piped panics when using K8S_BASELINE_ROLLOUT with spec.planner.alwaysPipelineSync: true on v0.47.3-rc0

[ffjlabo]

What happened:

When adding the k8s app with app.pipecd.yaml which has spec.planner.alwaysPipelineSync: true and K8S_BASELINE_ROLLOUT, piped fails with panic like this↓.
The piped keeps failing until it is canceled on the UI.

gx6v1_zp09_2tx_x/T/workspace1130338840/35fa4ef2-dd6f-40c0-acf2-d9a944b32d50-scheduler-192449208", "stage-name": "K8S_CANARY_ROLLOUT", "app-dir": "/var/folders/th/pq_q9v6j6_n_0fgx6v1_zp09_2tx_x/T/workspace1130338840/35fa4ef2-dd6f-40c0-acf2-d9a944b32d50-scheduler-192449208/target-deploysource/deploysource3508451428/repo-1/kubernetes/analysis-with-baseline"}
there are 1 planned/running deployments for scheduling	{"count": 1}
start executing kubernetes stage	{"deployment-id": "35fa4ef2-dd6f-40c0-acf2-d9a944b32d50", "app-id": "c6c93b81-0afa-47f3-a79d-2bbff89d7723", "project-id": "pipecd", "app-kind": "KUBERNETES", "working-dir": "/var/folders/th/pq_q9v6j6_n_0fgx6v1_zp09_2tx_x/T/workspace1130338840/35fa4ef2-dd6f-40c0-acf2-d9a944b32d50-scheduler-192449208", "stage-name": "K8S_BASELINE_ROLLOUT", "app-dir": "/var/folders/th/pq_q9v6j6_n_0fgx6v1_zp09_2tx_x/T/workspace1130338840/35fa4ef2-dd6f-40c0-acf2-d9a944b32d50-scheduler-192449208/target-deploysource/deploysource3508451428/repo-2/kubernetes/analysis-with-baseline"}
successfully reported 6 events about application live state	{"platform-provider": "kubernetes-dev"}
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x2 addr=0x18 pc=0x1046345a4]

goroutine 17863 [running]:
github.com/pipe-cd/pipecd/pkg/app/piped/executor/kubernetes.(*deployExecutor).ensureBaselineRollout(0x14000842800, {0x10514cf98, 0x14000f3e320})
	/Users/s14218/oss/pipe-cd/pipecd/pkg/app/piped/executor/kubernetes/baseline.go:46 +0x1b4
github.com/pipe-cd/pipecd/pkg/app/piped/executor/kubernetes.(*deployExecutor).Execute(0x14000842800, {0x10514d580, 0x140018eee70})
	/Users/s14218/oss/pipe-cd/pipecd/pkg/app/piped/executor/kubernetes/kubernetes.go:156 +0xb00
github.com/pipe-cd/pipecd/pkg/app/piped/controller.(*scheduler).executeStage(0x14000acb408, {0x10514d580, 0x140018eee70}, {{{}, {}, {}, 0x0}, 0x0, {0x0, 0x0, ...}, ...}, ...)
	/Users/s14218/oss/pipe-cd/pipecd/pkg/app/piped/controller/scheduler.go:541 +0xde4
github.com/pipe-cd/pipecd/pkg/app/piped/controller.(*scheduler).Run.func2()
	/Users/s14218/oss/pipe-cd/pipecd/pkg/app/piped/controller/scheduler.go:300 +0xb8
created by github.com/pipe-cd/pipecd/pkg/app/piped/controller.(*scheduler).Run in goroutine 17606
	/Users/s14218/oss/pipe-cd/pipecd/pkg/app/piped/controller/scheduler.go:299 +0xc50
exit status 2

K8S_BASELINE_ROLLOUT requires the previous running commit, which was deployed previously.
https://github.com/pipe-cd/pipecd/blob/master/pkg/app/piped/executor/kubernetes/baseline.go#L46

func (e *deployExecutor) ensureBaselineRollout(ctx context.Context) model.StageStatus {
	var (
		runningCommit   = e.Deployment.RunningCommitHash
		options         = e.StageConfig.K8sBaselineRolloutStageOptions
		variantLabel    = e.appCfg.VariantLabel.Key
		baselineVariant = e.appCfg.VariantLabel.BaselineValue
	)
	if options == nil {
		e.LogPersister.Errorf("Malformed configuration for stage %s", e.Stage.Name)
		return model.StageStatus_STAGE_FAILURE
	}

	// Load running manifests at the most successful deployed commit.
	e.LogPersister.Infof("Loading running manifests at commit %s for handling", runningCommit)
	ds, err := e.RunningDSP.Get(ctx, e.LogPersister)
	if err != nil {
		e.LogPersister.Errorf("Failed to prepare running deploy source (%v)", err)
		return model.StageStatus_STAGE_FAILURE
	}

But there isn't the one when adding the app first.
So e.RunningDSP is nil and causes panic.

This bug is created by the fix in #4916

What you expected to happen:

It should fail with an error on the stage when first adding the app and deploying it as PipelineSync.

How to reproduce it:

Create and add k8s app below.

app.pipecd.yaml
deployment.yaml
service.yaml

app.pipecd.yaml

apiVersion: pipecd.dev/v1beta1
kind: KubernetesApp
spec:
  name: analysis-with-baseline
  labels:
    env: example
    team: product
  planner:
    alwaysUsePipeline: true
  pipeline:
    stages:
      - name: K8S_CANARY_ROLLOUT
        with:
          replicas: 10%
      - name: K8S_BASELINE_ROLLOUT
        with:
          replicas: 10%
      - name: ANALYSIS
        with:
          duration: 10m
          threshold: 2
      - name: K8S_PRIMARY_ROLLOUT
      - name: K8S_CANARY_CLEAN
      - name: K8S_BASELINE_CLEAN

deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: analysis-with-baseline
  labels:
    app: analysis-with-baseline
spec:
  replicas: 3
  selector:
    matchLabels:
      app: analysis-with-baseline
      pipecd.dev/variant: primary
  template:
    metadata:
      labels:
        app: analysis-with-baseline
        pipecd.dev/variant: primary
    spec:
      containers:
      - name: helloworld
        image: ghcr.io/pipe-cd/helloworld:v0.30.0
        args:
          - server
        ports:
        - containerPort: 9085

service.yaml

apiVersion: v1
kind: Service
metadata:
  name: analysis-with-baseline
spec:
  selector:
    app: analysis-with-baseline
  ports:
    - protocol: TCP
      port: 9085
      targetPort: 9085

Environment:

• piped version: v0.47.3-rc0
• control-plane version:
• Others: