Edit wireguard client (#19)

* Add the ability to modify an existing client
* Update client page using Ajax

Dockerfile

@@ -35,6 +35,9 @@ RUN mkdir -p assets/plugins && \
     /build/node_modules/jquery-tags-input/ \
     assets/plugins/
 
+# Move custom assets
+RUN cp -r /build/custom/ assets/
+
 # Get go modules and build tool
 RUN go mod download && \
     go get github.com/GeertJohan/go.rice/rice

custom/js/helper.js

@@ -0,0 +1,60 @@
+function renderClientList(data) {
+    $.each(data, function(index, obj) {
+        // render client status css tag style
+        let clientStatusHtml = '>'
+        if (obj.Client.enabled) {
+            clientStatusHtml = `style="visibility: hidden;">`
+        }
+
+        // render client allocated ip addresses
+        let allocatedIpsHtml = "";
+        $.each(obj.Client.allocated_ips, function(index, obj) {
+            allocatedIpsHtml += `<small class="badge badge-secondary">${obj}</small>&nbsp;`;
+        })
+
+        // render client allowed ip addresses
+        let allowedIpsHtml = "";
+        $.each(obj.Client.allowed_ips, function(index, obj) {
+            allowedIpsHtml += `<small class="badge badge-secondary">${obj}</small>&nbsp;`;
+        })
+
+        // render client html content
+        let html = `<div class="col-sm-6" id="client_${obj.Client.id}">
+                        <div class="info-box">
+                            <div class="overlay" id="paused_${obj.Client.id}"` + clientStatusHtml
+                                + `<i class="paused-client fas fa-3x fa-play" onclick="resumeClient('${obj.Client.id}')"></i>
+                            </div>
+                            <img src="${obj.QRCode}" />
+                            <div class="info-box-content">
+                                <div class="btn-group">
+                                    <button onclick="location.href='/download?clientid=${obj.Client.id}'" type="button"
+                                        class="btn btn-outline-success btn-sm">Download</button>
+                                    <button type="button" class="btn btn-outline-primary btn-sm" data-toggle="modal"
+                                        data-target="#modal_edit_client" data-clientid="${obj.Client.id}"
+                                        data-clientname="${obj.Client.name}">Edit</button>
+                                    <button type="button" class="btn btn-outline-warning btn-sm" data-toggle="modal"
+                                        data-target="#modal_pause_client" data-clientid="${obj.Client.id}"
+                                        data-clientname="${obj.Client.name}">Disable</button>
+                                    <button type="button" class="btn btn-outline-danger btn-sm" data-toggle="modal"
+                                        data-target="#modal_remove_client" data-clientid="${obj.Client.id}"
+                                        data-clientname="${obj.Client.name}">Remove</button>
+                                </div>
+                                <hr>
+                                <span class="info-box-text"><i class="fas fa-user"></i> ${obj.Client.name}</span>
+                                <span class="info-box-text"><i class="fas fa-envelope"></i> ${obj.Client.email}</span>
+                                <span class="info-box-text"><i class="fas fa-clock"></i>
+                                    ${obj.Client.created_at}</span>
+                                <span class="info-box-text"><i class="fas fa-history"></i>
+                                    ${obj.Client.updated_at}</span>
+                                <span class="info-box-text"><strong>IP Allocation</strong></span>`
+                                + allocatedIpsHtml
+                                + `<span class="info-box-text"><strong>Allowed IPs</strong></span>`
+                                + allowedIpsHtml
+                            +`</div>
+                        </div>
+                    </div>`
+
+        // add the client html elements to the list
+        $('#client-list').append(html);
+    });
+}

