How to set environment variables in AWS lambda using Python

aws lambda environment variables python
lambda access environment variables node js
lambda environment variables cloudformation
serverless lambda environment variables
lambda set environment variables programmatically
aws lambda environment variables java
aws environment variables
terraform lambda environment variables

I'm trying to set environment variables in AWS lambda using python

initially I have an environment variable stackname with no value in lambda configuration.

def lambda_handler(event, context):
    if os.environ["stackname"]:
        print("Not empty")
        print(os.environ["stackname"])
    else:
        print("its empty")
        os.environ["stackname"]="mystack"
        print(os.environ["stackname"])

Now I'm seeing weird intermittent behaviour here for the first I expect to print

its empty
mystack

and from thereon whenever I execute lambda it should print

Not empty
mystack

for initial couple of times it prints

Not empty
mystack

but after couple or more executions lambda prints below which is weird.

  its empty
    mystack

Please suggest if this is any other better way to set environment variables which gives consistent output.

AWS Lambda functions run inside of an Amazon Linux environment. Sequential invocations of the same Lambda function may result in the function running on the same environment or a different environment. By environment I mean computer, container, etc.

This means that you cannot reliably set environment variables and expect them to be there on the next invocation.

A better approach is to store your run-time variables in persistent storage such as DynamoDB.

New for AWS Lambda – Environment Variables and Serverless , After changing environment variables in the $LATEST version, you can publish your updated Lambda function using the Lambda console or  To access the Environment Variables on your Python Lambda Code we need to import the os module. import os. Then on our lambda code we use os.environ to access the value of the Environment Variable. os.environ['KeyName'] The above will return the Value of the stated Environment Variable KeyName. Below is the code I used to retrieve the environment variables.

you can do it as you do in system using os

 import os
 os.environ['varible']='value'

Configure Lambda Environment Variables, How do I use an environment variable in AWS Lambda Python? Lambda encrypts environment variables with a key that it creates in your account (an AWS managed customer master key (CMK)). Use of this key is free. You can also choose to provide your own key for Lambda to use instead of the default key.

Why not just use the environment variable support provided by lambda? You can config the env vars when you create or update your function, and then reference those vars in your function code. Regarding why it prints out 'its empty', @John Hanley's answer is pretty accurate.

Using AWS Lambda Environment Variables, How do you write an AWS lambda function in Python? If you recall from earlier in the article, Lambda allows us to set environment variables when configuring the function. In this section, we’ll set up an environment variable to indicate what release environment our function is executing in, for example, DEV , STAGE , or PROD .

AWS Lambda Console: Accessing Environment Variables via Python, from scratch, so select the Author from scratch option. For a list of environment variables that are set by the Lambda runtime, see Runtime Environment Variables. Javascript is disabled or is unavailable in your browser.

How to Set and Get Environment Variables in Python, You can now set environment variables for your Lambda functions, making it easy for you to configure your code for development, test, and  You can run Python code in AWS Lambda. Lambda provides runtimes for Python that execute your code to process events. Your code runs in an environment that includes the SDK for Python (Boto 3), with credentials from an AWS Identity and Access Management (IAM) role that you manage.

How to Write Your First AWS Lambda Function, AWS Lambda functions run inside of an Amazon Linux environment. Sequential invocations of the same Lambda function may result in the  Unrelated: rather than use environment variables for credentials, you should use IAM roles for AWS credentials and use Parameter Store for other, non-AWS, credentials. IAM roles only covers the access keys for S3, not the HTTP auth creds to a third party service. @jordanm good point.

Comments
  • Do you know the difference between stateful and stateless?
  • Right, @JohnHanley. You can use environment variables (or any other persistent storage) to cache "expensive" information, that the first run in a container can get and the remaining runs in that container can use. But you can't expect the information to be there for any subsequent run of your function, which could be in a different container or even on a different EC2 instance.