com.google.cloud.functions.invoker.GcfEvents Maven / Gradle / Ivy
// Copyright 2020 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package com.google.cloud.functions.invoker;
import static java.nio.charset.StandardCharsets.UTF_8;
import static java.util.Map.entry;
import com.google.auto.value.AutoValue;
import com.google.cloud.functions.invoker.CloudFunctionsContext.Nullable;
import com.google.cloud.functions.invoker.CloudFunctionsContext.Resource;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonObject;
import io.cloudevents.CloudEvent;
import io.cloudevents.core.builder.CloudEventBuilder;
import java.net.URI;
import java.time.OffsetDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* Conversions from GCF events to CloudEvents.
*/
class GcfEvents {
private static final String FIREBASE_SERVICE = "firebase.googleapis.com";
private static final String FIREBASE_AUTH_SERVICE = "firebaseauth.googleapis.com";
private static final String FIREBASE_DB_SERVICE = "firebasedatabase.googleapis.com";
private static final String FIRESTORE_SERVICE = "firestore.googleapis.com";
private static final String PUB_SUB_SERVICE = "pubsub.googleapis.com";
private static final String STORAGE_SERVICE = "storage.googleapis.com";
private static final String PUB_SUB_MESSAGE_PUBLISHED = "google.cloud.pubsub.topic.v1.messagePublished";
private static final Map EVENT_TYPE_MAPPING = Map.ofEntries(
entry("google.pubsub.topic.publish", new PubSubEventAdapter(PUB_SUB_MESSAGE_PUBLISHED)),
entry("google.storage.object.finalize",
new StorageEventAdapter("google.cloud.storage.object.v1.finalized")),
entry("google.storage.object.delete",
new StorageEventAdapter("google.cloud.storage.object.v1.deleted")),
entry("google.storage.object.archive",
new StorageEventAdapter("google.cloud.storage.object.v1.archived")),
entry("google.storage.object.metadataUpdate",
new StorageEventAdapter("google.cloud.storage.object.v1.metadataUpdated")),
entry("providers/cloud.firestore/eventTypes/document.write",
new FirestoreFirebaseEventAdapter("google.cloud.firestore.document.v1.written",
FIRESTORE_SERVICE)),
entry("providers/cloud.firestore/eventTypes/document.create",
new FirestoreFirebaseEventAdapter("google.cloud.firestore.document.v1.created",
FIRESTORE_SERVICE)),
entry("providers/cloud.firestore/eventTypes/document.update",
new FirestoreFirebaseEventAdapter("google.cloud.firestore.document.v1.updated",
FIRESTORE_SERVICE)),
entry("providers/cloud.firestore/eventTypes/document.delete",
new FirestoreFirebaseEventAdapter("google.cloud.firestore.document.v1.deleted",
FIRESTORE_SERVICE)),
entry("providers/firebase.auth/eventTypes/user.create",
new FirebaseAuthEventAdapter("google.firebase.auth.user.v1.created")),
entry("providers/firebase.auth/eventTypes/user.delete",
new FirebaseAuthEventAdapter("google.firebase.auth.user.v1.deleted")),
entry("providers/google.firebase.analytics/eventTypes/event.log",
new FirestoreFirebaseEventAdapter("google.firebase.analytics.log.v1.written", FIREBASE_SERVICE)),
entry("providers/google.firebase.database/eventTypes/ref.create",
new FirebaseDatabaseEventAdapter("google.firebase.database.ref.v1.created")),
entry("providers/google.firebase.database/eventTypes/ref.write",
new FirebaseDatabaseEventAdapter("google.firebase.database.ref.v1.written")),
entry("providers/google.firebase.database/eventTypes/ref.update",
new FirebaseDatabaseEventAdapter("google.firebase.database.ref.v1.updated")),
entry("providers/google.firebase.database/eventTypes/ref.delete",
new FirebaseDatabaseEventAdapter("google.firebase.database.ref.v1.deleted")),
entry("providers/cloud.pubsub/eventTypes/topic.publish",
new PubSubEventAdapter(PUB_SUB_MESSAGE_PUBLISHED)),
entry("providers/cloud.storage/eventTypes/object.change",
new StorageEventAdapter("google.cloud.storage.object.v1.changed"))
);
private static final Gson GSON = new GsonBuilder().serializeNulls().create();
static CloudEvent convertToCloudEvent(Event legacyEvent) {
String eventType = legacyEvent.getContext().eventType();
EventAdapter eventAdapter = EVENT_TYPE_MAPPING.get(eventType);
