I have an error when starting SpringBootApplication:
Unexpected exception during bean creation; nested exception is java.lang.IllegalArgumentException: url values must be not be absolute.
I'm a beginner is SpringCloud, but I worked with Openshift (On first look it's basically the same things).
I have a cluster with GatewayApplication and some business microservices in it, wrote on Kotlin. Inside cluster microservices communicate by FeignClient without authentification. In consumer-service it looks like it:
#FeignClient(name = "producer-service")
#Headers("Content-Type: application/json")
interface MarketServiceFeign {
#GetMapping("https://somehost.ru/{id}/orders")
fun getUserDevices(
#PathVariable id: String,
): ResponseEntity<List<UserOrder>>
}
I tried find same case, but couldn't.
I tried to:
use #RequestLine from feign-core, but it doesn't work with #FeignClient
use feign.#Param for argument instead of org.springframework.web.bind.annotation.#PathVariable
use url with http instead of https
The thing I didn't take into account is that FeignClient goes to services into cluster by name, not by host. So I fixed it like that:
#FeignClient(name = "producer-service")
#Headers("Content-Type: application/json")
interface MarketServiceFeign {
#GetMapping("/{id}/orders")
fun getUserDevices(
#PathVariable id: String
): ResponseEntity<List<UserDevice>>
}
How I understand, instead of "https://somehost.ru" FeignClient uses service name "producer-service". Result url for FeignClient is "producer-service/{id}/orders".
I hope this helps someone.
If you want to use an absolute URL instead of using load-balancing, you need to pass it via the url attribute in the #FeignClient annotation. It's going to be a URL per Feign client, so you cannot pass it per-request via #RequestMapping annotations. You can only use them to provide the path segments that follow the host url. If you do not pass the url in #FeignClient, the name will be used as serviceId to fetch all the instances of that service (for example, from a service registry) and load-balancing will be performed under the hood to select an instance to send the request to.
Related
I use Ktor for a backend service and I'd like to log incoming requests. I have the feature installed and everything is great but how I can obtain the remote IP address?
call.request.origin.remoteHost
I use this line but I get a hostname, not the IP. I use the standard getByName method from the InetAddress class to get the IP.
Is there a better way?
You can't do this with Ktor as it is not Ktor's job to resolve IP addresses from domains.
What you can use however is Java's InetAddress:
val url = "http://google.com";
val ip = Inet4Address.getByName(url);
Depends on how accurate you want this information to be.
If you read through Ktor code, you'll see that the remoteHost is actually set from the HTTP X-Forwarded-Host header.
From API documentation:
* NEVER use it for user authentication as it can be easily falsified (user can simply set some HTTP headers
* such as X-Forwarded-Host so you should NEVER rely on it in any security checks.
* If you are going to use it to create a back-connection please do it with care as an offender can easily
* use it to force you to connect to some host that is not intended to be connected to so that may cause
* serious consequences.
A better way might be to get the IP from the application engine itself. Unfortunately, the ApplicationCall itself is private, so you'll have to resort to reflection, which isn't optimal:
class RoutingApplicationCall(private val call: ApplicationCall,
Still, this is possible:
// Getting the private field through reflection
val f = context::class.memberProperties.find { it.name == "call" }
f?.let {
// Making it accessible
it.isAccessible = true
val w = it.getter.call(context) as NettyApplicationCall
// Getting the remote address
val ip: SocketAddress? = w.request.context.pipeline().channel().remoteAddress()
println("IP: $ip")
}
We are using the new gcp cloud functions using Java / Kotlin.
As in the current reference implementations, we are returning org.springframework.messaging.support.GenericMessage objects.
So our code looks like this (Kotlin):
fun generatePdfInBase64(message: Message<Map<String, Any>>): Message<*> {
val document = process(message)
val encoded = Base64.getEncoder().encodeToString(document.document)
return GenericMessage(encoded)
}
We were not able to find any way to include a custom http response code to our message, e.g. 201 or something. The function only responds 200 in case of no exception or 500.
Does someone know of a way to do this?
Best wishes
Andy
As it is mentioned at the official documentation, the HttpResponse class has a method called setStatusCode where you are able to set the number of the status as your convenience
For example:
switch (request.getMethod()) {
case "GET":
response.setStatusCode(HttpURLConnection.HTTP_OK);
writer.write("Hello world!");
break;
On the other hand the constructor of the GenericMessage receives as parameter a payload, therefore I think you can create a string with a json format and use the constructor for create your GenericMessage instance with the status response you need.
If you want to know more about the statuds codes take a look at this document.
I have parameter classes with the #Searializable annotation:
#Serializable
data class ShowPostURL(
val date: String,
val titleSlug: String,
override val redirectTo: String? = null
)
and no matter what I do call.receive() won't work. I'm getting HTTP 415 errors and Ktor doesn't log anything. I've added the serialization support as well:
install(ContentNegotiation) {
json()
}
How do I fix this? This is how I'm trying to use it:
accept(ContentType.Any) {
get("/foo/{date}/{titleSlug}") {
val input = call.receive(ShowPostURL::class)
call.respondText("foo")
}
}
If I do a trace I can see that my route is matched, but it can't receive the parameters. Is this json() setup is supposed to work when I'm deserializing from url parameters like this?
Firstly, ContentNegotiation feature works only for receiving custom objects from the payload of POST, PUT and PATCH requests:
POST, PUT and PATCH requests have an associated request body (the payload). That payload is usually encoded.
In order to receive custom objects from the payload, you have to use the ContentNegotiation feature. This is useful for example to receive and send JSON payloads in REST APIs.
