DevExper

How to do secure Elasticsearch free with xpack security

2020-08-04T02:15:00.003-07:00

Yesterday, I have invested a couple of hours to secure eleasticsearch.

Elasticserch comes with a couple of security features.

If you need advance elasticsearch security features you need to have a look elasticsearch subscription features.

In this post, I would like to secure elasticsearch free with enabling basic authentication with the help of xpack security option.

I will use Docker to run elasticserach. To create users and passwords I will user elasticsearch commands in the running docker image.

I assume you have docker installed and running on your host machine and you know basics of docker. Here is the docker-compose file we will use :

Then you need to run the following command to login your docker container.


docker exec -it your-elastic-container-id /bin/bash

Then, we need to add a user with a password and role.

Elasticsearch xpack comes with build-in roles.

I will create a user with superuser role just for demo purposes.

elasticsearch-users useradd myuser -p mypassword -r superuser

Since xpack is activated, now you can use this username and password

with basic authentication to access elasticsearch api

How Clean Git Repository for Visual Studio Projects?

2018-03-02T18:00:00.000-08:00

Today I suddenly push a personal project of mine to a repository without .gitignore .gitignore is very helpful if you don't want to mess your git repo with machine generated files like compiled codes, build outputs, node_modules , node_modules , packages etc.

There is an offical gitignore file from github here
Or you can copy from gist I created. So I you want to clear your mess from your git repository with the help of .gitignore file or want to remove files that was tracked before new .gitignore run the following code. .gitignore file sample

Object to Json String C#

2018-02-27T06:53:00.000-08:00

Generally for logging purposes I'm need to convert object to Json sting. It is very helpful to keep track of incoming or outgoing objects. It is very easy but some time hard to remember as well. So It is better to keep this object to json conversion code here.

ASP.NET Web API IP Filter

2018-02-05T07:37:00.001-08:00

If you need to restrict an access to your some of the web controllers
it is safer to do with help of Asp.net web api filters.

The web api filters allows you to do several operations at OnActionExecuting stage.
You can block some requests and return 403 if you wish so.

I found RANDY BURDEN'S blog he has a nice implementation of a IP Filter for MVC.
I converted this code a bit which can be used in Asp.net Web API.

Azure ARM Template Connection String Settings

2017-05-09T16:03:00.000-07:00

Search "serverFarmId" keyword in your template.
paste the following code for connection settings.

By default db is mysql to set up other db types add 'type' key word.

value="2" SQL Database
value="1" SQL Server
value="0" MySQL
value="10" PostgreSQL
value="4" Notification Hub
value="5" Service Bus
value="6" Event Hub
value="7" Api Hub
value="8" Document DB
value="9" Redis Cache
value="3" Custom

For more detail about this subject please visit the perficient blog

 "siteConfig":  {  
             "connectionStrings": [  
                         {  
                         "name": "ConnString1",  
                         "connectionString": "Server=myServerAddress;Database=myDataBase;Trusted_Connection=True;"  
                         }  
                       ]  
                 }

Select as a XML MSSQL

2015-11-13T16:40:00.001-08:00

In Mssql you can get select result as XML by using following TSQL statement
SELECT * FROM TableName FOR XML path, root;

Implementing Thread Safe Singleton Pattern in C#

2015-05-19T14:59:00.002-07:00

Hi today I want to share Thread Safe Singleton code sample. I found this samples from Here You can use Singleton_Lazy class if you are using .net framework 4.0+

namespace Patterns
{
    
    public class Singleton
    {
        private static readonly Singleton instance = new Singleton();

        //Empty for laziness
        static Singleton() { }

        private Singleton() {

            Console.WriteLine("CCTOR");
        }

        public static Singleton Instance { get { return instance; } }

        public void DoSomeThing()
        {
            Console.WriteLine("DoSomeThing");
        }
    }




    public sealed class Singleton_Lazy
    {
        private static readonly Lazy<Singleton_Lazy> lazy =
            new Lazy<Singleton_Lazy>(() => new Singleton_Lazy(),true);

        public static Singleton_Lazy Instance { get { return lazy.Value; } }

        private Singleton_Lazy()
        {
            Console.WriteLine("CCTOR");
        }

        public void DoSomeThing()
        {
            Console.WriteLine("DoSomeThing");
        }
    }
}

System Time to varchar in Oracle

2015-04-28T07:29:00.001-07:00

You can use the following code to get system time as varchar in Oracle

ls_current_timestamp     VARCHAR2 (14) := SUBSTR (TO_CHAR (SYSTIMESTAMP, 'HH24:MI:SSxFF'), 1, 14);

Asp.net ajax Post example

2015-04-02T08:20:00.001-07:00

To ajax post your backend method you can use the following snippet
I assume that your page name is : ConfirmWaitingOperations.aspx
Your backend method is : DeclineOperationWeb
Code Behind :

[System.Web.Services.WebMethod()]
        public static void DeclineOperationWeb(object ConfirmId , object Result)
        {
        ...
        }

ASPX Part:

//In your JS function you can use the following ajax post code
        $.ajax({
                type: "POST",
                url: "ConfirmWaitingOperations.aspx/DeclineOperationWeb",
                data: "{ConfirmId:" + id + ",Result:'"+summary+"'}",
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                success: function (msg) {
                   alert("Your error here")
                   location.reload(); //refresh page may be 
                },
                error: function(xhr, textStatus, error){
                    alert("Your error here")
                    
                }
            });

Alter column size Oracle

2015-04-02T08:17:00.000-07:00

To Alter column size in Oracle you may use the following query. It helps if your size of input doesn't fit your column.

ALTER TABLE 
   MY_TABLE_NAME 
MODIFY 
   ( 
   MY_FIELD varchar2(250)
   );

How to find Oracle Package Errors with query

2015-03-20T06:55:00.003-07:00

You can find oracle package errors by executing the query below.

select e.owner,e.type,e.line, e.position,e.text, substr(s.text,1,500) source 
from dba_errors e, dba_source s 
where e.name=upper('YOUR_PACKAGE_NAME_HERE') 
and s.name=e.name 
and e.line =s.line 
order by 1,2,e.SEQUENCE;

Bootstrap Html.DropDownListFor in MVC 5 (razor)

2015-03-10T05:14:00.004-07:00

It was not easy apply bootstrap to Asp.Net Mvc DropDownList.
I found this bootstrap-select project on git hub which is a life saver. (Thank you guys :) )

Implementation
Add Js and Css codes from CDN

 <script src="//cdnjs.cloudflare.com/ajax/libs/bootstrap-select/1.6.3/js/bootstrap-select.min.js"></script>  
 <link href="//cdnjs.cloudflare.com/ajax/libs/bootstrap-select/1.6.3/css/bootstrap-select.min.css" rel="stylesheet" />

JQuery Part

 <script type="text/javascript">  
   $(document).ready(function () {  
     console.log("ready!");  
     Implement_Dropdownlist();  
     $('.selectpicker').selectpicker({  
       style: 'btn-info',  
       size: 4  
     });  
   });  
   </script>

Razor Part

  @Html.DropDownListFor(m =>; m.Country, new SelectList(Model.myList), new { @class = "selectpicker" })

XML to Object and Object To Xml in C#

2015-02-26T01:12:00.000-08:00

By using DeserializeObject method you can generate an object,
and by using SerializeObject method you can generate an xml string of that object.

  public object DeserializeObject(string toDeserialize, Type k)  
     {  
       XmlSerializer xmlSerializer = new XmlSerializer(k);  
       StringReader textReader = new StringReader(toDeserialize);  
       return xmlSerializer.Deserialize(textReader);  
     }  
     public string SerializeObject(object toSerialize, Type k)  
     {  
       XmlSerializer xmlSerializer = new XmlSerializer(k);  
       using (StringWriter textWriter = new StringWriter())  
       {  
         xmlSerializer.Serialize(textWriter, toSerialize);  
         return textWriter.ToString();  
       }  
     }

