This PR implements Nomad built-in support for running Consul Connect
terminating gateways. Such a gateway can be used by services running
inside the service mesh to access "legacy" services running outside
the service mesh while still making use of Consul's service identity
based networking and ACL policies.
https://www.consul.io/docs/connect/gateways/terminating-gateway
These gateways are declared as part of a task group level service
definition within the connect stanza.
service {
connect {
gateway {
proxy {
// envoy proxy configuration
}
terminating {
// terminating-gateway configuration entry
}
}
}
}
Currently Envoy is the only supported gateway implementation in
Consul. The gateay task can be customized by configuring the
connect.sidecar_task block.
When the gateway.terminating field is set, Nomad will write/update
the Configuration Entry into Consul on job submission. Because CEs
are global in scope and there may be more than one Nomad cluster
communicating with Consul, there is an assumption that any terminating
gateway defined in Nomad for a particular service will be the same
among Nomad clusters.
Gateways require Consul 1.8.0+, checked by a node constraint.
Closes#9445
Submitting a job with an ingress gateway in host networking mode
with an absent gateway.proxy block would cause the Nomad client
to panic on NPE.
The consul registration bits would assume the proxy stanza was
not nil, but it could be if the user does not supply any manually
configured envoy proxy settings.
Check the proxy field is not nil before using it.
Fixes#9669
Before, upstreams could only be defined using the default datacenter.
Now, the `datacenter` field can be set in a connect upstream definition,
informing consul of the desire for an instance of the upstream service
in the specified datacenter. The field is optional and continues to
default to the local datacenter.
Closes#8964
This PR adds initial support for running Consul Connect Ingress Gateways (CIGs) in Nomad. These gateways are declared as part of a task group level service definition within the connect stanza.
```hcl
service {
connect {
gateway {
proxy {
// envoy proxy configuration
}
ingress {
// ingress-gateway configuration entry
}
}
}
}
```
A gateway can be run in `bridge` or `host` networking mode, with the caveat that host networking necessitates manually specifying the Envoy admin listener (which cannot be disabled) via the service port value.
Currently Envoy is the only supported gateway implementation in Consul, and Nomad only supports running Envoy as a gateway using the docker driver.
Aims to address #8294 and tangentially #8647
In some refactoring, a bug was introduced where if the connect.proxy
stanza in a submitted job was nil, the default proxy configuration
would not be initialized with default values, effectively breaking
Connect.
connect {
sidecar_service {} # should work
}
In contrast, by setting an empty proxy stanza, the config values would
be inserted correctly.
connect {
sidecar_service {
proxy {} # workaround
}
}
This commit restores the original behavior, where having a proxy
stanza present is not required.
The unit test for this case has also been corrected.
Enable configuration of HTTP and gRPC endpoints which should be exposed by
the Connect sidecar proxy. This changeset is the first "non-magical" pass
that lays the groundwork for enabling Consul service checks for tasks
running in a network namespace because they are Connect-enabled. The changes
here provide for full configuration of the
connect {
sidecar_service {
proxy {
expose {
paths = [{
path = <exposed endpoint>
protocol = <http or grpc>
local_path_port = <local endpoint port>
listener_port = <inbound mesh port>
}, ... ]
}
}
}
stanza. Everything from `expose` and below is new, and partially implements
the precedent set by Consul:
https://www.consul.io/docs/connect/registration/service-registration.html#expose-paths-configuration-reference
Combined with a task-group level network port-mapping in the form:
port "exposeExample" { to = -1 }
it is now possible to "punch a hole" through the network namespace
to a specific HTTP or gRPC path, with the anticipated use case of creating
Consul checks on Connect enabled services.
A future PR may introduce more automagic behavior, where we can do things like
1) auto-fill the 'expose.path.local_path_port' with the default value of the
'service.port' value for task-group level connect-enabled services.
2) automatically generate a port-mapping
3) enable an 'expose.checks' flag which automatically creates exposed endpoints
for every compatible consul service check (http/grpc checks on connect
enabled services).
AndrewChubatiuk