Add field-selector argument to installations list

CONTRIBUTORS.md

@@ -86,3 +86,4 @@ and we will add you. **All** contributors belong here. 💯
 * [Troy Connor](https://github.com/troy0820)
 * [Phill Gibson](https://github.com/phillipgibson)
 * [Ludvig Liljenberg](https://github.com/ludfjig)
+* [Maninderjit Bindra](https://github.com/manisbindra)

cmd/porter/installations.go

@@ -74,6 +74,7 @@ Optional output formats include json and yaml.`,
 		"Skip the number of installations by a certain amount. Defaults to 0.")
 	f.Int64Var(&opts.Limit, "limit", 0,
 		"Limit the number of installations by a certain amount. Defaults to 0.")
+	f.StringVar(&opts.FieldSelector, "field-selector", "", "Selector (field query) to filter on, supports '=' (e.g. --field-selector bundle.version=0.2.0,status.action=install). All fields from the json output are supported.")
 
 	return cmd
 }

pkg/porter/list.go

@@ -13,6 +13,8 @@ import (
 	"get.porter.sh/porter/pkg/storage"
 	"get.porter.sh/porter/pkg/tracing"
 	dtprinter "github.com/carolynvs/datetime-printer"
+
+	"reflect"
 )
 
 const (
@@ -34,6 +36,7 @@ type ListOptions struct {
 	Labels        []string
 	Skip          int64
 	Limit         int64
+	FieldSelector string
 }
 
 func (o *ListOptions) Validate() error {
@@ -246,9 +249,21 @@ func (p *Porter) ListInstallations(ctx context.Context, opts ListOptions) (Displ
 	}
 
 	var displayInstallations DisplayInstallations
+	var fieldSelectorMap map[string]string
+	if opts.FieldSelector != "" {
+		fieldSelectorMap, err = parseFieldSelector(opts.FieldSelector)
+		if err != nil {
+			return nil, err
+		}
+	}
+
 	for _, installation := range installations {
 		di := NewDisplayInstallation(installation)
+		if opts.FieldSelector != "" && !doesInstallationMatchFieldSelectors(di, fieldSelectorMap) {
+			continue
+		}
 		displayInstallations = append(displayInstallations, di)
+
 	}
 	sort.Sort(sort.Reverse(displayInstallations))
 
@@ -322,3 +337,65 @@ func getDisplayInstallationStatus(installation storage.Installation) string {
 
 	return status
 }
+
+// Split the fieldSelector into a map of fields and values
+// e.g. "bundle.version=0.2.0,status.action=install" => map[string]string{"bundle.version": "0.2.0", "status.action": "install"}
+func parseFieldSelector(fieldSelector string) (map[string]string, error) {
+	fieldSelectorMap := make(map[string]string)
+	for _, field := range strings.Split(fieldSelector, ",") {
+		fieldParts := strings.Split(field, "=")
+		if len(fieldParts) != 2 {
+			return nil, fmt.Errorf("invalid field selector: %s", fieldSelector)
+		}
+		fieldSelectorMap[fieldParts[0]] = fieldParts[1]
+	}
+
+	return fieldSelectorMap, nil
+}
+
+// Check if the installation matches the field selectors
+func doesInstallationMatchFieldSelectors(installation DisplayInstallation, fieldSelectorMap map[string]string) bool {
+	for field, value := range fieldSelectorMap {
+		if !installationHasFieldWithValue(installation, field, value) {
+			return false
+		}
+	}
+	return true
+}
+
+// Check if the installation has the field with the value
+// e.g. installationHasFieldWithValue(installation, "bundle.version", "0.2.0") => true if installation.Bundle.Version (for which json tag is bunde.version) == "0.2.0"
+func installationHasFieldWithValue(installation DisplayInstallation, fieldJsonTagPath string, value string) bool {
+
+	fieldJsonTagPathParts := strings.Split(fieldJsonTagPath, ".")
+	current := reflect.ValueOf(installation)
+
+	for _, fieldJsonTagPart := range fieldJsonTagPathParts {
+		if current.Kind() != reflect.Struct {
+			return false
+		}
+		field := getFieldByJSONTag(current, fieldJsonTagPart)
+		if !field.IsValid() {
+			return false
+		}
+		current = field
+	}
+
+	return reflect.DeepEqual(current.Interface(), value)
+}
+
+// Return the reflect.value based on the field's json tag
+func getFieldByJSONTag(value reflect.Value, fieldJsonTag string) reflect.Value {
+	for i := 0; i < value.NumField(); i++ {
+		field := value.Type().Field(i)
+
+		reflectTag := field.Tag.Get("json")
+		if strings.Contains(reflectTag, ",") {
+			reflectTag = strings.Split(reflectTag, ",")[0]
+		}
+		if reflectTag == fieldJsonTag {
+			return value.Field(i)
+		}
+	}
+	return reflect.Value{}
+}