From 2aa93d64f1a5a5888c8a998084574c9042a2074e Mon Sep 17 00:00:00 2001
From: Andre Sterba <andre.sterba@stud.h-da.de>
Date: Tue, 11 Oct 2022 09:25:47 +0000
Subject: [PATCH] Add additional example application hostname-checker
See merge request danet/gosdn!376
Co-authored-by: Fabian Seidl <fabian.b.seidl@stud.h-da.de>
Co-authored-by: Malte Bauch <malte.bauch@tbnet.works>
---
Makefile | 8 +-
applications/hostname-checker/app.go | 127 ++++++++++++++++++++++++
applications/hostname-checker/device.go | 28 ++++++
applications/hostname-checker/main.go | 33 ++++++
4 files changed, 195 insertions(+), 1 deletion(-)
create mode 100644 applications/hostname-checker/app.go
create mode 100644 applications/hostname-checker/device.go
create mode 100644 applications/hostname-checker/main.go
diff --git a/Makefile b/Makefile
index 1be95526c..63557f708 100644
--- a/Makefile
+++ b/Makefile
@@ -56,7 +56,7 @@ generate-csbi-yang-models: install-tools
../../$(TOOLS_DIR)/go-ygot-generator-generator config.yaml gostructs.go &&\
go generate
-build: pre build-gosdn build-gosdnc build-orchestrator build-venv-manager build-arista-routing-engine-app
+build: pre build-gosdn build-gosdnc build-orchestrator build-venv-manager build-arista-routing-engine-app build-hostname-checker-app
build-gosdn: pre
$(GOBUILD) -trimpath -o $(BUILD_ARTIFACTS_PATH)/gosdn ./controller/cmd/gosdn
@@ -73,6 +73,9 @@ build-venv-manager: pre
build-arista-routing-engine-app: pre
$(GOBUILD) -trimpath -o $(BUILD_ARTIFACTS_PATH)/arista-routing-engine ./applications/arista-routing-engine
+build-hostname-checker-app: pre
+ $(GOBUILD) -trimpath -o $(BUILD_ARTIFACTS_PATH)/hostname-checker ./applications/hostname-checker
+
containerize-all: containerize-gosdn containerize-gosdnc containerize-orchestrator containerize-target
containerize-gosdn:
@@ -93,6 +96,9 @@ containerize-target:
containerize-arista-routing-engine-app:
docker buildx build --rm -t arista-routing-engine-app -f applications/arista-routing-engine/arista-routing-engine.Dockerfile .
+containerize-hostname-checker-app:
+ docker buildx build --rm -t hostname-checker-app -f applications/hostname-checker/hostname-checker.Dockerfile .
+
containerlab-start: containerize-all
sudo containerlab deploy --topo gosdn.clab.yaml
diff --git a/applications/hostname-checker/app.go b/applications/hostname-checker/app.go
new file mode 100644
index 000000000..01d6867c7
--- /dev/null
+++ b/applications/hostname-checker/app.go
@@ -0,0 +1,127 @@
+package main
+
+import (
+ "context"
+ "fmt"
+ "os"
+ "os/signal"
+ "syscall"
+ "time"
+
+ "code.fbi.h-da.de/danet/gosdn/api/go/gosdn/device"
+
+ "github.com/google/uuid"
+ "github.com/openconfig/ygot/ygot"
+
+ "code.fbi.h-da.de/danet/gosdn/application-framework/event"
+ "code.fbi.h-da.de/danet/gosdn/application-framework/models"
+ "google.golang.org/grpc"
+ "google.golang.org/grpc/credentials/insecure"
+)
+
+// Application is an example for a sdn application.
+type Application struct {
+ eventService event.ServiceInterface
+ stopChannel chan os.Signal
+ grpcClientConn *grpc.ClientConn
+}
+
+// Run runs the application.
