Ensure that log messages are sent correctly (per wire format).

[ericsnowcurrently]

We must be sure that the wire format syslog messages we send match the specification (see below). This patch does so.

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(see https://docs.google.com/document/d/1Dnn85mR8gUqmu9WhPtOMjLS4LftMbnCgtS-3dNomyNw/)

Syslog messages will be sent using the RFC 5424 message format (see more on the syslog protocol below). We make use of the structured data facility defined in the more recent RFC.

The value of "priority" is set by whether a log or audit message is being recorded.

Log Messages:
The facility code will be 1 (user level message). Severity will be mapped as follows:
Juju ERROR = Error (3)
Juju WARNING = Warning (4)
Juju INFO = Informational (6)
Juju DEBUG = Debug (7)
Juju TRACE = Debug (7)

Messages will use structured data to record relevant environment and user action parameters. Key pair definitions will be:

SDID: origin
enterpriseId: 28978 (Canonical, Ltd.)
software: jujud
swVersion:

SDID: model@28978
controller-uuid:
model-uuid:

SDID: log@28978
source: :
module: <the name of the source “module”>

Example log (error) message

<11>1 2016-02-28T09:57:10.804642398-05:00 172.12.3.1 juju - - [origin enterpriseId="28978" software="jujud" "2.0.0"] [model@28978 controller-uuid="deadbeef" model-uuid="deadbeef"] [log@28978 source-file="provider/ec2/storage.go" source-line="60"] Could not initialise machine block storage

(Review request: http://reviews.vapour.ws/r/5189/)

[ericsnowcurrently]

$$JFDI$$

[jujubot]

Status: merge request accepted. Url: http://juju-ci.vapour.ws:8080/job/github-merge-juju