We Keep Coding

how to convert this curl command to javascript fetch [duplicate]

I can hit this endpoint, http://catfacts-api.appspot.com/api/facts?number=99 via Postman and it returns JSON
Additionally I am using create-react-app and would like to avoid setting up any server config.
In my client code I am trying to use fetch to do the same thing, but I get the error:
No 'Access-Control-Allow-Origin' header is present on the requested
resource. Origin 'http://localhost:3000' is therefore not allowed
access. If an opaque response serves your needs, set the request's
mode to 'no-cors' to fetch the resource with CORS disabled.
So I am trying to pass in an object, to my Fetch which will disable CORS, like so:
fetch('http://catfacts-api.appspot.com/api/facts?number=99', { mode: 'no-cors'})
.then(blob => blob.json())
.then(data => {
console.table(data);
return data;
})
.catch(e => {
console.log(e);
return e;
});
Interestingly enough the error I get is actually a syntax error with this function. I am not sure my actual fetch is broken, because when I remove the { mode: 'no-cors' } object, and supply it with a different URL it works just fine.
I have also tried to pass in the object { mode: 'opaque'} , but this returns the original error from above.
I belive all I need to do is disable CORS.. What am I missing?

mode: 'no-cors' won’t magically make things work. In fact it makes things worse, because one effect it has is to tell browsers, “Block my frontend JavaScript code from seeing contents of the response body and headers under all circumstances.” Of course you never want that.
What happens with cross-origin requests from frontend JavaScript is that browsers by default block frontend code from accessing resources cross-origin. If Access-Control-Allow-Origin is in a response, then browsers relax that blocking and allow your code to access the response.
But if a site sends no Access-Control-Allow-Origin in its responses, your frontend code can’t directly access responses from that site. In particular, you can’t fix it by specifying mode: 'no-cors' (in fact that’ll ensure your frontend code can’t access the response contents).
However, one thing that will work: if you send your request through a CORS proxy.
You can also easily deploy your own proxy to Heroku in just 2-3 minutes, with 5 commands:
git clone https://github.com/Rob--W/cors-anywhere.git
cd cors-anywhere/
npm install
heroku create
git push heroku master
After running those commands, you’ll end up with your own CORS Anywhere server running at, for example, https://cryptic-headland-94862.herokuapp.com/.
Prefix your request URL with your proxy URL; for example:
https://cryptic-headland-94862.herokuapp.com/https://example.com
Adding the proxy URL as a prefix causes the request to get made through your proxy, which:
Forwards the request to https://example.com.
Receives the response from https://example.com.
Adds the Access-Control-Allow-Origin header to the response.
Passes that response, with that added header, back to the requesting frontend code.
The browser then allows the frontend code to access the response, because that response with the Access-Control-Allow-Origin response header is what the browser sees.
This works even if the request is one that triggers browsers to do a CORS preflight OPTIONS request, because in that case, the proxy also sends back the Access-Control-Allow-Headers and Access-Control-Allow-Methods headers needed to make the preflight successful.
I can hit this endpoint, http://catfacts-api.appspot.com/api/facts?number=99 via Postman
https://developer.mozilla.org/en-US/docs/Web/HTTP/Access_control_CORS explains why it is that even though you can access the response with Postman, browsers won’t let you access the response cross-origin from frontend JavaScript code running in a web app unless the response includes an Access-Control-Allow-Origin response header.
http://catfacts-api.appspot.com/api/facts?number=99 has no Access-Control-Allow-Origin response header, so there’s no way your frontend code can access the response cross-origin.
Your browser can get the response fine and you can see it in Postman and even in browser devtools—but that doesn’t mean browsers expose it to your code. They won’t, because it has no Access-Control-Allow-Origin response header. So you must instead use a proxy to get it.
The proxy makes the request to that site, gets the response, adds the Access-Control-Allow-Origin response header and any other CORS headers needed, then passes that back to your requesting code. And that response with the Access-Control-Allow-Origin header added is what the browser sees, so the browser lets your frontend code actually access the response.
So I am trying to pass in an object, to my Fetch which will disable CORS
You don’t want to do that. To be clear, when you say you want to “disable CORS” it seems you actually mean you want to disable the same-origin policy. CORS itself is actually a way to do that — CORS is a way to loosen the same-origin policy, not a way to restrict it.
But anyway, it’s true you can—in your local environment—do suff like give a browser runtime flags to disable security and run insecurely, or you can install a browser extension locally to get around the same-origin policy, but all that does is change the situation just for you locally.
No matter what you change locally, anybody else trying to use your app is still going to run into the same-origin policy, and there’s no way you can disable that for other users of your app.
You most likely never want to use mode: 'no-cors' in practice except in a few limited cases, and even then only if you know exactly what you’re doing and what the effects are. That’s because what setting mode: 'no-cors' actually says to the browser is, “Block my frontend JavaScript code from looking into the contents of the response body and headers under all circumstances.” In most cases that’s obviously really not what you want.
As far as the cases when you would want to consider using mode: 'no-cors', see the answer at What limitations apply to opaque responses? for the details. The gist of it is:
In the limited case when you’re using JavaScript to put content from another origin into a <script>, <link rel=stylesheet>, <img>, <video>, <audio>, <object>, <embed>, or <iframe> element (which works because embedding of resources cross-origin is allowed for those)—but for some reason you don’t want to/can’t do that just by having the markup of the document use the resource URL as the href or src attribute for the element.
When the only thing you want to do with a resource is to cache it. As alluded to in What limitations apply to opaque responses?, in practice the scenario that’s for is when you’re using Service Workers, in which case the API that’s relevant is the Cache Storage API.
But even in those limited cases, there are some important gotchas to be aware of; see the answer at What limitations apply to opaque responses? for the details.
I have also tried to pass in the object { mode: 'opaque'}
There is no 'opaque' request mode — opaque is instead just a property of the response, and browsers set that opaque property on responses from requests sent with no-cors mode.
But incidentally the word opaque is a pretty explicit signal about the nature of the response you end up with: “opaque” means you can’t see into any of its details; it blocks you from seeing.