handler/routes.go

@@ -92,6 +92,37 @@ func WireGuardClients() echo.HandlerFunc {
 	}
 }
 
+// GetClients handler return a list of Wireguard client data
+func GetClients() echo.HandlerFunc {
+	return func(c echo.Context) error {
+		// access validation
+		validSession(c)
+
+		clientDataList, err := util.GetClients(true)
+		if err != nil {
+			return c.JSON(http.StatusInternalServerError, jsonHTTPResponse{false, fmt.Sprintf("Cannot get client list: %v", err)})
+		}
+
+		return c.JSON(http.StatusOK, clientDataList)
+	}
+}
+
+// GetClient handler return a of Wireguard client data
+func GetClient() echo.HandlerFunc {
+	return func(c echo.Context) error {
+		// access validation
+		validSession(c)
+
+		clientID := c.Param("id")
+		clientData, err := util.GetClientByID(clientID, true)
+		if err != nil {
+			return c.JSON(http.StatusNotFound, jsonHTTPResponse{false, "Client not found"})
+		}
+
+		return c.JSON(http.StatusOK, clientData)
+	}
+}
+
 // NewClient handler
 func NewClient() echo.HandlerFunc {
 	return func(c echo.Context) error {
@@ -114,7 +145,7 @@ func NewClient() echo.HandlerFunc {
 		}
 
 		// validate the input Allocation IPs
-		allocatedIPs, err := util.GetAllocatedIPs()
+		allocatedIPs, err := util.GetAllocatedIPs("")
 		check, err := util.ValidateIPAllocation(serverInterface.Addresses, allocatedIPs, client.AllocatedIPs)
 		if !check {
 			return c.JSON(http.StatusBadRequest, jsonHTTPResponse{false, fmt.Sprintf("%s", err)})
@@ -157,6 +188,63 @@ func NewClient() echo.HandlerFunc {
 	}
 }
 
+// UpdateClient handler to update client information
+func UpdateClient() echo.HandlerFunc {
+	return func(c echo.Context) error {
+		// access validation
+		validSession(c)
+
+		_client := new(model.Client)
+		c.Bind(_client)
+
+		db, err := util.DBConn()
+		if err != nil {
+			log.Error("Cannot initialize database: ", err)
+			return c.JSON(http.StatusInternalServerError, jsonHTTPResponse{false, "Cannot access database"})
+		}
+
+		// validate client existence
+		client := model.Client{}
+		if err := db.Read("clients", _client.ID, &client); err != nil {
+			return c.JSON(http.StatusNotFound, jsonHTTPResponse{false, "Client not found"})
+		}
+
+		// read server information
+		serverInterface := model.ServerInterface{}
+		if err := db.Read("server", "interfaces", &serverInterface); err != nil {
+			log.Error("Cannot fetch server interface config from database: ", err)
+			return c.JSON(http.StatusBadRequest, jsonHTTPResponse{false, fmt.Sprintf("Cannot fetch server config: %s", err)})
+		}
+
+		// validate the input Allocation IPs
+		allocatedIPs, err := util.GetAllocatedIPs(client.ID)
+		check, err := util.ValidateIPAllocation(serverInterface.Addresses, allocatedIPs, _client.AllocatedIPs)
+		if !check {
+			return c.JSON(http.StatusBadRequest, jsonHTTPResponse{false, fmt.Sprintf("%s", err)})
+		}
+
+		// validate the input AllowedIPs
+		if util.ValidateAllowedIPs(_client.AllowedIPs) == false {
+			log.Warnf("Invalid Allowed IPs input from user: %v", _client.AllowedIPs)
+			return c.JSON(http.StatusBadRequest, jsonHTTPResponse{false, "Allowed IPs must be in CIDR format"})
+		}
+
+		// map new data
+		client.Name = _client.Name
+		client.Email = _client.Email
+		client.Enabled = _client.Enabled
+		client.AllocatedIPs = _client.AllocatedIPs
+		client.AllowedIPs = _client.AllowedIPs
+		client.UpdatedAt = time.Now().UTC()
+
+		// write to the database
+		db.Write("clients", client.ID, &client)
+		log.Infof("Updated client information successfully => %v", client)
+
+		return c.JSON(http.StatusOK, jsonHTTPResponse{true, "Updated client successfully"})
+	}
+}
+
 // SetClientStatus handler to enable / disable a client
 func SetClientStatus() echo.HandlerFunc {
 	return func(c echo.Context) error {
@@ -181,7 +269,7 @@ func SetClientStatus() echo.HandlerFunc {
 
 		client := model.Client{}
 		if err := db.Read("clients", clientID, &client); err != nil {
-			log.Error("Cannot fetch server interface config from database: ", err)
+			log.Error("Cannot get client from database: ", err)
 		}
 
 		client.Enabled = status
@@ -200,15 +288,16 @@ func DownloadClient() echo.HandlerFunc {
 			return c.JSON(http.StatusNotFound, jsonHTTPResponse{false, "Missing clientid parameter"})
 		}
 