How to Call Serialize and Deserialize methods example:

  if (Input.OperationType == XmlOperationType.SerializeObject)  
     {  
         Output.XmlResult = SerializeObject(Input.ObjectForXmlOperation, typeof(MyItem));  
     }  
   else if (Input.OperationType == XmlOperationType.DeserializeObject)  
     {  
         Output.ObjectResult = DeserializeObject(Input.ObjectXml, typeof(MyItem));  
      }

To Serialize and Deserialize an object don't forget following attributes

     [Serializable]  
     [DataContract]  
     [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]  
     [System.Xml.Serialization.XmlRootAttribute(Namespace = "", IsNullable = false)]  
     public class MyItem {..}

Assign value of property using by property name in C#

2015-02-26T00:50:00.001-08:00

C# you can assign property value by using its name example :

Don't for get to add

using System.Reflection;

 xItem.xInformation.xval.GetType().GetProperty("MyPropertyName").SetValue(xItem.xInformation.xval, valueYouWishToAssign,null);

Asp.net RadioButton with JS Confirmation

2014-10-30T14:44:00.000-07:00

Here is the way of Asp.net radiobutton with confirmation.

1. In code behind find radio buttons and add onclick event.
2. Write a JS function that can postback with option.
3. Catch postback parameter in Page load
(string parameter = Request["__EVENTARGUMENT"]; )
4. In RadioButtonSelectedIndexChanged event do what you need to do in confirm and not confirm.

PS: I know that is doesn't explain well the process but when you implement the code you will get it.

Code behind

 protected void Page_Load(object sender, EventArgs e)
        {
            string parameter = Request["__EVENTARGUMENT"];

            if(parameter!=null)
            if (parameter.Equals("Itrue") || parameter.Equals("Ifalse"))
            {
                confirm = parameter;

            }
            
            ListItem l1 = InterestTypeList.Items.FindByValue("stb");
            ListItem l2 = InterestTypeList.Items.FindByValue("spt");
            l1.Attributes.Add("onclick", "javascript:return validate_delete('" + l1.Value + "','" + InterestTypeList.ClientID + "')");
            l2.Attributes.Add("onclick", "javascript:return validate_delete('" + l2.Value + "','" + InterestTypeList.ClientID + "')");
            
        }

  protected void InterestCMRadioButtonListOnSelectedIndexChanged(object sender, EventArgs e)
        {
            if (confirm.Equals("Ifalse"))
            {
                // if not confirm

                return;
            }

            //    if confirm
            
        }

JS function to post back with options

  function validate_delete(InputValue, InputItem)
        {
                var item = document.getElementById(InputItem);
           
                var r = confirm("Confirm ?");
                if (r == true)
                {
                    setTimeout('__doPostBack(\'' + item.id + '\',\'' + "Itrue" + '\')', 0);
                    return true;
                }
                else {
                    setTimeout('__doPostBack(\'' + item.id + '\',\'' + "Ifalse" + '\')', 0);
                    return true;
                }


        }

2014-10-28T23:42:00.001-07:00

Add click function for UIImageView

  UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapDetected)];
  singleTap.numberOfTapsRequired = 1;
  [_settingImg setUserInteractionEnabled:YES];
  [_settingImg addGestureRecognizer:singleTap];

-(void)tapDetected{
    NSLog(@"single Tap on imageview");
    
    [self performSegueWithIdentifier:@"rankSegue" sender:self];
}

SQL JOINS explanation

2014-09-23T12:40:00.000-07:00

Today I found a great post which explains SQL Joins. If you are having trouble with SQL JOINS you will need this SQL JOIN explanation.

Eval and String split usage

2014-09-17T05:24:00.000-07:00

Today I was having trouble to split data item in grid like this post.

