Error : login failed on rabbitmq web-management console

If you have newly installed RabbitMQ server and trying to view queues or exchanges using RabbitMQ web management console you may see below error, while login with guest account.


In order to login to RabbitMQ web-management console using guest account, follow below steps

1. Enable web-management plugin
Use below command to enable the management plugin


# sudo rabbitmq-plugins enable rabbitmq_management


2. Once plugin is enabled, you will need to update the rabbitmq.config file. Create if not exists and edit "/etc/rabbitmq/rabbitmq.config" file.
Append below line to the file


[{rabbit, [{loopback_users, []}]}].


Do not miss last dot from the line. Once the changes are saved, restart RabbiMQ server using below command


# service rabbitmq-server restart


Now you should be able to login to management console with guest user account.




For more details about access control visit RabbitMQ Access Control

Error: No package erlang available.

If you are trying to install Erlang on CentOS 6.x or 5.x you might get below errors

[root@abcdef install]# yum install erlang
Failed to set locale, defaulting to C
Loaded plugins: fastestmirror, refresh-packagekit, security
Loading mirror speeds from cached hostfile
 * base: centos.mbni.med.umich.edu
 * extras: mirror.linux.duke.edu
 * updates: mirror.linux.duke.edu
Setting up Install Process
No package erlang available.
Error: Nothing to do

If you are getting these errors mean you don't have RHEL EPEL Repo updated to fetch Erlang builds. So you will need to update your repo. 

CentOS 5.x :

wget http://dl.fedoraproject.org/pub/epel/5/x86_64/epel-release-5-4.noarch.rpm
wget http://rpms.famillecollet.com/enterprise/remi-release-5.rpm
sudo rpm -Uvh remi-release-5*.rpm epel-release-5*.rpm

CentOS 6.x :

wget http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
wget http://rpms.famillecollet.com/enterprise/remi-release-6.rpm
sudo rpm -Uvh remi-release-6*.rpm epel-release-6*.rpm

Now You can try installing Erlang with command below

# yum install -y erlang

Run firefox OS on your Android Phone


Mozilla has released the Firefox OS 2.5 Developer Preview which you can try on your Android phone just like any other app.

The Firefox OS 2.5 has released apk which you can install on your Android device and by pressing home button it will start as new Home screen.

Going back to older home screen you can use ur Android as is.

Visit Mozilla Blog for more details. You can download apk from here.

Error: No module named SimpleHTTPServer

While running command "python -m SimpleHTTPServer" you may get error "No module named SimpleHTTPServer"

If you are using python 3 and above you may want to execute below command as SimpleHttpServer module is integrated in http.server
"python3 -m http.server"

Else try installing the SimpleHTTPServer module.

Enabling or hiding the Dashboard on MAC OS X Yosemite

You can enable or disable the Dashboard on MAC OS X using System Preferences.

Launch System Preferences -> Mission Control. 
Under Mission Control preferences you will find Dashboard and combobox of Dashboard Setting. Choose Off from the list items and Dashboard will disappear.


Full Screen start menu in Windows 10

If you like the Windows 8 full screen start menu then you can enable it on Windows 10 also.

On your Windows 10 machine launch Settings ( start menu -> Settings). Go to Personalisation -> Start. 

Under Start Behaviours enable "Use full screen start in Desktops" as shown in image below.

  

MAC : How to repair Permissions on MAC

If you upgraded your mac with recent update, and some of your apps are behaving weirdly, then you might want to repair the disk permissions. 

To perform this launch Disk Utility searching from "Spotlight Search", now from right pane select the disk where mac is installed. on left pane you will see the "Repair Disk Permissions" button. Click this button. This will start the repair operation. 

You can also select the "Show Details" check box to see what all permissions are corrected or failed. 

Error: Emulator64-x86 quit unexpectedly

If your MAC is showing crash report with error "Emulator64-x86 quit unexpectedly" while launching the Android emulator, and you have tried other solutions but didn't help then you might want to repair the Disk Permissions for your MAC.

Go to Disk Utility and select disk where mac is running and hit "Repair Disk Permissions". 

The issue might be with the Virtual memory permissions and this could solve the issue.

Errors running builder 'Android Resource Manager' on project 'project name'. java.lang.NullPointerException

You may get the error while compiling the Android app "Errors running builder 'Android Resource Manager' on project 'lock'. java.lang.NullPointerException". You could also get this error while creating a project and you wouldn't be able to create the project altogether.

There could be multiple reasons for the error : 
  • Your project file might be missing
  • The dependent project library might be missing or
  • You might be building an app with Activity but the respective API SDK might not be installed 
If above are not the reasons then you might want to check out this




Golang: Http POST Request with JSON Body example

Go standard library comes with "net/http" package which has excellent support for HTTP Client and Server.   In order to post JSON ...