open-consul/agent/configentry/merge_service_config.go

204 lines
6.9 KiB
Go

package configentry
import (
"fmt"
"github.com/hashicorp/go-hclog"
memdb "github.com/hashicorp/go-memdb"
"github.com/imdario/mergo"
"github.com/mitchellh/copystructure"
"github.com/hashicorp/consul/acl"
"github.com/hashicorp/consul/agent/structs"
)
type StateStore interface {
ReadResolvedServiceConfigEntries(memdb.WatchSet, string, *acl.EnterpriseMeta, []structs.ServiceID, structs.ProxyMode) (uint64, *ResolvedServiceConfigSet, error)
}
// MergeNodeServiceWithCentralConfig merges a service instance (NodeService) with the
// proxy-defaults/global and service-defaults/:service config entries.
// This common helper is used by the blocking query function of different RPC endpoints
// that need to return a fully resolved service defintion.
func MergeNodeServiceWithCentralConfig(
ws memdb.WatchSet,
state StateStore,
args *structs.ServiceSpecificRequest,
ns *structs.NodeService,
logger hclog.Logger) (uint64, *structs.NodeService, error) {
serviceName := ns.Service
var upstreams []structs.ServiceID
if ns.IsSidecarProxy() {
// This is a sidecar proxy, ignore the proxy service's config since we are
// managed by the target service config.
serviceName = ns.Proxy.DestinationServiceName
// Also if we have any upstreams defined, add them to the defaults lookup request
// so we can learn about their configs.
for _, us := range ns.Proxy.Upstreams {
if us.DestinationType == "" || us.DestinationType == structs.UpstreamDestTypeService {
sid := us.DestinationID()
sid.EnterpriseMeta.Merge(&ns.EnterpriseMeta)
upstreams = append(upstreams, sid)
}
}
}
configReq := &structs.ServiceConfigRequest{
Name: serviceName,
Datacenter: args.Datacenter,
QueryOptions: args.QueryOptions,
MeshGateway: ns.Proxy.MeshGateway,
Mode: ns.Proxy.Mode,
UpstreamIDs: upstreams,
EnterpriseMeta: ns.EnterpriseMeta,
}
// prefer using this vs directly calling the ConfigEntry.ResolveServiceConfig RPC
// so as to pass down the same watch set to also watch on changes to
// proxy-defaults/global and service-defaults.
cfgIndex, configEntries, err := state.ReadResolvedServiceConfigEntries(
ws,
configReq.Name,
&configReq.EnterpriseMeta,
upstreams,
configReq.Mode,
)
if err != nil {
return 0, nil, fmt.Errorf("Failure looking up service config entries for %s: %v",
ns.ID, err)
}
defaults, err := ComputeResolvedServiceConfig(
configReq,
upstreams,
false,
configEntries,
logger,
)
if err != nil {
return 0, nil, fmt.Errorf("Failure computing service defaults for %s: %v",
ns.ID, err)
}
mergedns, err := MergeServiceConfig(defaults, ns)
if err != nil {
return 0, nil, fmt.Errorf("Failure merging service definition with config entry defaults for %s: %v",
ns.ID, err)
}
return cfgIndex, mergedns, nil
}
// MergeServiceConfig merges the service into defaults to produce the final effective
// config for the specified service.
func MergeServiceConfig(defaults *structs.ServiceConfigResponse, service *structs.NodeService) (*structs.NodeService, error) {
if defaults == nil {
return service, nil
}
// We don't want to change s.registration in place since it is our source of
// truth about what was actually registered before defaults applied. So copy
// it first.
nsRaw, err := copystructure.Copy(service)
if err != nil {
return nil, err
}
// Merge proxy defaults
ns := nsRaw.(*structs.NodeService)
if err := mergo.Merge(&ns.Proxy.Config, defaults.ProxyConfig); err != nil {
return nil, err
}
if err := mergo.Merge(&ns.Proxy.Expose, defaults.Expose); err != nil {
return nil, err
}
if ns.Proxy.MeshGateway.Mode == structs.MeshGatewayModeDefault {
ns.Proxy.MeshGateway.Mode = defaults.MeshGateway.Mode
}
if ns.Proxy.Mode == structs.ProxyModeDefault {
ns.Proxy.Mode = defaults.Mode
}
if ns.Proxy.TransparentProxy.OutboundListenerPort == 0 {
ns.Proxy.TransparentProxy.OutboundListenerPort = defaults.TransparentProxy.OutboundListenerPort
}
if !ns.Proxy.TransparentProxy.DialedDirectly {
ns.Proxy.TransparentProxy.DialedDirectly = defaults.TransparentProxy.DialedDirectly
}
// remoteUpstreams contains synthetic Upstreams generated from central config (service-defaults.UpstreamConfigs).
remoteUpstreams := make(map[structs.ServiceID]structs.Upstream)
for _, us := range defaults.UpstreamIDConfigs {
parsed, err := structs.ParseUpstreamConfigNoDefaults(us.Config)
if err != nil {
return nil, fmt.Errorf("failed to parse upstream config map for %s: %v", us.Upstream.String(), err)
}
remoteUpstreams[us.Upstream] = structs.Upstream{
DestinationNamespace: us.Upstream.NamespaceOrDefault(),
DestinationPartition: us.Upstream.PartitionOrDefault(),
DestinationName: us.Upstream.ID,
Config: us.Config,
MeshGateway: parsed.MeshGateway,
CentrallyConfigured: true,
}
}
// localUpstreams stores the upstreams seen from the local registration so that we can merge in the synthetic entries.
// In transparent proxy mode ns.Proxy.Upstreams will likely be empty because users do not need to define upstreams explicitly.
// So to store upstream-specific flags from central config, we add entries to ns.Proxy.Upstream with those values.
localUpstreams := make(map[structs.ServiceID]struct{})
// Merge upstream defaults into the local registration
for i := range ns.Proxy.Upstreams {
// Get a pointer not a value copy of the upstream struct
us := &ns.Proxy.Upstreams[i]
if us.DestinationType != "" && us.DestinationType != structs.UpstreamDestTypeService {
continue
}
localUpstreams[us.DestinationID()] = struct{}{}
remoteCfg, ok := remoteUpstreams[us.DestinationID()]
if !ok {
// No config defaults to merge
continue
}
// The local upstream config mode has the highest precedence, so only overwrite when it's set to the default
if us.MeshGateway.Mode == structs.MeshGatewayModeDefault {
us.MeshGateway.Mode = remoteCfg.MeshGateway.Mode
}
// Merge in everything else that is read from the map
if err := mergo.Merge(&us.Config, remoteCfg.Config); err != nil {
return nil, err
}
// Delete the mesh gateway key from opaque config since this is the value that was resolved from
// the servers and NOT the final merged value for this upstream.
// Note that we use the "mesh_gateway" key and not other variants like "MeshGateway" because
// UpstreamConfig.MergeInto and ResolveServiceConfig only use "mesh_gateway".
delete(us.Config, "mesh_gateway")
}
// Ensure upstreams present in central config are represented in the local configuration.
// This does not apply outside of transparent mode because in that situation every possible upstream already exists
// inside of ns.Proxy.Upstreams.
if ns.Proxy.Mode == structs.ProxyModeTransparent {
for id, remote := range remoteUpstreams {
if _, ok := localUpstreams[id]; ok {
// Remote upstream is already present locally
continue
}
ns.Proxy.Upstreams = append(ns.Proxy.Upstreams, remote)
}
}
return ns, err
}