Graphs can be accessed via HTTP using the normal web management interface. This can be used as a direct link from a web browser, or using common tools such as curl and wget.
The web management interface (services/http) defines the port, allowed user list and also a trusted IP access list. The CQM config defines a secret which is used to authorise untrusted access using an SHA1 hash in the URL.
All CQM URLs are in the /cqm/ path.
To access a graph you simply need to request the URL that is the graph name, followed by the file extension. E.g. http://host:port/cqm/circuit.png.
Table I.1. File types
Extn | Format |
svg | SVG image |
png | PNG image |
csv | COMMA separated values list |
tsv | TAB separated values list |
txt | SPACE separated values list |
xml | XML data |
Without any date the data returned is the latest. This includes the last 24 to 25 hours.
You can display data for a specific date. This only makes sense for today, and during the first couple of hours of the day you can get yesterday in full.
The syntax is that of a date first in the form YYYY-MM-DD/, e.g. http://host:port/cqm/YYYY-MM-DD/circuit.png.
Authenticated access requires a prefix of a hex SHA1 string. e.g. http://host:port/cqm/longhexsha1/circuit.png or http://host:port/cqm/longhexsha1/YYYY-MM-DD/circuit.png.
The SHA1 is 40 character hex of the SHA1 hash made from the graph name, the date, and the http-secret. The date is in the form YYYY-MM-DD, and is today's date for undated access (based on local time).
This means a graph URL can be composed that is valid for a specific graph name for a specific day.
Note that an MD5 hash (32 character hex) can also be used instead, but SHA1 is the preferred method.