Add Target fallback support (#340)

* Update go-kong

* Update JSON schema

* Add failover target test

Author: mheap

go.mod

@@ -19,7 +19,7 @@ require (
 	github.com/hashicorp/go-retryablehttp v0.7.7
 	github.com/hexops/gotextdiff v1.0.3
 	github.com/kong/deck v1.50.0
-	github.com/kong/go-kong v0.67.0
+	github.com/kong/go-kong v0.68.0
 	github.com/samber/lo v1.50.0
 	github.com/shirou/gopsutil/v3 v3.24.5
 	github.com/ssgelm/cookiejarparser v1.0.1

go.sum

@@ -224,6 +224,10 @@ github.com/kong/go-apiops v0.1.47 h1:2Y4m36WY4YTOJPBFzaoa9BzKK7fu9c2IYznEwOaPC0c
 github.com/kong/go-apiops v0.1.47/go.mod h1:hKnHJ3UyeuG932SkI/yMpuT/PqSqGXNTS1zhno1lDqg=
 github.com/kong/go-kong v0.67.0 h1:54zXKc58IZpZdlJCv8p95SJjejTxT+cwbWXw97icCak=
 github.com/kong/go-kong v0.67.0/go.mod h1:J0vGB3wsZ2i99zly1zTRe3v7rOKpkhQZRwbcTFP76qM=
+github.com/kong/go-kong v0.67.1-0.20250912114108-d80cef212ee2 h1:Z7sbkIILPRhTFZJkvg7+mpBLd1/dDV0vLA0jCqFLa0U=
+github.com/kong/go-kong v0.67.1-0.20250912114108-d80cef212ee2/go.mod h1:J0vGB3wsZ2i99zly1zTRe3v7rOKpkhQZRwbcTFP76qM=
+github.com/kong/go-kong v0.68.0 h1:rQrLYRKXD6/xf41GBXj9Ns+woAH9p6a4VvcXNMiPZPI=
+github.com/kong/go-kong v0.68.0/go.mod h1:J0vGB3wsZ2i99zly1zTRe3v7rOKpkhQZRwbcTFP76qM=
 github.com/kong/go-slugify v1.0.0 h1:vCFAyf2sdoSlBtLcrmDWUFn0ohlpKiKvQfXZkO5vSKY=
 github.com/kong/go-slugify v1.0.0/go.mod h1:dbR2h3J2QKXQ1k0aww6cN7o4cIcwlWflr6RKRdcoaiw=
 github.com/kong/kubernetes-configuration v1.4.2 h1:/OafLbl2NucvgQV7Xf/uneIgjxmPPUeE92BrssfVAQY=

pkg/file/kong_json_schema.json

@@ -1290,6 +1290,9 @@
         },
         "weight": {
           "type": "integer"
+        },
+        "failover": {
+          "type": "boolean"
         }
       },
       "additionalProperties": false,
@@ -2088,6 +2091,9 @@
         },
         "weight": {
           "type": "integer"
+        },
+        "failover": {
+          "type": "boolean"
         }
       },
       "additionalProperties": false,

tests/integration/sync_test.go

@@ -691,6 +691,17 @@ var (
 		},
 	}
 
+	target_failover = []*kong.Target{
+		{
+			Target: kong.String("198.51.100.11:80"),
+			Upstream: &kong.Upstream{
+				ID: kong.String("a6f89ffc-1e53-4b01-9d3d-7a142bcd"),
+			},
+			Weight:   kong.Int(100),
+			Failover: kong.Bool(true),
+		},
+	}
+
 	targetZeroWeight = []*kong.Target{
 		{
 			Target: kong.String("198.51.100.11:80"),
@@ -2890,6 +2901,42 @@ func Test_Sync_Upstream_Target_With_Sticky_Sessions(t *testing.T) {
 	}
 }
 
+// test scope:
+//   - 3.11
+func Test_Sync_Upstream_Failover_Target(t *testing.T) {
+	// setup stage
+	client, err := getTestClient()
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+
+	tests := []struct {
+		name            string
+		initialKongFile string
+		kongFile        string
+		expectedState   utils.KongRawState
+	}{
+		{
+			name:     "creates a failover target",
+			kongFile: "testdata/sync/045-create-upstream-and-failover-target/kong.yaml",
+			expectedState: utils.KongRawState{
+				Upstreams: upstream,
+				Targets:   target_failover,
+			},
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			runWhen(t, "enterprise", ">=3.12.0")
+			setup(t)
+
+			sync(tc.kongFile)
+			testKongState(t, client, false, tc.expectedState, nil)
+		})
+	}
+}
+
 // test scope:
 //   - 3.x
 func Test_Sync_Upstream_Target_From_3x(t *testing.T) {
@@ -3094,9 +3141,9 @@ func Test_Sync_Upstreams_Target_ZeroWeight_3x(t *testing.T) {
 	}
 
 	tests := []struct {
-		name          string
-		kongFile      string
-		expectedState utils.KongRawState
+		name           string
+		kongFile       string
+		expectedState  utils.KongRawState
 		runWhenVersion string
 	}{
 		{

tests/integration/testdata/sync/045-create-upstream-and-failover-target/kong.yaml

@@ -0,0 +1,6 @@
+_format_version: "3.0"
+upstreams:
+  - name: upstream1
+    targets:
+      - target: 198.51.100.11:80
+        failover: true