Windows 2016 - Install AZ CLI & KUBECTL

#AZ CLI
msiexec /i https://aka.ms/installazurecliwindows

#Kubectl
curl.exe -LO "https://dl.k8s.io/release/v1.30.1/bin/windows/amd64/kubectl.exe"
kubectl version --client

az login --use-device-code

Ubuntu - Install K9S

wget https://github.com/derailed/k9s/releases/latest/download/k9s_linux_amd64.deb

sudo apt install ./k9s_linux_amd64.deb

rm k9s_linux_amd64.deb

Ubuntu - Install trivy image scanner

How to Install Trivy Image Scanner on Ubuntu (Step-by-Step Guide)

Trivy is a popular open-source vulnerability scanner used in DevSecOps pipelines to scan container images, file systems, and Kubernetes clusters. This guide shows how to install Trivy on Ubuntu using the official APT repository and run image vulnerability scans.

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Table of Contents

• What is Trivy?
• Why Use Trivy on Ubuntu?
• Remove Snap-installed Trivy
• Install Trivy Using APT
• Verify Trivy Installation
• Scan Docker Image with Trivy
• FAQ

---

What is Trivy?

Trivy is a simple and comprehensive vulnerability scanner for containers. It detects vulnerabilities in OS packages and application dependencies before deployment.

Why Use Trivy on Ubuntu?

• Easy installation
• Fast vulnerability scanning
• Widely used in CI/CD pipelines
• Supports Docker, Kubernetes, and filesystems

---

Remove Snap-installed Trivy (Recommended)

If Trivy was installed using Snap, remove it to avoid conflicts:

sudo snap remove trivy
which trivy

---

Install Trivy on Ubuntu Using Official APT Repository

sudo apt-get install -y wget gnupg lsb-release

wget -qO - https://aquasecurity.github.io/trivy-repo/deb/public.key | \
sudo gpg --dearmor -o /usr/share/keyrings/trivy.gpg

echo "deb [signed-by=/usr/share/keyrings/trivy.gpg] \
https://aquasecurity.github.io/trivy-repo/deb $(lsb_release -sc) main" | \
sudo tee /etc/apt/sources.list.d/trivy.list

sudo apt update
sudo apt install -y trivy

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Verify Trivy Installation

trivy --version
/usr/bin/trivy --version

---

Scan Docker Image Using Trivy

Full Vulnerability Scan

/usr/bin/trivy image sparkaks2:latest

Only Vulnerability Scan

/usr/bin/trivy image --scanners vuln --timeout 15m sparkaks2:latest

Only OS Package Scan

/usr/bin/trivy image --vuln-type os sparkaks2:latest

---

Frequently Asked Questions (FAQ)

Is Trivy free to use?

Yes, Trivy is open-source and free for vulnerability scanning.

Does Trivy support Kubernetes?

Yes, Trivy can scan Kubernetes clusters and manifests.

Which Ubuntu versions are supported?

Ubuntu 18.04, 20.04, 22.04, and newer.

---

Related Guides:
More DevOps & Azure Tutorials

apt-key warning when sudo apt update run

Issue: apt-key warning when sudo apt update run

Update below file:
cat /etc/apt/sources.list.d/download_docker_com_linux_ubuntu.list

sudo apt-key list
apt-key export 0EBFCD88 | sudo gpg --dearmour -o /usr/share/keyrings/docker.gpg
#edit file
sudo vim /etc/apt/sources.list.d/download_docker_com_linux_ubuntu.list

#from
deb https://download.docker.com/linux/ubuntu focal stable

#to
deb [arch=amd64 signed-by=/usr/share/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu focal stable

This should resolve issue.

Elasticsearch Index Red / Yellow

Issue: Elasticsearch Index Red / Yellow

Connect to Stack management in kibana:
Kibana -> DevTools

# Get cluster health
GET _cluster/health

# Get Index helath - Look for the red/yellow index
GET /_cat/indices

# Update number_of_replicas to 0.
PUT /.ds-logs-apm.error-default-2023.10.06-000002/_settings
{
  "number_of_replicas": 0
}

#This will change for all index with this patent
PUT /.ds-traces-apm-default-2023*/_settings
{
  "number_of_replicas": 0
}

This should resolve issue.

How to use tmux

Select current value

1. Create a new tmux session

tmux new -s logjob

2. Run your job inside tmux

tail -f /var/log/syslog

3. Disconnect (detach) from the tmux session

Ctrl + b, then d

4. List tmux sessions (optional)

tmux ls

5. Reconnect (attach) to the session

tmux attach -t logjob

6. Kill the session when done

tmux kill-session -t logjob

7. Create session and run job in one command

tmux new -s logjob "python log_job.py"

8. Detach from outside (if attached elsewhere)

tmux detach -s logjob

logrotate is not rotating logs

Issue: logrotate is not rotating logs files

logrotate update below file, let's start with this file:
cat /var/lib/logrotate/status

logrotate state -- version 2
"/var/log/ufw.log" 2022-3-20-6:25:1
"/var/log/nginx/web_xxx.access.log" 2022-3-23-6:25:1
"/var/log/nginx/access.log" 2018-8-2-21:0:0
"/var/log/apt/history.log" 2021-11-8-6:25:1
"/var/log/user.log" 2022-3-23-6:0:0

We can see some of the logs are rotating but not all so let's run logrotate in debug mode and look for the error if any
sudo /usr/sbin/logrotate -d /etc/logrotate.conf

compressing log with: /bin/gzip
renaming /home/deployer/apps/api_abc_co/shared/log/sidekiq.log.2.gz to /home/deployer/apps/api_abc_co/shared/log/sidekiq.log.3.gz (rotatecount 2, logstart 1, i 2),
renaming /home/deployer/apps/api_abc_co/shared/log/sidekiq.log.1.gz to /home/deployer/apps/api_abc_co/shared/log/sidekiq.log.2.gz (rotatecount 2, logstart 1, i 1),
renaming /home/deployer/apps/api_abc_co/shared/log/sidekiq.log.0.gz to /home/deployer/apps/api_abc_co/shared/log/sidekiq.log.1.gz (rotatecount 2, logstart 1, i 0),
copying /home/deployer/apps/api_abc_co/shared/log/sidekiq.log to /home/deployer/apps/api_abc_co/shared/log/sidekiq.log.1
truncating /home/deployer/apps/api_abc_co/shared/log/sidekiq.log
removing old log /home/deployer/apps/api_abc_co/shared/log/sidekiq.log.3.gz
error: error opening /home/deployer/apps/api_abc_co/shared/log/sidekiq.log.3.gz: No such file or directory

it's failing as it's unable to create a file. it's a bug. manually create a file and re-run logrotate in debug mode and fix all the errors.


This should resolve issue.