release notes for v0.21.0

[rvan...@google.com]

• blob

  • all: added a ListPage function for listing blobs in pages.
  • all: added bucket.IsAccessible.
  • all: added CreateTime and ETag to blob.Attributes.
  • all: added BeforeSign support to SignedURL.
  • azureblob: added support for local emulators via http.
  • azureblob: added support for setting the storage domain in URL opener.
  • azureblob: added MSI based authentication for Azure buckets, including signing.
  • s3blob: added access to s3manager.Uploader via As in WriterOptions.
  • fileblob: fixed List() when the bucket is rooted at /.
  • fileblob: added an Option to create the base fileblob directory if it does not already exist.
  • fileblob: added support for various As functions.

• runtimevar

  • NEW DRIVER for AWS Secrets Manager!
  • etcdvar: dropped support (hopefully temporarily, until they can fix their dependency issues).
  • httpvar: fixed to respect context when watching values.

• pubsub

  • all: now allowing batch size to decay when there aren't any messages.
  • awssnssqs: exposed the WaitTime parameter to AWS ReceiveMessage via a SubscriberOption.
  • awssnssqs: requesting Attributes be returned in messages (accessible via As).
  • azurepubsub: fixed bugs in error handling from ReceiveOne.

• docstore:

  • mongodocstore: no longer include revision field projection twice.

• secrets

  • localsecrets: now using separate key decoders for URL and Std base64.

• sql

  • awsmysql: add parsing of DSN options from the URL.