// serviceLookup is used to handle a service query
func (d *DNSServer) serviceLookup(network, datacenter, service, tag string, req, resp *dns.Msg) {
// Make an RPC request
args := structs.ServiceSpecificRequest{
Datacenter: datacenter,
ServiceName: service,
ServiceTag: tag,
TagFilter: tag != "",
QueryOptions: structs.QueryOptions{AllowStale: d.config.AllowStale},
}
var out structs.IndexedCheckServiceNodes
RPC:
if err := d.agent.RPC("Health.ServiceNodes", &args, &out); err != nil {
d.logger.Printf("[ERR] dns: rpc error: %v", err)
resp.SetRcode(req, dns.RcodeServerFailure)
return
}
// Verify that request is not too stale, redo the request
if args.AllowStale && out.LastContact > d.config.MaxStale {
args.AllowStale = false
d.logger.Printf("[WARN] dns: Query results too stale, re-requesting")
goto RPC
}
// If we have no nodes, return not found!
if len(out.Nodes) == 0 {
resp.SetRcode(req, dns.RcodeNameError)
return
}
// Determine the TTL
var ttl time.Duration
if d.config.ServiceTTL != nil {
var ok bool
ttl, ok = d.config.ServiceTTL[service]
if !ok {
ttl = d.config.ServiceTTL["*"]
}
}
// Filter out any service nodes due to health checks
out.Nodes = d.filterServiceNodes(out.Nodes)
// Perform a random shuffle
shuffleServiceNodes(out.Nodes)
// If the network is not TCP, restrict the number of responses
if network != "tcp" && len(out.Nodes) > maxServiceResponses {
out.Nodes = out.Nodes[:maxServiceResponses]
}
// Add various responses depending on the request
qType := req.Question[0].Qtype
d.serviceNodeRecords(out.Nodes, req, resp, ttl)
if qType == dns.TypeSRV {
d.serviceSRVRecords(datacenter, out.Nodes, req, resp, ttl)
}
}
func (s *HTTPServer) HealthServiceNodes(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
// Set default DC
args := structs.ServiceSpecificRequest{}
s.parseSource(req, &args.Source)
args.NodeMetaFilters = s.parseMetaFilter(req)
if done := s.parse(resp, req, &args.Datacenter, &args.QueryOptions); done {
return nil, nil
}
// Check for a tag
params := req.URL.Query()
if _, ok := params["tag"]; ok {
args.ServiceTag = params.Get("tag")
args.TagFilter = true
}
// Pull out the service name
args.ServiceName = strings.TrimPrefix(req.URL.Path, "/v1/health/service/")
if args.ServiceName == "" {
resp.WriteHeader(400)
resp.Write([]byte("Missing service name"))
return nil, nil
}
// Make the RPC request
var out structs.IndexedCheckServiceNodes
defer setMeta(resp, &out.QueryMeta)
if err := s.agent.RPC("Health.ServiceNodes", &args, &out); err != nil {
return nil, err
}
// Filter to only passing if specified
if _, ok := params[structs.HealthPassing]; ok {
out.Nodes = filterNonPassing(out.Nodes)
}
// Translate addresses after filtering so we don't waste effort.
translateAddresses(s.agent.config, args.Datacenter, out.Nodes)
// Use empty list instead of nil
for i, _ := range out.Nodes {
// TODO (slackpad) It's lame that this isn't a slice of pointers
// but it's not a well-scoped change to fix this. We should
// change this at the next opportunity.
if out.Nodes[i].Checks == nil {
out.Nodes[i].Checks = make(structs.HealthChecks, 0)
}
}
if out.Nodes == nil {
out.Nodes = make(structs.CheckServiceNodes, 0)
}
return out.Nodes, nil
}
func (s *HTTPServer) HealthServiceNodes(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
// Set default DC
args := structs.ServiceSpecificRequest{}
if done := s.parse(resp, req, &args.Datacenter, &args.QueryOptions); done {
return nil, nil
}
// Check for a tag
params := req.URL.Query()
if _, ok := params["tag"]; ok {
args.ServiceTag = params.Get("tag")
args.TagFilter = true
}
// Pull out the service name
args.ServiceName = strings.TrimPrefix(req.URL.Path, "/v1/health/service/")
if args.ServiceName == "" {
resp.WriteHeader(400)
resp.Write([]byte("Missing service name"))
return nil, nil
}
// Make the RPC request
var out structs.IndexedCheckServiceNodes
defer setMeta(resp, &out.QueryMeta)
if err := s.agent.RPC("Health.ServiceNodes", &args, &out); err != nil {
return nil, err
}
// Filter to only passing if specified
if _, ok := params["passing"]; ok {
out.Nodes = filterNonPassing(out.Nodes)
}
return out.Nodes, nil
}
// ServiceNodes returns all the nodes registered as part of a service including health info
func (h *Health) ServiceNodes(args *structs.ServiceSpecificRequest, reply *structs.IndexedCheckServiceNodes) error {
if done, err := h.srv.forward("Health.ServiceNodes", args, args, reply); done {
return err
}
// Verify the arguments
if args.ServiceName == "" {
