Template based json patch

template_test.go

func TestX(t *testing.T) {
	patchs := []Patch{
		Patch{
			Name: "telepresence",
			Template: []byte(`[
				{{ if .Data.Has "/spec/template/metadata/labels/version" }}
				{"op": "copy", "from": "/spec/template/metadata/labels/version", "path": "/spec/template/metadata/labels/version-source"},
				{{ end }}
				{"op": "replace", "path": "/metadata/name", "value": "{{.Data.Value "/metadata/name"}}-{{.NewVersion}}"},
				{"op": "replace", "path": "/spec/template/spec/replicas", "value": "1"},
				{"op": "replace", "path": "/spec/template/spec/containers/0/image", "value": "datawire/telepresence-k8s:{{.Vars.TelepresenceVersion}}"},
				{"op": "replace", "path": "/spec/template/metadata/labels/version", "value": "{{.NewVersion}}"},
				{"op": "replace", "path": "/spec/selector/matchLabels/version", "value": "{{.NewVersion}}"},
				{"op": "replace", "path": "/metadata/labels/version", "value": "{{.NewVersion}}"},
				{"op": "add", "path": "/spec/template/metadata/labels/telepresence", "value": "test"},
				{"op": "add", "path": "/spec/template/spec/containers/0/env/-", "value": {
					"name": "TELEPRESENCE_CONTAINER_NAMESPACE",
					"valueFrom": {
						"fieldRef": {
							"apiVersion": "v1",
							"fieldPath": "metadata.namespace"
						}
					}
				}
				},
				{"op": "remove", "path": "/spec/template/spec/containers/0/livenessProbe"},
				{"op": "remove", "path": "/spec/template/spec/containers/0/readinessProbe"},

					{{ template "basic-remove" }}
				]`),
			Variables: map[string]string{
				"TelepresenceVersion": "y",
			},
		},
		Patch{
			Name: "basic-remove",
			Template: []byte(`
				{"op": "remove", "path": "/metadata/resourceVersion"},
				{"op": "remove", "path": "/metadata/uid"},
				{"op": "remove", "path": "/metadata/generation"},
				{"op": "remove", "path": "/metadata/creationTimestamp"}
			`),
		},
	}

	e := NewEngine(patchs)

	modified, err := e.Run("telepresence", []byte(org), map[string]string{
		"TelepresenceVersion": "x",
	})
	if err != nil {
		fmt.Println(err)
	}
	fmt.Printf("Modified document: %s\n", modified)
}

var org = `
{
    "apiVersion": "extensions/v1beta1",
    "kind": "Deployment",
    "metadata": {
        "annotations": {
            "deployment.kubernetes.io/revision": "1",
            "kubectl.kubernetes.io/last-applied-configuration": "{\"apiVersion\":\"extensions/v1beta1\",\"kind\":\"Deployment\",\"metadata\":{\"annotations\":{},\"creationTimestamp\":null,\"name\":\"productpage-v1\",\"namespace\":\"bookinfo\"},\"spec\":{\"replicas\":1,\"selector\":null,\"strategy\":{},\"template\":{\"metadata\":{\"annotations\":{\"kiali.io/runtimes\":\"go\",\"prometheus.io/path\":\"/metrics\",\"prometheus.io/port\":\"9080\",\"prometheus.io/scheme\":\"http\",\"prometheus.io/scrape\":\"true\",\"sidecar.istio.io/inject\":\"true\"},\"creationTimestamp\":null,\"labels\":{\"app\":\"productpage\",\"version\":\"v1\"}},\"spec\":{\"containers\":[{\"env\":[{\"name\":\"SERVICE_NAME\",\"value\":\"productpage-v1\"},{\"name\":\"HTTP_ADDR\",\"value\":\":9080\"},{\"name\":\"SERVICE_CALL\",\"value\":\"http://reviews:9080/\"}],\"image\":\"docker.io/aslakknutsen/istio-workspace-test:latest\",\"imagePullPolicy\":\"Always\",\"livenessProbe\":{\"httpGet\":{\"path\":\"/healthz\",\"port\":9080},\"initialDelaySeconds\":1,\"periodSeconds\":3},\"name\":\"productpage\",\"ports\":[{\"containerPort\":9080}],\"readinessProbe\":{\"httpGet\":{\"path\":\"/healthz\",\"port\":9080},\"initialDelaySeconds\":1,\"periodSeconds\":3},\"resources\":{}}]}}},\"status\":{}}\n"
        },
        "creationTimestamp": "2019-07-13T08:46:46Z",
        "generation": 1,
        "labels": {
            "app": "productpage",
            "version": "v1"
        },
        "name": "productpage-v1",
        "namespace": "bookinfo",
        "resourceVersion": "638482",
        "selfLink": "/apis/extensions/v1beta1/namespaces/bookinfo/deployments/productpage-v1",
        "uid": "bf2a3655-a54a-11e9-b309-482ae3045b54"
    },
    "spec": {
        "progressDeadlineSeconds": 600,
        "replicas": 1,
        "revisionHistoryLimit": 10,
        "selector": {
            "matchLabels": {
                "app": "productpage",
                "version": "v1"
            }
        },
        "strategy": {
            "rollingUpdate": {
                "maxSurge": 1,
                "maxUnavailable": 1
            },
            "type": "RollingUpdate"
        },
        "template": {
            "metadata": {
                "annotations": {
                    "kiali.io/runtimes": "go",
                    "prometheus.io/path": "/metrics",
                    "prometheus.io/port": "9080",
                    "prometheus.io/scheme": "http",
                    "prometheus.io/scrape": "true",
                    "sidecar.istio.io/inject": "true"
                },
                "creationTimestamp": null,
                "labels": {
                    "app": "productpage",
                    "version": "v1"
                }
            },
            "spec": {
                "containers": [
                    {
                        "env": [
                            {
                                "name": "SERVICE_NAME",
                                "value": "productpage-v1"
                            },
                            {
                                "name": "HTTP_ADDR",
                                "value": ":9080"
                            },
                            {
                                "name": "SERVICE_CALL",
                                "value": "http://reviews:9080/"
                            }
                        ],
                        "image": "docker.io/aslakknutsen/istio-workspace-test:latest",
                        "imagePullPolicy": "Always",
                        "livenessProbe": {
                            "failureThreshold": 3,
                            "httpGet": {
                                "path": "/healthz",
                                "port": 9080,
                                "scheme": "HTTP"
                            },
                            "initialDelaySeconds": 1,
                            "periodSeconds": 3,
                            "successThreshold": 1,
                            "timeoutSeconds": 1
                        },
                        "name": "productpage",
                        "ports": [
                            {
                                "containerPort": 9080,
                                "protocol": "TCP"
                            }
                        ],
                        "readinessProbe": {
                            "failureThreshold": 3,
                            "httpGet": {
                                "path": "/healthz",
                                "port": 9080,
                                "scheme": "HTTP"
                            },
                            "initialDelaySeconds": 1,
                            "periodSeconds": 3,
                            "successThreshold": 1,
                            "timeoutSeconds": 1
                        },
                        "resources": {},
                        "terminationMessagePath": "/dev/termination-log",
                        "terminationMessagePolicy": "File"
                    }
                ],
                "dnsPolicy": "ClusterFirst",
                "restartPolicy": "Always",
                "schedulerName": "default-scheduler",
                "securityContext": {},
                "terminationGracePeriodSeconds": 30
            }
        }
    }
}
`