-		client, err := util.GetClientByID(clientID)
+		clientData, err := util.GetClientByID(clientID, false)
 		if err != nil {
 			log.Errorf("Cannot generate client id %s config file for downloading: %v", clientID, err)
 			return c.JSON(http.StatusNotFound, jsonHTTPResponse{false, "Client not found"})
 		}
+
 		// build config
 		server, _ := util.GetServer()
 		globalSettings, _ := util.GetGlobalSettings()
-		config := util.BuildClientConfig(client, server, globalSettings)
+		config := util.BuildClientConfig(*clientData.Client, server, globalSettings)
 
 		// create io reader from string
 		reader := strings.NewReader(config)
@@ -419,7 +508,7 @@ func SuggestIPAllocation() echo.HandlerFunc {
 		// we take the first available ip address from
 		// each server's network addresses.
 		suggestedIPs := make([]string, 0)
-		allocatedIPs, err := util.GetAllocatedIPs()
+		allocatedIPs, err := util.GetAllocatedIPs("")
 		if err != nil {
 			log.Error("Cannot suggest ip allocation. Failed to get list of allocated ip addresses: ", err)
 			return c.JSON(http.StatusInternalServerError, jsonHTTPResponse{false, "Cannot suggest ip allocation: failed to get list of allocated ip addresses"})

main.go

@@ -49,6 +49,7 @@ func main() {
 	app.POST("/login", handler.Login())
 	app.GET("/logout", handler.Logout())
 	app.POST("/new-client", handler.NewClient())
+	app.POST("/update-client", handler.UpdateClient())
 	app.POST("/client/set-status", handler.SetClientStatus())
 	app.POST("/remove-client", handler.RemoveClient())
 	app.GET("/download", handler.DownloadClient())
@@ -57,6 +58,8 @@ func main() {
 	app.POST("wg-server/keypair", handler.WireGuardServerKeyPair())
 	app.GET("/global-settings", handler.GlobalSettings())
 	app.POST("/global-settings", handler.GlobalSettingSubmit())
+	app.GET("/api/clients", handler.GetClients())
+	app.GET("/api/client/:id", handler.GetClient())
 	app.GET("/api/machine-ips", handler.MachineIPAddresses())
 	app.GET("/api/suggest-client-ips", handler.SuggestIPAllocation())
 	app.GET("/api/apply-wg-config", handler.ApplyServerConfig(tmplBox))

prepare_assets.sh

@@ -11,6 +11,9 @@ mkdir -p "${DIR}/assets/dist/js" "${DIR}/assets/dist/css" && \
   cp -r "${DIR}/node_modules/admin-lte/dist/js/adminlte.min.js" "${DIR}/assets/dist/js/adminlte.min.js" && \
   cp -r "${DIR}/node_modules/admin-lte/dist/css/adminlte.min.css" "${DIR}/assets/dist/css/adminlte.min.css"
 
+# Copy helper js
+cp -r "${DIR}/custom" "${DIR}/assets"
+
 # Copy plugins
 mkdir -p "${DIR}/assets/plugins" && \
   cp -r "${DIR}/node_modules/admin-lte/plugins/jquery" \

templates/base.html

@@ -66,6 +66,7 @@
                     Config</button>
                 <button onclick="location.href='/logout';" style="margin-left: 0.5em;" type="button"
                     class="btn btn-outline-danger btn-sm"><i class="nav-icon fas fa-sign-out-alt"></i> Logout</button>
+            </div>
         </nav>
         <!-- /.navbar -->
 