If you are trying to address this issue temporarily on your localhost, you can use this chrome extension : Allow CORS Access-Control-Allow-Origin
https://chrome.google.com/webstore/detail/allow-cors-access-control/lhobafahddgcelffkeicbaginigeejlf

If you are using Express as back-end you just have to install cors and import and use it in app.use(cors());.
If it is not resolved then try switching ports.
It will surely resolve after switching ports

So if you're like me and developing a website on localhost where you're trying to fetch data from Laravel API and use it in your Vue front-end, and you see this problem, here is how I solved it:
In your Laravel project, run command php artisan make:middleware Cors. This will create app/Http/Middleware/Cors.php for you.
Add the following code inside the handles function in Cors.php:
return $next($request)
->header('Access-Control-Allow-Origin', '*')
->header('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE, OPTIONS');
In app/Http/kernel.php, add the following entry in $routeMiddleware array:
‘cors’ => \App\Http\Middleware\Cors::class
(There would be other entries in the array like auth, guest etc. Also make sure you're doing this in app/Http/kernel.php because there is another kernel.php too in Laravel)
Add this middleware on route registration for all the routes where you want to allow access, like this:
Route::group(['middleware' => 'cors'], function () {
Route::get('getData', 'v1\MyController#getData');
Route::get('getData2', 'v1\MyController#getData2');
});
In Vue front-end, make sure you call this API in mounted() function and not in data(). Also make sure you use http:// or https:// with the URL in your fetch() call.
Full credits to Pete Houston's blog article.

