appengine-standard

blockchain-spanner

The concept of blockchain is simple: a scalable and globally consistent database that maintains a growing list of ordered records.

Using App Engine and Spanner it is possible to build a basic blockchain in 200 lines of code.

Pull requests are welcome.

Howto

Create a spanner instance :

gcloud beta spanner instances create  test-instance  --config=regional-us-central1 --description="My Instance" --nodes=1

Check that the instance is created :

gcloud beta spanner instances list

Deploy the appengine code :

goapp deploy -application <AppID> -version <version>

Create the database :

curl https://AppID.appspot.com/create

Check that the database is created :

gcloud beta spanner databases list --instance=test-instance

Check that the first block is created :

gcloud beta spanner databases execute-sql example-db --instance=test-instance --sql='SELECT * FROM Blocks'

Add block to the chain :

curl https://AppId.appspot.com/write?message=<yourNewBlockMessage>

Check that the block has been added

gcloud beta spanner databases execute-sql example-db --instance=test-instance --sql='SELECT * FROM Blocks'

Delete spanner instance !!!!!

gcloud beta spanner instances delete test-instance