andrewdmcleod / woodpecker-layer

Woodpecker charm layer

Overview

Woodpecker is a charm for testing networking between peers, and/or to arbitrary host:port combinations, e.g. www.google.com:80, with or without a 'send' string and a 'receive' string.

Status messages will either display an error with a check, or all ok. For detailed information see the juju logs.

Example usage for woodpecker could be to deploy one unit to bare metal, one to an lxc container - this would validate connection between the two.

Another example would be to use woodpecker to check all API endpoints in a particular bundle deployment, e.g. openstack, bigdata, etc.

Configuration

By default, port 31337 will be opened on each peer, and connectivity validated between each peer on that port. This can be modified to another port by providing a comma separated list to the check_ports configuration key.

Additionally, tcp port and ip combinations can be provided to the check_list string. A send string and receive string can also be defined to provide further testing, e.g.:

    juju set config woodpecker \
    check_list='
    google:www.google.com:80:get /:302,
    ubuntu_ftp:ftp.ubuntu.com:21:test:503,
    canonical:www.canonical.com:80'

This will cause woodpecker to connect to www.google.com, send "get /", and only return true if "302" is in the response string.

check_list access the following check formats:

• label:host:port Will just check that the tcp port is open
• label:host:port:send:receive Will send 'send' and check 'receive' is found in the response string.

All labels must be unique, and all checks must be specified each time the config value is set.

Workload Status

In addition to basic status messages, if a peer or remote host connection failure is detected, the workload status of the agent which has found the issue will be set to blocked.

Reactive States

This layer will set the following states:

• woodpecker-peer.failed Connection to the tcp port on its peer has failed
• woodpecker-hosts.failed One or more remote host checks have failed

Usage

juju deploy woodpecker 
juju add-unit woodpecker -n 1 --to lxc:1
juju set woodpecker check_ports='31337,1337'
juju set woodpecker check_list='
google_simple:www.google.com:80,
google_advanced:www.google.com:80:GET /:302'