+func (a *Application) Run() {
+ signal.Notify(a.stopChannel, os.Interrupt, syscall.SIGTERM)
+
+ a.eventService.SubscribeToEventType([]event.TypeToCallbackTuple{
+ {Type: event.Update, Callback: a.callback},
+ })
+ a.eventService.SetupEventReciever(a.stopChannel)
+
+ conn, err := grpc.Dial("localhost:55055", grpc.WithTransportCredentials(insecure.NewCredentials()))
+ if err != nil {
+ panic(err)
+ }
+
+ a.grpcClientConn = conn
+
+ var forever chan struct{}
+
+ go func() {
+ for {
+ select {
+ case <-a.stopChannel:
+ close(forever)
+ _ = a.grpcClientConn.Close()
+
+ return
+ }
+ }
+ }()
+
+ <-forever
+}
+
+func (a *Application) callback(event *event.Event) {
+ ctx := context.Background()
+ deviceServer := device.NewDeviceServiceClient(a.grpcClientConn)
+
+ request := &device.GetDeviceRequest{
+ Timestamp: time.Now().UnixNano(),
+ DeviceID: event.EntityID.String(),
+ }
+
+ response, err := deviceServer.Get(ctx, request)
+ if err != nil {
+ fmt.Printf("Error %+v\n ", err)
+ return
+ }
+
+ fmt.Printf("\n[APP] Device-ID: %v, Device-Name: %+v \n", response.Device.Id, response.Device.Name)
+
+ d := NewDevice(uuid.MustParse(response.Device.Id), response.Device.Name)
+
+ // Create 'root' path to be able to load the whole model from the store.
+ path, err := ygot.StringToPath("/", ygot.StructuredPath)
+ if err != nil {
+ panic(err)
+ }
+
+ // Use unmarshall from the devices SBI to unmarshall ygot json in go struct.
+ err = models.Unmarshal([]byte(response.Device.Model), path, &d.Model)
+ if err != nil {
+ panic(err)
+ }
+
+ if *d.Model.System.Config.Hostname != d.Name {
+ fmt.Printf("[APP] Device.Name (%s) doesn't match Device.Hostname (%s) in model! Updating...\n",
+ d.Name,
+ *d.Model.System.Config.Hostname,
+ )
+
+ *d.Model.System.Config.Hostname = d.Name
+
+ modelAsString, err := models.GetModelAsString(&d.Model)
+ if err != nil {
+ panic(err)
+ }
+
+ requestUpdate := &device.UpdateDeviceRequest{
+ Timestamp: time.Now().UnixNano(),
+ Device: &device.Device{
+ Id: d.UUID.String(),
+ Name: d.Name,
+ Model: modelAsString,
+ },
+ }
+
+ updateResponse, err := deviceServer.Update(ctx, requestUpdate)
+ if err != nil {
+ panic(err)
+ }
+
+ fmt.Printf("[APP] Update response: %+v", updateResponse)
+ } else {
+ fmt.Printf("[APP] Device.Name (%s) does match Device.Hostname (%s) in model! Nothing to do for me...\n",
+ d.Name,
+ *d.Model.System.Config.Hostname,
+ )
+ }
+}
diff --git a/applications/hostname-checker/device.go b/applications/hostname-checker/device.go
new file mode 100644
index 000000000..3c2a1af84
--- /dev/null
+++ b/applications/hostname-checker/device.go
@@ -0,0 +1,28 @@
+package main
+
+import (
+ "code.fbi.h-da.de/danet/gosdn/models/generated/arista"
+
+ "github.com/google/uuid"
+)
+
+// Device is a device.
+type Device struct {
+ // UUID represents the Devices UUID
+ UUID uuid.UUID
+
+ // Name is the device's human readable Name
+ Name string
+
+ // Device embeds a ygot.GoStruct containing the device details
+ Model arista.Device
+}
+
+// NewDevice creates a new device.
+func NewDevice(id uuid.UUID, name string) *Device {
+ return &Device{
+ UUID: id,
+ Model: arista.Device{},
+ Name: name,
+ }
+}
diff --git a/applications/hostname-checker/main.go b/applications/hostname-checker/main.go
new file mode 100644
index 000000000..d68ebc980
--- /dev/null
+++ b/applications/hostname-checker/main.go
@@ -0,0 +1,33 @@
+package main
+
+import (
+ "os"
+
+ "code.fbi.h-da.de/danet/gosdn/application-framework/event"
+ "code.fbi.h-da.de/danet/gosdn/application-framework/registration"
+ "github.com/sirupsen/logrus"
+)
+
+func main() {
+ queueCredentials, err := registration.Register("localhost:55055", "hostname-checker", "SecurePresharedToken")
+ if err != nil {
+ logrus.Errorf("failed to register application on control plane. %v", err)
+ os.Exit(1)
+ }
+
+ eventService, err := event.NewEventService(
+ queueCredentials,
+ []event.Topic{event.Device},
+ )
+ if err != nil {
+ logrus.Errorf("failed to create event service. %v", err)
+ os.Exit(1)
+ }
+
+ app := &Application{
+ eventService: eventService,
+ stopChannel: make(chan os.Signal, 1),
+ }
+
+ app.Run()
+}
--
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