Problem is Split Method wants an argument which is char and the syntax of asp.net doesn't allow you to use together double quotation mark "" and single one which is this ' '.

Eval("Total Cost").ToString().Split(Convert.ToChar('.'))[0] // gives you an error but

Eval("Total Cost").ToString().Split(Convert.ToChar("."))[0] // works well

good luck...

Set Width for TemplateField

2014-08-19T01:10:00.000-07:00

To set width for TemplateField in Asp.net you can use HeaderStyle like code below.

 <asp:TemplateField HeaderText="Select Operation" ItemStyle-HorizontalAlign="Center">  
           <HeaderStyle Width="112" />  
           <ItemTemplate>  
           .....  
           </ItemTemplate>  
           <ItemStyle Width="50px" />  
 </asp:TemplateField>

jQuery $(document).ready , UpdatePanels and Events

2014-08-13T06:57:00.002-07:00

Today I faced with a problem Update Panel and JQuery $(document).ready
When post back happens all my client side events were lost. To prevent this issue I used following solutions below.

 var prm = Sys.WebForms.PageRequestManager.getInstance();  
 prm.add_endRequest(function() {  
   // re-bind your jQuery events here  
 $(document).ready(function() {  
   // bind your jQuery events here initially  
 });  
 });

Here is the post which I used. http://stackoverflow.com/questions/256195/jquery-document-ready-and-updatepanels

Get Session in Static WebMethod

2014-08-11T23:39:00.000-07:00

Hi, One of my project I need to use a Static WebMethod to set session. But the compiler gives me an error like.

An object reference is required for the non-static field, method, or property 'System.Web.UI.Page.Session.get'

But if you still need to access session you may also try to use the following.

HttpContext.Current.Session["yourSessionVariable"];

and the following above your WebMethod

[WebMethod(EnableSession = true)]

Here in below I just copy and paste my working code.

  [WebMethod(EnableSession = true)]  
     public static void PutIntoCardsList(string cardName)  
     {  
       var cards = (List<Card>)HttpContext.Current.Session["sessionVals"];  
       if (cards != null)  
       {  
         cards.Add(new Card {CardName = cardName});  
       }  
       else  
       {  
         cards = new List<Card> {new Card {CardName = cardName}};  
       }  
       HttpContext.Current.Session["sessionVals"] = cards;  
     }

Now you can access session by using Static WebMethod.. Good Luck !!..

Eclipse Turkish Character Problem

2014-08-08T01:46:00.002-07:00

To solve Eclipse Turkish Character Problem you should change Text file encoding to UTF-8.

You can find this settings under Window -> Preferences select General menu and then Workspace and change Text file encoding option to UTF-8

Good Luck !!!

IF Sum is null convert it to 0 (zero)

2014-07-31T01:03:00.000-07:00

Oracle you may use the query below to convert SUM of totalPrice to zero when SUM result is null by using COALESCE

select COALESCE(SUM(totalPrice),0) "Total" from productPriceTable

Add existing project to GIT ( XCode 5)

2014-07-29T06:03:00.003-07:00

It was quite complicated for me to add existing project to GIT source control. I found this solution on stackoverflow.com . After following this steps I successfully commit my exiting project to bitbucket.

Quit Xcode (not sure if this is necessary but I do it just in case)
Run Terminal
Get into the project folder directory
find .
Find the file that says "UserInterfaceState.xcuserstate" and copy the entire filename up to the ./
echo "paste the UserInterfaceState.xcuserstate file here" >.gitignore
cat .gitignore
git init
git add .
git commit -m "You can type a comment here like now under source control"

You now have a repository and your project is under source control

Good Luck !

Show Hidden Files Mac

2014-07-29T06:00:00.001-07:00

Open your Terminal and paste the following commands.

killall cfprefsd
defaults write com.apple.finder AppleShowAllFiles TRUE
killall Finder

For not to show hidden files apply the following commands below

killall cfprefsd
defaults write com.apple.finder AppleShowAllFiles FALSE
killall Finder