[Bug]Invalid metadata label generated from deployment file

[lennon310]

We recently upgrade seldon-core to 0.3.2-SNAPSHOT and I'm seeing deployment failure since then.

The yaml file (It works before):

apiVersion: machinelearning.seldon.io/v1alpha2
kind: SeldonDeployment
metadata:
  labels:
    app: seldon
  name: xgboost
  namespace: seldon-core
spec:
  name: xgboost
  predictors:
  - componentSpecs:
    - spec:
        containers:
          - name: feature-transformer
            image: sem-docker.maven.dev.tripadvisor.com/feature_transformer:0.1
            env:
            - name: TRACING
              value: "1"
            - name: JAEGER_CONFIG_PATH
              value: /etc/tracing/config/tracing.yml
            - name: OMP_NUM_THREADS
              value: "6"
            resources:
              limits:
                cpu: 8
                memory: 4Gi
              requests:
                cpu: 1
                memory: 256Mi
            volumeMounts:
            - mountPath: /etc/tracing/config
              name: tracing-config

          - name: model
            env:
              - name: OMP_NUM_THREADS
                value: "6"
            envFrom:
              - secretRef:
                  name: s3-secret
            resources:
              limits:
                cpu: 8
                memory: 4Gi
              requests:
                cpu: 1
                memory: 256Mi
            volumeMounts:
            - mountPath: /etc/tracing/config
              name: tracing-config
        volumes:
        - name: tracing-config
          configMap:
            name: tracing-config
            items:
            - key: tracing.yml
              path: tracing.yml


    svcOrchSpec:
      env:
        - name: SELDON_LOG_LEVEL
          value: DEBUG
        - name: TRACING
          value: "1"
        - name: JAEGER_SERVICE_NAME
          value: xgboost
        - name: JAEGER_AGENT_HOST
          value: jaeger-agent.seldon-core.svc
        - name: JAEGER_AGENT_PORT
          value: "6831"
        - name: JAEGER_SAMPLER_TYPE
          value: const
        - name: JAEGER_SAMPLER_PARAM
          value: "1"
        - name: JAEGER_PROPAGATION
          value: "B3"
        - name: JAEGER_TAGS
          value: "deployment=xgboost"
      resources:
        limits:
          cpu: 4
          memory: 4Gi
        requests:
          cpu: 500m
          memory: 512Mi

    graph:
      children:
        - children: []
          implementation: XGBOOST_SERVER
          name: model
          modelUri: s3://model-image
          type: MODEL
      endpoint:
        type: REST
      name: feature-transformer
      type: TRANSFORMER
    name: transformer
    replicas: 1

and the error Stacktrace:

{"level":"error","ts":1565330078.7320366,"logger":"kubebuilder.controller","msg":"Reconciler error","controller":"seldondeployment-controller","request":"seldon-core/xgboost","error":"Deployment.apps \"xgboost-transformer-f1b02bb\" is invalid: [metadata.labels: Invalid value: \"xgboost-transformer-model-\": a valid label must be an empty string or consist of alphanumeric characters, '-', '_' or '.', and must start and end with an alphanumeric character (e.g. 'MyValue',  or 'my_value',  or '12345', regex used for validation is '(([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9])?'), spec.selector.matchLabels: Invalid value: \"xgboost-transformer-model-\": a valid label must be an empty string or consist of alphanumeric characters, '-', '_' or '.', and must start and end with an alphanumeric character (e.g. 'MyValue',  or 'my_value',  or '12345', regex used for validation is '(([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9])?'), spec.selector: Invalid value: v1.LabelSelector{MatchLabels:map[string]string{\"seldon-deployment-id\":\"xgboost-xgboost\", \"seldon-app\":\"xgboost-xgboost-transformer\", \"seldon-app-feature-transformer\":\"seldon-a92a7f27af7a8e7e336f86b4bf7713be\", \"seldon-app-model\":\"xgboost-transformer-model-\"}, MatchExpressions:[]v1.LabelSelectorRequirement(nil)}: invalid label selector]","stacktrace":"github.com/seldonio/seldon-operator/vendor/github.com/go-logr/zapr.(*zapLogger).Error\n\t/go/src/github.com/seldonio/seldon-operator/vendor/github.com/go-logr/zapr/zapr.go:128\ngithub.com/seldonio/seldon-operator/vendor/sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).processNextWorkItem\n\t/go/src/github.com/seldonio/seldon-operator/vendor/sigs.k8s.io/controller-runtime/pkg/internal/controller/controller.go:217\ngithub.com/seldonio/seldon-operator/vendor/sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).Start.func1\n\t/go/src/github.com/seldonio/seldon-operator/vendor/sigs.k8s.io/controller-runtime/pkg/internal/controller/controller.go:158\ngithub.com/seldonio/seldon-operator/vendor/k8s.io/apimachinery/pkg/util/wait.JitterUntil.func1\n\t/go/src/github.com/seldonio/seldon-operator/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go:133\ngithub.com/seldonio/seldon-operator/vendor/k8s.io/apimachinery/pkg/util/wait.JitterUntil\n\t/go/src/github.com/seldonio/seldon-operator/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go:134\ngithub.com/seldonio/seldon-operator/vendor/k8s.io/apimachinery/pkg/util/wait.Until\n\t/go/src/github.com/seldonio/seldon-operator/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go:88"}