aws cli lambda `update-function-configuration` deletes existing environment variables

Question

The documentation on the AWS cil lambda states that

...You provide only the parameters you want to change...

Which I assume means that the rest of the settings would still remain the same. However, say my lambda function has environment variables :

var1=old_val1
var2=old_val2
var3=old_val3

and then when I try doing something like this :

aws lambda update-function-configuration --function-name dummy_fun --environment '{"Variables":{"var1":"new_val1","var2":"new_val2"}}'

with the intention of updating the variables : var1 and var2 with the new values new_val1 and new_val2 respectively, although these 2 variables DO get updated, but the third one, var3, gets deleted !

Am I doing something wrong ? Or is there a way to make sure this doesn't happen?

I can definitely handle it using a workaround wherein I can fetch the current config and then update the env variables locally and then push the entire updated config, all of this through a python code etc. But, is that the only way to do it ? Or can there be a simpler way of doing it?

Michael - sqlbot Michael - sqlbot · Accepted Answer · 2018-09-28T08:02:09

You are misinterpreting the intention of the documentation.

You provide only the parameters you want to change.

--environment is the (singular) "parameter" that you are specifying should be changed -- not the individual variables.

The environment variables are configured en bloc so there is no concept of specifying only certain environment variables that you want to be different.

aws cli lambda `update-function-configuration` deletes existing environment variables

3 Answers