# Update $LATEST version of function

aws lambda update-function-code --function-name myfunction ….

# Publish new version of function

aws lambda publish-version --function-name myfunction

# Point alias to new version, weighted at 5% (original version at 95% of traffic)

aws lambda update-alias --function-name myfunction --name myalias --routing-config '{"AdditionalVersionWeights" : {"2" : 0.05} }'

# Verify that the new version is healthy

…

# Set the primary version on the alias to the new version and reset the additional versions (100% weighted)

aws lambda update-alias --function-name myfunction --name myalias --function-version 2 --routing-config '{}'