jeffjohnson9046

# From the second answer here - this SO answer gets all the credit:  
# https://stackoverflow.com/questions/32960857/how-to-convert-arbitrary-simple-json-to-csv-using-jq

# This is the filter to convert JSON to CSV output:
# NOTE:  This filter only works on "flat" JSON; nested properties don't work with this filter as-is.
jq -r '(.[0] | keys_unsorted) as $keys | ([$keys] + map([.[ $keys[] ]])) [] | @csv'

# For example:
aws ec2 describe-instances \
  --region us-west-2 \

jeffjohnson9046

# This is the function I created that's a wee bit less shitty than the file above.  I created a file called (oddly enough)
# ec2-instance-query.zsh and put it in my ~/.oh-my-zsh/custom directory.  After sourcing my ~/zshrc, I have a fancy-pants
# function for querying EC2 instances and ElasticIP addresses for a given IP:
function ec2-instance-query() {
    echo "Finding EC2 information for IP $1:"
    for r in `aws ec2 describe-regions --output text | cut -f4 | grep "us-"`
    do
        aws ec2 describe-instances \
            --region $r \
            --filter "Name=network-interface.addresses.association.public-ip, Values=$1" \

jeffjohnson9046

# I have several AWS profiles in my ~/.aws/config thus there are several access keys and secret keys in my 
# ~/.aws/credentials file.  Sometimes (e.g. when using kops or kubectl) I need to have the AWS_ACCESS_KEY_ID 
# and AWS_SECRET_ACCESS_KEY environment variables set.  There doesn't seem to be a way to use the aws cli to set these
# environment variables for me, so... well... here we are.
#
# This script will:
# * Look at the ~/.aws/credentials file for the specified profile
# * Get the next two lines beneath the profile name, which are the access_key_id and secret_key respectively
# * Export those two values as environment variables 
#

jeffjohnson9046

# NOTE: These steps assume that zsh is already installed

# Download and install iTerm2, which can be found here:  https://iterm2.com/downloads/

# Install oh-my-zsh (details and alternate installation instructions can be found here: https://github.com/ohmyzsh/ohmyzsh):
sh -c "$(curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"

# Install the Powerlevel9k theme for zsh (details for using the oh-my-zsh installation can be found here: https://github.com/Powerlevel9k/powerlevel9k/wiki/Install-Instructions#option-2-install-for-oh-my-zsh):
git clone https://github.com/bhilburn/powerlevel9k.git ~/.oh-my-zsh/custom/themes/powerlevel9k

jeffjohnson9046

# These commands demonstrate how to determine how much memory is availble on a k8s worker node and how much memory is 
# available to the k8s _container_ hosted on that node.
# Source:
#   https://shuheikagawa.com/blog/2017/05/27/memory-usage/
#
# Other interesting articles:
#   https://docs.docker.com/engine/docker-overview/#the-underlying-technology
#   https://docs.docker.com/config/containers/resource_constraints/
#
# These values are approximations, because according to the first article, calculating/determining available memory 

jeffjohnson9046

# Create a password-protected keystore.  Change the -keypass value to a password that meets your password policy.  LastPass (or some other password generator) can come in handy here for creating a password.
keytool -genkeypair -alias my-service-provider -keypass password -keyalg RSA -keysize 2048 -keystore my-sso-keystore.jks

# Use openssl to get the identity provider's public key as a file named sso.crt.
openssl s_client -connect my-sso-domain.example.com:443 > sso.crt

# Open the sso.crt file in any editor and remove everything around the BEGIN and END lines.  If required, concatenate with any intermediate certificates.
vi sso.crt

# When done editing, the file should look similar to this:

jeffjohnson9046

-- Set client encoding
\encoding UTF8

\set QUIET 1

-- print 'NULL' (instead of a blank) for any columns that have a null value
\pset null 'NULL'

-- Do not automatically commit after every statement
\set AUTOCOMMIT off

jeffjohnson9046

# Assume you have a directory structure that looks something like this:

ls -alh /path/to/my/directory
drwxr-xr-x  38 jeffjohnson  staff   1.2K Jul 18 11:07 ./
drwxr-xr-x   6 jeffjohnson  staff   192B Jun 23 15:00 ../
drwxr-xr-x  10 jeffjohnson  staff   320B Aug 28  2017 foo/
drwxr-xr-x  12 jeffjohnson  staff   384B Dec 18  2017 bar/
drwxr-xr-x  11 jeffjohnson  staff   352B Feb 26  2018 baz/
-rw-r--r--   1 jeffjohnson  staff   1.8M Aug 14  2017 some-update.sql
# list continues...

jeffjohnson9046

/**
Set the mongo shell prompt to display [user name]@[database name].  If the user or database name cannot
be captured, then display "<none>" instead.
*/
var prompt = function() {
        var user = db.runCommand({connectionStatus : 1}).authInfo.authenticatedUsers[0].user || "<none>";
        var dbLabel = db.getName() || "<none>";

        return user + "@" + dbLabel + ">";
}

jeffjohnson9046

# From here: https://stackoverflow.com/questions/2706797/finding-what-branch-a-git-commit-came-from

# First, make sure you have everything locally:
$ git fetch --all --tags --prune

# Show the local branches a commit is on (the "b4f8b91" is the first 7 characters of the commit hash):
$ git branch --contains b4f8b91
  develop
* feature/ast-3975
  master