This is because what appears after the colon can be either a port number or service name.

The following is a valid example where the service name is used instead of a port number:

	listener, err := net.Listen(&quot;tcp&quot;, &quot;localhost:https&quot;) // port 443
    // ...

The port mapping for a particular service can be looked up using [`net.LookupPort`](https://godoc.org/net#LookupPort). On Unix systems, the `/etc/services` file is sourced for the mappings.

For a number the default value is 0: if a function 

     func (u * URL) Port () string

 return number instead of sting the port will be 0

Port 0 is a reserved port in TCP/IP networking, meaning that it should not be used in TCP or UDP messages. However, port 0 carries special significance in network programming, particularly Unix socket programming: for requesting system-allocated, dynamic ports.

it is a need for programming in several functions



I was peeking at one of the Bootstrap examples that use the `card-deck` and `card` classes ([Pricing example](https://getbootstrap.com/docs/4.0/examples/pricing/)). I wondered how one can fix the button alignment if one of the lists has fewer items than the others.

[![Alignment issue][1]][1]

I would like all buttons to be vertically aligned (at the bottom of each card) but I couldn&#39;t figure out a way of doing this. I tried setting the [`.align-bottom`](https://getbootstrap.com/docs/4.0/utilities/vertical-align/) class as well as wrapping the button in `&lt;div class=&quot;align-text-bottom&quot;&gt;`. I also tried several suggestions from [this question about adding space](https://stackoverflow.com/q/12273588/3767239) however still no success (also the spacing should be variable such that it fills up the remaining space from the list).

Wrapping in [`&lt;div class=&quot;card-footer bg-white&quot;&gt;`](https://v4-alpha.getbootstrap.com/components/card/#card-groups) didn&#39;t yield the desired result either as it doesn&#39;t align the button at the bottom of the card and it creates some kind of border around it.

Does anyone have an idea?

__Edit:__ Here is a [jsfiddle](https://jsfiddle.net/bpb6d8j9/) that resembles the problem.

  [1]: https://i.stack.imgur.com/IGN7K.png

Bootstrap - align button to the bottom of card

Even though I manually configured JDK project structure [file/Project structure][1] it still shows this error 
FAILURE: Build failed with an exception.

`What went wrong:
Execution failed for task &#39;:sample:compileReleaseJavaWithJavac&#39;.
&gt; Could not find tools.jar. Please check that C:\Program Files\Java\jre1.8.0_151 contains a valid JDK installation.`

I&#39;m confused why it is still looking for C:\Program Files\Java\jre1.8.0_151 instead of JDK

 


  [1]: https://i.stack.imgur.com/VxQ2W.jpg

Could not find tools.jar. Please check that C:\Program Files\Java\jre1.8.0_151 contains a valid JDK installation

The [``Port``][1] method returns a string and not an integer. What is the reason for that and is it safe to prefix the port with &quot;:&quot;? 


  [1]: https://golang.org/pkg/net/url/#URL.Port

Why is port a string and not an integer?

<p>The <a href="https://golang.org/pkg/net/url/#URL.Port" target="_blank" rel="noopener noreferrer"><code>Port</code></a> method returns a string and not an integer. What is the reason for that and is it safe to prefix the port with ":"?</p>


I&#39;m triggering a `HTTP` request and I&#39;m getting a valid response from it. The response also has a header `X-Token` that I wish to read. I&#39;m trying the below code to read the headers, however, I get null as a result

    this.currentlyExecuting.request = this.http.request(reqParams.type, reqParams.url, {
        body: reqParams.body,
        responseType: &#39;json&#39;,
        observe: &#39;response&#39;
    }).subscribe(
        (_response: any) =&gt; {
            // Also tried _response.headers.init();
            const header = _response.headers.get(&#39;X-Token&#39;);
            console.log(header);
            onComplete(_response.body);
         },
        _error =&gt; {
            onComplete({
                code: -1,
                message: Constants.WEBSERVICE_INTERNET_NOT_CONNNECTED
            });
        }
    );


The response of the `API`, when checked in Chrome inspect, shows the header is present.

[![enter image description here][1]][1]


  [1]: https://i.stack.imgur.com/HCwZ8.png

Read response headers from API response - Angular 5 + TypeScript

With the latest [Firebase Update](https://firebase.google.com/support/releases#march_20_2018) callable functions were introduced. My question is whether [this new way](https://firebase.google.com/docs/functions/callable) is faster than the [&quot;old&quot; http triggers](https://firebase.google.com/docs/functions/http-events) and if it is more secure.

I have no expertise in this field, but I think the HTTP vs HTTPS might make a difference.

This is interesting to me because if the *callable functions* are faster, they have that advantage, but their disadvantage lies in the nature of flexibility: They cannot be reached by other sources.

