Conduit Connector S3

General

The S3 connector is one of Conduit builtin plugins. It provides both, a source and a destination S3 connectors.

How to build it

Run make.

Testing

Run make test to run all the tests. You must set the environment variables (AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_REGION) before you run all the tests. If not set, the tests that use these variables will be ignored.

S3 Source

The S3 Source Connector connects to a S3 bucket with the provided configurations, using aws.bucket, aws.accessKeyId,aws.secretAccessKey and aws.region. Then will call Configure to parse the configurations and make sure the bucket exists, If the bucket doesn't exist, or the permissions fail, then an error will occur. After that, the Open method is called to start the connection from the provided position.

Change Data Capture (CDC)

This connector implements CDC features for S3 by scanning the bucket for changes every pollingPeriod and detecting any change that happened after a certain timestamp. These changes (update, delete, create) are then inserted into a buffer that is checked on each Read request.

• To capture "delete" and "update", the S3 bucket versioning must be enabled.
• To capture "create" actions, the bucket versioning doesn't matter.

Position Handling

The connector goes through two modes.

• Snapshot mode: which loops through the S3 bucket and returns the objects that are already in there. The Position during this mode is the object key attached to an underscore, an "s" for snapshot, and the maxLastModifiedDate found so far. As an example: "thisIsAKey_s12345", which makes the connector know at what mode it is and what object it last read. The maxLastModifiedDate will be used when changing to CDC mode, the iterator will capture changes that happened after that.

• CDC mode: this mode iterates through the S3 bucket every pollingPeriod and captures new actions made on the bucket. the Position during this mode is the object key attached to an underscore, a "c" for CDC, and the object's lastModifiedDate in seconds. As an example: "thisIsAKey_c1634049397". This position is used to return only the actions with a lastModifiedDate higher than the last record returned, which will ensure that no duplications are in place.

Record Keys

The S3 object key uniquely identifies the objects in an Amazon S3 bucket, which is why a record key is the key read from the S3 bucket.

Configuration

The config passed to Configure can contain the following fields.

name	description	required	example
aws.accessKeyId	AWS access key id	yes	"THE_ACCESS_KEY_ID"
aws.secretAccessKey	AWS secret access key	yes	"SECRET_ACCESS_KEY"
aws.region	the AWS S3 bucket region	yes	"us-east-1"
aws.bucket	the AWS S3 bucket name	yes	"bucket_name"
pollingPeriod	polling period for the CDC mode, formatted as a time.Duration string. default is "1s"	no	"2s", "500ms"
prefix	the key prefix for S3 source	no	"conduit-"

Known Limitations

• If a pipeline restarts during the snapshot, then the connector will start scanning the objects from the beginning of the bucket, which could result in duplications.

S3 Destination

The S3 Destination Connector connects to an S3 bucket with the provided configurations, using aws.bucket, aws.accessKeyId,aws.secretAccessKey and aws.region. Then will call Configure to parse the configurations, If parsing was not successful, then an error will occur. After that, the Open method is called to start the connection. If the permissions fail, the connector will not be ready for writing to S3.

Writer

The S3 destination writer has a buffer with the size of bufferSize, for each time Write is called, a new record is added to the buffer. When the buffer is full, all the records from it will be written to the S3 bucket, and an ack function will be called for each record after being written.

Configuration

The config passed to Configure can contain the following fields.

name	description	required	example
aws.accessKeyId	AWS access key id	yes	"THE_ACCESS_KEY_ID"
aws.secretAccessKey	AWS secret access key	yes	"SECRET_ACCESS_KEY"
aws.region	the AWS S3 bucket region	yes	"us-east-1"
aws.bucket	the AWS S3 bucket name	yes	"bucket_name"
format	the destination format, either "json" or "parquet"	yes	"json"
bufferSize	the buffer size {when full, the files will be written to destination}, default is "1000", max is "100000"	no	"100"
prefix	the key prefix for S3 destination	no	"conduit-"