if (eventAdapter == null) {
throw new IllegalArgumentException("Unrecognized event type \"" + eventType + "\"");
}
return eventAdapter.convertToCloudEvent(legacyEvent);
}
@AutoValue
abstract static class SourceAndSubject {
/** The source URI, without the initial {@code ///}. */
abstract String source();
abstract @Nullable String subject();
static SourceAndSubject of(String source, String subject) {
return new AutoValue_GcfEvents_SourceAndSubject(source, subject);
}
}
private abstract static class EventAdapter {
private final String cloudEventType;
private final String defaultService;
EventAdapter(String cloudEventType, String defaultService) {
this.cloudEventType = cloudEventType;
this.defaultService = defaultService;
}
final CloudEvent convertToCloudEvent(Event legacyEvent) {
String jsonData = GSON.toJson(legacyEvent.getData());
jsonData = maybeReshapeData(legacyEvent, jsonData);
Resource resource = Resource.from(legacyEvent.getContext().resource());
String service = Optional.ofNullable(resource.service()).orElse(defaultService);
String resourceName = resource.name();
SourceAndSubject sourceAndSubject = convertResourceToSourceAndSubject(resourceName, legacyEvent);
URI source = URI.create("//" + service + "/" + sourceAndSubject.source());
OffsetDateTime timestamp =
Optional.ofNullable(legacyEvent.getContext().timestamp())
.map(s -> OffsetDateTime.parse(s, DateTimeFormatter.ISO_DATE_TIME))
.orElse(null);
return CloudEventBuilder.v1()
.withData(jsonData.getBytes(UTF_8))
.withDataContentType("application/json")
.withId(legacyEvent.getContext().eventId())
.withSource(source)
.withSubject(sourceAndSubject.subject())
.withTime(timestamp)
.withType(cloudEventType)
.build();
}
String maybeReshapeData(Event legacyEvent, String jsonData) {
return jsonData;
}
SourceAndSubject convertResourceToSourceAndSubject(String resourceName, Event legacyEvent) {
return SourceAndSubject.of(resourceName, null);
}
}
private static class PubSubEventAdapter extends EventAdapter {
PubSubEventAdapter(String cloudEventType) {
super(cloudEventType, PUB_SUB_SERVICE);
}
@Override
String maybeReshapeData(Event legacyEvent, String jsonData) {
JsonObject jsonObject = GSON.fromJson(jsonData, JsonObject.class);
jsonObject.addProperty("messageId", legacyEvent.getContext().eventId());
jsonObject.addProperty("publishTime", legacyEvent.getContext().timestamp());
JsonObject wrapped = new JsonObject();
wrapped.add("message", jsonObject);
return GSON.toJson(wrapped);
}
}
private static class StorageEventAdapter extends EventAdapter {
private static final Pattern STORAGE_RESOURCE_PATTERN =
Pattern.compile("^(projects/_/buckets/[^/]+)/(objects/.*?)(?:#\\d+)?$");
StorageEventAdapter(String cloudEventType) {
super(cloudEventType, STORAGE_SERVICE);
}
@Override
SourceAndSubject convertResourceToSourceAndSubject(String resourceName, Event legacyEvent) {
Matcher matcher = STORAGE_RESOURCE_PATTERN.matcher(resourceName);
if (matcher.matches()) {
String resource = matcher.group(1);
String subject = matcher.group(2);
return SourceAndSubject.of(resource, subject);
}
return super.convertResourceToSourceAndSubject(resourceName, legacyEvent);
}
}
private static class FirestoreFirebaseEventAdapter extends EventAdapter {
private static final Pattern FIRESTORE_RESOURCE_PATTERN =
Pattern.compile("^(projects/.+)/((documents|refs)/.+)$");
FirestoreFirebaseEventAdapter(String cloudEventType, String defaultService) {
super(cloudEventType, defaultService);
}
@Override
SourceAndSubject convertResourceToSourceAndSubject(String resourceName, Event legacyEvent) {
Matcher matcher = FIRESTORE_RESOURCE_PATTERN.matcher(resourceName);
if (matcher.matches()) {
String resource = matcher.group(1);
String subject = matcher.group(2);
return SourceAndSubject.of(resource, subject);
}
return super.convertResourceToSourceAndSubject(resourceName, legacyEvent);
}
@Override
String maybeReshapeData(Event legacyEvent, String jsonData) {
// The reshaping code is disabled for now, because the specification for how the legacy "params"
// field should be represented in a CloudEvent is in flux.
if (true || legacyEvent.getContext().params().isEmpty()) {
return jsonData;
}
JsonObject jsonObject = GSON.fromJson(jsonData, JsonObject.class);
JsonObject wildcards = new JsonObject();
legacyEvent.getContext().params().forEach((k, v) -> wildcards.addProperty(k, v));
jsonObject.add("wildcards", wildcards);
return GSON.toJson(jsonObject);
}
}
private static class FirebaseDatabaseEventAdapter extends EventAdapter {
private static final Pattern FIREBASE_DB_RESOURCE_PATTERN =
Pattern.compile("^projects/_/(instances/[^/]+)/((documents|refs)/.+)$");
FirebaseDatabaseEventAdapter(String cloudEventType) {
super(cloudEventType, FIREBASE_DB_SERVICE);
}
@Override
SourceAndSubject convertResourceToSourceAndSubject(String resourceName, Event legacyEvent) {
Matcher matcher = FIREBASE_DB_RESOURCE_PATTERN.matcher(resourceName);
String location = parseLocation(legacyEvent);
if (matcher.matches() && location != null) {
String resource = String.format("projects/_/locations/%s/%s", location, matcher.group(1));
String subject = matcher.group(2);
return SourceAndSubject.of(resource, subject);
}
return super.convertResourceToSourceAndSubject(resourceName, legacyEvent);
}
private String parseLocation(Event legacyEvent) {
String domain = legacyEvent.getContext().domain();
if (domain == null) {
return null;
}
// The default location for firebaseio.com is us-central1
if ("firebaseio.com".equals(domain)) {
return "us-central1";
}
// Otherwise the location can be inferred from the first subdomain
String[] subdomains = domain.split("\\.");
if (subdomains.length > 1) {
return subdomains[0];
}
return null;
}
}
private static class FirebaseAuthEventAdapter extends EventAdapter {
FirebaseAuthEventAdapter(String cloudEventType) {
super(cloudEventType, FIREBASE_AUTH_SERVICE);
}
@Override
SourceAndSubject convertResourceToSourceAndSubject(String resourceName, Event legacyEvent) {
String subject = null;
JsonObject data = legacyEvent.getData().getAsJsonObject();
if (data.has("uid")) {
subject = "users/" + data.get("uid").getAsString();
}
return SourceAndSubject.of(resourceName, subject);
}
@Override
String maybeReshapeData(Event legacyEvent, String jsonData) {
JsonObject jsonObject = GSON.fromJson(jsonData, JsonObject.class);
if (!jsonObject.has("metadata")) {
return jsonData;
}
JsonObject metadata = jsonObject.getAsJsonObject("metadata");
if (metadata.has("createdAt")) {
metadata.add("createTime", metadata.get("createdAt"));
metadata.remove("createdAt");
}
if (metadata.has("lastSignedInAt")) {
metadata.add("lastSignInTime", metadata.get("lastSignedInAt"));
metadata.remove("lastSignedInAt");
}
return GSON.toJson(jsonObject);
}
}
}
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