You can also set up a reverse proxy which adds the CORS headers using a self-hosted CORS Anywhere or Just CORS if you want a managed solution.
https://justcors.com/<id>/<your-requested-resource>
http://cors-anywhere.com/<your-requested-resource>

Very easy solution (2 min to config) is to use local-ssl-proxy package from npm
The usage is straight pretty forward:
1. Install the package:
npm install -g local-ssl-proxy
2. While running your local-server mask it with the local-ssl-proxy --source 9001 --target 9000
P.S: Replace --target 9000 with the -- "number of your port" and --source 9001 with --source "number of your port +1"

Solution for me was to just do it server side
I used the C# WebClient library to get the data (in my case it was image data) and send it back to the client. There's probably something very similar in your chosen server-side language.
//Server side, api controller
[Route("api/ItemImage/GetItemImageFromURL")]
public IActionResult GetItemImageFromURL([FromQuery] string url)
{
ItemImage image = new ItemImage();
using(WebClient client = new WebClient()){
image.Bytes = client.DownloadData(url);
return Ok(image);
}
}
You can tweak it to whatever your own use case is. The main point is client.DownloadData() worked without any CORS errors. Typically CORS issues are only between websites, hence it being okay to make 'cross-site' requests from your server.
Then the React fetch call is as simple as:
//React component
fetch(`api/ItemImage/GetItemImageFromURL?url=${imageURL}`, {
method: 'GET',
})
.then(resp => resp.json() as Promise<ItemImage>)
.then(imgResponse => {
// Do more stuff....
)}

I had a similar problem with my browser debugger saying my response.body was null but fiddler and the developer tools show it as populated that turned out to be basically the same scenario as this. I was using a local Angular application hitting a Web Api service running on IISExpress. I fixed it by following the steps outlined here to find the correct applicationhost.config file to add a Access-Control-Allow-Origin header like so:
<customHeaders>
<clear />
<add name="X-Powered-By" value="ASP.NET" />
<add name="Access-Control-Allow-Origin" value="*" />
<add name="Access-Control-Allow-Headers" value="Content-Type" />
</customHeaders>

If all the above solutions don't work, probably it's because of the file permissions as sometimes even if you have fixed the non-cors problem using Heroku or another way, it throws 403 forbidden error. Set the directory/file permissions like this:
Permissions and ownership errors
A 403 Forbidden error can also be caused by incorrect ownership or permissions on your web content files and folders.
Permissions
Rule of thumb for correct permissions:
Folders: 755
Static Content: 644
Dynamic Content: 700

Parse external json using Fetch API in jsfiddle [duplicate]

I can hit this endpoint, http://catfacts-api.appspot.com/api/facts?number=99 via Postman and it returns JSON
Additionally I am using create-react-app and would like to avoid setting up any server config.
In my client code I am trying to use fetch to do the same thing, but I get the error:
No 'Access-Control-Allow-Origin' header is present on the requested
resource. Origin 'http://localhost:3000' is therefore not allowed
access. If an opaque response serves your needs, set the request's
mode to 'no-cors' to fetch the resource with CORS disabled.
So I am trying to pass in an object, to my Fetch which will disable CORS, like so:
fetch('http://catfacts-api.appspot.com/api/facts?number=99', { mode: 'no-cors'})
.then(blob => blob.json())
.then(data => {
console.table(data);
return data;
})
.catch(e => {
console.log(e);
return e;
});
Interestingly enough the error I get is actually a syntax error with this function. I am not sure my actual fetch is broken, because when I remove the { mode: 'no-cors' } object, and supply it with a different URL it works just fine.
I have also tried to pass in the object { mode: 'opaque'} , but this returns the original error from above.
I belive all I need to do is disable CORS.. What am I missing?

