Basic config and some initialisation

cmd/goplum/goplum.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"github.com/csmith/goplum"
 	"github.com/csmith/goplum/internal"
 	"log"
 	"os"
@@ -14,4 +15,6 @@ func main() {
 	for i := range plugins {
 		log.Printf("Plugin %d is '%s' with %d checks, %d notifiers\n", i, plugins[i].Name(), len(plugins[i].Checks()), len(plugins[i].Notifiers()))
 	}
+
+	goplum.Initialise(plugins, "config.json")
 }

cmd/goplumdev/goplumdev.go

@@ -15,4 +15,6 @@ func main() {
 	for i := range plugins {
 		log.Printf("Plugin %d is '%s' with %d checks, %d notifiers\n", i, plugins[i].Name(), len(plugins[i].Checks()), len(plugins[i].Notifiers()))
 	}
+
+	goplum.Initialise(plugins, "config.json")
 }

config.go

@@ -0,0 +1,29 @@
+package goplum
+
+import (
+	"encoding/json"
+	"os"
+	"time"
+)
+
+type Config struct {
+	Checks []ConfiguredCheck `json:"checks"`
+}
+
+type ConfiguredCheck struct {
+	Name     string          `json:"name"`
+	Check    string          `json:"check"`
+	Interval time.Duration   `json:"interval"`
+	Params   json.RawMessage `json:"params"`
+}
+
+func LoadConfig(path string) (*Config, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	config := &Config{}
+	return config, json.NewDecoder(f).Decode(config)
+}

config.json

@@ -0,0 +1,11 @@
+{
+  "checks": [
+    {
+      "name": "Google",
+      "check": "http",
+      "params": {
+        "url": "https://www.google.com/"
+      }
+    }
+  ]
+}

plugins.go

@@ -12,8 +12,7 @@ type Plugin interface {
 // e.g. making a HTTP request, or opening a TCP socket.
 type Check interface {
 	Name() string
-	Help() string
-	Create(config json.RawMessage) Task
+	Create(config json.RawMessage) (Task, error)
 }
 
 type Task interface {

plugins/http/http.go

@@ -1,6 +1,10 @@
 package http
 
-import "github.com/csmith/goplum"
+import (
+	"encoding/json"
+	"github.com/csmith/goplum"
+	"net/http"
+)
 
 type Plugin struct{}
 
@@ -9,10 +13,40 @@ func (h Plugin) Name() string {
 }
 
 func (h Plugin) Checks() []goplum.Check {
-	return nil
+	return []goplum.Check{Check{}}
 }
 
 func (h Plugin) Notifiers() []goplum.Notifier {
 	return nil
 }
 
+type params struct {
+	Url string `json:"url"`
+}
+
+type Check struct{}
+
+func (c Check) Name() string {
+	return "http"
+}
+
+func (c Check) Create(config json.RawMessage) (goplum.Task, error) {
+	p := params{}
+	err := json.Unmarshal(config, &p)
+	if err != nil {
+		return nil, err
+	}
+
+	return Task{p}, nil
+}
+
+type Task struct {
+	params params
+}
+
+func (t Task) Execute() goplum.Result {
+	r, err := http.Get(t.params.Url)
+	return goplum.Result{
+		Good: err == nil && r.StatusCode >= 400,
+	}
+}

plum.go

@@ -0,0 +1,35 @@
+package goplum
+
+import "log"
+
+func Initialise(plugins []Plugin, configPath string) {
+	config, err := LoadConfig(configPath)
+	if err != nil {
+		log.Fatalf("Unable to read config: %v", err)
+	}
+
+	checks := make(map[string]Check)
+	for i := range plugins {
+		cs := plugins[i].Checks()
+		for j := range cs {
+			checks[cs[j].Name()] = cs[j]
+		}
+	}
+	log.Printf("Found %d checks from %d plugins\n", len(checks), len(plugins))
+
+	tasks := make([]Task, 0)
+	for i := range config.Checks {
+		cc := config.Checks[i]
+		check, ok := checks[cc.Check]
+		if !ok {
+			log.Fatalf("Invalid check name in config: %s", cc.Check)
+		}
+
+		t, err := check.Create(cc.Params)
+		if err != nil {
+			log.Fatalf("Unable to create check '%s': %v", cc.Name, err)
+		}
+
+		tasks = append(tasks, t)
+	}
+}