Lambda dig Layer

Adds support for the awesome DNS tool dig to your Lambda function.

Install it by going to your AWS console, navigation to Lambda, followed by Layers, Create layer, upload this zip and use the ARN in your Lambda function.

START RequestId: b7abb31c-10a2-11e9-859c-b9daa8e62050 Version: $LATEST

; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.68.rc1.58.amzn1 <<>> NS com. @a.gtld-servers.net.
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 39470
;; flags: qr aa rd; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 12
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;com.				IN	NS

;; ANSWER SECTION:
com.			172800	IN	NS	l.gtld-servers.net.
com.			172800	IN	NS	d.gtld-servers.net.
com.			172800	IN	NS	h.gtld-servers.net.
com.			172800	IN	NS	m.gtld-servers.net.
com.			172800	IN	NS	i.gtld-servers.net.
com.			172800	IN	NS	b.gtld-servers.net.
com.			172800	IN	NS	e.gtld-servers.net.
com.			172800	IN	NS	f.gtld-servers.net.
com.			172800	IN	NS	g.gtld-servers.net.
com.			172800	IN	NS	a.gtld-servers.net.
com.			172800	IN	NS	j.gtld-servers.net.
com.			172800	IN	NS	k.gtld-servers.net.
com.			172800	IN	NS	c.gtld-servers.net.

;; ADDITIONAL SECTION:
l.gtld-servers.net.	172800	IN	A	192.41.162.30
l.gtld-servers.net.	172800	IN	AAAA	2001:500:d937::30
d.gtld-servers.net.	172800	IN	A	192.31.80.30
d.gtld-servers.net.	172800	IN	AAAA	2001:500:856e::30
h.gtld-servers.net.	172800	IN	A	192.54.112.30
h.gtld-servers.net.	172800	IN	AAAA	2001:502:8cc::30
m.gtld-servers.net.	172800	IN	A	192.55.83.30
m.gtld-servers.net.	172800	IN	AAAA	2001:501:b1f9::30
i.gtld-servers.net.	172800	IN	A	192.43.172.30
i.gtld-servers.net.	172800	IN	AAAA	2001:503:39c1::30
b.gtld-servers.net.	172800	IN	A	192.33.14.30
b.gtld-servers.net.	172800	IN	AAAA	2001:503:231d::2:30

;; Query time: 10 msec
;; SERVER: 192.5.6.30#53(192.5.6.30)
;; WHEN: Sat Jan  5 04:31:06 2019
;; MSG SIZE  rcvd: 509



END RequestId: b7abb31c-10a2-11e9-859c-b9daa8e62050
REPORT RequestId: b7abb31c-10a2-11e9-859c-b9daa8e62050	Duration: 1206.05 ms	Billed Duration: 1300 ms 	Memory Size: 128 MB	Max Memory Used: 35 MB	

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Building a new version

Please see the (AWS guide to create a deployment package](https://aws.amazon.com/premiumsupport/knowledge-center/lambda-linux-binary-package/). The following steps are tailored to dig.

1. Launch an Amazon EC2 instance from the latest Amazon Linux AMI
2. Connect to the instance, and then install tools to extract the packages:
   • sudo yum install -y yum-utils rpmdevtools
3. Download and extract the libraries and the dependencies:
   • cd /tmp
   • yumdownloader bind-utils.x86_64
   • rpmdev-extract *rpm
4. Copy the libraries into a directory for the Lambda deployment package:
   • sudo mkdir -p /var/task
   • sudo chown ec2-user:ec2-user /var/task
   • cd /var/task
   • /bin/cp /tmp/bind-utils-9.8.2-0.68.rc1.59.amzn1.x86_64/usr/* /var/task -R (note: replace bind-utils-9.8.2-0.68.rc1.59.amzn1.x86_64 with the respective directory name)
5. Copy all dependencies into the Lambda deployment package:
   • mkdir /var/task/lib
   • Get a list of all dependencies - ldd /usr/bin/dig
   • Copy each of the listed dependencies into your deployment package lib folder: eg. sudo /bin/cp /usr/lib64/liblwres.so.80 /var/task/lib/liblwres.so.80
6. Create a deployment package ZIP:
   • cd /var/task
   • zip -r9 /tmp/dig-layer.zip *
7. Download a copy of dig-layer.zip (eg. via SFTP) and upload as a new layer in your Lambda console