Startup scripts

COHORTE system is composed of several Nodes. Only one node is specified to be Top Composer. It manages the components distribution among the available participating nodes.

In this chapter, we will detail how to create and start COHORTE nodes using simple command lines.

Creating nodes

To create COHORTE node, you have to use the provided cohorte-create-node command.

Usage

$ ./cohorte-create-node [-h] [-n NODE_NAME] [-a APP_NAME]

Options

This command has the following options :

  -h, --help            show this help message and exit

  -n NODE_NAME, --name NODE_NAME
                        Name of the node
  -a APP_NAME, --app-name APP_NAME
                        application's symbolic name

Results

This command will create a directory containing the following structure:

• node_name correspond to the provided name by the user using the --name option.
• run is the starting script. It will be detail in the next section (Starting nodes)
• repo is a directory where user provided bundles should be placed.
• conf is a directory containing configuration files. Only one configuration file is created initially (composition.js), other files are generated by run script in this location.

Here is the content of the generated conf/composition.jsfile. You should add component descriptions on the indicated zone (see Composition Specification).

{ 
  "name": "default-application",
  "root": {
    "name": "default-application-composition",
    "components": [
      /* your component descriptions here */
    ]
  }
}

Only the node started as Top Composer (see next section) should have this configuration file completed. Other nodes started as simple nodes will ignore this file.

Starting nodes

To start a COHORTE node, you have to use the generated run command (this command calls cohorte-start-node internal command).

Usage

$ ./run [-h] [-a APPLICATION_ID]
        [--use-config CONFIG_FILE] [--update-config]
        [--show-config] [-b BASE_ABSOLUTE_PATH]
        [-n NODE_NAME] [--top-composer IS_TOP_COMPOSER]
        [--composition-file COMPOSITION_FILE]
        [--auto-start AUTO_START]
        [--web-admin WEB_ADMIN_PORT]
        [--shell-admin SHELL_ADMIN_PORT]
        [--transport TRANSPORT_MODES]
        [--xmpp-server XMPP_SERVER]
        [--xmpp-port XMPP_PORT]
        [--http-ipv HTTP_IPV]

Options

There are different kind of options depending on the use of the actual node.

Mandatory options

  -a APPLICATION_ID, --app-id APPLICATION_ID
                        Application's ID

All the nodes participating for a given application should have the same APPLICATION_ID.

Startup configuration options

  --use-config CONFIG_FILE  Configuration file to use for starting cohorte node.
                        By default the run.js file is used if available
  --update-config       Update startup configuration file with provided
                        options
  --show-config         Show startup configuration file content
  -b BASE_ABSOLUTE_PATH, --base BASE_ABSOLUTE_PATH
                        absolute file path of the node's directory

We can write the startup configurations in a separate JSON file (see How to use startup configuration files section). This options will simplify the command options list and allows sharing the same startup configurations between several nodes.

Information about the node to start

  -n NODE_NAME, --node NODE_NAME
                        Node name
  --top-composer IS_TOP_COMPOSER
                        Flag indicating that this node is a Top Composer
  --composition-file COMPOSITION_FILE
                        Composition file (by default 'composition.js'). All
                        composition files should be placed on 'conf' directory
  --auto-start AUTO_START
                        Auto-start the composition if this node is a Top
                        Composer
  --web-admin WEB_ADMIN_PORT
                        Node web admin port
  --shell-admin SHELL_ADMIN_PORT
                        Node remote shell port

We can provide a different node name than the already provided when the node is created (by using –node option). One important option of cohorte nodes is the --top-composer. If set, the node will be considered as a Top Composer (manages all the distribution of components among the available nodes). Users can also provide customised informations such as the http port to use for the web-admin component (see monitoring chapter), or the port to use for the remote shell admin component.

Information about the transport protocols to use

  --transport TRANSPORT_MODES
                        Transport mode (http and/or xmpp - seperated by comma)
  --xmpp-server XMPP_SERVER
                        XMPP server
  --xmpp-port XMPP_PORT
                        XMPP server port
  --http-ipv HTTP_IPV
                        HTTP IP version to use (when transport mode is http)

The --transport option allow the use to choose which transport protocol to use between the actual node and the other nodes participating in the same application. You can provide a common seperated list of the supported protocols (http and xmpp for the moment). Each protocol need additional configuration options that should be provided seperataly using dedicated options (–xmpp-server for instance to mention the XMPP server to use).

How to use startup configuration files

To avoid re-typing the same options each time a node is started, or to share the same configuration between several nodes, you can provide a startup configuration file which contains such startup configurations. The content of such file is described hereafter.

run.js

{	
	"application-id": "ABCDEF",

	"node": {		
		"name": "node-rasp",
		"top-composer": true,
		"web-admin": 9001,
		"shell-admin": 9001		
	},
	"transport": ["xmpp"],
	"transport-xmpp": {
		"xmpp-server": "charmanson.isandlatech.com",
		"xmpp-port": 5222
	}
}

• To show the content of the startup configuration file :

$ ./run --show-config 

• To use other configuration file than the default run.js file :

$ ./run --use-config other_run_conf.js

• Update the startup configuration using command options (–some-configuration should be replaced with a supported options list):

$ ./run --update-config --some-configurations 

This will update all the provided options within the startup configuration file (run.js).

Connection modes

Using HTTP

./run --app-id myapplication --transport http 

The discovery is done using TCP multi-caste feature. This limits the scope of the discovered COHORET nodes to only available at a local network area LAN. To deploy you COHORTE nodes at the Internet level, you should use XMPP mode.

Using XMPP

You need to start the Top Composer with the following configurations :

./run --app-id myapplication --transport xmpp \
--xmpp-server server_url \
--xmpp-port 5222 \

The XMPP server should accept anonymous connections and `multi-user chat.

Using HTTP/XMPP

You can use the two transport protocols in the same time. At runtime, only one is used, if it does not work COHORTE choose the other one.