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  1. Service Binding
  2. APPSVC-548

Express custom variables with jsonpath

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      Upstream

      https://github.com/redhat-developer/service-binding-operator/issues/388

      Goal

      Custom variables help ServiceBinding users define their own binding secret fields by stitching together information from one or morer backing services using the Go templating language.

      The goal of this epic is to ALSO let the users express the same thing using jsonpath which a lot of users find significantly easier to write.

      Example:

      apiVersion: apps.openshift.io/v1alpha1
      kind: ServiceBindingRequest
      metadata:
        name: binding-request
        namespace: service-binding-demo
      spec:
        applications:
          - resourceRef: java-app
            group: apps
            version: v1
            resource: deployments
        services:
          - group: postgresql.baiju.dev
            version: v1alpha1
            kind: Database
            resourceRef: db-demo
        dataMapping:
          - name: JDBC_URL
            value: 'jdbc:postgresql://{{ .status.dbConnectionIP }}:{{ .status.dbConnectionPort }}/{{ .status.dbName }}'
          - name: DB_USER
            value: '{{ index .status.dbConfigMap "db.username" }}'
          - name: DB_PASSWORD
            value: '{{ index .status.dbConfigMap "db.password" }}'
      

      The goal of this epic is to let the users express the same thing using jsonpath which a lot of users find significantly easier to write.

      Why is this important ?

      • Supporting jsonpath provides users a way to express custom variables in a format which is friendlier than Go templates in a lot of scenarios.
      • Some users prefer jsonpath while others prefer Go templates.

      Below is a comparison on use of Go templates v/s jsonpath

      customEnvVar:
          - name: KAFKA_BOOTSTRAP_SERVERS
            value: |-
              {{- range .status.listeners -}}
                {{- if and (eq .type "plain") (gt (len .addresses) 0) -}}
                  {{- with (index .addresses 0) -}}
                    {{ .host }}:{{ .port }}
                  {{- end -}}
                {{- end -}}
              {{- end -}}
      

      Equivalent use of jsonpath

      customEnvVar:
          - name: KAFKA_BOOTSTRAP_SERVERS
            value: {range .status.listeners[?(@.type=="plain")].addresses[0]}{@.host}:{@.port}{end}
      
      

              Unassigned Unassigned
              shbose Shoubhik Bose
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                Updated:
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