@@ -245,7 +246,28 @@
     <script src="static/plugins/jquery-tags-input/dist/jquery.tagsinput.min.js"></script>
     <!-- AdminLTE App -->
     <script src="static/dist/js/adminlte.min.js"></script>
+    <!-- Custom js -->
+    <script src="static/custom/js/helper.js"></script>
     <script>
+        // populateClient function for render new client info
+        // on the client page.
+        function populateClient(client_id) {
+            $.ajax({
+                cache: false,
+                method: 'GET',
+                url: '/api/client/' + client_id,
+                dataType: 'json',
+                contentType: "application/json",
+                success: function (resp) {
+                    renderClientList([resp]);
+                },
+                error: function (jqXHR, exception) {
+                    const responseJson = jQuery.parseJSON(jqXHR.responseText);
+                    toastr.error(responseJson['message']);
+                }
+            });
+        }
+
         // submitNewClient function for new client form submission
         function submitNewClient() {
             const name = $("#client_name").val();
@@ -260,7 +282,6 @@
 
             const data = {"name": name, "email": email, "allocated_ips": allocated_ips, "allowed_ips": allowed_ips,
             "enabled": enabled};
-            console.log(data);
 
             $.ajax({
                 cache: false,
@@ -269,12 +290,12 @@
                 dataType: 'json',
                 contentType: "application/json",
                 data: JSON.stringify(data),
-                success: function(data) {
+                success: function(resp) {
                     $("#modal_new_client").modal('hide');
                     toastr.success('Created new client successfully');
-                    // Refresh the home page (clients page) after adding successfully
+                    // Update the home page (clients page) after adding successfully
                     if (window.location.pathname === "/") {
-                        location.reload();
+                        populateClient(resp.id);
                     }
                 },
                 error: function(jqXHR, exception) {
@@ -356,7 +377,7 @@
                     },
                     client_email: {
                         required: "Please enter an email address",
-                        email: "Please enter a vaild email address"
+                        email: "Please enter a valid email address"
                     },
                 },
                 errorElement: 'span',
@@ -376,6 +397,8 @@
         // New Client modal event
         $(document).ready(function () {
             $("#modal_new_client").on('shown.bs.modal', function (e) {
+                $("#client_name").val("");
+                $("#client_email").val("");
                 $("#client_allocated_ips").importTags('');
                 updateIPAllocationSuggestion();
             });

templates/clients.html

@@ -24,55 +24,61 @@ Wireguard Clients
 <section class="content">
     <div class="container-fluid">
         <!-- <h5 class="mt-4 mb-2">Wireguard Clients</h5> -->
-        <div class="row">
+        <div class="row" id="client-list">
-            {{range .clientDataList}}
-            <div class="col-sm-6" id="client_{{.Client.ID}}">
-                <div class="info-box">
-                    <div class="overlay" id="paused_{{.Client.ID}}"
-                        {{if eq .Client.Enabled true}}style="visibility: hidden;" {{end}}>
-                        <i class="paused-client fas fa-3x fa-play" onclick="resumeClient('{{.Client.ID}}')"></i>
-                    </div>
-                    <img
-                        src="{{ .QRCode }}" />
-                    <div class="info-box-content">
-                        <div class="btn-group">
-                            <button onclick="location.href='/download?clientid={{ .Client.ID }}'" type="button"
-                                class="btn btn-outline-success btn-sm">Download</button>
-                            <!-- <button type="button" class="btn btn-outline-primary btn-sm">Edit</button> -->
-                            <button type="button" class="btn btn-outline-warning btn-sm" data-toggle="modal"
-                                data-target="#modal_pause_client" data-clientid="{{ .Client.ID }}"
-                                data-clientname="{{ .Client.Name }}">Disable</button>
-                            <button type="button" class="btn btn-outline-danger btn-sm" data-toggle="modal"
-                                data-target="#modal_remove_client" data-clientid="{{ .Client.ID }}"
-                                data-clientname="{{ .Client.Name }}">Remove</button>
-                        </div>
-                        <hr>
-                        <span class="info-box-text"><i class="fas fa-user"></i> {{ .Client.Name }}</span>
-                        <span class="info-box-text"><i class="fas fa-envelope"></i> {{ .Client.Email }}</span>
-                        <span class="info-box-text"><i class="fas fa-clock"></i>
-                            {{ .Client.CreatedAt.Format "2 Jan 2006 15:04" }}</span>
-                        <span class="info-box-text"><i class="fas fa-history"></i>
-                            {{ .Client.UpdatedAt.Format "2 Jan 2006 15:04" }}</span>
-                        <span class="info-box-text"><strong>IP Allocation</strong></span>
-                        {{range .Client.AllocatedIPs}}
-                        <small class="badge badge-secondary">{{.}}</small>
-                        {{end}}
-                        <span class="info-box-text"><strong>Allowed IPs</strong></span>
-                        {{range .Client.AllowedIPs}}
-                        <small class="badge badge-secondary">{{.}}</small>
-                        {{end}}
-                    </div>
-                    <!-- /.info-box-content -->
-                </div>
-                <!-- /.info-box -->
-            </div>
-            <!-- /.col -->
-            {{end}}
         </div>
         <!-- /.row -->
     </div>
 </section>
 
