GetLoadBalancerState convenience method

Signed-off-by: Matt Siwiec <rizzza@users.noreply.github.com>

pkg/metadata/metadata.go

@@ -1,5 +1,15 @@
 package metadata
 
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+
+	"go.infratographer.com/x/gidx"
+
+	"go.infratographer.com/load-balancer-api/pkg/client"
+)
+
 // LoadBalancerState is the state of a load balancer
 type LoadBalancerState string
 
@@ -11,3 +21,53 @@ const (
 	LoadBalancerStateDeleted     LoadBalancerState = "deleted"
 	LoadBalancerStateUpdating    LoadBalancerState = "updating"
 )
+
+var (
+	// ErrStatusNotFound is returned when a status is not found in the payload
+	ErrStatusNotFound = errors.New("status not found")
+
+	// ErrInvalidStatusData is returned when the status json data is invalid
+	ErrInvalidStatusData = errors.New("invalid status json data")
+)
+
+// ErrUnknownLoadBalancerState is returned when the load balancer state is unknown
+type ErrUnknownLoadBalancerState struct {
+	State string
+}
+
+func (e ErrUnknownLoadBalancerState) Error() string {
+	return "unknown load balancer state: " + e.State
+}
+
+// GetLoadbalancerState returns the status of a load balancer
+func GetLoadbalancerState(metadataStatuses client.MetadataStatuses, statusNamespaceID gidx.PrefixedID) (LoadBalancerState, error) {
+	for _, status := range metadataStatuses.Edges {
+		if status.Node.StatusNamespaceID == statusNamespaceID.String() {
+			// we've found the loadbalancer status namespace we are looking fah
+			data := map[string]string{}
+			if err := json.Unmarshal(status.Node.Data, &data); err != nil {
+				// bad data stored in metadata-api, drop the message and move on
+				return "", fmt.Errorf("%w: %s", ErrInvalidStatusData, err)
+			}
+
+			if state, ok := data["state"]; ok {
+				switch state {
+				case string(LoadBalancerStateCreating):
+					fallthrough
+				case string(LoadBalancerStateTerminating):
+					fallthrough
+				case string(LoadBalancerStateActive):
+					fallthrough
+				case string(LoadBalancerStateDeleted):
+					fallthrough
+				case string(LoadBalancerStateUpdating):
+					return LoadBalancerState(state), nil
+				default:
+					return "", ErrUnknownLoadBalancerState{State: state}
+				}
+			}
+		}
+	}
+
+	return "", ErrStatusNotFound
+}

pkg/metadata/metadata_test.go

@@ -0,0 +1,82 @@
+package metadata
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"go.infratographer.com/load-balancer-api/pkg/client"
+)
+
+func TestGetLoadbalancerState(t *testing.T) {
+	t.Run("valid status", func(t *testing.T) {
+		statuses := client.MetadataStatuses{
+			Edges: []client.MetadataStatusEdges{
+				{
+					Node: client.MetadataStatusNode{
+						StatusNamespaceID: "metasns-loadbalancer-status",
+						Data:              json.RawMessage(`{"state": "active"}`),
+					},
+				},
+				{
+					Node: client.MetadataStatusNode{
+						StatusNamespaceID: "metasns-some-other-namespace",
+						Data:              json.RawMessage(`{"key": "value"}`),
+					},
+				},
+			},
+		}
+
+		state, err := GetLoadbalancerState(statuses, "metasns-loadbalancer-status")
+		assert.Nil(t, err)
+		assert.Equal(t, LoadBalancerStateActive, state)
+	})
+
+	t.Run("bad json data", func(t *testing.T) {
+		statuses := client.MetadataStatuses{
+			Edges: []client.MetadataStatusEdges{
+				{
+					Node: client.MetadataStatusNode{
+						StatusNamespaceID: "metasns-loadbalancer-status",
+						Data:              json.RawMessage(`{"state"}`),
+					},
+				},
+			},
+		}
+
+		state, err := GetLoadbalancerState(statuses, "metasns-loadbalancer-status")
+		assert.NotNil(t, err)
+		assert.Empty(t, state)
+		assert.ErrorIs(t, err, ErrInvalidStatusData)
+	})
+
+	t.Run("status not found", func(t *testing.T) {
+		statuses := client.MetadataStatuses{
+			Edges: []client.MetadataStatusEdges{},
+		}
+
+		state, err := GetLoadbalancerState(statuses, "metasns-loadbalancer-status")
+		assert.NotNil(t, err)
+		assert.Empty(t, state)
+		assert.ErrorIs(t, err, ErrStatusNotFound)
+	})
+
+	t.Run("unknown state", func(t *testing.T) {
+		statuses := client.MetadataStatuses{
+			Edges: []client.MetadataStatusEdges{
+				{
+					Node: client.MetadataStatusNode{
+						StatusNamespaceID: "metasns-loadbalancer-status",
+						Data:              json.RawMessage(`{"state": "unknown"}`),
+					},
+				},
+			},
+		}
+
+		state, err := GetLoadbalancerState(statuses, "metasns-loadbalancer-status")
+		assert.NotNil(t, err)
+		assert.Empty(t, state)
+		assert.ErrorIs(t, err, ErrUnknownLoadBalancerState{State: "unknown"})
+	})
+}