Google Cloud Functions Environment Variables Test

Test Google Cloud Function that uses environment variables (recently added functionality on Google Cloud).

Also be sure to check out the Google documentation for this.

I also wrote a Medium article about this.

Setup

Ensure that you have Google's gcloud commands installed and updated to the latest, including the beta commands. Also ensure that you have a Google Cloud project set up with Cloud Functions enabled.

In Terminal, clone this repo and cd to the folder containing it.

In index.js, we have a function helloEnvVars. This expects to be able to access three environment variables named:

SUCH_SECRET
MANY_ENCRYPTS
SO_FINALLY_CAUGHT_UP_WITH_AWS

and will display their names and values in a HTML table. As you can see, the value for each environment variable is retrieved in the same was as any other Node.js code:

process.env.VAR_NAME

Deployment

This is a HTTP function so deploy as follows:

gcloud functions deploy helloEnvVars --trigger-http --project <Your Google Cloud Project ID>

Then test by pointing the browser at the URL that gcloud output at the end of the deployment, which looks something like this:

https://<region>-<projectId>.cloudfunctions.net/helloEnvVars

Note that all three environment variables show UNKNOWN for their value.

Setting Environment Variables

Google provides two ways to supply values for the environment variables.

Individually from the Command Line

Supply name/value pairs when deploying the function e.g. (note we have to use beta for this):

gcloud beta functions deploy helloEnvVars --trigger-http --set-env-vars SUCH_SECRET=hello --project <Your Google Cloud Project ID>

Multiple from the Command Line

Multiple values can be provided together, note also have to be careful about quoting and escaping values:

gcloud beta functions deploy helloEnvVars --trigger-http --set-env-vars SUCH_SECRET="Ssssh it's a secret",MANY_ENCRYPTS="rTgHi0444452\!",SO_FINALLY_CAUGHT_UP_WITH_AWS="Oh yes" --project <Your Google Cloud Project ID>

From a YAML File

Environment variables can also be set via a YAML file (which will overwrite all existing variable values and unset any that aren't listed in the file).

Example env.yaml:

SUCH_SECRET: Ssssh it's a secret
MANY_ENCRYPTS: rTgHi0444452!
SO_FINALLY_CAUGHT_UP_WITH_AWS: Oh yes

Deploy as follows (note we have to use beta for this):

gcloud beta functions deploy helloEnvVars --trigger-http --env-vars-file env.yaml --project <Your Google Cloud Project ID>

Then refresh the browser to see the new values.

Updating Environment Variables

To change the value of a deployed environment variable use --update-env-vars, which works like --set-env-vars:

gcloud beta functions deploy helloEnvVars --trigger-http --update-env-vars SUCH_SECRET="Updated",MANY_ENCRYPTS="Also updated",SO_FINALLY_CAUGHT_UP_WITH_AWS="Updated too" --project <Your Google Cloud Project ID>

(You can also use --set-env-vars to overwrite the values of existing environment variables and --update-env-vars to add set values for new environment values, so theese seem pretty interchangeable ¯\_(ツ)_/¯).

Deleting Environment Variables

Environment variables are deleted as follows:

Selective Delete

(Again note we have to use beta for this):

gcloud beta functions deploy helloEnvVars --trigger-http --remove-env-vars SUCH_SECRET,MANY_ENCRYPTS --project <Your Google Cloud Project ID>

Remove All

(Again note we have to use beta for this):

gcloud beta functions deploy helloEnvVars --trigger-http --clear-env-vars --project <Your Google Cloud Project ID>

Notes

Environment variables are scoped by function, so are not shared between functions - you need to add separate environment variables for each function even if they are deployed together and/or exist in the same source code file
The maximum allowable size for environment variables is 32kb per function
You should probably add any YAML files that you use to store environment variable values in to your project's .gitignore file as you likely don't want these adding to source control!
A deployment failure will not update any environment variables, only a completely successful deployment updates environment variables
Once environment variables are set, deploying the function again without specifying any environment variable options will leave the current settings intact. e.g. this does not change the values of any environment variables, nor unset any that previously existed: gcloud functions deploy helloEnvVars --trigger-http --project <Your Google Cloud Project ID>
The current values of all environment variables will be displayed in the output of gcloud every time you deploy a function

Gotchas

Escaping Values on Command Line

Don't forget to quote and escape values when using --set-env-vars or --update-env-vars:

gcloud beta functions deploy helloEnvVars --trigger-http --set-env-vars SUCH_SECRET="Ssssh it's a secret",MANY_ENCRYPTS="rTgHi0444452\!",SO_FINALLY_CAUGHT_UP_WITH_AWS="Oh yes" --project <Your Google Cloud Project ID>

Boolean and Int Types with YAML

When deploying environment variables in a YAML file, be careful of values that can be coerced to boolean or int types by the YAML parser e.g.:

SO_FINALLY_CAUGHT_UP_WITH_AWS: true

These cause deployment errors:

ERROR: gcloud crashed (ValidationError): Expected type <type 'unicode'> for field value, found True (type <type 'bool'>)

Workaround is to make the value a string:

SO_FINALLY_CAUGHT_UP_WITH_AWS: "true"

The same applies for numeric values, for example:

MANY_ENCRYPTS: 12

will error on deploy, but:

MANY_ENCRYPTS: "12"

will not.

simonprickett / google-cloud-functions-environment-variables