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How to install mysql2 0.5.3 gem on Ruby 2.7.8 + Homebrew MySQL 8.0 environment

# this is installed via asdf
$ ruby -v
ruby 2.7.8p225 (2023-03-30 revision 1f4d455848) [x86_64-darwin24]

$ brew list --versions | grep mysql
mysql-client 9.0.1
[email protected] 8.0.39

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How to find a pod by UID?

Option #1

kubectl get pods -A -o json | jq -r '.items[] | select(.metadata.uid == "<UID>") | .metadata.name, .metadata.namespace'

Option #2

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How to run a temporary psql container in Kubernetes for testing/debugging?

$ k run psql-client --rm -i --tty --image jbergknoff/postgresql-client --command /bin/sh
/ # which psql
/usr/bin/psql

/ # psql --version
psql (PostgreSQL) 12.3

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How to sort htop by CPU or Memory?

Sort by CPU

htop -s PERCENT_CPU

Sort by Memory / RAM

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# Replace the THE_SECRET_NAME
k get pods -A -o json | jq -r '.items[] | select(.spec.imagePullSecrets!=null)  | select(.spec.imagePullSecrets[].name=="THE_SECRET_NAME") | {namespace: .metadata.namespace, name: .metadata.name}'

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kubectl get clusterissuers -o json | jq -r '.items[] | select(.spec.acme != null) | select(.spec.acme.solvers[0] | keys[0]=="dns01") | {name: .metadata.name, provider: (.spec.acme.solvers[0].dns01 | keys[0])}'

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How to displays a brief summary of all IPv4 addresses assigned to the network interfaces Linux system?

Command:

ip -4 -br a

Sample output:

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How to check which network interface will be used to route/send packets for specific IP address?

# Install `ip` tool
apt update -y
apt install iproute2 -y

# Check
ip r get 8.8.8.8 fibmatch

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Get all Prometheus metrics and descriptions/help texts

Requirement:

• promtool

As JSON

curl -sg 'http://prom-server:prom-port/api/v1/metadata' | jq -r '.data'

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How to install promtool by Prometheus?

# Fetch latest version
TAG=$(curl -s https://api.github.com/repos/prometheus/prometheus/releases | jq -r '.[] | .tag_name' | head -n 1)
echo $TAG

# Remove the `v` prefix
VERSION=$(echo $TAG | sed 's/v//')
echo $VERSION