January 2019 Archives

January 21st, 2019April 10th, 2019

Using NodePing To Send Downtime Notifications To Slack

So I’m a huge fan of the service NodePing. NodePing is a service used to monitor websites and service availability, and can ping hosts, monitor HTTP/HTTPS, other services like POP3/IMAP, DNS, and more! It can also perform “advanced HTTP” monitoring and check the HTTP response code or the content from the response! I pretty much use NodePing to monitor all of my hobbyist projects, as well as those belonging to friends.

One thing that gets tricky, however, is how to do alerting. NodePing lets you do email and text notifications, but neither feels “right” to me, especially if you want to alert multiple people at once. So I came up with a better way: sending webhooks into Slack! In this post, I am going to walk you through the process of making this happen.

Requirements

First, you’ll need to purchase a plan on NodePing. Plans on NodePing start at $8/month, but I personally recommend the $15/month plan as you can monitor up to 200(!) different services with it. You’ll also need to create your own Slack instance, and Slack has a free tier, which I recommend.

After creating a Slack instance, I recommend downloading and configuring both the Desktop and mobile clients to connect to your Slack instance.

Setting Up A Webhook In Slack and NodePing

Now that you’re signed up with both services, you’ll need to create a webhook in Slack. To do that, go to the “Applications” page on Slack’s website and choose the “Incoming Webhooks” app. Add a new integration and copy the URL of the webhook into your clipboard:

Note that whichever Slack channel you send alerts to is completely up to you. My personal recommendation is to create a separate channel just for alerts from NodePing.

January 14th, 2019March 16th, 2019

9 Essential WordPress Plugins

One does not simply appear in search engine results

When I made the move to WordPress a few weeks ago I had a lot to learn, both in terms of functionality that WordPress had to offer, as well as plugins that I could install and which of those plugins actually worked well!

So I’m going to spend this post sharing what plugins I found the most useful so that anyone else who is getting into WordPress can have an easier time getting started.

Open Graph

Open Graph and Twitter Card Tags

Even if you don’t use Facebook or Twitter, chances are that your visitors do and they share your content on those sites. So this plugin is probably the most important plugin of the entire list, because it adds the appropriate meta tags to ensure that when your content is shared on either service, it is rendered correctly.

Furthermore, the Open Graph plugin allows you to set a default image and override it with other an image from the post itself or one uploaded separately:

Again, I cannot stress it enough–if you want your content to look presentable on social media sites, you need to use this plugin. Otherwise, you are passing up a huge opportunity.

January 5th, 2019May 18th, 2019

Fixing Image Sizes on WordPress Attachment Pages

One of the neat things about WordPress is that when you upload an image and then include that image in a blog post, you can decide where that image links to. The image can link to nothing at all, the raw image, or an “attachment page” which contains that image and a caption.

That said, something that has caused me grief for out of the box WordPress builds has been the image on the media page being really small. Take for example, this picture of a freeloading cheetah. When I upload the picture, the attachment page looks like this:

Just look at that. A tiny image and a bunch of the page being completely unused. Disgraceful. Surely we can do better!

As it turns out, tweaking a single line of code can be used to change the size of all images on media pages.

January 5th, 2019July 20th, 2019

Using Splunk on Hotel Internet

Splunk> Finding your faults, just like Mom.

In a previous post, I wrote about using Splunk to monitor network health. While useful for home and office use, there’s another valuable use for this app, and that’s when traveling.

In my case, over my Christmas vacation, I checked into a Mom and Pop hotel, or rather a motel! It was about 24 rooms all in a row, occupying a single floor. Since they were on a budget, their Internet offering consisted of what appeared to be 5 or 6 Linksys routers set up every few rooms. You’d simply connect to the closest access point and have Internet.

But there was a problem: determining which access point was closest to me! The signal strength indicator on my computer showed several of them were 3/3 bars so that wasn’t much help. I tried connecting to the first one, but had virtually no Internet connectivity.

That’s when I fired up Splunk:

SPLUNK_START_ARGS=--accept-license \
TARGETS=google.com,1.1.1.1,8.8.8.8,192.168.1.1 \
   bash <(curl -s https://raw.githubusercontent.com/dmuth/splunk-network-health-check/master/go.sh)

Running that command will print up a confirmation screen so that you can back out and change any options (such as hosts to ping), and when you’re ready, just hit <ENTER> to start the container.

In the above example, I added in the TARGETS environment variable, and was sure to include 192.168.1.1, which was the IP for each router (they were all the same). Then I set Splunk “real-time mode” and periodically checked that tab as I was working. This is what I saw:

Testing 3 separate hotel Access Points with Splunk

January 4th, 2019July 20th, 2019

Introducing: Splunk Lab!

Splunk> Australian for grep.

In a previous post, I wrote about using Splunk to monitor network health and connectivity. While building that project, I thought it would be nice if I could build a more generic application which could be used to perform ad hoc data analysis on pre-existing data without having to go through a complicated process each time I wanted to do some analytics.

So I built Splunk Lab! It is a Dockerized version of Splunk which, when started, will automatically ingest entire directories of logs. Furthermore, if started with the proper configuration, any dashboards or field extractions which are created will persist after the container is terminated, which means they can be used again in the future.

A typical use case for me has been to run this on my webserver to go through my logs on a particularly busy day and see what hosts or pages are generating the most traffic. I’ve also used this when a spambot starts hitting my website for invalid URLs.

So let’s just jump right in with an example:

SPLUNK_START_ARGS=--accept-license \
   bash <(curl -s https://raw.githubusercontent.com/dmuth/splunk-lab/master/go.sh)

This will print a confirmation screen where you can back out to modify options. By default, logs are read from logs/, config files and dashboards are stored in app/, and data that Splunk ingests is written to data/.

Once the container is running, you will be able to access it at https://localhost:8000/ with the username “admin” and the password that you specified at startup.

First things first, let’s verify our data was loaded and do some field extractions!

Main Index
Field Extractions