I would like to discuss the current implementation of the SQL Gateway support in SQL Cli Client and how it can be improved.
1) *hosname:port/v1 vs https://hostname:port/flink-clusters/session-cluster-1/v1 * Currently, the *--endpoint* parameter needs to be specified in the *InetSocketAddress* format, i.e. *hostname:port.* While this works fine for basic use cases, it does not support the placement of the gateway behind a proxy or using an Ingress for routing to a specific Flink cluster based on the URL path. I.e. it expects *some.hostname.com:9001 <http://some.hostname.com:9001>* to directly serve requests on *some.hostname.com:9001/v1 <http://some.hostname.com:9001/v1>* . Mapping to a non-root location, i.e. *some.hostname.com:9001/flink-clusters/sql-preview-cluster-1/v1 <http://some.hostname.com:9001/flink-clusters/sql-preview-cluster-1/v1>* is not supported. Since the client talks to the gateway via its REST endpoint, I believe that the right format for the *--endpoint* parameter is *URL*, not *InetSocketAddress* . 2) *HTTPS support* Another related issue is that internally SQL Client uses Flink’s *RestClient* [1]. This client decides whether to enable SSL not on the basis of the URL schema (https://...), but based on Flink configuration, namely a global *security.ssl.rest.enabled* parameter [2] (which is also used for the REST server-side configuration ). When this parameter is set to true, it automatically requires user-supplied *security.ssl.rest.truststore* and *security.ssl.rest.keystore* to be configured - there is no default option to use certificates from JDK. I was wondering if there is any real benefit in handling the low-level Netty channels and certificates manually for the use case of connecting between SQL Cli Client and SQL Gateway REST API. There is already a dependency on *OkHttpClient* in *flink-metrics*. I would like to hear what you think about switching to *OkHttp* and adding the ability to optionally load custom certificates there rather than patching *RestClient*. [1] https://github.com/apache/flink/blob/5dddc0dba2be20806e67769314eecadf56b87a53/flink-table/flink-sql-client/src/main/java/org/apache/flink/table/client/gateway/ExecutorImpl.java#L359 [2] https://github.com/apache/flink/blob/5d9e63a16f079399c6b51547284bb96db0326bdb/flink-runtime/src/main/java/org/apache/flink/runtime/rest/RestClientConfiguration.java#L103 Best, Alex Fedulov
