Settings

All settings for a particular configuration are encapsulated into a single JSON object which consists of key-value pairs. Each section below will consist of an object that contains the keys and information required to properly configure each key.

Repository

The repository key contains all remote/local relationship data, including paths to the executable. This is the most important field and the only one that is actually required.

key	description	valid values	default value
remote	the name of the remote	any string	"origin"
remote path	the remote url or path	any string	-
local path	the local path	any string	-
branch	the git branch to sync	any string	"master"
executable	the executable	string/path	"/usr/bin/git" or "C:\Program Files\Git\bin\git.exe"

Example of repository object (JSON):

{
    "repository": {
        "remote": "origin",
        "remote path": "https://github.com/slightlynybbled/dummy.git",
        "local path": "C:/_code/_git_example",
        "branch": "master",
        "type": "git",
        "executable": "/usr/bin/git"
    }
}

The equivalent INI:

[repository]
remote = origin
remote path = https://github.com/slightlynybbled/dummy.git
local path = C:/_code/_git_example
branch = master
type = git
executable = /usr/bin/git

Testing

The test key is reserved, but not currently implemented.

Timing

If no timing is specified, then the default will be 60 seconds. If only a minimum is specified, then the remote will be checked at that interval. Finally, if a minimum and a maximum are specified, then the remote will be checked for updates at a random time between the minimum and maximum values.

key	description	valid values	default value
minimum	minimum time in seconds	any integer	60
maximum	maximum time in seconds	any string	-

Example of timing object (JSON):

"timing": {
    "minimum": 30,
    "maximum": 300
},

The equivalent INI:

[timing]
minimum = 30
maximum = 300

Application

The application key is used to identify the application that is to be started and monitored. On remote update, this is the application that will be stopped, updated, and reloaded.

key	description	valid values	default value
start	the start executable	any integer	60

Example of application object (JSON):

"application": {
    "start": "python -m dummy_app.py"
},

The equivalent INI:

[application]
start = python -m dummy_app.py

Scripts

There are two times at which an arbitrary script or group of scripts must be executed and that is pre-pull and post-pull. The pre-pull scripts are supplied as a JSON array, with each being executed in succession.

This scripts will execute two scripts before the pull and will reboot the machine after the pull:

"scripts": {
    "pre-pull": [
        "/bin/ls /home/ubuntu/ > /home/ubuntu/values.txt", 
        "/bin/ls /etc/ > /home/ubuntu/values.txt"
    ],
    "post-pull": ["sudo reboot"]
}

The equivalent INI:

[scripts]
pre-pull = /bin/ls /home/ubuntu/ > /home/ubuntu/values.txt, /bin/ls /etc/ > /home/ubuntu/values.txt
post-pull = sudo reboot

Note that in the INI file, each command is separated by a comma ,.

Health Monitoring/Watchdog

Applications sometimes require health monitoring and restart. Huddle provides two methods of health monitoring, http-based and socket-based. The http-based monitoring simply checks the remote URL and ensures that the response string is contained in the URL response. The socket-based monitoring will poll a socket on the application and ensure that the response string is contained within the response.

key	description	valid values	default value
period	the watchdog period, in seconds	integer or float	60
host	the IP address or url to monitor	http or ip address	'127.0.0.1'
port	the TCP port to monitor	string or integer	60
request	string to be sent to the application	string	'watchdog'
response	the expected response from a healthy instance	string	-

"watchdog": {
    "period": 60,
    "host": "127.0.0.1",
    "port": "8888",
    "request": "watchdog",
    "response": "OK"
}

The equivalent INI:

[watchdog]
period = 10
host = 127.0.0.1
port = 8888
request = watchdog
response = OK

Example Configuration Scripts

Minimal File Sync

This configuration will keep the local C:/_code/_git_example directory in synce with the remote develop branch. It will not start or run any applications.

{
    "repository": {
        "remote": "origin",
        "remote path": "https://github.com/slightlynybbled/dummy.git",
        "local path": "C:/_code/_git_example",
        "branch": "develop",
        "executable": "C:/Program Files/Git/bin/git"
    }
}

Syncing/Run an Application

This configuration will sync every 60s to 600s. When there is an update, this application will be halted, updated, then restarted after the update.

{
    "repository": {
        "remote": "origin",
        "remote path": "https://github.com/slightlynybbled/dummy.git",
        "local path": "C:/_code/_git_example",
        "branch": "master",
        "executable": "C:/Program Files/Git/bin/git"
    },

    "timing": {
        "minimum": 60,
        "maximum": 600
    },

    "application": {
        "start": "python -m dummy_app.py"
    }
}

Sync Application/Reboot Server

This configuration will check the remote every 60s and, when new data is available, huddle will stop the application and reboot the machine with a post-pull script.

{
    "repository": {
        "remote": "origin",
        "remote path": "https://github.com/slightlynybbled/dummy.git",
        "local path": "C:/_code/_git_example",
        "executable": "/usr/bin/git"
    },

    "application": {
        "start": "python -m dummy_app.py"
    },

    "scripts": {
        "post-pull": ["/sbin/reboot"]
    }
}

Sync Application with Watchdog

This configuration will check the remote every 60s and, when new data is available, huddle will stop the application, pull the new application version, then restart the application.

Huddle will also send a query to port 8888 on the local machine every 15 seconds with the string 'watchdog'. If the response from the application does not contain the string 'OK', then huddle will stop the application and restart it.

{
    "repository": {
        "remote": "origin",
        "remote path": "https://github.com/slightlynybbled/dummy.git",
        "local path": "C:/_code/_git_example",
        "executable": "/usr/bin/git"
    },

    "application": {
        "start": "python -m dummy_app.py"
    },

    "watchdog": {
        "period": 15,
        "host": "127.0.0.1",
        "port": "8888",
        "request": "watchdog",
        "response": "OK"
    }
}