refactor configuration format to allow multiple checks

main.go

@@ -17,14 +17,21 @@ func main() {
   c := monitor.Config{}
   json.Unmarshal(file, &c)
 
-  handlers := make([]monitor.GenericHandler, 2)
-  handlers[0] = monitor.NewLogHandler()
-  handlers[1] = monitor.NewCloudflareHandler(c.Cloudflare)
+  for _, check := range c.Checks {
+    handlers := make([]*monitor.GenericHandler, 0)
 
-  engine := monitor.CreateEngine(handlers)
+    for _, reaction := range check.Reactions {
+      handler := monitor.CreateHandler(reaction)
 
-  for _, endpoint := range c.Hosts {
-    monitor.CreateCheck(c.Interval, engine, endpoint)
+      if handler == nil {
+        continue
+      }
+
+      handlers = append(handlers, handler)
+    }
+
+    engine := monitor.CreateEngine(handlers)
+    monitor.CreateCheck(check.Interval, engine, check.Target)
   }
 
   select{}

monitor/cloudflare.go

@@ -6,16 +6,20 @@ import (
   "fmt"
 )
 
-func NewCloudflareHandler(config CloudflareConfig) GenericHandler {
+func newCloudflareHandler(config ReactionConfig) *GenericHandler {
+  if config.Options["email"] == "" || config.Options["apiKey"] == "" || config.Options["domain"] == "" || config.Options["name"] == "" || config.Options["ttl"] == "" {
+    log.Fatal(fmt.Sprintf("Misconfigured cloudflare handler: %#v", config))
+  }
+
   return runHandler(make(chan Transition, 5), &cloudflareHandler{
     config,
-    cloudflare.NewClient(config.Email, config.ApiKey),
+    cloudflare.NewClient(config.Options["email"], config.Options["apiKey"]),
     make(map[string]bool),
   })
 }
 
 type cloudflareHandler struct{
-  config CloudflareConfig
+  config ReactionConfig
   client *cloudflare.Client
   actuallyDownHosts map[string]bool
 }
@@ -26,20 +30,20 @@ func (this *cloudflareHandler) handle(transition Transition) {
       log.Print(fmt.Sprintf(
         "Removed cloudflare record for `%s`: `%v`\n",
         transition.RecordValue,
-        removeCloudflareRecord(this.client, this.config, transition.RecordValue)))
+        this.removeCloudflareRecord(transition.RecordValue)))
 
     case Up:
       log.Print(fmt.Sprintf(
         "Added cloudflare record for `%s`: `%v`\n",
         transition.RecordValue,
-        addCloudflareRecord(this.client, this.config, transition.RecordValue)))
+        this.addCloudflareRecord(transition.RecordValue)))
 
     case Unknown: //just leave it how it was, going up/down is idempotent anyways
   }
 }
 
-func removeCloudflareRecord(client *cloudflare.Client, config CloudflareConfig, recordValue string) bool {
-  records, err := client.RetrieveRecordsByName(config.Domain, config.Name)
+func (this *cloudflareHandler) removeCloudflareRecord(recordValue string) bool {
+  records, err := this.client.RetrieveRecordsByName(this.config.Options["Domain"], this.config.Options["Name"])
 
   if err != nil {
     return false
@@ -51,22 +55,22 @@ func removeCloudflareRecord(client *cloudflare.Client, config CloudflareConfig,
       continue
     }
 
-    exitStatus = exitStatus && client.DestroyRecord(config.Domain, record.Id) == nil
+    exitStatus = exitStatus && this.client.DestroyRecord(this.config.Options["domain"], record.Id) == nil
   }
 
   return exitStatus
 }
 
-func addCloudflareRecord(client *cloudflare.Client, config CloudflareConfig, recordValue string) bool {
+func (this *cloudflareHandler) addCloudflareRecord(recordValue string) bool {
   opts := cloudflare.CreateRecord{
     "A",
-    config.Name,
+    this.config.Options["name"],
     recordValue,
     "1",
     "0",
   }
 
-  _, err := client.CreateRecord(config.Domain, &opts)
+  _, err := this.client.CreateRecord(this.config.Options["domain"], &opts)
 
   if err != nil {
     return fmt.Sprintf("%s", err) == "API Error: The record already exists."

monitor/config.go

@@ -1,21 +1,22 @@
 package monitor
 
-type HostConfig struct {
-  Host string
+type Config struct {
+  Checks []CheckConfig
+}
+
+type CheckConfig struct {
+  Interval uint16
+  Target TargetConfig
+  Reactions []ReactionConfig
+}
+
+type TargetConfig struct {
   Type string
+  Host string
   Options map[string]string
 }
 
-type CloudflareConfig struct {
-  Email string
-  ApiKey string
-  Domain string
-  Name string
-  Ttl string
-}
-
-type Config struct {
-  Cloudflare CloudflareConfig
-  Hosts []HostConfig
-  Interval uint16
+type ReactionConfig struct {
+  Type string
+  Options map[string]string
 }

monitor/createCheck.go

@@ -10,7 +10,7 @@ import (
 type checkConfig struct {
   engine *Engine
   interval time.Duration
-  host HostConfig
+  host TargetConfig
 }
 
 type httpChecker struct {
@@ -57,7 +57,7 @@ func newHttpChecker(config checkConfig) *httpChecker {
   return &checker
 }
 
-func CreateCheck(interval uint16, engine *Engine, host HostConfig) {
+func CreateCheck(interval uint16, engine *Engine, host TargetConfig) {
   config := checkConfig{
     engine,
     time.Duration(int64(interval)) * time.Second,

monitor/engine.go

@@ -1,14 +1,11 @@
 package monitor
 
-import (
-)
-
 type Engine struct {
   Input chan Result
-  output []GenericHandler
+  output []*GenericHandler
 }
 
-func CreateEngine(handlers []GenericHandler) *Engine {
+func CreateEngine(handlers []*GenericHandler) *Engine {
   input := make(chan Result)
 
   engine := Engine{

monitor/handler.go

@@ -8,13 +8,23 @@ type GenericHandler struct {
   channel chan Transition
 }
 
-func runHandler(input chan Transition, handler handler) GenericHandler {
+func runHandler(input chan Transition, handler handler) *GenericHandler {
   go func() {
     for true {
       handler.handle(<-input)
     }
   }()
-  return GenericHandler{
+  return &GenericHandler{
     input,
   }
 }
+
+func CreateHandler(handler ReactionConfig) *GenericHandler {
+  switch handler.Type {
+    case "cloudflare":
+      return newCloudflareHandler(handler)
+    case "log":
+      return newLogHandler(handler)
+  }
+  return nil
+}

monitor/log.go

@@ -5,7 +5,7 @@ import (
   "log"
 )
 
-func NewLogHandler() GenericHandler {
+func newLogHandler(config ReactionConfig) *GenericHandler {
   return runHandler(make(chan Transition), &logHandler{})
 }