I had my old PC laying around doing nothing for about a year. I am reviving it by putting it back at my desk and installing Linux Mint.
I love the fact that once you install the OS, pretty much everything is good to go. There is no spending so much time to get certain device to work because of driver issues. I can just start to use everything I want.
I cannot emphasize hard enough how great Linux Mint is. I would think it is up for prime time to take over the desktop world. I understand non-tech people may say they cannot play games with Linux. I guess they can just stick with Windows but Linux is very very capable of running computations. This blog runs on Linux, and even really big enterprise sized applications run on Linux. My daily work revolves around it and I am having so much fun.
I am thinking… If you are a tech and don’t even bother to learn Linux, you would have a serious disadvantage as an engineer.
Just recently, my own blog really helped me perform a great work and all of the articles that helped it were related to Linux. Obviously, my company uses Linux for all of our production purposes and I am so glad I spent a lot of time digging into it and blogged about it.
With the latest toy of vagrant, I am having so much fun!
Checksum is finger print of a file. If two files have the same checksum, they are identical files.
There are several types of checksum and the ones we use the most are MD5 and SHA256 based on my experience. Here is the sample code in Python.
import hashlib
class playground(unittest.TestCase):
def test_sha256(self):
file_name = 'test.jpg'
with open(file_name, 'rb') as file:
bytes = file.read()
hash = hashlib.sha256(bytes).hexdigest()
print(hash)
def test_md5(self):
file_name = 'test.jpg'
with open(file_name, 'rb') as file:
print(hashlib.md5(file.read()).hexdigest())
As a result, the SHA256 of test.jpg is c91834ce2d9e57edb6ccd118c10e5fb3b0eacfb8a8ecda73ae6680ced50009de and MD5 is 61a6ef0dd8c606fc0eb4c676f0e4296a
You don’t need Python to calculate these checksums. Here is the example you can run on your Mac or Linux. I’m sure you can run it on your Linux Subsystem on Windows as well.
I had a chance to learn vagrant at work. It is created by Hashicorp which is the creator of Terraform. I love what they have done. You can easily provision a VM locally and manage them. Looks like it requires VirtualBox as its hypervisor. You may want to install it beforehand. I learned that VirtualBox and Hyper-V can co-exist if you are on Windows.
You may want to decide which directory you init it from because it places Vagrantfile which has configurations of the VM. You can make changes to it as you see fit.
To start the vagrant VM, execute…
vagrant up
Just like that you can spin up a VM. To get into the VM via ssh, just enter…
vagrant ssh
You can do port forwarding to the VM so you can spin up test environment on the VM.
This is the best toy I have had in the last year or so. 🙂
Edit: There are other types of providers that Vagrant supports. Hyper-V is one of them, so it should work with Hyper-V as well. https://www.vagrantup.com/docs/providers
I am wanting to make sure Docker engine is present on my Jenkins host. To prove that Docker is not installed yet, here is the result of sudo systemctl status docker on the Jenkins host.
Unit docker.service could not be found.
Here is the Ansible playbook I came up with. The target host is an Oracle Linux 7 on ARM64 processor.
When installing Ansible on Linux, ansible.cfg and hosts files are at /etc/ansible. Instead of changing the files there, I am going to create a more contained Ansible environment.
I am doing this because of the following 3 reasons.
The configuration and host list does not get affected by external changes.
The changes can be traced with source control like Git.
The changes can be reviewed by your peers for any error.
Let’s create the ansible.cfg file.
ansible-config init --disabled -t all > ansible.cfg
Now I am going to create hosts file in the same directory with the following content.
Obviously, azureuser does not have permission to write out the file, so how do we do sudo in Ansible?
You just have to pass --become parameter to do sudo in Ansible.
ansible-playbook-3 test.yaml --become
PLAY [My playbook] *******************************************************************************************************************************
TASK [Gathering Facts] ***************************************************************************************************************************
ok: [ansibletest.westcentralus.cloudapp.azure.com]
TASK [Leaving a mark] ****************************************************************************************************************************
[WARNING]: Consider using the file module with state=touch rather than running 'touch'. If you need to use command because file is insufficient
you can add 'warn: false' to this command task or set 'command_warnings=False' in ansible.cfg to get rid of this message.
changed: [ansibletest.westcentralus.cloudapp.azure.com]
PLAY RECAP ***************************************************************************************************************************************
ansibletest.westcentralus.cloudapp.azure.com : ok=2 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
After executing it, I checked the file and it was created.
