feat(service): Add Service

pkg/service/dummy.go

@@ -0,0 +1,23 @@
+// (c) Cartesi and individual authors (see AUTHORS)
+// SPDX-License-Identifier: Apache-2.0 (see LICENSE)
+
+package service
+
+// A Service implementation that does nothing
+type DummyService struct {
+	Service
+}
+
+type CreateDummyInfo struct {
+	CreateInfo
+}
+
+func CreateDummy(ci CreateDummyInfo, null *DummyService) error {
+	return Create(&ci.CreateInfo, &null.Service)
+}
+
+func (s *DummyService) Alive() bool       { return true }
+func (s *DummyService) Ready() bool       { return true }
+func (s *DummyService) Reload() []error   { return nil }
+func (s *DummyService) Tick() []error     { return nil }
+func (s *DummyService) Stop(bool) []error { return nil }

pkg/service/list.go

@@ -0,0 +1,148 @@
+// (c) Cartesi and individual authors (see AUTHORS)
+// SPDX-License-Identifier: Apache-2.0 (see LICENSE)
+
+package service
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+)
+
+// A Service implementation in terms of a list of other services
+type ListService struct {
+	Service
+	Children []*Service
+}
+
+type CreateListInfo struct {
+	CreateInfo
+}
+
+func CreateList(ci CreateListInfo, list *ListService) error {
+	err := Create(&ci.CreateInfo, &list.Service)
+	if err != nil {
+		return err
+	}
+
+	if ci.CreateInfo.TelemetryCreate {
+		list.ServeMux.Handle("/"+list.Name+"/readyz",
+			http.HandlerFunc(list.ReadyHandler))
+		list.ServeMux.Handle("/"+list.Name+"/livez",
+			http.HandlerFunc(list.AliveHandler))
+	}
+	return nil
+}
+
+func (me *ListService) Alive() bool {
+	alive := true
+	for _, s := range me.Children {
+		alive = alive && s.Alive()
+	}
+	return alive
+}
+
+func (me *ListService) Ready() bool {
+	allReady := true
+	for _, s := range me.Children {
+		ready := s.Ready()
+		allReady = allReady && ready
+	}
+	return allReady
+}
+
+func (me *ListService) Reload() []error {
+	var all []error
+	for _, s := range me.Children {
+		es := s.Reload()
+		all = append(all, es...)
+	}
+	return all
+}
+
+/*
+// Simple tick runs children one at a time
+func (me *ListService) Tick() []error {
+	var all []error
+	for _, s := range me.Children {
+		all = append(all, s.Tick()...)
+	}
+	return all
+}
+*/
+
+// *
+func (me *ListService) Tick() []error {
+	c := make(chan []error)
+	var all []error
+	for _, s := range me.Children {
+		go func() {
+			c <- s.Tick()
+		}()
+	}
+
+	limit := time.Duration(0.95 * float64(me.Service.PollInterval))
+	deadline := time.After(limit)
+	for range me.Children {
+		select {
+		case errs := <-c:
+			all = append(all, errs...)
+		case <-deadline:
+			me.Logger.Warn("Tick:time limit exceeded",
+				"service", me.Name,
+				"limit", limit)
+			return all
+		}
+	}
+	return all
+}
+
+//*/
+
+func (me *ListService) Stop(force bool) []error {
+	var all []error
+	for _, s := range me.Children {
+		es := s.Stop(force)
+		all = append(all, es...)
+	}
+	return all
+}
+
+func (me *ListService) AliveHandler(w http.ResponseWriter, r *http.Request) {
+	ss := []string{}
+
+	allAlive := true
+	for _, s := range me.Children {
+		alive := s.Alive()
+		allAlive = allAlive && alive
+		ss = append(ss, fmt.Sprintf("%s: %v", s.Name, alive))
+	}
+	ss = append(ss, fmt.Sprintf("%s: %v", me.Name, allAlive))
+
+	if allAlive {
+		http.Error(w, strings.Join(ss, "\n"),
+			http.StatusInternalServerError)
+	} else {
+		fmt.Fprintf(w, strings.Join(ss, "\n"))
+	}
+}
+
+func (me *ListService) ReadyHandler(w http.ResponseWriter, r *http.Request) {
+	ss := []string{}
+
+	allReady := true
+	for _, s := range me.Children {
+		ready := s.Ready()
+		allReady = allReady && ready
+		ss = append(ss, fmt.Sprintf("%s: %v", s.Name, ready))
+	}
+	ss = append(ss, fmt.Sprintf("%s: %v", me.Name, allReady))
+
+	if allReady {
+		http.Error(w, strings.Join(ss, "\n"),
+			http.StatusInternalServerError)
+	} else {
+		fmt.Fprintf(w, strings.Join(ss, "\n"))
+	}
+}