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).
In addition to exposing compilation over the API cleaned up the structures that would be exchanged to be cleaner and easier to support and understand.
Also removed ability to configure the envoy OverprovisioningFactor.
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.
* 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
* connect: validate upstreams and prevent duplicates
* Actually run Upstream.Validate() instead of ignoring it as dead code.
* Prevent two upstreams from declaring the same bind address and port.
It wouldn't work anyway.
* Prevent two upstreams from being declared that use the same
type+name+namespace+datacenter. Due to how the Upstream.Identity()
function worked this ended up mostly being enforced in xDS at use-time,
but it should be enforced more clearly at register-time.
Secondary CA initialization steps are:
• Wait until the primary will be capable of signing intermediate certs. We use serf metadata to check the versions of servers in the primary which avoids needing a token like the previous implementation that used RPCs. We require at least one alive server in the primary and the all alive servers meet the version requirement.
• Initialize the secondary CA by getting the primary to sign an intermediate
When a primary dc is configured, if no existing CA is initialized and for whatever reason we cannot initialize a secondary CA the secondary DC will remain without a CA. As soon as it can it will initialize the secondary CA by pulling the primaries roots and getting the primary to sign an intermediate.
This also fixes a segfault that can happen during leadership revocation. There was a spot in the secondaryCARootsWatch that was getting the CA Provider and executing methods on it without nil checking. Under normal circumstances it wont be nil but during leadership revocation it gets nil'ed out. Therefore there is a period of time between closing the stop chan and when the go routine is actually stopped where it could read a nil provider and cause a segfault.
Auto-encrypt meant to fallback to the default port when it wasn't provided, but it hadn't been because of an issue with the error handling. We were checking against an incomplete error value:
"missing port in address" vs "address $HOST: missing port in address"
Additionally, all RPCs to AutoEncrypt.Sign were using a.config.ServerPort, so those were updated to use ports resolved by resolveAddrs, if they are available.
* Allow setting the mesh gateway mode for an upstream in config files
* Add envoy integration test for mesh gateways
This necessitated many supporting changes in most of the other test cases.
Add remote mode mesh gateways integration test
The main change is that we no longer filter service instances by health,
preferring instead to render all results down into EDS endpoints in
envoy and merely label the endpoints as HEALTHY or UNHEALTHY.
When OnlyPassing is set to true we will force consul checks in a
'warning' state to render as UNHEALTHY in envoy.
Fixes#6171
* Display nicely Networks (CIDR) in runtime configuration
CIDR mask is displayed in binary in configuration.
This add support for nicely displaying CIDR in runtime configuration.
Currently, if a configuration contains the following lines:
"http_config": {
"allow_write_http_from": [
"127.0.0.0/8",
"::1/128"
]
}
A call to `/v1/agent/self?pretty` would display
"AllowWriteHTTPFrom": [
{
"IP": "127.0.0.0",
"Mask": "/wAAAA=="
},
{
"IP": "::1",
"Mask": "/////////////////////w=="
}
]
This PR fixes it and it will now display:
"AllowWriteHTTPFrom": [ "127.0.0.0/8", "::1/128" ]
* Added test for cidr nice rendering in `TestSanitize()`.
* Update go-bexpr to v0.1.1
This brings in:
• `in`/`not in` operators to do substring matching
• `matches` / `not matches` operators to perform regex string matching.
* Add the capability to auto-generate the filtering selector ops tables for our docs
This fixes pathological cases where the write throughput and snapshot size are both so large that more than 10k log entries are written in the time it takes to restore the snapshot from disk. In this case followers that restart can never catch up with leader replication again and enter a loop of constantly downloading a full snapshot and restoring it only to find that snapshot is already out of date and the leader has truncated its logs so a new snapshot is sent etc.
In general if you need to adjust this, you are probably abusing Consul for purposes outside its design envelope and should reconsider your usage to reduce data size and/or write volume.
All these changes should have no side-effects or change behavior:
- Use bytes.Buffer's String() instead of a conversion
- Use time.Since and time.Until where fitting
- Drop unnecessary returns and assignment
I can only assume we want to check for the retrieved `updatedToken` to not be
nil, before accessing it below.
`token` can't possibly be nil at this point, as we accessed `token.AccessorID`
just before.
* Ensure the mesh gateway configuration comes back in the api within each upstream
* Add a test for the MeshGatewayConfig in the ToAPI functions
* Ensure we don’t use gateways for dc local connections
* Update the svc kind index for deletions
* Replace the proxycfg.state cache with an interface for testing
Also start implementing proxycfg state testing.
* Update the state tests to verify some gateway watches for upstream-targets of a discovery chain.
