Using Jq to work with JSON

While starting to work with Packer & Terraform, our deployment server needed some information about the AMIs that are being built. This sounds like a job for jq

#!/bin/bash

TMP=$(mktemp /dev/shm/JQ_XXXXXXXXXXXXXXX)
echo $TMP

echo Create a new JSON data set.
sleep 1
jq -Rn '{ "firewall": { amiId: "ami-1234", base: "amazon-linux-2", built: "'$(date +%F_%T)'" }}' > $TMP
cat $TMP | jq
sleep 5

echo Append to a JSON data set.
sleep 1
cat $TMP | jq '.["webserver"].amiId="ami-5678"' > ${TMP}.swap && mv ${TMP}.swap $TMP
cat $TMP | jq '.["webserver"].base="centos-7"' > ${TMP}.swap && mv ${TMP}.swap $TMP
cat $TMP | jq
sleep 5

echo Get all values for an entry by name
sleep 1
cat $TMP | jq '.["firewall"]'
sleep 5

echo Get the amiId by name
sleep 1
cat $TMP | jq '.["firewall"].amiId'
sleep 5

echo Set the amiId by name
sleep 1
cat $TMP | jq '.["firewall"].amiId="AMI-9876"' # > ${TMP}.swap && mv swap $TMP
sleep 5

echo Select a data set by exact match
sleep 1
cat $TMP | jq 'with_entries(select(.value.base=="centos-7"))'
sleep 5

echo Select a data set by partial match
sleep 1
cat $TMP | jq 'with_entries(select(.value.base | startswith("amazon")))'
sleep 5

rm -f $TMP

Create a new JSON data set.

Append to a JSON data set.

Get all values for an entry by name.

Get the amiId by name

Set the amiId by name

Select a data set by exact match

Select a data set by partial match

The One Line Python Directory Web Server

While testing some adjustments to iptables I needed a simple way to test web requests. This is a handy way to serve a directory and a simple way to see if the firewall is working.

On the server-side create directory content that will be hosted from a one-line Python script.

mkdir /tmp/fakeserver

cd /tmp/fakeserver

git clone https://github.com/torvalds/linux.git

sudo python -m SimpleHTTPServer 80

On the client-side use wget to spider and download the entire content of the server.
Replace <TEST SERVER> with the servers IP or resolvable name.

mkdir /tmp/fakeserver

cd /tmp/fakeserver

wget --mirror --convert-links --adjust-extension \
--page-requisites --no-parent http://<TEST SERVER>/