comment: true title: Target Nodes description: Tags, nodes, and how to target them with wire Tool.#

Target Nodes#

{{ $frontmatter.description }}

Targeting Specific Nodes#

wire apply --on without an @ prefix interprets as a literal node name. For example:

$ wire apply switch --on node-a,node-b

Will switch-to-configuration on node a, and node b.

Reading from Stdin#

Passing --on - will read whitespace-separated nodes and tags from stdin. This can be combined with normal --on usage.

For example:

$ echo "node-a node-b" | wire apply --on @other --on -

Will apply on node-a, node-b, and all nodes with the tag @other.

Tag Basics#

Nodes can have tags, which allows you to easily target multiple, related nodes for deployment.

let
  sources = import ./npins;
  wire = import sources.wire;
in wire.makeHive {
  meta.nixpkgs = import sources.nixpkgs { };

  node-1 = {
    # ...
    deployment.tags = ["cloud"];
  };
  node-2 = {
    # ...
    deployment.tags = ["cloud", "virtual"];
  };
  node-3 = {
    # ...
    deployment.tags = ["on-prem"];
  };
  node-4 = {
    # ...
    deployment.tags = ["virtual"];
  };
  node-5 = {
    # Untagged
  };
}

To target all nodes with a specific tag, prefix tags with an @. For example, to deploy only nodes with the cloud tag, use

$ wire apply --on @cloud

Further Examples#

::: info

Other operations such as an --ignore argument are unimplemented as of wire v0.2.0.

:::

Mixing Tags with Node Names#

You can mix tags and node names with --on:

$ wire apply --on @cloud --on node-5

This will deploy all nodes in @cloud, alongside the node node-5.

Targeting Many Tags (Union)#

You can specify many tags together:

$ wire apply --on @cloud @on-prem

This is a union between @cloud and @on-prem.