confluent-kafka-go v1.1.0

• OAUTHBEARER SASL authentication (KIP-255) by Ron Dagostini (@rondagostino) at StateStreet.
• Offset commit metadata (@damour, #353)
• Requires librdkafka v1.1.0 or later

Noteworthy librdkafka v1.1.0 changes

Full librdkafka v1.1.0 release notes.

• SASL OAUTHBEARER support (by @rondagostino at StateStreet)
• In-memory SSL certificates (PEM, DER, PKCS#12) support (by @noahdav at Microsoft)
• Pluggable broker SSL certificate verification callback (by @noahdav at Microsoft)
• Use Windows Root/CA SSL Certificate Store (by @noahdav at Microsoft)
• ssl.endpoint.identification.algorithm=https (off by default) to validate the broker hostname matches the certificate. Requires OpenSSL >= 1.0.2.
• Improved GSSAPI/Kerberos ticket refresh

Upgrade considerations

• Windows SSL users will no longer need to specify a CA certificate file/directory (ssl.ca.location), librdkafka will load the CA certs by default from the Windows Root Certificate Store.
• SSL peer (broker) certificate verification is now enabled by default (disable with enable.ssl.certificate.verification=false)
• %{broker.name} is no longer supported in sasl.kerberos.kinit.cmd since kinit refresh is no longer executed per broker, but per client instance.

SSL

New configuration properties:

• ssl.key.pem - client's private key as a string in PEM format
• ssl.certificate.pem - client's public key as a string in PEM format
• enable.ssl.certificate.verification - enable(default)/disable OpenSSL's builtin broker certificate verification.
• enable.ssl.endpoint.identification.algorithm - to verify the broker's hostname with its certificate (disabled by default).
• The private key data is now securely cleared from memory after last use.

Enhancements

• Bump message.timeout.ms max value from 15 minutes to 24 days (@sarkanyi)

Fixes

• SASL GSSAPI/Kerberos: Don't run kinit refresh for each broker, just per client instance.
• SASL GSSAPI/Kerberos: Changed sasl.kerberos.kinit.cmd to first attempt ticket refresh, then acquire.
• SASL: Proper locking on broker name acquisition.
• Consumer: max.poll.interval.ms now correctly handles blocking poll calls, allowing a longer poll timeout than the max poll interval.