return fmt.Errorf("Must provide service name")
}
// Get the nodes
state := h.srv.fsm.State()
err := h.srv.blockingRPC(
&args.QueryOptions,
&reply.QueryMeta,
state.GetQueryWatch("CheckServiceNodes"),
func() error {
var index uint64
var nodes structs.CheckServiceNodes
var err error
if args.TagFilter {
index, nodes, err = state.CheckServiceTagNodes(args.ServiceName, args.ServiceTag)
} else {
index, nodes, err = state.CheckServiceNodes(args.ServiceName)
}
if err != nil {
return err
}
reply.Index, reply.Nodes = index, nodes
if len(args.NodeMetaFilters) > 0 {
var filtered structs.CheckServiceNodes
for _, node := range nodes {
if structs.SatisfiesMetaFilters(node.Node.Meta, args.NodeMetaFilters) {
filtered = append(filtered, node)
}
}
reply.Nodes = filtered
}
if err := h.srv.filterACL(args.Token, reply); err != nil {
return err
}
return h.srv.sortNodesByDistanceFrom(args.Source, reply.Nodes)
})
// Provide some metrics
if err == nil {
metrics.IncrCounter([]string{"consul", "health", "service", "query", args.ServiceName}, 1)
if args.ServiceTag != "" {
metrics.IncrCounter([]string{"consul", "health", "service", "query-tag", args.ServiceName, args.ServiceTag}, 1)
}
if len(reply.Nodes) == 0 {
metrics.IncrCounter([]string{"consul", "health", "service", "not-found", args.ServiceName}, 1)
}
}
return err
}
// serviceLookup is used to handle a service query
func (d *DNSServer) serviceLookup(network, datacenter, service, tag string, req, resp *dns.Msg) {
// Make an RPC request
args := structs.ServiceSpecificRequest{
Datacenter: datacenter,
ServiceName: service,
ServiceTag: tag,
TagFilter: tag != "",
}
var out structs.IndexedCheckServiceNodes
if err := d.agent.RPC("Health.ServiceNodes", &args, &out); err != nil {
d.logger.Printf("[ERR] dns: rpc error: %v", err)
resp.SetRcode(req, dns.RcodeServerFailure)
return
}
// If we have no nodes, return not found!
if len(out.Nodes) == 0 {
resp.SetRcode(req, dns.RcodeNameError)
return
}
// Filter out any service nodes due to health checks
out.Nodes = d.filterServiceNodes(out.Nodes)
// Perform a random shuffle
shuffleServiceNodes(out.Nodes)
// If the network is not TCP, restrict the number of responses
if network != "tcp" && len(out.Nodes) > maxServiceResponses {
out.Nodes = out.Nodes[:maxServiceResponses]
}
// Add various responses depending on the request
qType := req.Question[0].Qtype
d.serviceNodeRecords(out.Nodes, req, resp)
if qType == dns.TypeSRV {
d.serviceSRVRecords(datacenter, out.Nodes, req, resp)
}
}
// serviceLookup is used to handle a service query
func (d *DNSServer) serviceLookup(network, datacenter, service, tag string, req, resp *dns.Msg) {
// Make an RPC request
args := structs.ServiceSpecificRequest{
Datacenter: datacenter,
ServiceName: service,
ServiceTag: tag,
TagFilter: tag != "",
QueryOptions: structs.QueryOptions{
Token: d.agent.config.ACLToken,
AllowStale: *d.config.AllowStale,
},
}
var out structs.IndexedCheckServiceNodes
RPC:
if err := d.agent.RPC("Health.ServiceNodes", &args, &out); err != nil {
d.logger.Printf("[ERR] dns: rpc error: %v", err)
resp.SetRcode(req, dns.RcodeServerFailure)
return
}
// Verify that request is not too stale, redo the request
if args.AllowStale && out.LastContact > d.config.MaxStale {
args.AllowStale = false
d.logger.Printf("[WARN] dns: Query results too stale, re-requesting")
goto RPC
}
// Determine the TTL
var ttl time.Duration
if d.config.ServiceTTL != nil {
var ok bool
ttl, ok = d.config.ServiceTTL[service]
if !ok {
ttl = d.config.ServiceTTL["*"]
}
}
// Filter out any service nodes due to health checks
out.Nodes = out.Nodes.Filter(d.config.OnlyPassing)
// If we have no nodes, return not found!
if len(out.Nodes) == 0 {
d.addSOA(d.domain, resp)
resp.SetRcode(req, dns.RcodeNameError)
return
}
// Perform a random shuffle
out.Nodes.Shuffle()
// Add various responses depending on the request
qType := req.Question[0].Qtype
if qType == dns.TypeSRV {
d.serviceSRVRecords(datacenter, out.Nodes, req, resp, ttl)
} else {
d.serviceNodeRecords(datacenter, out.Nodes, req, resp, ttl)
}
// If the network is not TCP, restrict the number of responses
if network != "tcp" {
wasTrimmed := trimUDPResponse(d.config, resp)
// Flag that there are more records to return in the UDP response
if wasTrimmed && d.config.EnableTruncate {
resp.Truncated = true
}
}
// If the answer is empty and the response isn't truncated, return not found
if len(resp.Answer) == 0 && !resp.Truncated {
d.addSOA(d.domain, resp)
return
}
}