Informer

Informer runs basic checks for web things, then exits.

It is useful as either a cron job, or after 'changing things' to make sure everything still works.

The config files are XML (yes XML, it's just - good for this), containing the sites and servers to be checked.

Multiple config files are combined, all sections can be repeated except for SMTP.

A is a website, or api, a set of tests for text based urls.

A is an OS (or container) running somewhere.

Each and can have any number of and tags which will be emailed and called respecively for any checks which fail, or errors.

One tag configures settings for sending emails to the various addresses.

Any number of tags define API urls to call. See http://prowlapp.com/ for a very handy iOS Push app you could use.

Overall Format

<?xml version="1.0" encoding="UTF-8"?>
<informer>
	<site name="Example">	
		<email address="test@example.com"/>
		<email address="test2@example.com"/>
		<redirect>
			<from>http://example.com/</from>
			<to>http://www.example.com/</to>
		</redirect>
		<search url="http://www.example.com/">
			<string>Example</string>
			<string>Example2</string>
		</search>
	</site>
</informer>

Site Checks

A site file is

<site name="GitHub">
	...
</site>

Search

Search for strings in the given url.

<search url="https://github.com">
	<string>GitHub</string>
	<string>UA-1234567-1</string>
</search>

Redirect

Check that a url redirects to another

<redirect>
	<from>http://github.com</from>
	<to>https://github.com</to>
</redirect>

Client Config

The following work for Search, Redirect and Data checks

	<cookie name="auth_token">
		testtoken
	</cookie>
	<header name="Accept">application/json</header>
	
	<client insecure="true" timeout="10">
		<cert>/var/lib/keys/test_cert.pem</cert>
		<key>/var/lib/keys/test_key.pem</key>
	</client>

Self Signed Certificates

inseucre='true'

Data - Logs

Checks a log, where lines begin with the date, for activity in the last [quietPeriod]. Date and Period formats use the golang time package

http://golang.org/pkg/time/

Note that currently, the parsing assumes a fixed width for the date / format - the first len(format) characters are parsed.

URL and client settings as per search

<data name='log-check'>
	<log url="http://example.com/log.log">
		<format>2006-01-02 17:05:06</format>
		<quietPeriod>1h</quietPeriod>
	</log>
</data>

Data - JSON

Checks for values in a JSON file.

URL and client settings as per search.

Keys are walked from the root.

time - Parses a time according to format, and makes sure it is at most [age] old. A format of UNIX is a timestamp.

number - Compares the number in the key. max, min, eq, neq All are parsed as float64s, so eq and neq may behave poorly.

Future:

• array count
• string compare
• time compare properly

<data name='json-check'>
	<json url="http://example.com/stat.json">
		<time key="meta.reported">
			<format>UNIX</format>
			<age>1h10m</age>
		</time>
		<number key="errors.count">
			<max>20</max>
			<min>1</min>
			<eq>15</eq>
			<neq>19</neq>
		</number>
	</json>
</data>

Groups

The default runs only elements in the root object.

Specify a '--group [name]' flag to run only the group with the given name.

Useful to separate hourly checks from daily checks.

'--group all' runs everything

<informer>
	<site .../>
	<group name='daily'>
		<site .../>
		<data .../>
	</group>
</informer>

SMTP Config

<smtp>
	<fromAddress>test@test.com</fromAddress>
	<password>secret</password>
	<serverAddress>smtp.gmail.com</serverAddress>
	<serverPort>587</serverPort>
	<username>informer@test.com</username>
</smtp>

API Config

<api name="prowl-dw">
	<url>https://api.prowlapp.com/publicapi/add</url>
	<method>POSTFORM</method>
	<postval key="apikey">0a0a0a0a0a0a0a</postval>
	<postval key="application">Informer Fail</postval>
	<postval key="event">#title</postval>
	<postval key="description">#body</postval>
</api>

Server Checks

Server checks are not fully implemented yet

At this stage, only disks are checked for servers.

<server hostname="localhost">
	<email address="test@test.com"/>
	<email address="example+informer-localhost@gmail.com"/>
	<api name="prowl"/>
	<disk filesystem="/dev/xda1">
		<minBytes>30000000</minBytes>
	</disk>
	<disk filesystem="/dev/xda2">
		<minPercent>10</minPercent>
	</disk>
</server>

• minBytes: check that there are more than x bytes free on the disk
• minPercent: check that there is more than x% of the disk free.