When receiving, the Content-Type of the request will be used to determine which ContentConverter will be used to process that request
Secondly, there are three out of the box ContentConverter available:
GsonConverter, JacksonConverter and SerializationConverter.
Each of these converters has its own configuration function: gson, jackson and serialization respectively. You use json configuration function which is most likely is not appropriate for the configuration of ContentNegotiation.
To solve your problem you can access URL parameters by referring them with call.parameters and manually create ShowPostURL object. Then serialize it with the kotlinx.serialization framework if needed.
Also, you can write your own ContentConverter to implement custom logic for receiving typed objects.
This article, https://devblogs.microsoft.com/aspnet/improvements-in-net-core-3-0-for-troubleshooting-and-monitoring-distributed-apps/, tells me that the field TraceId is available as a correlation id, which is great!
info: Microsoft.AspNetCore.Routing.EndpointMiddleware[1]
=> ConnectionId:0HLR1BR0PL1CH
=> RequestPath:/weatherforecastproxy
RequestId:0HLR1BR0PL1CH:00000001,
SpanId:|363a800a-4cf070ad93fe3bd8.,
TraceId:363a800a-4cf070ad93fe3bd8,
ParentId: Executed endpoint 'FrontEndApp.Controllers.WeatherForecastProxyController.Get
(FrontEndApp)'
In fact, I can see that in our log sink this works as advertised: When web application A serves a request and in doing so invokes web application B, both of them write the same TraceId value to the log.
As far as I understand, any ASP.NET Core application that receives an incoming Request-Id header will attach the same header to outgoing requests, but if the header does not exist on the incoming request, an new value will be generated for the outgoing request.
We have been asked to add that value to the response from web application A, but it is (not surprisingly) not available on the incoming request.
I have been looking at the System.Diagnostics.Activity class, but accessing Activity.Current isn't giving me an instance with anything useful - the TraceID is just {} - i.e. empty.
My question is this: How can I access the TraceId value in the context of a web application?
-S
I had the same problem when I tried to add a header with TraceId value.
Doing some tests with ModelValidation, I saw then in this kind of error response the "traceId" value was correct, but I couldn't obtain this value from http context variable in any way.
Then I went to net core source code to see DefaultProblemDetailsFactory implementation and surprise! The "traceId" value is obtained doing this:
var traceId = Activity.Current?.Id ?? httpContext?.TraceIdentifier;
Yes, you can get THE traceId using Activity static variable.
You can get tracid and spanid in dictionary.
using var subject = _tracer.BuildSpan($"Operation").StartActive();
var spanContext = subject.Span.Context;
var dictionary = new Dictionary<string, string>();
_tracer.Inject(spanContext, BuiltinFormats.TextMap, new TextMapInjectAdapter(dictionary));
I have a camel route which processes a message from a process queue and sends it to upload queue.
from("activemq:queue:process" ).routeId("activemq_processqueue")
.process(exchange -> {
SomeImpl impl = new SomeImpl();
impl.process(exchange);
})
.to(ExchangePattern.InOnly, "activemq:queue:upload");
In impl.process I am populating an Id and destination server path. Now I need to define a new route which consumes messages from upload queue ,and copy a local folder (based on Id generated in previous route) and upload it to destination folder which is an ftp server (this is also populated in previous route)
So how to design a new route where both from and to endpoints are dynamic which would look something like below ?
from("activemq:queue:upload" )
.from("file:basePath/"+{idFromExchangeObject})
.to("ftp:"+{serverIpFromExchangeObject}+"/"+{pathFromExchangeObject});
I think there is a better alternative for your case, taking as granted that you are using a Camel version newer than 2.16.(alternatives for a previous version exist but the are more complicated and don't look elegant - ( e.g consumerTemplate & recipientList).
You can replace the first "dynamic from" with pollEnrich which enriches the message using a polling consumer and simple expression to build the dynamic file endpoint. For the second part, as already mentioned, a dynamic uri .toD will do the job. So your route would look like this:
from("activemq:queue:upload" )
.pollEnrich().simple("file:basePath/${header.idFromExchangeObject})
.aggregationStrategy(new ExampleAggregationStrategy()) // * see explanation
.timeout(2000) // the timeout is optional but recommended
.toD("ftp:${header.serverIpFromExchangeObject}/${header.pathFromExchangeObject}")
See content enricher section "Using dynamic uris"
http://camel.apache.org/content-enricher.html .
You will need an aggregation strategy, to combine the original exchange with the resource exchange in order to make sure that the headers serverIpFromExchangeObject, pathFromExchangeObject will be included in the aggregated exchange after the enrichment. If you don't include the custom strategy then Camel will by default use the body obtained from the resource. Have a look at the ExampleAggregationStrategy example in content-enricher.html to see how this works.
For the .toD() have a look at http://camel.apache.org/how-to-use-a-dynamic-uri-in-to.html
Adding a dynamic to endpoint in Camel (as noted in the comment) can be done with the .toD() which is described on this page on the Camel site.
I don't know of any fromD() equivalent. However, you could add a dynamic route by calling the addRoutes method on the CamelContext. This is described on this page on the Camel site.
Expanding slightly on the example from the Camel site here is something that should get you heading in the right direction.
public void process(Exchange exchange) throws Exception {
String idFromExchangeObject = ...
String serverIpFromExchangeObject = ...
String pathFromExchangeObject = ...
exchange.getContext().addRoutes(new RouteBuilder() {
public void configure() {
from("file:basePath/"+ idFromExchangeObject)
.to("ftp:"+ serverIpFromExchangeObject +"/"+pathFromExchangeObject);
}
});
}
There may be other options in Camel as well since this framework has an amazing number of EIP and capabilities.