This patch improves the watches for services on large cluster:
each service has now its own index, such watches on a specific service
are not modified by changes in the global catalog.
It should improve a lot the performance of tools such as consul-template
or libraries performing watches on very large clusters with many
services/watches.
- register endpoints with supported methods
- support OPTIONS requests, indicating supported methods
- extract method validation (error 405) from individual endpoints
- on 405 where multiple methods are allowed, create a single Allow
header with comma-separated values, not multiple Allow headers.
Because this code was doing pointer equality checks, it would work for
the case of a failed attempted RPC because the objects are from the
manager itself:
https://github.com/hashicorp/consul/blob/v1.0.3/agent/consul/rpc.go#L283-L302
But the pointer check would always fail for events coming in from the
Serf path because the server object is newly-created:
https://github.com/hashicorp/consul/blob/v1.0.3/agent/router/serf_adapter.go#L14-L40
This means that we didn't proactively shift RPC traffic away from a
failed server, we'd have to wait for an RPC to fail, which exposes
the error to the calling client.
By switching over to a name check vs. a pointer check we get the correct
behavior. We added a DEBUG log as well to help observe this behavior during
integrated testing.
Related to #3863 since the fix here needed the same logic duplicated, owing
to the complicated atomic stuff.
/cc @dadgar for a heads up in case this also affects Nomad.
Previously a change was made to make the file writing atomic,
but that wasn't enough to cover something like an OS crash so we
needed something here to handle the situation more gracefully.
Fixes#1221.
Docker/Openshift/Kubernetes mount the config file as a symbolic link and
IsDir returns true if the file is a symlink. Before calling IsDir, the
symlink should be resolved to determine if it points at a file or
directory.
Fixes#3753
