[docker/actions] unset GOOGLE_CREDENTIALS (#4972)

CHANGELOG.md

@@ -9,6 +9,9 @@ CHANGELOG
 - Go SDK: Input type interfaces should declare pointer type impls where appropriate
   [#4911](https://github.com/pulumi/pulumi/pull/4911)
 
+- Fixes issue where base64-encoded GOOGLE_CREDENTIALS causes problems with other commands
+  [#4972](https://github.com/pulumi/pulumi/pull/4972)
+
 ## 2.5.0 (2020-06-25)
 
 - Go program gen: prompt array conversion, unused range vars, id handling

dist/actions/entrypoint.sh

@@ -82,6 +82,8 @@ if [ ! -z "$GOOGLE_CREDENTIALS" ]; then
     # Check if GOOGLE_CREDENTIALS is base64 encoded 
     if [[ $GOOGLE_CREDENTIALS =~ ^([A-Za-z0-9+/]{4})*([A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{2}==)?$ ]]; then
         echo "$GOOGLE_CREDENTIALS"|base64 -d > $GOOGLE_APPLICATION_CREDENTIALS
+        # unset for other gcloud commands using this variable.
+        unset GOOGLE_CREDENTIALS
     else
         echo "$GOOGLE_CREDENTIALS" > $GOOGLE_APPLICATION_CREDENTIALS
     fi