+<div class="modal fade" id="modal_edit_client">
+    <div class="modal-dialog">
+        <div class="modal-content">
+            <div class="modal-header">
+                <h4 class="modal-title">Edit Client</h4>
+                <button type="button" class="close" data-dismiss="modal" aria-label="Close">
+                    <span aria-hidden="true">&times;</span>
+                </button>
+            </div>
+            <form name="frm_edit_client" id="frm_edit_client">
+                <div class="modal-body">
+                    <input type="hidden" id="_client_id" name="_client_id">
+                    <div class="form-group">
+                        <label for="_client_name" class="control-label">Name</label>
+                        <input type="text" class="form-control" id="_client_name" name="_client_name">
+                    </div>
+                    <div class="form-group">
+                        <label for="_client_email" class="control-label">Email</label>
+                        <input type="text" class="form-control" id="_client_email" name="client_email">
+                    </div>
+                    <div class="form-group">
+                        <label for="_client_allocated_ips" class="control-label">IP Allocation</label>
+                        <input type="text" data-role="tagsinput" class="form-control" id="_client_allocated_ips">
+                    </div>
+                    <div class="form-group">
+                        <label for="_client_allowed_ips" class="control-label">Allowed IPs</label>
+                        <input type="text" data-role="tagsinput" class="form-control" id="_client_allowed_ips">
+                    </div>
+                    <div class="form-group">
+                        <div class="icheck-primary d-inline">
+                            <input type="checkbox" id="_enabled">
+                            <label for="_enabled">
+                                Enable this client
+                            </label>
+                        </div>
+                    </div>
+                </div>
+                <div class="modal-footer justify-content-between">
+                    <button type="button" class="btn btn-default" data-dismiss="modal">Cancel</button>
+                    <button type="submit" class="btn btn-success">Save</button>
+                </div>
+            </form>
+        </div>
+        <!-- /.modal-content -->
+    </div>
+    <!-- /.modal-dialog -->
+</div>
+<!-- /.modal -->
+
 <div class="modal fade" id="modal_pause_client">
     <div class="modal-dialog">
         <div class="modal-content bg-warning">
@@ -120,6 +126,23 @@ Wireguard Clients
 
