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.