If the *callable functions* have no advantages in terms of speed or security I do not see a reason to switch it up.

Are Callable Cloud Functions better than HTTP functions?

I&#39;m trying to upgrade a project from .Net core 1.1 to .Net core 2.0 there&#39;s a lot of breaking changes.

One of the things I&#39;m currently having an issue with is that `HttpContext.Authentication` is now obsolete.  

I&#39;ve been trying to figure out how to get the Access token for the current request.   I need to make a call to another API which requires a bearer token.

**Old Method .Net core 1.1**

    [Authorize]
    public async Task&lt;IActionResult&gt; ClientUpdate(ClientModel client)
    {
        var accessToken = await HttpContext.Authentication.GetTokenAsync(&quot;access_token&quot;);
        return View();
    }

**Method .Net core 2.0**

This is not working becouse context isnt registered.

    [Authorize]
    public async Task&lt;IActionResult&gt; ClientUpdate(ClientModel client)
    {
        var accessToken = await context.HttpContext.GetTokenAsync(&quot;access_token&quot;); 
        return View();
    }

&gt; Unable to resolve service for type &#39;Microsoft.AspNetCore.Http.HttpContext&#39;

I tried registering it but that doesnt work either 

    public ConsoleController(IOptions&lt;ServiceSettings&gt; serviceSettings, HttpContext context) 

In startup.cs

    services.TryAddSingleton&lt;HttpContext, HttpContext&gt;();

**Update:**

This returns null

    var accessToken = await HttpContext.GetTokenAsync(&quot;access_token&quot;);  


**Startup.cs  ConfigureServices**

I wouldn&#39;t be surprised if it was something in the startup as there were a lot of breaking changes here as well.

    services.Configure&lt;ServiceSettings&gt;(Configuration.GetSection(&quot;ServiceSettings&quot;));
    //services.TryAddSingleton&lt;HttpContext, HttpContext&gt;();
    services.TryAddSingleton&lt;IHttpContextAccessor, HttpContextAccessor&gt;();
    services.AddMvc();
    services.AddAuthentication(options =&gt;
            {
                options.DefaultScheme = CookieAuthenticationDefaults.AuthenticationScheme;
                options.DefaultChallengeScheme = OpenIdConnectDefaults.AuthenticationScheme;
            })
            .AddCookie()
            .AddOpenIdConnect(options =&gt;
            {
                options.Authority = &quot;http://localhost:5000&quot;;
                options.ClientId = &quot;testclient&quot;;
                options.ClientSecret = &quot;secret&quot;;
                options.ResponseType = &quot;code id_token&quot;;
                options.RequireHttpsMetadata = false;
                options.GetClaimsFromUserInfoEndpoint = true;
            });

**Startup.cs  Configure**


    loggerFactory.AddDebug();
    if (env.IsDevelopment())
    {
        app.UseDeveloperExceptionPage();
        app.UseBrowserLink();
    }
    else
    {
        app.UseExceptionHandler(&quot;/Home/Error&quot;);
    }
    JwtSecurityTokenHandler.DefaultInboundClaimTypeMap.Clear();
    app.UseStaticFiles();
    app.UseAuthentication();
    app.UseMvc(routes =&gt;
    {
        routes.MapRoute(
            name: &quot;default&quot;,
            template: &quot;{controller=Home}/{action=Index}/{id?}&quot;);
    });

How to get access token from HttpContext in .Net core 2.0

I am using Laravel to create a RESTFUL application and I test the application with Postman. Currently, there is an issue for `PATCH` or `PUT` if the data sent from Postman with form-data.

    // Parameter `{testimonial}` will be sent to backend.
    Route::post  (&#39;testimonials/{testimonial}&#39;, &#39;TestimonialController@update&#39;);

    // Parameter `{testimonial}` will not be sent to backend (`$request-&gt;all()` will be empty) if sent from Postman with form-data.
    Route::patch (&#39;testimonials/{testimonial}&#39;, &#39;TestimonialController@update&#39;);
    Route::put   (&#39;testimonials/{testimonial}&#39;, &#39;TestimonialController@update&#39;);

* Using form-data, `$request-&gt;all()` will be okay for `POST`.
* Using x-www-form-urlencoded, `$request-&gt;all()` will be okay for `PATCH`, `PUT`, and `POST`.
* However, if I am sending `PUT` and `PATCH` with form-data from Postman, the `$request-&gt;all()` will be empty (the parameters will not be sent to backend).

Right now the solution is to use `POST` for updating a model. I want to know why `PATCH` and `PUT` is not working when sent with form-data from Postman.