mode: 'no-cors' won’t magically make things work. In fact it makes things worse, because one effect it has is to tell browsers, “Block my frontend JavaScript code from seeing contents of the response body and headers under all circumstances.” Of course you never want that.
What happens with cross-origin requests from frontend JavaScript is that browsers by default block frontend code from accessing resources cross-origin. If Access-Control-Allow-Origin is in a response, then browsers relax that blocking and allow your code to access the response.
But if a site sends no Access-Control-Allow-Origin in its responses, your frontend code can’t directly access responses from that site. In particular, you can’t fix it by specifying mode: 'no-cors' (in fact that’ll ensure your frontend code can’t access the response contents).
However, one thing that will work: if you send your request through a CORS proxy.
You can also easily deploy your own proxy to Heroku in just 2-3 minutes, with 5 commands:
git clone https://github.com/Rob--W/cors-anywhere.git
cd cors-anywhere/
npm install
heroku create
git push heroku master
After running those commands, you’ll end up with your own CORS Anywhere server running at, for example, https://cryptic-headland-94862.herokuapp.com/.
Prefix your request URL with your proxy URL; for example:
https://cryptic-headland-94862.herokuapp.com/https://example.com
Adding the proxy URL as a prefix causes the request to get made through your proxy, which:
Forwards the request to https://example.com.
Receives the response from https://example.com.
Adds the Access-Control-Allow-Origin header to the response.
Passes that response, with that added header, back to the requesting frontend code.
The browser then allows the frontend code to access the response, because that response with the Access-Control-Allow-Origin response header is what the browser sees.
This works even if the request is one that triggers browsers to do a CORS preflight OPTIONS request, because in that case, the proxy also sends back the Access-Control-Allow-Headers and Access-Control-Allow-Methods headers needed to make the preflight successful.
I can hit this endpoint, http://catfacts-api.appspot.com/api/facts?number=99 via Postman
https://developer.mozilla.org/en-US/docs/Web/HTTP/Access_control_CORS explains why it is that even though you can access the response with Postman, browsers won’t let you access the response cross-origin from frontend JavaScript code running in a web app unless the response includes an Access-Control-Allow-Origin response header.
http://catfacts-api.appspot.com/api/facts?number=99 has no Access-Control-Allow-Origin response header, so there’s no way your frontend code can access the response cross-origin.
Your browser can get the response fine and you can see it in Postman and even in browser devtools—but that doesn’t mean browsers expose it to your code. They won’t, because it has no Access-Control-Allow-Origin response header. So you must instead use a proxy to get it.
The proxy makes the request to that site, gets the response, adds the Access-Control-Allow-Origin response header and any other CORS headers needed, then passes that back to your requesting code. And that response with the Access-Control-Allow-Origin header added is what the browser sees, so the browser lets your frontend code actually access the response.
So I am trying to pass in an object, to my Fetch which will disable CORS
You don’t want to do that. To be clear, when you say you want to “disable CORS” it seems you actually mean you want to disable the same-origin policy. CORS itself is actually a way to do that — CORS is a way to loosen the same-origin policy, not a way to restrict it.
But anyway, it’s true you can—in your local environment—do suff like give a browser runtime flags to disable security and run insecurely, or you can install a browser extension locally to get around the same-origin policy, but all that does is change the situation just for you locally.
No matter what you change locally, anybody else trying to use your app is still going to run into the same-origin policy, and there’s no way you can disable that for other users of your app.
You most likely never want to use mode: 'no-cors' in practice except in a few limited cases, and even then only if you know exactly what you’re doing and what the effects are. That’s because what setting mode: 'no-cors' actually says to the browser is, “Block my frontend JavaScript code from looking into the contents of the response body and headers under all circumstances.” In most cases that’s obviously really not what you want.
As far as the cases when you would want to consider using mode: 'no-cors', see the answer at What limitations apply to opaque responses? for the details. The gist of it is:
In the limited case when you’re using JavaScript to put content from another origin into a <script>, <link rel=stylesheet>, <img>, <video>, <audio>, <object>, <embed>, or <iframe> element (which works because embedding of resources cross-origin is allowed for those)—but for some reason you don’t want to/can’t do that just by having the markup of the document use the resource URL as the href or src attribute for the element.
When the only thing you want to do with a resource is to cache it. As alluded to in What limitations apply to opaque responses?, in practice the scenario that’s for is when you’re using Service Workers, in which case the API that’s relevant is the Cache Storage API.
But even in those limited cases, there are some important gotchas to be aware of; see the answer at What limitations apply to opaque responses? for the details.
I have also tried to pass in the object { mode: 'opaque'}
There is no 'opaque' request mode — opaque is instead just a property of the response, and browsers set that opaque property on responses from requests sent with no-cors mode.
But incidentally the word opaque is a pretty explicit signal about the nature of the response you end up with: “opaque” means you can’t see into any of its details; it blocks you from seeing.

