Error that prevent python installing modules

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Message: '[present-rich] %s'
Arguments: (UpgradePrompt(old='22.1.2', new='22.2.1'),)

Fixing Method

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# uninstall pip
sudo pip uninstall pip
# install pip through apt
sudo apt install python3-pip
# upgrade pip to the latest version
python3 -m pip install --user --upgrade pip

Build Container

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docker build -t username/repository-name .
# tag the image
docker build -t username/example-node-app
# Verify images
docker images

Run Docker image

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docker run -p 80:80 username/example-nodeapp
# check the running container 
docker ps

Method 1: Creating a Snapshot

• Pros: Cost less storage resources.
• Cons: Can’t stored on secondary block device as backup.

Method 2: Replicate the vm

• Pros: Fulll VM that is able to be migrated on a different system.
• Cons:
  • Need extra step if the second storage is added.
  • Cost double current VM storage.

Method 3: Deploy a dedicate VM via terraform with libvirt as provider (devops approach)

Refer to following guide to prebuilt your system. Be advised, you have install a terraform and libvirt plugin for the system. Although it’s not a lengthy process, it may cause some issues on different linux distribution.

• Pros: Able to spawning mutiple instances. Can be utilized with gits.
• Cos: Hard to migrate current stable system, especially the configuration.

Add and UPdate Git Submoules

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git submodule add  <remote_url> <destination_folder>

Source/Reference:

• https://devconnected.com/how-to-add-and-update-git-submodules/

How to Clean Ubuntu Repository

Bug or Error

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Err http://ppa.launchpad.net natty/main Sources                                   
  404  Not Found
Err http://ppa.launchpad.net natty/main i386 Packages                             
  404  Not Found

Problem

• Repository can’t be connected or no longer available.
• Wrong repo info added.

Solution

• Search for apt sources files .
  ls /etc/apt/sources.list.d
• remove the unwanted or corrupted file. For instance, the file cause the error is myppa.list. Type the following to remove the file.
  rm -/etc/apt/sources.list.d/corrupted_app.list

Create a Virtual enviroment with Python

1. To create a folder to store virtual enviroment info.

python3 -m venv .venv

2. To activate virual enviroment, type the following line.
   source .venv/bin/activate

Implications of Cloud Operation Model

• Things to consider:
  • Scheduling
  • API structures
• Deploying applications over ticketing system.
• Development -> Networking -> Security -> Operations

Private Cloud

• VSphere.
• AD/LDAP (identity).
• Terraform (provisioning).

AWS

• EKS/ECS Lambda
• CloudMap AppMesh
• AWS IAM (identity)
• CloudFormation (Provisioning)

Youtube:

• Webinar: Describing Cloud Architecture.

Overview

• This is part of lpic2 exam, objective 200.1 - Measure and Troubleshoot Resource Usage.

vmstat command

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# Display disk statitics
$vmstat -d
nvme0n1  54705  32017 4802359   17720 348189  80080 4514130  276470      0    163

free command

• Concept of memory: cpu can’t talk to memory right away, it talks to buffer of the ram first. Buffer access cached for access binary. For example, when a command is executed at the first time, it will be stored in the cache. In the same time, the metadat is stored in buffere.
• When a command is executed, the buffer will be
• free -h, will have the following output.

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              total        used        free      shared  buff/cache   available
Mem:            23G        8.4G         11G        373M        3.2G         14G
Swap:           34G          0B         34G

• Explaination:
  • free: is for immediately accessed.
  • buffer: metadata for cache (pointer of memory page).
  • cache: store binary for immediate access.
  • shared:

The available will reflect the buffer/cache, shared and free.

• To clear and buffer and cache, we can use the following command.

  • To clear the buffer.

    1	sync; echo 2 > /proc/sys/vm/drop_caches

  • To clear the cache.

    1	sync; echo 3 > /proc/sys/vm/drop_caches

Sample of Editing Netplan

For ethernet

For wifi

• Create a file in /etc/netplan
  • Set up the wifi with dhcp

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network:
  version: 2
  renderer: networkd
  wifis:
    wlp2s0:
      nameservers:
        addresses: 
          - 8.8.8.8
          - 8.8.4.4
      access-points:
        "AP_Name":
          password: "wifi_pass"
      dhcp4: true 

• Set up the wifi with static IP

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network:
  version: 2
  renderer: networkd
  wifis:
    wlp2s0:
      dhcp4: no
 					addresses: [192.168.1.100/24]
  '  ''  ''  ''  'gateway4: 192.168.1.1
	 				nameservers:
								addresses: [192.168.1.1,8.8.8.8]
					 access-points:
	 						"accespoint_name":
											password: "your_pass"

• Finally, type netplan generate && netplan apply to apply the configuration.

#References:

• Real time demo link:

Spinning up Cloud Instances

What needed:

• API key from the Vultr Account.
• SSH public key for remote access.

Sample of terraform

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# Configure the vultr provider

provider "vultr" {
  api_key = "provided by vultr server"
  rate_limit = 700
  retry_limit = 3 
}


# creat an ssh key
resource "vultr_ssh_key" "my_ssh_key" {
  name = "ssh-key"
  # normally it would be in ./ssh/id_rsa.pub
  ssh_key = "ssh-rsa <ssh-public-key> anpham@dell-laptop"

}

# Create a web server
resource "vultr_server" "web-nginx" {
  plan_id = "201" 
  region_id = "6"  # atlanta servers
  os_id = "167"  # centos os 
  tag = "made-by-terraform"
  hostname = "web-server"
}