External netlets, launcher, Jnode and bootstrap netlets

We've just said that a node does not have any user interface, and it does not have any direct access to the outside world. This would make it rather difficult to control, and even boot.

Therefore we have the concept of an external netlet. This is any ordinary application which happens to have a node embedded in it. It can boot the node, and the node sees it as another netlet, hence the name. This external netlet is the administration netlet and has special access to the node and its resources.

External netlets are therefore how a Jtrix node can be part of another application. In fact, a node cannot run without an external netlet.

One example of an external netlet is launcher which is jtrix.org's shell-like console tool to access and manage several Jtrix applications from a single remote location. It has a node embedded in it so it can run small netlets which send the user's commands back to the main Jtrix application to process.

Another example is Jnode, the node with a command line start-up. This enables a single instance of Nodality to act as part of a group and helps resource management.

When we start Jnode we can specify a number of netlets it should initialise. These are called bootstrap netlets. We can grant them I/O access to specific files, which security would otherwise prevent. Let's not confuse bootstrap netlets with external netlets--Jnode is the external netlet, because it's the application which embeds the node, and the external netlet controls the node. The bootstrap netlets are the ones given on the Jnode command line, which it controls.