How to automate the generation of the table schema json for aws dynamodb create-table?

Question

Currently if I run aws dynamodb create-table --generate-cli-skeleton, it will generate a template for me to fill in column definitions etc to create a new dynamodb table.

I want to be able to dump the table layout from another dynamodb table and use it as a json input to the create-table command.

However when I use aws dynamodb describe-table to generate a json, it is structurally different from the cli skeleton file.

What is the easier way to create such a json file based on an existing table?

Answer 1

I posted the answer to the same question here:

https://stackoverflow.com/questions/42100210/how-to-export-an-existing-dynamo-table-schema-to-json#answer-67695947

Summary:

AWS_PROFILE=xyz aws dynamodb describe-table --table-name MyTable > mytable_full.json

# Pull out just what is minimally needed for table-creation:
#
#  TableName
#  KeySchema
#  AttributeDefinitions (must only contain attributes used in keys)
#  Global/Local Secondary Indexes
#  Defaults BillingMode to PAY_PER_REQUEST
#   (any provisioning can be set up manually based on load)

jq <mytable_full.json '.Table | {TableName, KeySchema, AttributeDefinitions} + (try {LocalSecondaryIndexes: [ .LocalSecondaryIndexes[] | {IndexName, KeySchema, Projection} ]} // {}) + (try {GlobalSecondaryIndexes: [ .GlobalSecondaryIndexes[] | {IndexName, KeySchema, Projection} ]} // {}) + {BillingMode: "PAY_PER_REQUEST"}' ​>mytable.json

AWS_PROFILE=xyz aws dynamodb create-table --cli-input-json file://mytable.json