Release 1.13.0

API Changes

• channelz: move APIs to internal except channelz service (#2157)
• grpclb: split grpclb out of top level grpc package (#2107)

New Features

• credentials/alts: Add AuthInfoFromContext utility API (#2062)
• status: Introduce FromContextError convenience function (#2057)

Bug Fixes

• internal/grpcrand: new package for concurrency-safe randoms (#2106)
• codes: fix: marshal/unmarshal a Code to JSON fails (#2116)
  • Special Thanks: @fho
• transport: fix race between new stream and window updates (#2144)
• status: handle invalid utf-8 characters (#2109) (#2134)
• grpclb: don't log grpclb server ending connection as error (#2162)
  • Special Thanks: @krzysztofdrys
• alts: copy more credentials fields in Clone() (#2119)
• transport: notify controlbuf that transport is gracefully closing to ensure proper cleanup (#2158)
• transport: avoid extra work for keepalive when it's disabled. (#2148)
• transport: account for user configured small io write buffer. (#2092)
• grpc: do not percent encode character tilde (#2139)
• grpclb: backoff for RPC call if init handshake was unsucessful (#2077)
• transport: reduce error logs (#2117)
• resolver: throw an error for non-default DNS authority. (#2067)
  • Special Thanks: @jsha
• transport/server: fix race between writing status and header (#2074)

Documentation

• documentation: add stream lifecycle doc to NewStream (#2060)
• clarify CloseSend vs CloseAndRecv; better formatting (#2071)
• documentation: Add initial documentation on concurrency (#2034)
  • Special Thanks: @enocom
• Clarify newCCResolverWrapper documentation. (#2100)
  • Special Thanks: @gnoack
• documentation: create doc describing grpc-go's log levels and their usages (#2033)