// [Route("Subscribe")]
public async Task <AcknowledgeAction> SubscribeAsync(SubscribeAction action)
{
var connectionId = CurrentRequest.RequestContext.ConnectionId;
LogInfo($"Subscribe request from: {connectionId}");
// validate request
if (string.IsNullOrEmpty(action.Rule))
{
return(action.AcknowledgeError("missing or invalid rule name"));
}
// retrieve connection record
var connection = await _dataTable.GetConnectionRecordAsync(connectionId);
if (connection == null)
{
LogInfo("Connection was removed");
return(action.AcknowledgeError("connection gone"));
}
if (connection.State == ConnectionState.Failed)
{
LogInfo("Connection is in failed state");
throw Abort(action.AcknowledgeError("connection reset required"));
}
if (connection.SubscriptionArn == null)
{
LogInfo("Client has not announced itself");
return(action.AcknowledgeError("client is unannounced"));
}
if (connection.State != ConnectionState.Open)
{
LogInfo("Connection is not open (state: {0})", connection.State);
throw Abort(action.AcknowledgeError("action not allowed"));
}
// validate pattern
var validPattern = false;
try {
validPattern = EventPatternMatcher.IsValid(JObject.Parse(action.Pattern));
} catch {
// nothing to do
}
if (!validPattern)
{
return(action.AcknowledgeError("invalid pattern"));
}
// create or update event rule
await _dataTable.CreateOrUpdateRuleRecordAsync(new RuleRecord {
Rule = action.Rule,
Pattern = action.Pattern,
ConnectionId = connection.ConnectionId
});
return(action.AcknowledgeOk());
}
public void Pattern_with_null_serialized_is_valid()
{
// arrange
var pattern = JObject.Parse("{\"source\":[\"Sample.BlazorEventsSample:1.0-DEV@stevebv7-lambdasharp-cor-deploymentbucketresource-9h53iqcat7uj::MyBlazorApp\"],\"detail-type\":[\"Sample.BlazorEventsSample.MyBlazorApp.Shared.TodoItem\"],\"resources\":[\"lambdasharp:tier:SteveBv7\"],\"detail\":null}");
// act
var isValid = EventPatternMatcher.IsValid(pattern);
// assert
isValid.Should().BeTrue();
}
public void Empty_pattern_is_not_valid()
{
// arrange
var pattern = JObject.Parse(@"{}");
// act
var isValid = EventPatternMatcher.IsValid(pattern);
// assert
isValid.Should().BeFalse();
}
public void Pattern_with_invalid_filter_is_not_valid()
{
// arrange
var pattern = JObject.Parse(@"{
""Foo"": [ { ""Bar"": 42 } ]
}");
// act
var isValid = EventPatternMatcher.IsValid(pattern);
// assert
isValid.Should().BeFalse();
}
public void Pattern_with_exists_null_is_not_valid()
{
// arrange
var pattern = JObject.Parse(@"{
""Foo"": [ { ""exists"": null } ]
}");
// act
var isValid = EventPatternMatcher.IsValid(pattern);
// assert
isValid.Should().BeFalse();
}
public void Pattern_with_cidr_bad_prefix_is_not_valid()
{
// arrange
var pattern = JObject.Parse(@"{
""Foo"": [ { ""cidr"": ""1.1.1.1/42"" } ]
}");
// act
var isValid = EventPatternMatcher.IsValid(pattern);
// assert
isValid.Should().BeFalse();
}
public void Pattern_with_numeric_two_operations_is_valid()
{
// arrange
var pattern = JObject.Parse(@"{
""Foo"": [ { ""numeric"": [ "">"", 42, ""<"", 404 ] } ]
}");
// act
var isValid = EventPatternMatcher.IsValid(pattern);
// assert
isValid.Should().BeTrue();
}
public void Pattern_with_anything_but_content_filter_is_valid()
{
// arrange
var pattern = JObject.Parse(@"{
""Foo"": [ { ""anything-but"": { ""prefix"": ""Bar"" } } ]
}");
// act
var isValid = EventPatternMatcher.IsValid(pattern);
// assert
isValid.Should().BeTrue();
}
public void Pattern_with_anything_but_numeric_is_valid()
{
// arrange
var pattern = JObject.Parse(@"{
""Foo"": [ { ""anything-but"": 42 } ]
}");
// act
var isValid = EventPatternMatcher.IsValid(pattern);
// assert
isValid.Should().BeTrue();
}
public void Pattern_with_prefix_list_is_not_valid()
{
// arrange
var pattern = JObject.Parse(@"{
""Foo"": [ { ""prefix"": [ ""Bar"" ] } ]
}");
// act
var isValid = EventPatternMatcher.IsValid(pattern);
// assert
isValid.Should().BeFalse();
}
public void Pattern_with_null_is_valid()
{
// arrange
var pattern = JObject.Parse(@"{
""Foo"": [ null ]
}");
// act
var isValid = EventPatternMatcher.IsValid(pattern);
// assert
isValid.Should().BeTrue();
}
public void Pattern_with_nested_list_is_not_valid()
{
// arrange
var pattern = JObject.Parse(@"{
""Foo"": [ [ 42 ] ]
}");
// act
var isValid = EventPatternMatcher.IsValid(pattern);
// assert
isValid.Should().BeFalse();
}
public void Empty_event_is_not_matched()
{
// arrange
var evt = JObject.Parse(@"{}");
var pattern = JObject.Parse(@"{
""Foo"": [ ""Bar"" ]
}");
// act
var isMatch = EventPatternMatcher.IsMatch(evt, pattern);
// assert
isMatch.Should().BeFalse();
}
public void Event_with_not_exists_is_matched()
{
// arrange
var evt = JObject.Parse(@"{}");
var pattern = JObject.Parse(@"{
""Foo"": [ { ""exists"": false } ]
}");
// act
var isMatch = EventPatternMatcher.IsMatch(evt, pattern);
// assert
isMatch.Should().BeTrue();
}
public void Event_with_prefix_is_not_matched()
{
// arrange
var evt = JObject.Parse(@"{
""Foo"": ""Bar""
}");
var pattern = JObject.Parse(@"{
""Foo"": [ { ""prefix"": ""F"" } ]
}");
// act
var isMatch = EventPatternMatcher.IsMatch(evt, pattern);
// assert
isMatch.Should().BeFalse();
}
public void Event_with_list_is_matched()
{
// arrange
var evt = JObject.Parse(@"{
""Foo"": [ ""Bar"" ]
}");
var pattern = JObject.Parse(@"{
""Foo"": [ ""Bar"" ]
}");
// act
var isMatch = EventPatternMatcher.IsMatch(evt, pattern);
// assert
isMatch.Should().BeTrue();
}
public void Event_with_cidr_mismatch_is_not_matched()
{
// arrange
var evt = JObject.Parse(@"{
""Foo"": ""Bar""
}");
var pattern = JObject.Parse(@"{
""Foo"": [ { ""cidr"": ""192.168.1.1/24"" } ]
}");
// act
var isMatch = EventPatternMatcher.IsMatch(evt, pattern);
// assert
isMatch.Should().BeFalse();
}
public void Event_with_numeric_one_operation_type_mismatch_is_not_matched()
{
// arrange
var evt = JObject.Parse(@"{
""Foo"": ""Bar""
}");
var pattern = JObject.Parse(@"{
""Foo"": [ { ""numeric"": [ "">="", 40 ] } ]
}");
// act
var isMatch = EventPatternMatcher.IsMatch(evt, pattern);
// assert
isMatch.Should().BeFalse();
}
public void Event_with_numeric_two_operation_is_matched()
{
// arrange
var evt = JObject.Parse(@"{
""Foo"": 42
}");
var pattern = JObject.Parse(@"{
""Foo"": [ { ""numeric"": [ "">="", 40, ""<"", 404 ] } ]
}");
// act
var isMatch = EventPatternMatcher.IsMatch(evt, pattern);
// assert
isMatch.Should().BeTrue();
}
public void Event_with_anything_but_is_matched()
{
// arrange
var evt = JObject.Parse(@"{
""Foo"": ""Bar""
}");
var pattern = JObject.Parse(@"{
""Foo"": [ { ""anything-but"": { ""prefix"": ""F"" } } ]
}");
// act
var isMatch = EventPatternMatcher.IsMatch(evt, pattern);
// assert
isMatch.Should().BeTrue();
}
public void Event_with_nested_prefix_is_matched()
{
// arrange
var evt = JObject.Parse(@"{
""Foo"": {
""Bar"": ""ABC""
}
}");
var pattern = JObject.Parse(@"{
""Foo"": {
""Bar"": [ { ""prefix"": ""A"" } ]
}
}");
// act
var isMatch = EventPatternMatcher.IsMatch(evt, pattern);
// assert
isMatch.Should().BeTrue();
}
public override async Task <APIGatewayHttpApiV2ProxyResponse> ProcessMessageAsync(APIGatewayHttpApiV2ProxyRequest request)
{
LogInfo($"Message received at {request.RequestContext.Http.Method}:{request.RawPath}?{request.RawQueryString}");
// validate invocation method
if (request.RequestContext.Http.Method != "POST")
{
LogInfo("Unsupported request method {0}", request.RequestContext.Http.Method);
return(BadRequest());
}
// validate request token
if (
!request.QueryStringParameters.TryGetValue("token", out var token) ||
(token != _httpApiToken)
)
{
LogInfo("Missing or invalid request token");
return(BadRequest());
}
// validate request websocket
if (
!request.QueryStringParameters.TryGetValue("ws", out var connectionId) ||
string.IsNullOrEmpty(connectionId)
)
{
LogInfo("Invalid websocket connection id");
return(BadRequest());
}
// validate request id
if (
!request.QueryStringParameters.TryGetValue("rid", out var requestId) ||
string.IsNullOrEmpty(requestId)
)
{
LogInfo("Invalid request id");
return(BadRequest());
}
// check if request is a subscription confirmation
var topicSubscription = LambdaSerializer.Deserialize <TopicSubscriptionPayload>(request.Body);
if (topicSubscription.Type == "SubscriptionConfirmation")
{
// confirm it's for the expected topic ARN
if (topicSubscription.TopicArn != _eventTopicArn)
{
LogWarn("Wrong Topic ARN for subscription confirmation (Expected: {0}, Received: {1})", _eventTopicArn, topicSubscription.TopicArn);
return(BadRequest());
}
// confirm subscription
await HttpClient.GetAsync(topicSubscription.SubscribeURL);
// send welcome action to websocket connection
await SendMessageToConnection(new AcknowledgeAction {
RequestId = requestId,
Status = "Ok"
}, connectionId);
return(Success("Confirmed"));
}
// validate SNS message
var snsMessage = LambdaSerializer.Deserialize <SNSEvent.SNSMessage>(request.Body);
if (snsMessage.Message == null)
{
LogWarn("Invalid SNS message received: {0}", request.Body);
return(BadRequest());
}
// validate CloudWatch event
var cloudWatchEvent = LambdaSerializer.Deserialize <CloudWatchEventPayload>(snsMessage.Message);
if (
(cloudWatchEvent.Source == null) ||
(cloudWatchEvent.DetailType == null) ||
(cloudWatchEvent.Resources == null)
)
{
LogInfo("Invalid CloudWatch event received: {0}", snsMessage.Message);
return(BadRequest());
}
// check if the keep-alive event was received
if (
(cloudWatchEvent.Source == "aws.events") &&
(cloudWatchEvent.DetailType == "Scheduled Event") &&
(cloudWatchEvent.Resources.Count == 1) &&
(cloudWatchEvent.Resources[0] == _keepAliveRuleArn)
)
{
// send keep-alive action to websocket connection
await SendMessageToConnection(new KeepAliveAction(), connectionId);
return(Success("Ok"));
}
// determine what rules are matching
JObject evt;
try {
evt = JObject.Parse(snsMessage.Message);
} catch (Exception e) {
LogError(e, "invalid message");
return(BadRequest());
}
var rules = await _dataTable.GetConnectionRulesAsync(connectionId);
var matchedRules = rules
.Where(rule => {
try {
var pattern = JObject.Parse(rule.Pattern);
return(EventPatternMatcher.IsMatch(evt, pattern));
} catch (Exception e) {
LogError(e, "invalid event pattern: {0}", rule.Pattern);
return(false);
}
}).Select(rule => rule.Rule)
.ToList();
if (matchedRules.Any())
{
await SendMessageToConnection(
new EventAction {
Rules = matchedRules,
Source = cloudWatchEvent.Source,
Type = cloudWatchEvent.DetailType,
Event = snsMessage.Message
},
connectionId
);
}
return(Success("Ok"));
// local functions
APIGatewayHttpApiV2ProxyResponse Success(string message)
=> new APIGatewayHttpApiV2ProxyResponse
{
Body = message,
Headers = new Dictionary <string, string> {
["Content-Type"] = "text/plain"
},
StatusCode = (int)HttpStatusCode.OK
};
