This is documentation for the next version of Alloy. For the latest stable release, go to the latest version.
declare block
declare
is an optional configuration block used to define a new custom component.
declare
blocks must be given a label that determines the name of the custom component.
Example
declare "COMPONENT_NAME" {
COMPONENT_DEFINITION
}
Arguments
The declare
block has no predefined schema for its arguments.
The body of the declare
block is used as the component definition.
The body can contain the following:
- argument blocks
- export blocks
- declare blocks
- import blocks
- Component definitions (either built-in or custom components)
The declare
block may not contain any configuration blocks that aren’t listed above.
Exported fields
The declare
block has no predefined schema for its exports.
The fields exported by the declare
block are determined by the export blocks found in its definition.
Example
This example creates and uses a custom component that self-collects process metrics and forwards them to an argument specified by the user of the custom component:
declare "self_collect" {
argument "metrics_output" {
optional = false
comment = "Where to send collected metrics."
}
prometheus.scrape "selfmonitor" {
targets = [{
__address__ = "127.0.0.1:12345",
}]
forward_to = [argument.metrics_output.value]
}
}
self_collect "example" {
metrics_output = prometheus.remote_write.example.receiver
}
prometheus.remote_write "example" {
endpoint {
url = REMOTE_WRITE_URL
}
}