Purging Dead AWS Route53 Records via Ansible

We aren’t a big shop, but we use AWS Autoscale Groups .. That means nodes spin up and down all day long .. Got some traffic ?? Add nodes .. Traffic is low ?? Drop nodes .. Someone accidentally terminates a node ?? Add nodes .. Someone sneezes funny ?? Drop nodes ..

This goes on all day long to get as close to “right-sizing” our infrastructure as we can ..

We also name our nodes using a simple formula for various monitoring and orchestration purposes .. For example:

asg-<application>-<environment>-<availability-zone>-<instance-id>.example.com

asg-login-prod-us-east-1a-i-abc123xyz.example.com

Yes, i understand an argument could be made this is an anti-pattern .. “Greg, you don’t need to name the stinking node .. It is cattle — nobody cares !!” .. I get it, I really do — but sometimes it’s nice just to have a name ..

So then, with all this spinning up and down of nodes and the related creation of Route53 records — you can end up with a lot of dead entries .. For whatever reason, you may wish purge these dead entries — and OBVIOUSLY you do NOT want to do this manually .. So what to do ??

Well, I might have a solution for you .. Go ahead and check out this GitHub repo: https://github.com/gkspranger/aws-route53-purge-dead-records .. It’s a simple playbook and role that will purge AWS Route53 records for a given hosted zone and a known naming pattern, while making sure to NOT delete records of nodes that are currently running ..

WARNING It can cause damage, so please be sure to review and understand what is going on with the playbook and role ..

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Dear Nagios

Dear Nagios,

I’m sorry, but it’s over ..

No, no, no .. It’s not you, it’s me .. I’ve changed — let me explain ..

You’ve been great these past 7 years .. Better than great — you basically defined what monitoring means to me .. Yes, we’ve both said things we regret — but we always ended back together ..

This time, it’s different ..

I found someone ..

Their name is TIG (Telegraf, InfluxDB, Grafana) ..

STOP THAT !! THAT’S NOT NICE .. Yes, they’re younger than you — but it’s not about that .. NO !! NO !! NO !! I’m not going through a midlife crisis .. Like I said earlier — I’ve changed .. Simply put, I now care more about metrics now than I do monitoring ..

Yeesss, I know you offer performance data .. You know I know that .. We’ve dated for almost a decade — let’s at least be honest with one another ..

Uh huh .. Uh huh .. Uh huh .. No, not this time, not ever .. Uh huh .. Uh huh .. Uh huh .. Believe me, I wish there was a way, I just don’t see it happening ..

OK !! THAT’S ENOUGH !! This is getting abusive now — I’m going to leave ..

Thank you for being with me ..

Thank you for teaching me ..

But it’s time to go ..

Splunk Host Tags

Did you know you can tag a host in Splunk ?? I didn’t !! Do you know how much time tags would have saved me from having to craft a most excellent Splunk search to capture just the right hosts ?? Me neither — but I’m guessing it’s a lot ..

So instead of my searches looking like this:

# get all staging RMI nodes -- hard
index=* ( host=rmi1.s.* OR host=rmi2.s.* OR host=rmi3.s.* ) source=*tomcat* earliest=-1h

They can now look like this:

# get all staging RMI nodes -- easy
index=* tag=rmi tag=stage source=*tomcat* earliest=-1h

I know, I know — I could achieve the same level of excellence using targeted indexes (index=rmi_stage) and/or various regex filters .. Some of that, unfortunately, is out of my control ..

OK .. So how can you manage this without having to use the GUI ?? Easy !! You just need to drop a config file in the proper location (for me it’s: /opt/splunk/etc/system/local/tags.conf) on the search head, and away you go .. The syntax is pretty basic:

# tagging host login.example.net with PROD, TOMCAT, and LOGIN
[host=login.example.net]
prod = enabled
tomcat = enabled
login = enabled

Below’s a nice little example of how I automated this using Ansible (big surprise there 🙂 and the EC2 dynamic inventory script ..

He Shoots .. He Fails !!

For the past 6 months I have been working on a lean startup .. It was (<<infer all you want here) a chatbot interface for a financial services CRM — and did not end well 😦 That said, I did some of my best Ansible/AWS work and my server-side JavaScript (Node.js) and understanding of the Hubot internals improved exponentially ..

So I want to share !!

I can’t get into too many details, but the overall concept was that every customer would be running a micro instance with our custom Hubot code installed .. This instance would pull code updates, if any, every 5 minutes and infrastructure updates, if any, every 15 minutes ..  In addition, a customer could participate in pilot programs — AKA branch work ..

I really liked how I was able to mitigate the use of a “command node” and just run Ansible locally and on a schedule .. Also, I was able to automate pretty much everything — from VPC creation all the way to autoscaling groups ..

Anyway, here’s the link: https://github.com/gkspranger/failed-chatbot .. Maybe it will help one of you out there in Internets land ..

Qik-n-EZ: Nagios AWS EC2 Hosts via Ansible

Sooo .. You are monitoring a fleet of AWS EC2 hosts via Nagios, and have yet to find an easy way to manage their host definitions .. Good news (if you happen to be using Ansible dynamic inventories) !! I created an Ansible template that loops thru all your EC2s and creates them for you ..

In addition, you can easily define Nagios service dependencies, helping you zero in on the root problem more quickly ..

Hubot with Handlebars :-3

So you’ve met Hal — he’s my bud .. That said, I’ve never been a fan of how I “reply” to Hubot commands .. For example:

“Greg, what’s your problem ?? Hal brings you beer !!” .. True, true .. But I want more !! I want to be more like my developer friends and apply an MVC design pattern to my Hubot development .. Specifically, I want my “views” to be beautiful and maintainable, while having the ability to use complex data “models” ..

Hello Handlebars !! Long story short, I can easily build semantic templates, compile output, and send as a Hubot reply .. For example:

Here’s the template:

Here’s the Slack output: