TICK stack

I’ve been using the TelegrafInfluxDBChronograf-Kapacitor stack for a couple of months at home and at work, for monitoring the state of devices, process and home automation.

We actually I’ve been using the Telegraf-InfluxDB-Grafana stack – I have no idea why they decided to create Chronograf as a fork of Grafana, but it really is pretty rubbish in comparison.

That said, overall the solution is brilliant – Telegraf is pretty good at grabbing stats from your servers, and is highly configurable (at least on Linux – the Windows version could do with some work). The only area that really lets it down is the inability to sum up stats when monitoring processes, so anything that spawns child processes tends to make a mess of the stats.

Influx is very easy to use – the line protocol mechanism for adding data with a simple web request makes it very accessible, with a simple bash script and some sed reformatting able to create a data dump very easily. It seems pretty disk intensive, but I guess that’s always going to be the case with something writing datapoints every minute. Getting used to a timeseries database takes a bit of patience, with pretty limited options for querying, but it’s worth it for the performance and space saving. The only significant lack here is handling of offsets – it’s a very clear use-case to compare timeseries from two equivalent points in time, and surprising it isn’t supported.

Then Grafana tops it off with flexible and powerful visualisation.

I’d recommended anyone who is looking after any sort of IT system to have a play around with it.

Hosting Hassles

I’ve been using Vidahost for my web hosting for many years, and until the last couple of months their service was superb. But then I made the mistake of moving to a newer shared server – and everything went wrong.

I suspect the new host is just overloaded, but email was unusably slow several times each day, the (virtually unused) website similarly sluggish, and then the final straw they blocked my home IP address because of too many IMAP requests. OK, it was a bit high – but in a multi-device family that’s the new normal.

I’ve now moved to AWS for hosting and Infomaniak for email – so far so good, the “free” (for a year) EC2 server is much faster, as is the (not free) email.

Since I was moving, I also migrated to WordPress from Movable Type – seems OK, although it’s a lot less flexible in terms of accessing the underlying HTML.

Confluence User Cloud Macro

This user macro will display users in a specific group in a cloud-like format, as shown below.

## Macro Name: user-cloud
## Macro title: User Cloud
## Description: Displays a list of users in a cloud-like format
## Category: Confluence content
## Body processing: Unrendered

## @param Group:title=Group|type=string|required=true|desc=Group name
## @param MinWidth:title=Minimum Width|type=string|required=true|desc=Minimum width in CSS units (e.g. px)|default=120px
## @param PicSize:title=Picture Size|type=string|required=true|desc=Picture height in CSS units (e.g. px)|default=60px
## @param Border:title=Border Colour|type=string|required=false|desc=Border Colour
## @param Fill:title=Fill Colour|type=string|required=false|desc=Fill Colour

#foreach($user in $userAccessor.getMembers($userAccessor.getGroup($paramGroup)))
  <span style="background: $paramFill; min-width: $paramMinWidth; text-align: center; display: inline-block; border: 1px solid $paramBorder; padding: 6px; margin: 8px; border-radius: 4px">
    <img style="height: $paramPicSize; border-radius: 3px" src="$userAccessor.getUserProfilePicture($user).getUriReference()"><br/>
    <a href="/display/~$user.getName()">$user.getFullName()</a>
  </span>
#end

The layout can be customized for border, background, minimum width of block, and picture height; each item is a span which will flow depending on the width which in turn depends on the specified minimum and the name length.

Names are links to the user’s profile page.

The image below can be used as the icon.

Confluence – hiding content from PDF export

Confluence has the ability to produce reasonable PDF exports of pages, which can be further customized using CSS to add corporate logos, footers etc.

As a wiki much of the power comes from dynamic features such as links to related items, or making notes at the end of pages, but this is not always appropriate or useful in a static export.

The following macro adds a section to a page which will not be exported.

Creating the Macro

Create a new User Macro (Administration – Configuration – User Macros) with the following details

|Macro Name|hidden-pdf-panel| |Visibility|Visible to all users in the Macro Browser| |Macro Title|Hidden PDF Panel| |Description|A panel which will be hidden when exported to PDF| |Categories|Formatting| |Documentation URL|This page URL| |Macro Body Processing|Rendered|

Template code below

## Macro title: Hidden PDF Panel
## Macro has a body: Y
## Body processing: Rendered

## @noparams

<div class="pdfhidden" style="position: relative; margin: 0px -8px; border: 2px dashed #CCCCCC; padding: 4px"><div style="font-size: 10px; font-weight: bold; color: #CCCCCC; position: absolute; top: 0px; right: 2px">hidden</div>$body</div>

Setting the CSS for the PDF Export

Edit the Global PDF Styles (Administration – Look and Feel – PDF Stylesheet) to add the following CSS snippet at the end:

/* Hidden panels */
div.pdfhidden {
  display: none;
}

That’s it – you can now use the macro on pages to have non-PDF-exported content, like this:

Date from Unix Timestamp

I always have to fire up Excel to get a date/time from a Unix timestamp… so here’s a quick Javascript that does it: