Victory goes to the player who makes the next-to-last mistake
February 15, 2018 Leave a comment
Add the following lines to the /etc/sysconfig/docker file and restart the docker
other_args="-H tcp://0.0.0.0:4243 -H unix:///var/run/docker.sock"
Restart Docker
service docker restart
Now check the docker API using the following command
curl host:4243/info
September 29, 2016 Leave a comment
/etc/fstab contains information about the disks. It has the details about where the partitions and storage devices should be mounted. We usually configure automount, disk quota, mount points etc in this fstab.
Inorder to test the entries or modifications in fstab without restart the following commands will be helpful
mount -a
The above command will mount all the filesystems mentioned in the fstab. This is just like a refresh command to activate the entries in fstab.
mount -fav
The above command will help if you don’t want to apply the modifications in the fstab and want to validate the entries only. This will just fake the entries in the fstab without applying the changes. This is a very useful command.
May 24, 2016 1 Comment
Nowadays majority of us are using some cloud services. Amazon Web Services is one of the popular provider among all the other cloud service providers. Just like we upgrade our harddisk or mounting new drives to physical machines, we can attach new block storages to Amazon EC2 also. Amazon provides a service called EBS (Elastic Block Storage). There are various types of EBS with various speed and cost. Example are magnetic, SSD etc.
Attaching a new EBS to a running EC2 instance is very simple. We can do this programatically as well as using the console. Here I am explaining the basic steps to perform this operation using the console.
May 23, 2016 Leave a comment
To disable the SELinux by modifying /etc/sysconfig/selinux file, we have to perform a reboot. In some cases, we may not be able to perform a reboot because this involves a downtime of the system. In this situations we can disable SELinux by using a simple command. This will not disable SELinux permanently. The effect will last until the next reboot, but you have the option to edit the selinux file so that it will be in the disabled state even after the reboot also. The steps for disabling selinux permanently are explained in my previous post.
The command the check the status of SELinux is given below.
sestatus
This may show enforcing or permissive or disabled. In permissive mode, SELinux will not block anything, but merely warns you. The line will show enforcing when it’s actually blocking.
To disable the SELinux temporarily we can use the following command. This has to be executed as root or using sudo.
setenforce 0
After this command execution we can check the status of selinux using sestatus command. If it is permissive, we are good to go. 🙂
May 23, 2016 Leave a comment
Security-Enhanced Linux (SELinux) is a security architecture integrated into the 2.6.x kernel using the Linux Security Modules. It is a project of the United States National Security Agency (NSA) and the SELinux community. SELinux integration into Red Hat Enterprise Linux was a joint effort between the NSA and Red Hat.
Most of the application needs SELinux to be turned off. Turning off selinux is simple. You can use the following steps to turn off selinux in RHEL or CentOS 6 and 7 operating systems.
Open the file /etc/sysconfig/selinux . The contents will be similar as below.
# This file controls the state of SELinux on the system. # SELINUX= can take one of these three values: # enforcing - SELinux security policy is enforced. # permissive - SELinux prints warnings instead of enforcing. # disabled - SELinux is fully disabled. SELINUX=disabled # SELINUXTYPE= type of policy in use. Possible values are: # targeted - Only targeted network daemons are protected. # strict - Full SELinux protection. SELINUXTYPE=targeted
The contents are self explanatory. Change the value of SELINUX as disabled and save the file. Then reboot the system.
