or function

3. Set environment variables programmatically

5. Accessing Environment Variables in Google Kubernetes Engine (GKE)

In Google Kubernetes Engine, environment variables are defined in the deployment.yaml file within the spec.containers.env section.

Example of setting environment variables in a GKE deployment:

yaml
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apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-app
spec:
  replicas: 1
  template:
    spec:
      containers:
      - name: my-container
        image: my-image
        env:
        - name: MY_VARIABLE
          value: "value"

Once your GKE pod is running, your application can access these variables in the same way.

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Tips for Using Environment Variables in Google Cloud

• Use Google Cloud Secret Manager: For sensitive information like API keys or passwords, use Google Cloud Secret Manager to store them securely and access them at runtime.

• Consistent Naming Conventions: Keep your environment variables consistent and meaningful. For example, DB_HOST, API_KEY, SECRET_KEY.

• Automate Configuration: Use deployment scripts or infrastructure-as-code tools like Terraform to automate setting environment variables in your Google Cloud resources.

Frequently Asked Questions (FAQs)

1. How do I securely store sensitive data in Google Cloud?
Use Google Cloud’s Secret Manager to store sensitive information such as API keys, passwords, and tokens. You can then access them as environment variables in your application.

2. Can I change environment variables after deployment?
Yes, you can change environment variables after deployment by updating the configuration files (like app.yaml for App Engine or the deployment file for Kubernetes) and redeploying the application.

3. Are environment variables in Google Cloud persistent across VM instances?
No, environment variables in Compute Engine are not persistent unless they are stored in a configuration file like .bashrc or passed through metadata at instance creation.

4. How do I debug environment variable issues in Google Cloud?
You can use gcloud commands to check if the environment variables are set correctly on your VM or app and use logs for troubleshooting. For example, gcloud app logs read for App Engine.

5. Can environment variables be used in Google Cloud Functions?
Yes, you can use environment variables in Google Cloud Functions by specifying them during deployment using the --set-env-vars flag.

For more detailed information, you can refer to the Google Cloud documentation.