Add documentation, change config format

README.md

@@ -74,15 +74,17 @@ All durations are specified as string that will be parsed [like this](https://pk
         - `"sum"` means that values from the child levels are summed up for the parent level
         - `"avg"` means that values from the child levels are averaged for the parent level
     - `scope`: Unused at the moment, should be something like `"node"`, `"socket"` or `"hwthread"`
-- `nats`: Url of NATS.io server (The `updates` channel will be subscribed for metrics), example: "nats://localhost:4222"
-- `http-api-address`: Where to listen via HTTP, example: ":8080"
+- `nats`:
+    - `address`: Url of NATS.io server, example: "nats://localhost:4222"
+- `http-api`:
+    - `address`: Address to bind to, for example `0.0.0.0:8080`
+    - `https-cert-file` and `https-key-file`: Optional, if provided enable HTTPS using those files as certificate/key.
 - `jwt-public-key`: Base64 encoded string, use this to verify requests to the HTTP API
 - `retention-on-memory`: Keep all values in memory for at least that amount of time
 - `checkpoints`:
     - `interval`: Do checkpoints every X seconds/minutes/hours
     - `directory`: Path to a directory
     - `restore`: After a restart, load the last X seconds/minutes/hours of data back into memory
-
 - `archive`:
     - `interval`: Move and compress all checkpoints not needed anymore every X seconds/minutes/hours
     - `directory`: Path to a directory

api.go

@@ -307,7 +307,7 @@ func authentication(next http.Handler, publicKey ed25519.PublicKey) http.Handler
 	})
 }
 
-func StartApiServer(ctx context.Context, address string, httpsConfig *HttpsConfig) error {
+func StartApiServer(ctx context.Context, httpConfig *HttpConfig) error {
 	r := mux.NewRouter()
 
 	r.HandleFunc("/api/free", handleFree)
@@ -322,7 +322,7 @@ func StartApiServer(ctx context.Context, address string, httpsConfig *HttpsConfi
 
 	server := &http.Server{
 		Handler:      r,
-		Addr:         address,
+		Addr:         httpConfig.Address,
 		WriteTimeout: 15 * time.Second,
 		ReadTimeout:  15 * time.Second,
 	}
@@ -337,14 +337,14 @@ func StartApiServer(ctx context.Context, address string, httpsConfig *HttpsConfi
 	}
 
 	go func() {
-		if httpsConfig != nil {
-			log.Printf("API https endpoint listening on '%s'\n", address)
-			err := server.ListenAndServeTLS(httpsConfig.CertFile, httpsConfig.KeyFile)
+		if httpConfig.CertFile != "" && httpConfig.KeyFile != "" {
+			log.Printf("API https endpoint listening on '%s'\n", httpConfig.Address)
+			err := server.ListenAndServeTLS(httpConfig.CertFile, httpConfig.KeyFile)
 			if err != nil && err != http.ErrServerClosed {
 				log.Println(err)
 			}
 		} else {
-			log.Printf("API http endpoint listening on '%s'\n", address)
+			log.Printf("API http endpoint listening on '%s'\n", httpConfig.Address)
 			err := server.ListenAndServe()
 			if err != nil && err != http.ErrServerClosed {
 				log.Println(err)

config.json

@@ -15,8 +15,12 @@
         "interval": "168h",
         "directory": "./var/archive"
     },
+    "http-api": {
+        "address": "0.0.0.0:8081",
+        "https-cert-file": null,
+        "https-key-file": null
+    },
     "retention-in-memory": "48h",
-    "http-api-address": "0.0.0.0:8081",
     "nats": null,
     "jwt-public-key": "kzfYrYy+TzpanWZHJ5qSdMj5uKUWgq74BWhQG6copP0="
 }

lineprotocol.go

@@ -20,8 +20,8 @@ type Metric struct {
 // Connect to a nats server and subscribe to "updates". This is a blocking
 // function. handleLine will be called for each line recieved via nats.
 // Send `true` through the done channel for gracefull termination.
-func ReceiveNats(address string, handleLine func(dec *lineprotocol.Decoder) error, workers int, ctx context.Context) error {
-	nc, err := nats.Connect(address)
+func ReceiveNats(conf *NatsConfig, handleLine func(dec *lineprotocol.Decoder) error, workers int, ctx context.Context) error {
+	nc, err := nats.Connect(conf.Address)
 	if err != nil {
 		return err
 	}
@@ -64,7 +64,7 @@ func ReceiveNats(address string, handleLine func(dec *lineprotocol.Decoder) erro
 		return err
 	}
 
-	log.Printf("NATS subscription to 'updates' on '%s' established\n", address)
+	log.Printf("NATS subscription to 'updates' on '%s' established\n", conf.Address)
 
 	<-ctx.Done()
 	err = sub.Unsubscribe()

metric-store.go

@@ -15,23 +15,38 @@ import (
 )
 
 type MetricConfig struct {
+	// Interval in seconds at which measurements will arive.
 	Frequency int64 `json:"frequency"`
+
+	// Can be 'sum', 'avg' or null. Describes how to aggregate metrics from the same timestep over the hierarchy.
 	Aggregation string `json:"aggregation"`
+
+	// Unused for now.
 	Scope string `json:"scope"`
 }
 
-type HttpsConfig struct {
-	CertFile string `json:"cert"`
-	KeyFile  string `json:"key"`
+type HttpConfig struct {
+	// Address to bind to, for example "0.0.0.0:8081"
+	Address string `json:"address"`
+
+	// If not the empty string, use https with this as the certificate file
+	CertFile string `json:"https-cert-file"`
+
+	// If not the empty string, use https with this as the key file
+	KeyFile string `json:"https-key-file"`
+}
+
+type NatsConfig struct {
+	// Address of the nats server
+	Address string `json:"address"`
 }
 
 type Config struct {
 	Metrics           map[string]MetricConfig `json:"metrics"`
 	RetentionInMemory string                  `json:"retention-in-memory"`
-	Nats              string                  `json:"nats"`
+	Nats              *NatsConfig             `json:"nats"`
 	JwtPublicKey      string                  `json:"jwt-public-key"`
-	HttpApiAddress    string                  `json:"http-api-address"`
-	HttpsConfig       *HttpsConfig            `json:"https"`
+	HttpConfig        *HttpConfig             `json:"http-api"`
 	Checkpoints       struct {
 		Interval string `json:"interval"`
 		RootDir  string `json:"directory"`
@@ -195,14 +210,14 @@ func main() {
 	wg.Add(1)
 
 	go func() {
-		err := StartApiServer(ctx, conf.HttpApiAddress, conf.HttpsConfig)
+		err := StartApiServer(ctx, conf.HttpConfig)
 		if err != nil {
 			log.Fatal(err)
 		}
 		wg.Done()
 	}()
 
-	if len(conf.Nats) != 0 {
+	if conf.Nats != nil {
 		wg.Add(1)
 
 		go func() {