 {{define "bottom_js"}}
     <script>
+        function populateClientList() {
+            $.ajax({
+                cache: false,
+                method: 'GET',
+                url: '/api/clients',
+                dataType: 'json',
+                contentType: "application/json",
+                success: function (data) {
+                    renderClientList(data);
+                },
+                error: function (jqXHR, exception) {
+                    const responseJson = jQuery.parseJSON(jqXHR.responseText);
+                    toastr.error(responseJson['message']);
+                }
+            });
+        }
+
         function setClientStatus(clientID, status) {
             const data = {"id": clientID, "status": status};
             $.ajax({
@@ -130,7 +153,7 @@ Wireguard Clients
                 contentType: "application/json",
                 data: JSON.stringify(data),
                 success: function (data) {
-                    console.log("Set client " + clientID + " status to " + status)
+                    console.log("Set client " + clientID + " status to " + status);
                 },
                 error: function (jqXHR, exception) {
                     const responseJson = jQuery.parseJSON(jqXHR.responseText);
@@ -152,6 +175,11 @@ Wireguard Clients
         }
     </script>
     <script>
+        // load client list
+        $(document).ready(function () {
+            populateClientList();
+        })
+
         // modal_pause_client modal event
         $("#modal_pause_client").on('show.bs.modal', function (event) {
             const button = $(event.relatedTarget);
@@ -206,5 +234,147 @@ Wireguard Clients
                 });
             });
         });
+
+        // Edit client modal event
+        $(document).ready(function () {
+            $("#modal_edit_client").on('shown.bs.modal', function (event) {
+                let modal = $(this);
+                const button = $(event.relatedTarget);
+                const client_id = button.data('clientid');
+
+                // IP Allocation tag input
+                modal.find("#_client_allocated_ips").tagsInput({
+                    'width': '100%',
+                    'height': '75%',
+                    'interactive': true,
+                    'defaultText': 'Add More',
+                    'removeWithBackspace': true,
+                    'minChars': 0,
+                    'maxChars': 18,
+                    'placeholderColor': '#666666'
+                });
+
+                // AllowedIPs tag input
+                modal.find("#_client_allowed_ips").tagsInput({
+                    'width': '100%',
+                    'height': '75%',
+                    'interactive': true,
+                    'defaultText': 'Add More',
+                    'removeWithBackspace': true,
+                    'minChars': 0,
+                    'maxChars': 18,
+                    'placeholderColor': '#666666'
+                });
+
+                // update client modal data
+                $.ajax({
+                    cache: false,
+                    method: 'GET',
+                    url: '/api/client/' + client_id,
+                    dataType: 'json',
+                    contentType: "application/json",
+                    success: function (resp) {
+                        const client = resp.Client;
+
+                        modal.find(".modal-title").text("Edit Client " + client.name);
+                        modal.find("#_client_id").val(client.id);
+                        modal.find("#_client_name").val(client.name);
+                        modal.find("#_client_email").val(client.email);
+
+                        modal.find("#_client_allocated_ips").importTags('');
+                        client.allocated_ips.forEach(function (obj) {
+                            modal.find("#_client_allocated_ips").addTag(obj);
+                        });
+
+                        modal.find("#_client_allowed_ips").importTags('');
+                        client.allowed_ips.forEach(function (obj) {
+                            modal.find("#_client_allowed_ips").addTag(obj);
+                        });
+
+                        modal.find("#_enabled").prop("checked", client.enabled);
+                    },
+                    error: function (jqXHR, exception) {
+                        const responseJson = jQuery.parseJSON(jqXHR.responseText);
+                        toastr.error(responseJson['message']);
+                    }
+                });
+            });
+        });
+
+        // submitEditClient function for updating an existing client
+        function submitEditClient() {
+            const client_id = $("#_client_id").val();
+            const name = $("#_client_name").val();
+            const email = $("#_client_email").val();
+            const allocated_ips = $("#_client_allocated_ips").val().split(",");
+            const allowed_ips = $("#_client_allowed_ips").val().split(",");
+            let enabled = false;
+
+            if ($("#_enabled").is(':checked')){
+                enabled = true;
+            }
+
+            const data = {"id": client_id, "name": name, "email": email, "allocated_ips": allocated_ips,
+                "allowed_ips": allowed_ips, "enabled": enabled};
+
+            $.ajax({
+                cache: false,
+                method: 'POST',
+                url: '/update-client',
+                dataType: 'json',
+                contentType: "application/json",
+                data: JSON.stringify(data),
+                success: function(resp) {
+                    $("#modal_edit_client").modal('hide');
+                    toastr.success('Updated client successfully');
+                     // Refresh the home page (clients page) after updating successfully
+                    location.reload();
+                },
+                error: function(jqXHR, exception) {
+                    const responseJson = jQuery.parseJSON(jqXHR.responseText);
+                    toastr.error(responseJson['message']);
+                }
+            });
+        }
+
+        // Edit client form validation
+        $(document).ready(function () {
+            $.validator.setDefaults({
+                submitHandler: function () {
+                    submitEditClient();
+                }
+            });
+            $("#frm_edit_client").validate({
+                rules: {
+                    client_name: {
+                        required: true,
+                    },
+                    client_email: {
+                        required: true,
+                        email: true,
+                    },
+                },
+                messages: {
+                    client_name: {
+                        required: "Please enter a name"
+                    },
+                    client_email: {
+                        required: "Please enter an email address",
+                        email: "Please enter a valid email address"
+                    },
+                },
+                errorElement: 'span',
+                errorPlacement: function (error, element) {
+                    error.addClass('invalid-feedback');
+                    element.closest('.form-group').append(error);
+                },
+                highlight: function (element, errorClass, validClass) {
+                    $(element).addClass('is-invalid');
+                },
+                unhighlight: function (element, errorClass, validClass) {
+                    $(element).removeClass('is-invalid');
+                }
+            });
+        });
     </script>
 {{end}}

