Documentation about using environment variables with Fission functions

[sanketsudake]

Users often get confused if they can use environment variables with Fission functions.
Based on yes/no we should document it accordingly and provide samples/details.

[Stradivario]

I have found out some details about setting up environment variables https://docs.fission.io/docs/usage/function/access-secret-cfgmap-in-function/

I am curious about the part where i need to use file system fs in order to get value from the secrets or config and how does this will reduce the fast bootstrap of the function ? Since every read or write operation cost something and for such a small process to load data using fs on every request sounds a bit slow.

Can someone help me to understand if i am correct or wrong ?

[sanketsudake]

Hi @Stradivario You will have to do to lazyloading for secrets/configmaps values unless you have a requirement of it reading every time.

You will have to read values as per your secret or configmap reference. As mentioned here,
https://docs.fission.io/docs/usage/function/access-secret-cfgmap-in-function/

If you are looking for adding env variables directly currently editing podSpec is one of the way. Though it requires familiarity with Kubernetes and CRDs.
It would go in here.
https://doc.crds.dev/github.com/fission/fission/fission.io/Environment/[email protected]#spec-runtime-podspec-containers-env

We are certainly looking for a native way to inject env variables apart from secret/configmap reference.

[Stradivario]

@sanketsudake thank you for the brief explanation it helps me a lot to understand the actual fission system.

With this approach editing the podSpec sounds cool but it breaks the usage of the platform as Multi Tenant.

What i mean is that if we want every lambda to be configurable per project based we will be in the situation where we have the same environment variables present inside every lambda on every project leading to mixed configurations. So to mitigate this the approach with secrets and configs is more understandable reading them from the file system since that way we can specify different environments per lambda based.

Cheers !