Also:
- add back an internal http endpoint to dump a compiled discovery chain for debugging purposes
Before the CompiledDiscoveryChain.IsDefault() method would test:
- is this chain just one resolver step?
- is that resolver step just the default?
But what I forgot to test:
- is that resolver step for the same service that the chain represents?
This last point is important because if you configured just one config
entry:
kind = "service-resolver"
name = "web"
redirect {
service = "other"
}
and requested the chain for "web" you'd get back a **default** resolver
for "other". In the xDS code the IsDefault() method is used to
determine if this chain is "empty". If it is then we use the
pre-discovery-chain logic that just uses data embedded in the Upstream
object (and still lets the escape hatches function).
In the example above that means certain parts of the xDS code were going
to try referencing a cluster named "web..." despite the other parts of
the xDS code maintaining clusters named "other...".
Both 'consul config write' and server bootstrap config entries take a
decoding detour through mapstructure on the way from HCL to an actual
struct. They both may take in snake_case or CamelCase (for consistency)
so need very similar handling.
Unfortunately since they are operating on mirror universes of structs
(api.* vs structs.*) the code cannot be identitical, so try to share the
kind-configuration and duplicate the rest for now.
* Ensure we MapWalk the proxy config in the NodeService and ServiceNode structs
This gets rid of some json encoder errors in the catalog endpoints
* Allow passing explicit bind addresses to envoy
* Move map walking to the ConnectProxyConfig struct
Any place where this struct gets JSON encoded will benefit as opposed to having to implement it everywhere.
* Fail when a non-empty address is provided and not bindable
* camel case
* Update command/connect/envoy/envoy.go
Co-Authored-By: Paul Banks <banks@banksco.de>
* Retry the creation of the test server three times.
* Reduce the retry timeout for the API wait to 2 seconds, opting to fail faster and start over.
* Remove wait for leader from server creation. This wait can be added on a test by test basis now that the function is being exported.
* Remove wait for anti-entropy sync. This is built into the existing WaitForSerfCheck func, so that can be used if the anti-entropy wait is needed
Previously a sequence of events like:
Start
Stop
Start
Stop
would segfault on the second stop because the original ctx and cancel func were only initialized during the constructor and not during Start.
* Make cluster names SNI always
* Update some tests
* Ensure we check for prepared query types
* Use sni for route cluster names
* Proper mesh gateway mode defaulting when the discovery chain is used
* Ignore service splits from PatchSliceOfMaps
* Update some xds golden files for proper test output
* Allow for grpc/http listeners/cluster configs with the disco chain
* Update stats expectation
* connect: allow overriding envoy listener bind_address
* Update agent/xds/config.go
Co-Authored-By: Kyle Havlovitz <kylehav@gmail.com>
* connect: allow overriding envoy listener bind_port
* envoy: support unix sockets for grpc in bootstrap
Add AgentSocket BootstrapTplArgs which if set overrides the AgentAddress
and AgentPort to generate a bootstrap which points Envoy to a unix
socket file instead of an ip:port.
* Add a test for passing the consul addr as a unix socket
* Fix config formatting for envoy bootstrap tests
* Fix listeners test cases for bind addr/port
* Update website/source/docs/connect/proxies/envoy.md
maxIndexWatchTxn was only watching the IndexEntry of the max index of all the entries. It needed to watch all of them regardless of which was the max.
Also plumbed the query source through in the proxy config to help better track requests.
The clusters/endpoints test were still relying on deterministic ordering of clusters/endpoints which cannot be relied upon due to golang purposefully not providing any guarantee about consistent interation ordering of maps.
Also fixed a small bug in the connect proxy cluster generation that was causing the clusters slice to be double the size it needed to with the first half being all nil pointers.
* Fix some tests that I broke when refactoring the ConfigSnapshot
* Make sure the MeshGateway config is added to all the right api structs
* Fix some more tests
The general problem was that a the CA config which contained the trust domain was happening outside of the blocking mechanism so if the client started the blocking query before the primary dcs roots had been set then a state trust domain was being pushed down.
This was fixed here but in the future we should probably fixup the CA initialization code to not initialize the CA config twice when it doesn’t need to.
* Prune Servers from WAN and LAN
* cleaned up and fixed LAN to WAN
* moving things around
* force-leave remove from serfWAN, create pruneSerfWAN
* removed serfWAN remove, reduced complexity, fixed comments
* add another place to remove from serfWAN
* add nil check
* Update agent/consul/server.go
Co-Authored-By: Paul Banks <banks@banksco.de>
With this you should be able to fetch all of the relevant discovery
chain config entries from the state store in one query and then feed
them into the compiler outside of a transaction.
There are a lot of TODOs scattered through here, but they're mostly
around handling fun edge cases and can be deferred until more of the
plumbing works completely.