feat: Add flags to set listening address/port

The schema defines the absence of state->open to represent the unknown
state. Previously it was not possible to explicitly set this state via
the HTTP endpoints.

types.SpaceAPIState.Open is now an enum which is either unknown, closed,
or open. Custom IsZero() and MarshalJSON() methods on the type ensure
marshaling the value yields a boolean for open/closed and an empty byte
slice for unknown (resulting in the field being absent from the final
response).

The handlers.StateOpenDELETE() function has been added to expose this
behavior.

Switching to encoding/json/v2 required raising the minimum Go version in
go.mod to 1.27.

Closes: CCCHH/spaceapid!37
Fixes:  CCCHH/spaceapid#38

config/config.go

@@ -2,7 +2,7 @@ package config
 
 import (
 	"bytes"
-	"encoding/json"
+	"encoding/json/v2"
 	"flag"
 	"fmt"
 	"log"
@@ -78,9 +78,7 @@ func ParseConfiguration() (conf SpaceapidConfig) {
 		}
 
 		// Parse JSON
-		dec := json.NewDecoder(bytes.NewReader(file))
-		dec.DisallowUnknownFields()
-		err = dec.Decode(&conf)
+		err = json.UnmarshalRead(bytes.NewReader(file), &conf, json.RejectUnknownMembers(true))
 		if err != nil {
 			log.Fatalln("Could not parse spaceapid config file:", err)
 		}

go.mod

@@ -1,3 +1,3 @@
 module git.hamburg.ccc.de/ccchh/spaceapid
 
-go 1.22
+go 1.27

handlers/root.go

@@ -1,7 +1,7 @@
 package handlers
 
 import (
-	"encoding/json"
+	"encoding/json/v2"
 	"log"
 	"net/http"
 
@@ -19,7 +19,7 @@ func Root(resp *types.SpaceAPIResponse) func(http.ResponseWriter, *http.Request)
 		}
 
 		// Serialize response
-		response, err := json.Marshal(resp)
+		response, err := json.Marshal(resp, json.Deterministic(true))
 		if err != nil {
 			log.Println("Failed to serialize JSON response:", err)
 			w.WriteHeader(http.StatusInternalServerError)

handlers/state.go

@@ -10,7 +10,7 @@ import (
 	"git.hamburg.ccc.de/ccchh/spaceapid/types"
 )
 
-func StateOpen(
+func StateOpenPUT(
 	authDB config.HTTPBACredentials, validCredentials []config.HTTPBACredentialID,
 	resp *types.SpaceAPIState,
 ) func(http.ResponseWriter, *http.Request) {
@@ -22,7 +22,7 @@ func StateOpen(
 		}
 
 		// Parse request body
-		newState, err := strconv.ParseBool(string(body))
+		doorNowOpen, err := strconv.ParseBool(string(body))
 		if err != nil {
 			log.Println("Failed to parse request body from", r.RemoteAddr, "with error:", err)
 			http.Error(w, "HTTP request body should either be true or false", http.StatusBadRequest)
@@ -30,7 +30,28 @@ func StateOpen(
 		}
 
 		// Set SpaceAPI response values
-		resp.Open = newState
+		if doorNowOpen {
+			resp.Open = types.SpaceAPIStateOpenIsOpen
+		} else {
+			resp.Open = types.SpaceAPIStateOpenIsClosed
+		}
+		resp.LastChange = time.Now().Unix()
+	}
+}
+
+func StateOpenDELETE(
+	authDB config.HTTPBACredentials, validCredentials []config.HTTPBACredentialID,
+	resp *types.SpaceAPIState,
+) func(http.ResponseWriter, *http.Request) {
+	return func(w http.ResponseWriter, r *http.Request) {
+		_, err := updateEndpointValidator(authDB, validCredentials, w, r)
+		if err != nil {
+			log.Println(err)
+			return
+		}
+
+		// Set SpaceAPI response values
+		resp.Open = types.SpaceAPIStateOpenIsUnknown
 		resp.LastChange = time.Now().Unix()
 	}
 }

main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"flag"
+	"fmt"
 	"log"
 	"net/http"
 	"os"
@@ -16,11 +17,15 @@ import (
 )
 
 var (
-	flagHelp bool
-	version  string
+	flagHelp      bool
+	listenAddress string
+	listenPort    string
+	version       string
 )
 
 func init() {
+	flag.StringVar(&listenAddress, "i", "", "IP address the HTTP server should bind to (all available addresses by default)")
+	flag.StringVar(&listenPort, "p", "8080", "Port the HTTP server should listen on")
 	flag.BoolVar(&flagHelp, "h", false, "Print help output")
 }
 