If you are trying to address this issue temporarily on your localhost, you can use this chrome extension : Allow CORS Access-Control-Allow-Origin
https://chrome.google.com/webstore/detail/allow-cors-access-control/lhobafahddgcelffkeicbaginigeejlf

If you are using Express as back-end you just have to install cors and import and use it in app.use(cors());.
If it is not resolved then try switching ports.
It will surely resolve after switching ports

So if you're like me and developing a website on localhost where you're trying to fetch data from Laravel API and use it in your Vue front-end, and you see this problem, here is how I solved it:
In your Laravel project, run command php artisan make:middleware Cors. This will create app/Http/Middleware/Cors.php for you.
Add the following code inside the handles function in Cors.php:
return $next($request)
->header('Access-Control-Allow-Origin', '*')
->header('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE, OPTIONS');
In app/Http/kernel.php, add the following entry in $routeMiddleware array:
‘cors’ => \App\Http\Middleware\Cors::class
(There would be other entries in the array like auth, guest etc. Also make sure you're doing this in app/Http/kernel.php because there is another kernel.php too in Laravel)
Add this middleware on route registration for all the routes where you want to allow access, like this:
Route::group(['middleware' => 'cors'], function () {
Route::get('getData', 'v1\MyController#getData');
Route::get('getData2', 'v1\MyController#getData2');
});
In Vue front-end, make sure you call this API in mounted() function and not in data(). Also make sure you use http:// or https:// with the URL in your fetch() call.
Full credits to Pete Houston's blog article.

You can also set up a reverse proxy which adds the CORS headers using a self-hosted CORS Anywhere or Just CORS if you want a managed solution.
https://justcors.com/<id>/<your-requested-resource>
http://cors-anywhere.com/<your-requested-resource>

Very easy solution (2 min to config) is to use local-ssl-proxy package from npm
The usage is straight pretty forward:
1. Install the package:
npm install -g local-ssl-proxy
2. While running your local-server mask it with the local-ssl-proxy --source 9001 --target 9000
P.S: Replace --target 9000 with the -- "number of your port" and --source 9001 with --source "number of your port +1"

Solution for me was to just do it server side
I used the C# WebClient library to get the data (in my case it was image data) and send it back to the client. There's probably something very similar in your chosen server-side language.
//Server side, api controller
[Route("api/ItemImage/GetItemImageFromURL")]
public IActionResult GetItemImageFromURL([FromQuery] string url)
{
ItemImage image = new ItemImage();
using(WebClient client = new WebClient()){
image.Bytes = client.DownloadData(url);
return Ok(image);
}
}
You can tweak it to whatever your own use case is. The main point is client.DownloadData() worked without any CORS errors. Typically CORS issues are only between websites, hence it being okay to make 'cross-site' requests from your server.
Then the React fetch call is as simple as:
//React component
fetch(`api/ItemImage/GetItemImageFromURL?url=${imageURL}`, {
method: 'GET',
})
.then(resp => resp.json() as Promise<ItemImage>)
.then(imgResponse => {
// Do more stuff....
)}

