Struct Variable

pub struct Variable<'a> {
    pub scope: Option<Scope>,
    pub name: &'a str,
    pub value: f64,
}

Define and publish variables and constants.

VARIABLE [SCOPE] name = value

It defines a variable that can be used in alarms.
This is also used for setting constants (like the max connections a server may accept).

Examples:

use netdata_plugin::{Variable, Scope};
let v = Variable {
   scope: Some(Scope::GLOBAL),
   name: "variable_name",
   value: 3.14f64,
};
assert_eq!(v.to_string(), "VARIABLE GLOBAL variable_name = 3.14");

Variables support 2 Scopes:

• GLOBAL or HOST to define the variable at the host level.
• LOCAL or CHART to define the variable at the chart level. Use chart-local variables when the same variable may exist for different charts (i.e. Netdata monitors 2 mysql servers, and you need to set the max_connections each server accepts). Using chart-local variables is the ideal to build alarm templates.

The position of the VARIABLE line output, sets its default scope (in case you do not specify a scope). So, defining a VARIABLE before any CHART, or between END and BEGIN (outside any chart), sets GLOBAL scope, while defining a VARIABLE just after a CHART or a DIMENSION, or within the BEGIN - END block of a chart, sets LOCAL scope.

These variables can be set and updated at any point.

Variable names should use alphanumeric characters, the . and the _.

The value is floating point (Netdata used long double).

Variables are transferred to upstream Netdata servers (streaming and database replication).

Fields

scope: Option<Scope>

name: &'a str

value: f64

Trait Implementations

impl<'a> Clone for Variable<'a>

fn clone(&self) -> Variable<'a>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> Debug for Variable<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a> Default for Variable<'a>

fn default() -> Variable<'a>

Returns the “default value” for a type.

impl<'a> Display for Variable<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.