With this change, the default dialer checks environment variables to see if proxy is needed. If so, it dials to the proxy and does an HTTP CONNECT handshake.
This modifies the WithBlock behavior somewhat to block until there is at least
one valid connection. Previously, each connection would be made serially until
all had completed successfully, with any errors returned to the caller. Errors
are now only returned due to connecting to a backend if a balancer is not used,
or if there is an error starting the balancer itself.
Fixes#976
The :authority pseudo-header for a gRPC Client defaults to the host
portion of the dialed target and can only be overwritten by providing a
TransportCredentials. However, there are cases where setting this header
independent of any tranport security is valid. In my particular case,
in order to leverage Envoy for request routing, the cluster/service name
must be provided in the :authority header. This may also be useful in a
testing context.
This patch adds a DialOption to overwrite the authority header,
even if TransportCredentials are provided (I'd imagine you'd only ever
need to specify one or the other).
* Add the initial service config support
* start scWatcher later
* remove timeoutCh
* address the comments
* deal with dial timeout
* defer cancel for the newly created context for correct lifetime management
* fix the defer order
* added other 2 missing cancels
Prior to this change, it was possible for `DialContext` to return
`(nil, err)` without properly closing the `ClientConn`, resulting in an
unavoidable leak of the `resetAddrConn` goroutine.
Previously, cancellation of the context would cause these transient
errors to be swallowed since the function would return before the
log line was reached.
