comments and more logging

app/discovery/discovery.go

@@ -6,6 +6,7 @@ package discovery
 
 import (
 	"context"
+	"log"
 	"regexp"
 	"sync"
 )
@@ -63,10 +64,14 @@ func (s *Service) Run(ctx context.Context) error {
 		case <-ctx.Done():
 			return ctx.Err()
 		case <-ch:
-			m := s.mergeLists()
+			log.Printf("[DEBUG] new update event received")
+			lst := s.mergeLists()
+			for _, m := range lst {
+				log.Printf("[INFO] match for %s: %s %s %s", m.ProviderID, m.Server, m.SrcMatch.String(), m.Dst)
+			}
 			s.lock.Lock()
-			s.mappers = make([]UrlMapper, len(m))
+			s.mappers = make([]UrlMapper, len(lst))
-			copy(s.mappers, m)
+			copy(s.mappers, lst)
 			s.lock.Unlock()
 		}
 	}

app/discovery/discovery_test.go

@@ -20,8 +20,8 @@ func TestService_Do(t *testing.T) {
 		},
 		ListFunc: func() ([]UrlMapper, error) {
 			return []UrlMapper{
-				{SrcMatch: regexp.MustCompile("^/api/svc1/(.*)"), Dst: "http://127.0.0.1:8080/blah1/$1"},
+				{Server: "*", SrcMatch: regexp.MustCompile("^/api/svc1/(.*)"), Dst: "http://127.0.0.1:8080/blah1/$1"},
-				{SrcMatch: regexp.MustCompile("^/api/svc2/(.*)"), Dst: "http://127.0.0.2:8080/blah2/$1/abc"},
+				{Server: "*", SrcMatch: regexp.MustCompile("^/api/svc2/(.*)"), Dst: "http://127.0.0.2:8080/blah2/$1/abc"},
 			}, nil
 		},
 		IDFunc: func() ProviderID {
@@ -34,7 +34,7 @@ func TestService_Do(t *testing.T) {
 		},
 		ListFunc: func() ([]UrlMapper, error) {
 			return []UrlMapper{
-				{SrcMatch: regexp.MustCompile("/api/svc3/xyz"), Dst: "http://127.0.0.3:8080/blah3/xyz"},
+				{Server: "localhost", SrcMatch: regexp.MustCompile("/api/svc3/xyz"), Dst: "http://127.0.0.3:8080/blah3/xyz"},
 			}, nil
 		},
 		IDFunc: func() ProviderID {
@@ -51,6 +51,7 @@ func TestService_Do(t *testing.T) {
 	assert.Equal(t, context.DeadlineExceeded, err)
 	assert.Equal(t, 3, len(svc.mappers))
 	assert.Equal(t, PIFile, svc.mappers[0].ProviderID)
+	assert.Equal(t, "*", svc.mappers[0].Server)
 	assert.Equal(t, "^/api/svc1/(.*)", svc.mappers[0].SrcMatch.String())
 	assert.Equal(t, "http://127.0.0.1:8080/blah1/$1", svc.mappers[0].Dst)
 

app/discovery/provider/docker.go

@@ -7,7 +7,7 @@ import (
 	"strings"
 	"time"
 
-	dclient "github.com/fsouza/go-dockerclient"
+	dc "github.com/fsouza/go-dockerclient"
 	log "github.com/go-pkgz/lgr"
 	"github.com/pkg/errors"
 
@@ -16,7 +16,11 @@ import (
 
 //go:generate moq -out docker_client_mock.go -skip-ensure -fmt goimports . DockerClient
 
-// Docker emits all changes from all containers states
+// Docker provide watch compatible changes from containers
+// and maps by default from ^/api/%s/(.*) to http://%s:%d/$1, i.e. http://example.com/api/my_container/something
+// will be mapped to http://172.17.42.1:8080/something. Ip will be the internal ip of the container and port - exposed the one
+// Alternatively labels can alter this. dpx.route sets source route, and dpx.dest sets the destination. Optional dpx.server enforces
+// match by server name (hostname).
 type Docker struct {
 	DockerClient DockerClient
 	Excludes     []string
@@ -25,8 +29,8 @@ type Docker struct {
 
 // DockerClient defines interface listing containers and subscribing to events
 type DockerClient interface {
-	ListContainers(opts dclient.ListContainersOptions) ([]dclient.APIContainers, error)
+	ListContainers(opts dc.ListContainersOptions) ([]dc.APIContainers, error)
-	AddEventListener(listener chan<- *dclient.APIEvents) error
+	AddEventListener(listener chan<- *dc.APIEvents) error
 }
 
 // containerInfo is simplified docker.APIEvents for containers only
@@ -98,7 +102,7 @@ func (d *Docker) ID() discovery.ProviderID { return discovery.PIDocker }
 // activate starts blocking listener for all docker events
 // filters everything except "container" type, detects stop/start events and publishes signals to eventsCh
 func (d *Docker) events(ctx context.Context, client DockerClient, eventsCh chan struct{}) error {
-	dockerEventsCh := make(chan *dclient.APIEvents)
+	dockerEventsCh := make(chan *dc.APIEvents)
 	if err := client.AddEventListener(dockerEventsCh); err != nil {
 		return errors.Wrap(err, "can't add even listener")
 	}
@@ -132,14 +136,14 @@ func (d *Docker) events(ctx context.Context, client DockerClient, eventsCh chan
 
 func (d *Docker) listContainers() (res []containerInfo, err error) {
 
-	portExposed := func(c dclient.APIContainers) (int, bool) {
+	portExposed := func(c dc.APIContainers) (int, bool) {
 		if len(c.Ports) == 0 {
 			return 0, false
 		}
 		return int(c.Ports[0].PrivatePort), true
 	}
 
-	containers, err := d.DockerClient.ListContainers(dclient.ListContainersOptions{All: false})
+	containers, err := d.DockerClient.ListContainers(dc.ListContainersOptions{All: false})
 	if err != nil {
 		return nil, errors.Wrap(err, "can't list containers")
 	}

app/discovery/provider/file.go

@@ -25,7 +25,7 @@ type File struct {
 func (d *File) Events(ctx context.Context) <-chan struct{} {
 	res := make(chan struct{})
 
-	// no need to queue multiple events or wait
+	// no need to queue multiple events
 	trySubmit := func(ch chan struct{}) {
 		select {
 		case ch <- struct{}{}:

app/discovery/provider/static.go

@@ -12,7 +12,7 @@ import (
 
 // Static provider, rules are server,from,to
 type Static struct {
-	Rules []string
+	Rules []string // each rule is 2 or 3 elements comma separated. [server,]source url,destination
 }
 
 // Events returns channel updating once