I had a similar problem with my browser debugger saying my response.body was null but fiddler and the developer tools show it as populated that turned out to be basically the same scenario as this. I was using a local Angular application hitting a Web Api service running on IISExpress. I fixed it by following the steps outlined here to find the correct applicationhost.config file to add a Access-Control-Allow-Origin header like so:
<customHeaders>
<clear />
<add name="X-Powered-By" value="ASP.NET" />
<add name="Access-Control-Allow-Origin" value="*" />
<add name="Access-Control-Allow-Headers" value="Content-Type" />
</customHeaders>

If all the above solutions don't work, probably it's because of the file permissions as sometimes even if you have fixed the non-cors problem using Heroku or another way, it throws 403 forbidden error. Set the directory/file permissions like this:
Permissions and ownership errors
A 403 Forbidden error can also be caused by incorrect ownership or permissions on your web content files and folders.
Permissions
Rule of thumb for correct permissions:
Folders: 755
Static Content: 644
Dynamic Content: 700

Are there any alternatives to overriding the 'host' header programatically

I have two services I'm running locally on docker images. One of them is an nginx server with configuration to proxy requests to various other services, and the other is a simple React GraphiQL UI.
The nginx server is not explicitly set up to run on localhost, but when making requests with curl/postman I can explicitly set the host header to be that of the actual url (rather than localhost) and it will then find the correct config and the request will succeed.
The issue is that I would like to call the server from a local instance of my UI, but it's failing because I can't overwrite the host header. I've tried to manually add it to my react fetch request but when I check the request in the browser the header isn't there. After some searching I then found some slack posts saying it's not possible, although no references to why.
return fetch(
edgeUrl(environment) + "/some/endpoint",
{
method: "POST",
headers: {
'Authorization': 'Bearer ' + getApiKey(partner, environment),
'host': 'actual.host.com',
'origin': 'http://localhost/'
},
body: JSON.stringify({ query })
}
)
Is there any other way to override the host used in requests? Possibly another http library I could use? I'd prefer not to have to configure the nginx server for localhost as it is owned by another team.

You should not try change the host header. The browser won't allow you to, and it's not the right way to do it.
As I see it, you have 2 options:
Configure NGINX to accept requests to localhost, if that is its' actually hostname.
Change the hosts file, to include your domain to point to 127.0.0.1, which is equivalent to adding it to DNS.
The Windows Hosts file is located here: C:\Windows\System32\drivers\etc\hosts.
You should add the following to your hosts file after the comments #.
actual.host.com 127.0.0.1

For anyone interested here's some information on possible attacks using the host header and why it's useful to validate it, which is what this service is doing.
https://portswigger.net/web-security/host-header
https://infosecwriteups.com/identifying-escalating-http-host-header-injection-attacks-7586d0ff2c67
I'm going to ask the other team if I can add localhost configuration to their nginx config so that I can make requests locally, looks like my coworker was misinformed in suggesting I override the host header.

CORS policy error while calling remote URL in Angular

Try to call remote API Url but, getting Access-Control-Allow-Origin error. I tried many things like following but, nothing works.
proxy.conf.js
const PROXY_CONFIG = [
{
context: [
"/api/planets"
],
target: "https://swapi.co",
secure: false,
changeOrigin: true,
logLevel: "debug",
bypass: function (req, res, proxyOptions) {
req.headers["Access-Control-Allow-Origin"] = "*";
req.headers["X-Forwarded-Host"] = "localhost:8090";
req.headers["X-Forwarded-For"] = "localhost";
req.headers["X-Forwarded-Port"] = "8090";
req.headers["X-Forwarded-Proto"] = "http";
}
}
];
module.exports = PROXY_CONFIG;
Running with ng serve --port 8090 --proxy-config proxy.conf.js
Can't make any changes in server side because I am using third party API.