APIGatewayHttpApiV2ProxyResponse BadRequest()
=> new APIGatewayHttpApiV2ProxyResponse
{
Body = "Bad Request",
Headers = new Dictionary <string, string> {
["Content-Type"] = "text/plain"
},
StatusCode = (int)HttpStatusCode.BadRequest
};
}
private async Task <APIGatewayHttpApiV2ProxyResponse> DispatchEvent(string connectionId, string message)
{
// validate EventBridge event
var eventBridgeEvent = LambdaSerializer.Deserialize <EventBridgeventPayload>(message);
if (
(eventBridgeEvent.Source == null) ||
(eventBridgeEvent.DetailType == null) ||
(eventBridgeEvent.Resources == null)
)
{
LogInfo("Invalid EventBridge event received: {0}", message);
return(BadRequestResponse());
}
// check if the keep-alive event was received
if (
(eventBridgeEvent.Source == "aws.events") &&
(eventBridgeEvent.DetailType == "Scheduled Event") &&
(eventBridgeEvent.Resources?.Count == 1) &&
(eventBridgeEvent.Resources[0] == _keepAliveRuleArn)
)
{
// retrieve connection record
var connection = await _dataTable.GetConnectionRecordAsync(connectionId);
if (connection == null)
{
return(SuccessResponse("Gone"));
}
if (connection.State != ConnectionState.Open)
{
return(SuccessResponse("Ignored"));
}
// send keep-alive action to websocket connection
LogInfo("KeepAlive tick");
await SendActionToConnection(new KeepAliveAction(), connectionId);
return(SuccessResponse("Ok"));
}
// determine what rules are matching the event
JObject evt;
try {
evt = JObject.Parse(message);
} catch (Exception e) {
LogError(e, "invalid message");
return(BadRequestResponse());
}
var rules = await _dataTable.GetAllRuleRecordAsync(connectionId);
var matchedRules = rules
.Where(rule => {
try {
var pattern = JObject.Parse(rule.Pattern);
return(EventPatternMatcher.IsMatch(evt, pattern));
} catch (Exception e) {
LogError(e, "invalid event pattern: {0}", rule.Pattern);
return(false);
}
}).Select(rule => rule.Rule)
.ToList();
if (matchedRules.Any())
{
LogInfo($"Event matched {matchedRules.Count():N0} rules: {string.Join(", ", matchedRules)}");
await SendActionToConnection(
new EventAction {
Rules = matchedRules,
Source = eventBridgeEvent.Source,
Type = eventBridgeEvent.DetailType,
Event = message
},
connectionId
);
}
else
{
LogInfo("Event matched no rules");
}
return(SuccessResponse("Ok"));
}
// [Route("Subscribe")]
public async Task <AcknowledgeAction> SubscribeAsync(SubscribeAction action)
{
var connectionId = CurrentRequest.RequestContext.ConnectionId;
LogInfo($"Subscribe request from: {connectionId}");
// validate request
if (string.IsNullOrEmpty(action.Rule))
{
return(new AcknowledgeAction {
RequestId = action.RequestId,
Status = "Error",
Message = "Missing or invalid rule name"
});
}
// retrieve websocket connection record
var connection = await _dataTable.GetConnectionAsync(connectionId);
if (connection == null)
{
LogInfo("Connection was removed");
return(new AcknowledgeAction {
RequestId = action.RequestId,
Rule = action.Rule,
Status = "Error",
Message = "Connection gone"
});
}
// validate pattern
var validPattern = false;
try {
validPattern = EventPatternMatcher.IsValid(JObject.Parse(action.Pattern));
} catch {
// nothing to do
}
if (!validPattern)
{
return(new AcknowledgeAction {
RequestId = action.RequestId,
Rule = action.Rule,
Status = "Error",
Message = "Invalid pattern"
});
}
// create or update event rule
await _dataTable.CreateOrUpdateRuleAsync(new RuleRecord {
Rule = action.Rule,
Pattern = action.Pattern,
ConnectionId = connection.ConnectionId
});
return(new AcknowledgeAction {
RequestId = action.RequestId,
Rule = action.Rule,
Status = "Ok"
});
}