@@ -59,7 +64,10 @@ func main() {
 	)
 	// state->open
 	http.HandleFunc("PUT /state/open",
-		handlers.StateOpen(conf.Credentials, conf.Dynamic.State.Open.AllowedCredentials, &conf.Response.State),
+		handlers.StateOpenPUT(conf.Credentials, conf.Dynamic.State.Open.AllowedCredentials, &conf.Response.State),
+	)
+	http.HandleFunc("DELETE /state/open",
+		handlers.StateOpenDELETE(conf.Credentials, conf.Dynamic.State.Open.AllowedCredentials, &conf.Response.State),
 	)
 	// state->message
 	http.HandleFunc("PUT /state/message",
@@ -91,5 +99,5 @@ func main() {
 
 	// Start webserver
 	log.Println("Starting HTTP server...")
-	log.Fatalln(http.ListenAndServe(":8080", nil))
+	log.Fatalln(http.ListenAndServe(fmt.Sprintf("%s:%s", listenAddress, listenPort), nil))
 }

persistence/persistentState.go

@@ -1,7 +1,8 @@
 package persistence
 
 import (
-	"encoding/json"
+	"encoding/json/jsontext"
+	"encoding/json/v2"
 	"errors"
 	"log"
 	"os"
@@ -20,7 +21,7 @@ func MergeOldState(response *types.SpaceAPIResponse) {
 	var (
 		err            error
 		oldState       []byte
-		persistedState types.PersistentSpaceState
+		persistedState types.PersistentState
 	)
 
 	log.Println("Merging old state from", persistentStatePath, "...")
@@ -87,27 +88,38 @@ func SaveCurrentState(response types.SpaceAPIResponse) {
 	defer file.Close()
 
 	// Create persistent state
-	persistentStateV14 := types.PersistentSpaceState{
-		State: struct {
-			Open       bool   `json:"open"`
-			LastChange int64  `json:"lastchange"`
-			Message    string `json:"message,omitempty"`
-		}{Open: response.State.Open, LastChange: response.State.LastChange, Message: response.State.Message},
+	var (
+		isOpen    bool
+		isUnknown bool
+	)
+	switch response.State.Open {
+	case types.SpaceAPIStateOpenIsUnknown:
+		isUnknown = true
+	case types.SpaceAPIStateOpenIsClosed:
+		break
+	case types.SpaceAPIStateOpenIsOpen:
+		isOpen = true
+	}
+	persistentState := types.PersistentState{
+		State: types.PersistentSpaceState{
+			Open: isOpen, IsUnknown: isUnknown,
+			LastChange: response.State.LastChange, Message: response.State.Message,
+		},
+		Sensors: make(map[string][]types.PersistentEnvironmentSensor),
 	}
 	// Save sensor state
-	persistentStateV14.Sensors = make(map[string][]types.PersistentEnvironmentSensor)
 	for key, environmentSensors := range response.Sensors {
-		persistentStateV14.Sensors[key] = make([]types.PersistentEnvironmentSensor, len(environmentSensors))
+		persistentState.Sensors[key] = make([]types.PersistentEnvironmentSensor, len(environmentSensors))
 		for i, sensor := range environmentSensors {
-			persistentStateV14.Sensors[key][i].Value = sensor.Value
-			persistentStateV14.Sensors[key][i].Location = sensor.Location
-			persistentStateV14.Sensors[key][i].Name = sensor.Name
-			persistentStateV14.Sensors[key][i].LastChange = sensor.LastChange
+			persistentState.Sensors[key][i].Value = sensor.Value
+			persistentState.Sensors[key][i].Location = sensor.Location
+			persistentState.Sensors[key][i].Name = sensor.Name
+			persistentState.Sensors[key][i].LastChange = sensor.LastChange
 		}
 	}
 
 	// Serialize persistent state
-	marshal, err := json.MarshalIndent(persistentStateV14, "", "\t")
+	marshal, err := json.Marshal(persistentState, json.JoinOptions(jsontext.Multiline(true), jsontext.SpaceAfterComma(true)))
 	if err != nil {
 		log.Fatalln("Failed serializing persistent state... error:", err)
 	}

types/v15.go

@@ -1,5 +1,9 @@
 package types
 
+import (
+	"encoding/json/v2"
+)
+
 const CurrentMessageVersion = "15"
 
 // SpaceAPIResponse represents the contents of the SpaceAPI message
@@ -114,19 +118,50 @@ type SpaceAPILocationAreas struct {
 	SquareMeters float64 `json:"square_meters"` // REQUIRED
 }
 
+type SpaceAPIStateOpen int
+
+const (
+	SpaceAPIStateOpenIsUnknown = iota
+	SpaceAPIStateOpenIsClosed
+	SpaceAPIStateOpenIsOpen
+)
+
+func (state SpaceAPIStateOpen) MarshalJSON() ([]byte, error) {
+	switch state {
+	case SpaceAPIStateOpenIsClosed:
+		return json.Marshal(false)
+	case SpaceAPIStateOpenIsOpen:
+		return json.Marshal(true)
+	default:
+		return []byte{}, nil
+	}
+}
+
+func (state SpaceAPIStateOpen) IsZero() bool {
+	return state == SpaceAPIStateOpenIsUnknown
+}
+
 type SpaceAPIState struct {
-	Open          bool   `json:"open,omitempty"`
-	LastChange    int64  `json:"lastchange,omitempty"`
-	TriggerPerson string `json:"trigger_person,omitempty"`
-	Message       string `json:"message,omitempty"`
+	Open          SpaceAPIStateOpen `json:"open,omitzero"`
+	LastChange    int64             `json:"lastchange,omitempty"`
+	TriggerPerson string            `json:"trigger_person,omitempty"`
+	Message       string            `json:"message,omitempty"`
 	Icon          struct {
 		Open   string `json:"open,omitempty"`   // REQUIRED
 		Closed string `json:"closed,omitempty"` // REQUIRED
 	} `json:"icon,omitzero"`
 }
 
-func (s *SpaceAPIState) FromPersistentSpaceState(ps PersistentSpaceState) {
-	s.Open = ps.State.Open
+func (s *SpaceAPIState) FromPersistentSpaceState(ps PersistentState) {
+	if ps.State.IsUnknown {
+		s.Open = SpaceAPIStateOpenIsUnknown
+	} else {
+		if ps.State.Open {
+			s.Open = SpaceAPIStateOpenIsOpen
+		} else {
+			s.Open = SpaceAPIStateOpenIsClosed
+		}
+	}
 	s.LastChange = ps.State.LastChange
 	s.Message = ps.State.Message
 }
@@ -147,15 +182,18 @@ type EnvironmentSensor struct {
 	LastChange  int64   `json:"lastchange,omitempty"`
 }
 
-type PersistentSpaceState struct {
-	State struct {
-		Open       bool   `json:"open"`
-		LastChange int64  `json:"lastchange"`
-		Message    string `json:"message,omitempty"`
-	} `json:"state"`
+type PersistentState struct {
+	State   PersistentSpaceState                     `json:"state"`
 	Sensors map[string][]PersistentEnvironmentSensor `json:"sensors,omitempty"`
 }
 
+type PersistentSpaceState struct {
+	Open       bool   `json:"open"`
+	IsUnknown  bool   `json:"is_unknown"`
+	LastChange int64  `json:"lastchange"`
+	Message    string `json:"message,omitempty"`
+}
+
 type PersistentEnvironmentSensor struct {
 	Value      float64 `json:"value"`
 	Location   string  `json:"location,omitempty"`