vutkin

Listing all container images being used in kubernetes cluster

Getting all images referenced in pod specs:

kubectl get pods -A -o json  |
  jq -r '[.items[].spec | (.initContainers // empty | .[].image), .containers[].image] | unique | sort | .[]'

Getting all images cached on nodes:

vutkin

###################################################
##
## Alertmanager YAML configuration for routing.
##
## Will route alerts with a code_owner label to the slack-code-owners receiver 
## configured above, but will continue processing them to send to both a
## central Slack channel (slack-monitoring) and PagerDuty receivers
## (pd-warning and pd-critical)
##

vutkin

kubectl get pods --sort-by='.status.containerStatuses[0].restartCount'

vutkin

# List of kube_*_labels metrics - not all of these are useful for alerting. 
# kube_certificatesigningrequest_labels
kube_certificatesigningrequest_labels * on (certificatesigningrequest) group_right(label_team) (
  ...insert expression here
)

# kube_cronjob_labels
kube_cronjob_labels * on (cronjob, namespace) group_right(label_team) (
  ...insert expression here
)

vutkin

Kill user tty/pts sessions in Linux

Commands

• w: show who is logged on and what they are doing
• who: show who is logged on
• tty: show current users pseudo terminal
• ps -ft pts/1: get process id for the pseudo terminal
• pkill: signal process based on name and other attributes

vutkin

#!/bin/bash

set -eu -o pipefail

count=$(find . -depth 1 -name "*.HEIC" | wc -l | sed 's/[[:space:]]*//')
echo "converting $count files .HEIC files to .jpg"

magick mogrify -monitor -format jpg *.HEIC

echo "Remove .HEIC files? [y/n]"

vutkin

kafkacat -b localhost:9092 \
         -t _kafka-connect-group-01-status \
         -C \
         -o-3 \
         -c3 \
         -f 'Topic %t / Partition %p / Offset: %o / Timestamp: %T\nHeaders: %h\nKey (%K bytes): %k\nPayload (%S bytes): %s\n--\n'

vutkin

Retrieving Docker Image Sizes

There are two metrics that are important to consider when discussing the size of Docker images.

1. Compressed size - This is often referred to as the wire size. This affects how fast/slow images can be pulled from a registry. This impacts the first run experience on machines where images are not cached.
2. Uncompressed size - This is often referred to as the size on disk. This affects how much local storage is required to support your Docker workloads.

The example commands shown below will work on Windows, MacOS, and Linux.

How to Measure the Compressed Size

vutkin

# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software

vutkin

Producer

Setup
bin/kafka-topics.sh --zookeeper esv4-hcl197.grid.linkedin.com:2181 --create --topic test-rep-one --partitions 6 --replication-factor 1
bin/kafka-topics.sh --zookeeper esv4-hcl197.grid.linkedin.com:2181 --create --topic test --partitions 6 --replication-factor 3

Single thread, no replication

bin/kafka-run-class.sh org.apache.kafka.clients.tools.ProducerPerformance test7 50000000 100 -1 acks=1 bootstrap.servers=esv4-hcl198.grid.linkedin.com:9092 buffer.memory=67108864 batch.size=8196