Try adding plugin like https://chrome.google.com/webstore/detail/allow-cors-access-control/lhobafahddgcelffkeicbaginigeejlf?hl=en in your chrome browser.
Since you cant change the server side config, so this plugin can do the trick. The browser by default blocks CORS

Since You cannot make any changes on remote server. So it can be escaped using Reverse proxy server. I also faced the same issue while calling linkedin services.
a. There is an https://cors-anywhere.herokuapp.com/ you can append this before your url
and it will temporarily resolve CORS issues.
Since in enterprise scenario you can not use herokuapp.com before your application specific names so better to set below proxy server.
b. Second approach is using rever-proxy approach and set up your own server (local or remote ) for reverse proxying.
https://stackoverflow.com/q/29670703/7562674
You can also implement reverse-proxy like implementation using Spring and Jersey.
https://github.com/hhimanshusharma70/cors-escape

As the error says, a header named Access-Control-Allow-Origin must be present in a CORS response.
Since swapi.co responses include the Access-Control-Allow-Origin header for correct CORS requests (can be tested with a simple fetch('https://swapi.co/api/planets/') from your browser's dev console), the issue may be because of your proxy settings.
Try modifying the response in the proxy bypass method:
bypass: function (req, res, proxyOptions) {
...
// Note that this is "res", not "req".
res.headers["Access-Control-Allow-Origin"] = "*";
...
}

You can't! End of story. If the owner of the api has decided not to allow cross origin requests then you can't. If your are not going to host your app on the https://swapi.co domain then you will not be able to use the api directly from Angular and you will need some kind of pass through api call on the server from .NET, Node, PHP, Java etc.

Cross Origin Request with Kohana and JavaScript

I'm trying to implement some code that will allow me to have one sub-domain communicate with another sub-domain, e.g. one.example.com and two.example.com. The two sites have the ability to share cookies and session data as I have set the cookie to use .example.com.
When I visit either site via standard HTTP I can dump the session and see the expected data. However if I do this via JavaScript with jQuery $.ajax() the dumped session data is empty. In both cases I use PHP to dump the session data.
I have tried the following solution but to no luck yet (http://forum.kohanaframework.org/discussion/9895/problem-session-expired-with-ajax/p1). I'm also using a slightly newer version of Kohana (3.3).
I've also tried setting the headers as soon as they reach the controller:
$this->response->headers('Access-Control-Allow-Origin', 'http://one.example.com');
$this->response->headers('Access-Control-Allow-Credentials', 'true');
$this->response->headers('Access-Control-Allow-Methods', 'POST, GET, OPTIONS');
However the Chrome inspector still shows the Access-Control-Allow-Origin as *.

The Problem
The problem I was having was due to a setting in my Apache config file which looked like this:
<IfModule mod_headers.c>
Header set Access-Control-Allow-Origin "*"
</IfModule>
In order to solve my particular problem I simple removed / commented out the above code as it was overriding the headers I sent from PHP.
My implemented solution was then quite simple. In the following example we'll assume that I am making a call from one.example.com (the main website) to two.example.com (a sub-site).
Kohana / PHP
In my PHP I set the following headers, I've chosen to do this in my parent Controller. You could create your own Cors class or helper if you prefer. Basically you don't want to have this code duplicated hundreds of times throughout your project.
$this->response->headers('Access-Control-Allow-Origin', 'http://one.example.com');
$this->response->headers('Access-Control-Allow-Credentials', 'true');
$this->response->headers('Access-Control-Allow-Methods', 'POST, GET, OPTIONS');
JavaScript / jQuery
In my $.ajax() requests I then have to make sure to set the xhrFields.withCredentials property to true.
$.ajax({
url: 'two.example.com',
xhrFields: {
withCredentials: true
}
});
Or I could set it globally for all ajax requests like so:
$(document).ajaxSend(function (event, xhr, settings) {
settings.xhrFields = {
withCredentials: true
};
});
For more information check the $.ajax documentation: http://api.jquery.com/jQuery.ajax/
Further Reading
For further information checkout the following resources:
https://code.google.com/p/html5security/wiki/CrossOriginRequestSecurity
http://enable-cors.org/