22 May
2017
22 May
'17
2:51 p.m.
ID: 4733
Title: Check_MK graphs can now be exported as PNG images
Component: metrics
Level: 2
Class: New feature
Version: 1.5.0i1
It is now possible to export the Check_MK graphs as static PNG images. This mechanism
can be used to to integrate the graphs in 3rd party tools. For example, you can use it
to add graphs to NagVis maps or to the hover menu of NagVis.
The new page is named <tt>graph_image.py</tt>. The page is receiving a single
request
parameter that is structured equal to the JSON/python graph API (See werk #8643).
The request object is structured like this:
F+:
{
"specification": [..., ...],
"data_range": {
"time_range" : [..., ...],
}
}
F-:
The specification is using the Check_MK internal graph specification
format. The first element is the specification type (<tt>template</tt>,
<tt>custom</tt> or <tt>explicit</tt>. The structure of the second
element
depends on the type. Please take a look at the examples below to get an idea
of it.
The time range is given in two unix timestamps, the start time and the
end time. But the whole <tt>data_range</tt> specification is optional. In
case you don't provide it, the 25h graph will be rendered.
The answer to this request is a single, dynamically rendered, PNG image.
Please note that this request is done in the context of the currently logged
in user. So the user that opens a page containing this snippet needs to be
authenticated with the Check_MK GUI and able to see the image. Otherwise the
user won't be able to see the image.
The most common use case will be to add the image generated by this. The
following snippets show how it can be embedded:
F+:
<img
src="http://mycmkserver/mysite/check_mk/graph_image.py?request={%22specification%22:%20[%22template%22,%20{%22service_description%22:%20%22CPU%20load%22,%20%22site%22:%20%22mysite%22,%20%22host_name%22:%20%22myhost%22}]}">
F-:
This will try to open the image from the Check_MK site <tt>mysite</tt> on
the server <tt>mycmkserver</tt>. The graph is specified by the following
request object in URL encoded form:
F+:
{
"specification": ["template", {
"service_description": "CPU load",
"site": "mysite",
"host_name": "myhost"
}]
}
F-:
It is also possible to adapt the rendering attributes of the graph using the
<tt>render_options</tt> data structure. This example hides the legend and the
title of the graph and sets a custom image size:
F+:
<img
src="http://mycmkserver/mysite/check_mk/graph_image.py?request={%22specification%22:%20[%22template%22,%20{%22service_description%22:%20%22CPU%20load%22,%20%22site%22:%20%22mysite%22,%20%22host_name%22:%20%22myhost%22}],%20%22render_options%22:%20{%22show_legend%22:%20false,%20%22show_title%22:%20false,%20%22size%22:%20[50,15]}}">
F-:
Again, the human friendly formated request object:
F+:
{
"specification": ["template", {
"service_description": "CPU load",
"site": "mysite",
"host_name": "myhost"
}],
"render_options": {
"show_legend": false,
"show_title": false,
"size": [ 50, 15 ]
}
}
F-:
In case you want to render custom graphs, you can use a specification like this
in your request. Replace <tt>custom_graph_1</tt> with the ID of the custom
graph
you like to see:
F+:
["custom", "custom_graph_1"]
F-: