Added state perstistance

- Define new state directory to hold the last dns update config and push it into the config, default to state/
- Refactoring, move updaterequest into service and out of webapp. Keep only the form parsing there. Specifically, move the processing code into the service package, it shouldn't be in the webapp.
- Add code to load and save the last updaterequest into a state file (watch out to keep the possibly unhashed password out of it).
- Add a command line option to load all available state files given the current configured user list from the command line.
- Refactor user configuartion loading to separate it from user authentication, claen up the code.
- We now require the username in the config, to make handling it in state updates easier. This will allow easier transition to DB style storage anyway.
- Update .gitignore

service/updaterequest.go

@@ -0,0 +1,120 @@
+package service
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net"
+)
+
+type UpdateRequest struct {
+	IPv4     net.IP
+	IPv6     net.IP
+	UserName string
+	Password string `json:"-"`
+	IPv6Net  *net.IPNet
+	Config   *UserConfig `json:"-"`
+}
+
+func (ur *UpdateRequest) String() string {
+	return fmt.Sprintf("IPv4: %v, IPv6: %v, UserName: %v, Password: %v, IPv6Net: %v",
+		ur.IPv4, ur.IPv6, ur.UserName, ur.Password, ur.IPv6Net)
+}
+
+func (ur *UpdateRequest) PrettyPrint() string {
+	s, err := json.MarshalIndent(ur, "", " ")
+	if err != nil {
+		log.Fatalf("Failed to pretty print UpdateRequest via JSON: %v", err)
+	}
+	return string(s)
+}
+
+func (ur *UpdateRequest) SaveStateFile() error {
+	data, err := json.MarshalIndent(ur, "", " ")
+	if err != nil {
+		return fmt.Errorf("failed to convert state for user %s to JSON: %v",
+			ur.UserName, err)
+	}
+	filename := ur.Config.GetStateFileName()
+	if err = ioutil.WriteFile(filename, data, 0640); err != nil {
+		return fmt.Errorf("failed to to write sate file for user %s to file %s: %v",
+			ur.UserName, filename, err)
+	}
+	return nil
+}
+
+func LoadStateFile(uc *UserConfig) (*UpdateRequest, error) {
+	filename := uc.GetStateFileName()
+	data, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read state file %s for user %s, %v",
+			uc.UserName, filename, err)
+	}
+	var ur UpdateRequest
+	if err = json.Unmarshal(data, &ur); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal state JSON for user %s: %v",
+			uc.UserName, err)
+	}
+	ur.Config = uc
+	return &ur, nil
+}
+
+func (ur *UpdateRequest) Process() error {
+	nfu := NewNFTUpdate()
+
+	if err := DNSUpdateEntry(ur.Config.Domain, ur.Config.Router.Hostname, ur.IPv4, ur.IPv6); err != nil {
+		return fmt.Errorf("failed to update router DNS: %v", err)
+	}
+	if ur.Config.Router.NFT.Table != "" {
+		if ur.IPv4 != nil && ur.Config.Router.NFT.Set4 != "" {
+			if err := nfu.AddIP(ur.Config.Router.NFT.Table, ur.Config.Router.NFT.Set4, ur.IPv4); err != nil {
+				return fmt.Errorf("failed to update IPv4 Router NFT setup: %v", err)
+			}
+		}
+		if ur.IPv6 != nil && ur.Config.Router.NFT.Set6 != "" {
+			if err := nfu.AddIP(ur.Config.Router.NFT.Table, ur.Config.Router.NFT.Set6, ur.IPv6); err != nil {
+				return fmt.Errorf("failed to update IPv6 Router NFT setup: %v", err)
+			}
+		}
+	}
+
+	for _, other := range ur.Config.Others {
+		fullV6IP := other.ConvertIIDToAddress(ur.IPv6Net)
+		if other.RegisterV4 {
+			if err := DNSUpdateEntry(ur.Config.Domain, other.Hostname, ur.IPv4, fullV6IP); err != nil {
+				return fmt.Errorf("failed to update DNS for host %s: %v", other.Hostname, err)
+			}
+		} else {
+			if err := DNSUpdateEntry(ur.Config.Domain, other.Hostname, nil, fullV6IP); err != nil {
+				return fmt.Errorf("failed to update DNS for host %s: %v", other.Hostname, err)
+			}
+		}
+
+		if other.NFT.Table != "" {
+			if other.NFT.Set6 != "" {
+				if err := nfu.AddIP(other.NFT.Table, other.NFT.Set6, fullV6IP); err != nil {
+					return fmt.Errorf("failed to update IPv6 NFT setup for host %s: %v", other.Hostname, err)
+				}
+			}
+			if other.RegisterV4 && other.NFT.Set4 != "" {
+				if err := nfu.AddIP(other.NFT.Table, other.NFT.Set4, ur.IPv4); err != nil {
+					return fmt.Errorf("failed to update IPv6 NFT setup for host %s: %v", other.Hostname, err)
+				}
+			}
+		}
+	}
+
+	log.Println("Summary of collected NFT Updates:")
+	log.Println(nfu.PrettyPrint())
+
+	if err := nfu.Process(); err != nil {
+		return fmt.Errorf("failed to update NFT Setup: %v", err)
+	}
+
+	if err := ur.SaveStateFile(); err != nil {
+		return fmt.Errorf("failed to save state file: %v", err)
+	}
+
+	return nil
+}