util/db.go

@@ -209,7 +209,7 @@ func GetClients(hasQRCode bool) ([]model.ClientData, error) {
 			server, _ := GetServer()
 			globalSettings, _ := GetGlobalSettings()
 
-			png, _ := qrcode.Encode(BuildClientConfig(client, server, globalSettings), qrcode.Medium, 256)
+			png, err := qrcode.Encode(BuildClientConfig(client, server, globalSettings), qrcode.Medium, 256)
 			if err == nil {
 				clientData.QRCode = "data:image/png;base64," + base64.StdEncoding.EncodeToString([]byte(png))
 			} else {
@@ -226,18 +226,34 @@ func GetClients(hasQRCode bool) ([]model.ClientData, error) {
 }
 
 // GetClientByID func to query a client from the database
-func GetClientByID(clientID string) (model.Client, error) {
+func GetClientByID(clientID string, hasQRCode bool) (model.ClientData, error) {
 	client := model.Client{}
+	clientData := model.ClientData{}
 
 	db, err := DBConn()
 	if err != nil {
-		return client, err
+		return clientData, err
 	}
 
 	// read client information
 	if err := db.Read("clients", clientID, &client); err != nil {
-		return client, err
+		return clientData, err
 	}
 
-	return client, nil
+	// generate client qrcode image in base64
+	if hasQRCode {
+		server, _ := GetServer()
+		globalSettings, _ := GetGlobalSettings()
+
+		png, err := qrcode.Encode(BuildClientConfig(client, server, globalSettings), qrcode.Medium, 256)
+		if err == nil {
+			clientData.QRCode = "data:image/png;base64," + base64.StdEncoding.EncodeToString([]byte(png))
+		} else {
+			fmt.Print("Cannot generate QR code: ", err)
+		}
+	}
+
+	clientData.Client = &client
+
+	return clientData, nil
 }

util/util.go

@@ -173,7 +173,7 @@ func GetIPFromCIDR(cidr string) (string, error) {
 }
 
 // GetAllocatedIPs to get all ip addresses allocated to clients and server
-func GetAllocatedIPs() ([]string, error) {
+func GetAllocatedIPs(ignoreClientID string) ([]string, error) {
 	allocatedIPs := make([]string, 0)
 
 	// initialize database directory
@@ -211,6 +211,7 @@ func GetAllocatedIPs() ([]string, error) {
 			return nil, err
 		}
 
+		if client.ID != ignoreClientID {
 			for _, cidr := range client.AllocatedIPs {
 				ip, err := GetIPFromCIDR(cidr)
 				if err != nil {
@@ -219,6 +220,7 @@ func GetAllocatedIPs() ([]string, error) {
 				allocatedIPs = append(allocatedIPs, ip)
 			}
 		}
+	}
 
 	return allocatedIPs, nil
 }