package health import ( "context" "github.com/hashicorp/consul/agent/cache" "github.com/hashicorp/consul/agent/structs" "github.com/hashicorp/consul/agent/submatview" "github.com/hashicorp/consul/proto/pbsubscribe" ) // Client provides access to service health data. type Client struct { NetRPC NetRPC Cache CacheGetter ViewStore MaterializedViewStore MaterializerDeps MaterializerDeps CacheName string UseStreamingBackend bool QueryOptionDefaults func(options *structs.QueryOptions) } type NetRPC interface { RPC(method string, args interface{}, reply interface{}) error } type CacheGetter interface { Get(ctx context.Context, t string, r cache.Request) (interface{}, cache.ResultMeta, error) Notify(ctx context.Context, t string, r cache.Request, cID string, ch chan<- cache.UpdateEvent) error } type MaterializedViewStore interface { Get(ctx context.Context, req submatview.Request) (submatview.Result, error) Notify(ctx context.Context, req submatview.Request, cID string, ch chan<- cache.UpdateEvent) error } func (c *Client) ServiceNodes( ctx context.Context, req structs.ServiceSpecificRequest, ) (structs.IndexedCheckServiceNodes, cache.ResultMeta, error) { if c.useStreaming(req) && (req.QueryOptions.UseCache || req.QueryOptions.MinQueryIndex > 0) { c.QueryOptionDefaults(&req.QueryOptions) result, err := c.ViewStore.Get(ctx, c.newServiceRequest(req)) if err != nil { return structs.IndexedCheckServiceNodes{}, cache.ResultMeta{}, err } meta := cache.ResultMeta{Index: result.Index, Hit: result.Cached} return *result.Value.(*structs.IndexedCheckServiceNodes), meta, err } out, md, err := c.getServiceNodes(ctx, req) if err != nil { return out, md, err } // TODO: DNSServer emitted a metric here, do we still need it? if req.QueryOptions.AllowStale && req.QueryOptions.MaxStaleDuration > 0 && out.QueryMeta.LastContact > req.MaxStaleDuration { req.AllowStale = false err := c.NetRPC.RPC("Health.ServiceNodes", &req, &out) return out, cache.ResultMeta{}, err } return out, md, err } func (c *Client) getServiceNodes( ctx context.Context, req structs.ServiceSpecificRequest, ) (structs.IndexedCheckServiceNodes, cache.ResultMeta, error) { var out structs.IndexedCheckServiceNodes if !req.QueryOptions.UseCache { err := c.NetRPC.RPC("Health.ServiceNodes", &req, &out) return out, cache.ResultMeta{}, err } raw, md, err := c.Cache.Get(ctx, c.CacheName, &req) if err != nil { return out, md, err } value, ok := raw.(*structs.IndexedCheckServiceNodes) if !ok { panic("wrong response type for cachetype.HealthServicesName") } return *value, md, nil } func (c *Client) Notify( ctx context.Context, req structs.ServiceSpecificRequest, correlationID string, ch chan<- cache.UpdateEvent, ) error { if c.useStreaming(req) { sr := c.newServiceRequest(req) return c.ViewStore.Notify(ctx, sr, correlationID, ch) } return c.Cache.Notify(ctx, c.CacheName, &req, correlationID, ch) } func (c *Client) useStreaming(req structs.ServiceSpecificRequest) bool { return c.UseStreamingBackend && !req.Ingress && req.Source.Node == "" } func (c *Client) newServiceRequest(req structs.ServiceSpecificRequest) serviceRequest { return serviceRequest{ ServiceSpecificRequest: req, deps: c.MaterializerDeps, } } // Close any underlying connections used by the client. func (c *Client) Close() error { if c == nil { return nil } return c.MaterializerDeps.Conn.Close() } type serviceRequest struct { structs.ServiceSpecificRequest deps MaterializerDeps } func (r serviceRequest) CacheInfo() cache.RequestInfo { return r.ServiceSpecificRequest.CacheInfo() } func (r serviceRequest) Type() string { return "agent.rpcclient.health.serviceRequest" } func (r serviceRequest) NewMaterializer() (submatview.Materializer, error) { view, err := newHealthView(r.ServiceSpecificRequest) if err != nil { return nil, err } deps := submatview.Deps{ View: view, Logger: r.deps.Logger, Request: newMaterializerRequest(r.ServiceSpecificRequest), } return submatview.NewRPCMaterializer(pbsubscribe.NewStateChangeSubscriptionClient(r.deps.Conn), deps), nil }