PATCH and PUT Request Does not Working with form-data

I&#39;m using Axios while programing in ReactJS and I pretend to send a DELETE request to my server.

To do so I need the headers:

    headers: {
      &#39;Authorization&#39;: ...
    }
and the body is composed of

    var payload = {
        &quot;username&quot;: ..
    }

I&#39;ve been searching in the inter webs and only found that the DELETE method requires a &quot;param&quot; and accepts no &quot;data&quot;.

I&#39;ve been trying to send it like so:

    axios.delete(URL, payload, header);

or even

    axios.delete(URL, {params: payload}, header);

But nothing seems to work...

Can someone tell me if its possible (I presume it is) to send a DELETE request with both headers and body and how to do so ?

Thank you in advance!

Axios Delete request with body and headers?

**Problem:**

When I run the same go test twice the second run is not done at all. The results are the cached ones from the first run.

    PASS    
    ok      tester/apitests    (cached)

**Links**

I already checked https://golang.org/cmd/go/#hdr-Testing_flags but there is no cli flag for that purpose.

**Question:**

**Is there a possibility to force go test to always run test and not to cache test results.**



Force retesting or disable test caching

I&#39;ve been given instructions to run `go get &lt;some-remote-git-repo&gt;` which seems to succeed, but it&#39;s not clear to me where the package was installed to so I can run an executable from it.

Per https://golang.org/doc/code.html#remote it seems it will be installed in `$GOPATH/bin` but `$GOPATH` isn&#39;t defined in my shell (though the `go get` command seems to work fine). Go is installed via Homebrew.

Where does go get install packages?

Hi I&#39;m trying to retrieve the function/method of one struct but I&#39;m using an interface as parameter and using this interface I&#39;m trying to access the function of the struct. To demonstrate what I want below is my code

    // Here I&#39;m trying to use &quot;GetValue&quot; a function of RedisConnection but since &quot;c&quot; is an interface it doesn&#39;t know that I&#39;m trying to access the RedisConnection function. How Do I fix this?
    func GetRedisValue(c Connection, key string) (string, error) {
    	value, err := c.GetValue(key)

    	return value, err
    }

    // Connection ...
    type Connection interface {
	    GetClient() (*redis.Client, error)
    }

    // RedisConnection ...
    type RedisConnection struct {}

    // NewRedisConnection ...
    func NewRedisConnection() Connection {
	    return RedisConnection{}
    }

    // GetClient ...
    func (r RedisConnection) GetClient() (*redis.Client, error) {
	    redisHost := &quot;localhost&quot;
    	redisPort := &quot;6379&quot;

    	if os.Getenv(&quot;REDIS_HOST&quot;) != &quot;&quot; {
	    	redisHost = os.Getenv(&quot;REDIS_HOST&quot;)
    	}

	    if os.Getenv(&quot;REDIS_PORT&quot;) != &quot;&quot; {
    		redisPort = os.Getenv(&quot;REDIS_PORT&quot;)
	    }

    	client := redis.NewClient(&amp;redis.Options{
	    	Addr:     redisHost + &quot;:&quot; + redisPort,
		    Password: &quot;&quot;, // no password set
    		DB:       0,  // use default DB
	    })

    	return client, nil
    }

    // GetValue ...
    func (r RedisConnection) GetValue(key string) (string, error) {
	    client, e := r.GetClient()
    	result, err := client.Ping().Result()
    	return result, nil
    }

Golang Cast interface to struct

I have an outer and inner loop, each iterating over a range. I want to exit the outer loop when a condition is satisfied inside the inner loop.

I have a solution which works using two &#39;break&#39;s, one inside the inner loop and one inside the outerloop, just outside the inner loop (a very simplified case for demonstration):

    package main
    
    import (
    	&quot;fmt&quot;
    )
    
    func main() {
    	
    	word := &quot;&quot;
    	for _, i := range(&quot;ABCDE&quot;) {
    		for _,j := range(&quot;ABCDE&quot;) {
    			word = string(i) + string(j)
    			fmt.Println(word)
    			if word == &quot;DC&quot; {
    				break
    			}
    		}
    		if word == &quot;DC&quot; {
    			break
    		}
    	}
    	// More logic here that needs to be executed
    }
[Go Playground][1]

There is no problem with this solution, but it just looks patched and ugly to me. Is there a better way to do this?

I can try and have another for conditional loop outside the outer loop in the previous solution and have a label and use continue with the label. But as you can see, this approach isn&#39;t any more elegant than the solution with break.

    package main
    
    import (
    	&quot;fmt&quot;
    )
    
    func main() {
    
    	word := &quot;&quot;
    
    Exit:
    	for word != &quot;DC&quot; {
    		for _, i := range &quot;ABCDE&quot; {
    			for _, j := range &quot;ABCDE&quot; {
    				word = string(i) + string(j)
    				fmt.Println(word)
    				if word == &quot;DC&quot; {
    					continue Exit
    				}
    			}
    		}
    	}
    	// More logic here that needs to be executed
    }
[Go Playground][2]

I have seen similar questions here pertaining to other languages (C, C#, Python etc). But what I am really interested to see is whether there is any trick with Go constructs such as &#39;for select&#39;.


  [1]: https://play.golang.org/p/URY29ukzp9A
  [2]: https://play.golang.org/p/cWrqtDV34L4

How to break out of nested loops in Go?

I&#39;m trying out Go&#39;s new modules system and am having trouble accessing local packages. The following project is in a folder on my desktop outside my gopath.

My project structure looks like:

    /
      - /platform
          - platform.go
      - main.go
      - go.mod

----

    // platform.go
    package platform
    
    import &quot;fmt&quot;

    func Print() {
        fmt.Println(&quot;Hi&quot;)
    }


---

    // main.go
    package main
    
    import &quot;platform&quot;

    func main() {
        platform.Print()
    }

`go build main.go` tells me

    cannot find module for path platform

Accessing local packages within a go module (go 1.11)

Cannot bind to some ports due to permission denied

A Kubernetes [`Service`](https://kubernetes.io/docs/concepts/services-networking/service/) can have a `targetPort` and `port` in the service definition:

&lt;!-- language: lang-yaml --&gt;

    kind: Service
    apiVersion: v1
    metadata:
      name: my-service
    spec:
      selector:
        app: MyApp
      ports:
      - protocol: TCP
        port: 80
        targetPort: 9376

What is the difference between the `port` and `targetPort`?

Difference between targetPort and port in Kubernetes Service definition

I have a Windows application that needs to use ports `50005` and `50006` but it is being blocked.

I see the following when I run `netsh int ip show excludedportrange protocol=tcp`:

    Protocol tcp Port Exclusion Ranges
    
    Start Port    End Port
    ----------    --------
    5357        5357
    49709       49808
    49809       49908
    49909       50008
    50009       50108
    50109       50208
    50280       50379
    
    * - Administered port exclusions.

So something on my machine is reserving ports `49909` to `50008`, which is presumably what is causing my application to fail. I&#39;ve tried deleting this `excludedportrange` with the following command:

    netsh int ip delete excludedportrange protocol=tcp numberofports=100 startport=49909

But I see an error `Access is denied.`, which makes me think that whatever is reserving this ports is actively running, but I have no idea what that could be. 

What&#39;s also weird is that after running that command, even though I saw an error, if I reboot the `excludedportrange` will be different.

As a sanity check I&#39;ve also run `resmon.exe` and confirmed that there is nothing running on ports `50005` and `50006`.

How can I tell what is adding the `excludedportrange`?

**EDIT:** I&#39;ve narrowed this down to Hyper-V. If I disable Hyper-V then those ports are not excluded.

How to see what is reserving ephemeral port ranges on Windows?

one application is running on port 3000 and I want to run another application on a different port of the default port. How I change this in React Next.js.
My **package.js** script is 

    &quot;scripts&quot;: {
        &quot;test&quot;: &quot;echo \&quot;Error: no test specified\&quot; &amp;&amp; exit 1&quot;,
        &quot;dev&quot;: &quot;next&quot;,
        &quot;build&quot;: &quot;next build&quot;,
        &quot;start&quot;: &quot;next start&quot;
      },

and start script command is
`npm run dev`

How to Set port in next.js

I am trying to start a docker container with the below command.

    docker run -it -p 50070:50070 -p 8088:8088 -p 8080:8080 suhothayan/hadoop-spark-pig-hive:2.9.2 bash

It ended up with the following error.

&gt; docker: error response from daemon: Ports are not available: listen tcp 0.0.0.0/50070: bind: An attempt was made to access a socket in a way forbidden by its access permissions.

As I understand, the error has occurred as the port 50070 is used by another process. I&#39;ve tried to identify the process in order to kill that with the below command in the command prompt, but it does not give an output nor an error.

    netstat -ano | findstr :50080



Content Type	Original Author	Original Content on Stackoverflow
Question	user6216224	View Question on Stackoverflow
Solution 1 - Http	Tim Cooper	View Answer on Stackoverflow
Solution 2 - Http	Fadid	View Answer on Stackoverflow

Why is port a string and not an integer?

Http Problem Overview

Http Solutions

Solution 1 - Http

Solution 2 - Http

Could not find tools.jar. Please check that C:\Program Files\Java\jre1.8.0_151 contains a valid JDK installation

Bootstrap - align button to the bottom of card

Attributions