package structs import ( "encoding/json" "fmt" "time" "github.com/hashicorp/consul/lib" ) // CompiledDiscoveryChain is the result from taking a set of related config // entries for a single service's discovery chain and restructuring them into a // form that is more usable for actual service discovery. type CompiledDiscoveryChain struct { ServiceName string Namespace string // the namespace that the chain was compiled within Datacenter string // the datacenter that the chain was compiled within // CustomizationHash is a unique hash of any data that affects the // compilation of the discovery chain other than config entries or the // name/namespace/datacenter evaluation criteria. // // If set, this value should be used to prefix/suffix any generated load // balancer data plane objects to avoid sharing customized and // non-customized versions. CustomizationHash string `json:",omitempty"` // Protocol is the overall protocol shared by everything in the chain. Protocol string `json:",omitempty"` // StartNode is the first key into the Nodes map that should be followed // when walking the discovery chain. StartNode string `json:",omitempty"` // Nodes contains all nodes available for traversal in the chain keyed by a // unique name. You can walk this by starting with StartNode. // // NOTE: The names should be treated as opaque values and are only // guaranteed to be consistent within a single compilation. Nodes map[string]*DiscoveryGraphNode `json:",omitempty"` // Targets is a list of all targets used in this chain. Targets map[string]*DiscoveryTarget `json:",omitempty"` } func (c *CompiledDiscoveryChain) WillFailoverThroughMeshGateway(node *DiscoveryGraphNode) bool { if node.Type != DiscoveryGraphNodeTypeResolver { return false } failover := node.Resolver.Failover if failover != nil && len(failover.Targets) > 0 { for _, failTargetID := range failover.Targets { failTarget := c.Targets[failTargetID] switch failTarget.MeshGateway.Mode { case MeshGatewayModeLocal, MeshGatewayModeRemote: return true } } } return false } // IsDefault returns true if the compiled chain represents no routing, no // splitting, and only the default resolution. We have to be careful here to // avoid returning "yep this is default" when the only resolver action being // applied is redirection to another resolver that is default, so we double // check the resolver matches the requested resolver. func (c *CompiledDiscoveryChain) IsDefault() bool { if c.StartNode == "" || len(c.Nodes) == 0 { return true } node := c.Nodes[c.StartNode] if node == nil { panic("not possible: missing node named '" + c.StartNode + "' in chain '" + c.ServiceName + "'") } if node.Type != DiscoveryGraphNodeTypeResolver { return false } if !node.Resolver.Default { return false } target := c.Targets[node.Resolver.Target] return target.Service == c.ServiceName && target.Namespace == c.Namespace } // ID returns an ID that encodes the service, namespace, and datacenter. // This ID allows us to compare a discovery chain target to the chain upstream itself. func (c *CompiledDiscoveryChain) ID() string { return chainID("", c.ServiceName, c.Namespace, c.Datacenter) } func (c *CompiledDiscoveryChain) CompoundServiceName() ServiceName { entMeta := NewEnterpriseMetaInDefaultPartition(c.Namespace) return NewServiceName(c.ServiceName, &entMeta) } const ( DiscoveryGraphNodeTypeRouter = "router" DiscoveryGraphNodeTypeSplitter = "splitter" DiscoveryGraphNodeTypeResolver = "resolver" ) // DiscoveryGraphNode is a single node in the compiled discovery chain. type DiscoveryGraphNode struct { Type string Name string // this is NOT necessarily a service // fields for Type==router Routes []*DiscoveryRoute `json:",omitempty"` // fields for Type==splitter Splits []*DiscoverySplit `json:",omitempty"` // fields for Type==resolver Resolver *DiscoveryResolver `json:",omitempty"` // shared by Type==resolver || Type==splitter LoadBalancer *LoadBalancer `json:",omitempty"` } func (s *DiscoveryGraphNode) IsRouter() bool { return s.Type == DiscoveryGraphNodeTypeRouter } func (s *DiscoveryGraphNode) IsSplitter() bool { return s.Type == DiscoveryGraphNodeTypeSplitter } func (s *DiscoveryGraphNode) IsResolver() bool { return s.Type == DiscoveryGraphNodeTypeResolver } func (s *DiscoveryGraphNode) MapKey() string { return fmt.Sprintf("%s:%s", s.Type, s.Name) } // compiled form of ServiceResolverConfigEntry type DiscoveryResolver struct { Default bool `json:",omitempty"` ConnectTimeout time.Duration `json:",omitempty"` Target string `json:",omitempty"` Failover *DiscoveryFailover `json:",omitempty"` } func (r *DiscoveryResolver) MarshalJSON() ([]byte, error) { type Alias DiscoveryResolver exported := &struct { ConnectTimeout string `json:",omitempty"` *Alias }{ ConnectTimeout: r.ConnectTimeout.String(), Alias: (*Alias)(r), } if r.ConnectTimeout == 0 { exported.ConnectTimeout = "" } return json.Marshal(exported) } func (r *DiscoveryResolver) UnmarshalJSON(data []byte) error { type Alias DiscoveryResolver aux := &struct { ConnectTimeout string *Alias }{ Alias: (*Alias)(r), } if err := lib.UnmarshalJSON(data, &aux); err != nil { return err } var err error if aux.ConnectTimeout != "" { if r.ConnectTimeout, err = time.ParseDuration(aux.ConnectTimeout); err != nil { return err } } return nil } // compiled form of ServiceRoute type DiscoveryRoute struct { Definition *ServiceRoute `json:",omitempty"` NextNode string `json:",omitempty"` } // compiled form of ServiceSplit type DiscoverySplit struct { Weight float32 `json:",omitempty"` NextNode string `json:",omitempty"` } // compiled form of ServiceResolverFailover type DiscoveryFailover struct { Targets []string `json:",omitempty"` } // DiscoveryTarget represents all of the inputs necessary to use a resolver // config entry to execute a catalog query to generate a list of service // instances during discovery. type DiscoveryTarget struct { // ID is a unique identifier for referring to this target in a compiled // chain. It should be treated as a per-compile opaque string. ID string `json:",omitempty"` Service string `json:",omitempty"` ServiceSubset string `json:",omitempty"` Namespace string `json:",omitempty"` Partition string `json:",omitempty"` Datacenter string `json:",omitempty"` MeshGateway MeshGatewayConfig `json:",omitempty"` Subset ServiceResolverSubset `json:",omitempty"` // External is true if this target is outside of this consul cluster. External bool `json:",omitempty"` // SNI is the sni field to use when connecting to this set of endpoints // over TLS. SNI string `json:",omitempty"` // Name is the unique name for this target for use when generating load // balancer objects. This has a structure similar to SNI, but will not be // affected by SNI customizations. Name string `json:",omitempty"` } func NewDiscoveryTarget(service, serviceSubset, namespace, datacenter string) *DiscoveryTarget { t := &DiscoveryTarget{ Service: service, ServiceSubset: serviceSubset, Namespace: namespace, Datacenter: datacenter, } t.setID() return t } func chainID(subset, service, namespace, dc string) string { // NOTE: this format is similar to the SNI syntax for simplicity if subset == "" { return fmt.Sprintf("%s.%s.%s", service, namespace, dc) } return fmt.Sprintf("%s.%s.%s.%s", subset, service, namespace, dc) } func (t *DiscoveryTarget) setID() { t.ID = chainID(t.ServiceSubset, t.Service, t.Namespace, t.Datacenter) } func (t *DiscoveryTarget) String() string { return t.ID } func (t *DiscoveryTarget) ServiceID() ServiceID { return NewServiceID(t.Service, t.GetEnterpriseMetadata()) }