Commit Graph

8 Commits

Author SHA1 Message Date
freddygv 3966677aaf Finish removing useInDatacenter 2021-10-26 23:36:01 -06:00
freddygv feaebde1f1 Remove useInDatacenter from disco chain requests
useInDatacenter was used to determine whether the mesh gateway mode of
the upstream should be returned in the discovery chain target. This
commit makes it so that the mesh gateway mode is returned every time,
and it is up to the caller to decide whether mesh gateways should be
watched or used.
2021-10-26 23:35:21 -06:00
Dhia Ayachi 96d7842118
partition dicovery chains (#10983)
* partition dicovery chains

* fix default partition for OSS
2021-09-07 16:29:32 -04:00
R.B. Boyer 0675e0606e
connect: generate the full SNI names for discovery targets in the compiler rather than in the xds package (#6340) 2019-08-19 13:03:03 -05:00
R.B. Boyer 64fc002e03
connect: fix failover through a mesh gateway to a remote datacenter (#6259)
Failover is pushed entirely down to the data plane by creating envoy
clusters and putting each successive destination in a different load
assignment priority band. For example this shows that normally requests
go to 1.2.3.4:8080 but when that fails they go to 6.7.8.9:8080:

- name: foo
  load_assignment:
    cluster_name: foo
    policy:
      overprovisioning_factor: 100000
    endpoints:
    - priority: 0
      lb_endpoints:
      - endpoint:
          address:
            socket_address:
              address: 1.2.3.4
              port_value: 8080
    - priority: 1
      lb_endpoints:
      - endpoint:
          address:
            socket_address:
              address: 6.7.8.9
              port_value: 8080

Mesh gateways route requests based solely on the SNI header tacked onto
the TLS layer. Envoy currently only lets you configure the outbound SNI
header at the cluster layer.

If you try to failover through a mesh gateway you ideally would
configure the SNI value per endpoint, but that's not possible in envoy
today.

This PR introduces a simpler way around the problem for now:

1. We identify any target of failover that will use mesh gateway mode local or
   remote and then further isolate any resolver node in the compiled discovery
   chain that has a failover destination set to one of those targets.

2. For each of these resolvers we will perform a small measurement of
   comparative healths of the endpoints that come back from the health API for the
   set of primary target and serial failover targets. We walk the list of targets
   in order and if any endpoint is healthy we return that target, otherwise we
   move on to the next target.

3. The CDS and EDS endpoints both perform the measurements in (2) for the
   affected resolver nodes.

4. For CDS this measurement selects which TLS SNI field to use for the cluster
   (note the cluster is always going to be named for the primary target)

5. For EDS this measurement selects which set of endpoints will populate the
   cluster. Priority tiered failover is ignored.

One of the big downsides to this approach to failover is that the failover
detection and correction is going to be controlled by consul rather than
deferring that entirely to the data plane as with the prior version. This also
means that we are bound to only failover using official health signals and
cannot make use of data plane signals like outlier detection to affect
failover.

In this specific scenario the lack of data plane signals is ok because the
effectiveness is already muted by the fact that the ultimate destination
endpoints will have their data plane signals scrambled when they pass through
the mesh gateway wrapper anyway so we're not losing much.

Another related fix is that we now use the endpoint health from the
underlying service, not the health of the gateway (regardless of
failover mode).
2019-08-05 13:30:35 -05:00
R.B. Boyer 782c647bf4
connect: simplify the compiled discovery chain data structures (#6242)
This should make them better for sending over RPC or the API.

Instead of a chain implemented explicitly like a linked list (nodes
holding pointers to other nodes) instead switch to a flat map of named
nodes with nodes linking other other nodes by name. The shipped
structure is just a map and a string to indicate which key to start
from.

Other changes:

* inline the compiler option InferDefaults as true

* introduce compiled target config to avoid needing to send back
  additional maps of Resolvers; future target-specific compiled state
  can go here

* move compiled MeshGateway out of the Resolver and into the
  TargetConfig where it makes more sense.
2019-08-01 22:44:05 -05:00
R.B. Boyer 4666599e18
connect: reconcile how upstream configuration works with discovery chains (#6225)
* connect: reconcile how upstream configuration works with discovery chains

The following upstream config fields for connect sidecars sanely
integrate into discovery chain resolution:

- Destination Namespace/Datacenter: Compilation occurs locally but using
different default values for namespaces and datacenters. The xDS
clusters that are created are named as they normally would be.

- Mesh Gateway Mode (single upstream): If set this value overrides any
value computed for any resolver for the entire discovery chain. The xDS
clusters that are created may be named differently (see below).

- Mesh Gateway Mode (whole sidecar): If set this value overrides any
value computed for any resolver for the entire discovery chain. If this
is specifically overridden for a single upstream this value is ignored
in that case. The xDS clusters that are created may be named differently
(see below).

- Protocol (in opaque config): If set this value overrides the value
computed when evaluating the entire discovery chain. If the normal chain
would be TCP or if this override is set to TCP then the result is that
we explicitly disable L7 Routing and Splitting. The xDS clusters that
are created may be named differently (see below).

- Connect Timeout (in opaque config): If set this value overrides the
value for any resolver in the entire discovery chain. The xDS clusters
that are created may be named differently (see below).

If any of the above overrides affect the actual result of compiling the
discovery chain (i.e. "tcp" becomes "grpc" instead of being a no-op
override to "tcp") then the relevant parameters are hashed and provided
to the xDS layer as a prefix for use in naming the Clusters. This is to
ensure that if one Upstream discovery chain has no overrides and
tangentially needs a cluster named "api.default.XXX", and another
Upstream does have overrides for "api.default.XXX" that they won't
cross-pollinate against the operator's wishes.

Fixes #6159
2019-08-01 22:03:34 -05:00
R.B. Boyer 1cc6d07d0f
add test for discovery chain agent cache-type (#6130) 2019-07-15 10:09:52 -05:00