Params & asset URLs

:param and :assetUrl are text directives with a special behaviour: they are evaluated before Markdown is processed, so they resolve even inside code blocks and directive attributes. That is why every source block on this page escapes them as \:param / \:assetUrl - otherwise the source would show the resolved value instead of the literal directive.

:param injects a value defined under params in contentspec.yaml, so a repeated string, URL or number is defined once and referenced everywhere.

Properties: key (string, the param to display), defaultValue (string, shown if the key has no value).

This template's contentspec.yaml defines:

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params:
  name:
    first: John
    last: Doe
  foo: Bar
  awsBlogLink: https://aws.amazon.com/blogs/aws/
  levels:
    - 100
    - 200
    - 300
    - 400

Rendered:

The value of foo is Bar. Available levels: 100, 200, 300.

Source:

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The value of `foo` is :param{key="foo"}. Available levels: :param{key=levels[0]}, :param{key=levels[1]}, :param{key=levels[2]}.

Rendered:

Welcome John Doe!

Source:

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Welcome :param{key=name.first} :param{key=name.last}!

If the key has no value, defaultValue is shown instead.

Rendered:

The secret to life is 42.

Source:

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The secret to life is :param{key=secretToLife defaultValue=42}.

globals.baseUrl (ends in a trailing slash) and globals.locale are always available.

Rendered:

curl /buildsstatic/cf-templates/setup.yaml -s -o my.file

Source:

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curl :param{key=globals.baseUrl}static/cf-templates/setup.yaml -s -o my.file

:assetUrl renders an absolute, environment-correct URL for an asset. It is mainly used to embed a full asset URL inside a copy/paste command, where relative paths would not expand.

Properties: path (string, relative location of the asset), source (repo | s3, default repo). repo points at /static; s3 points at the uploaded assets bucket.

Wrap :assetUrl in single quotes inside shell commands so the shell does not interpret & in the signed URL.

Rendered:

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curl '/builds/static/resources/template.yaml' --output template.yaml

Source:

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```bash
curl ':assetUrl{path="/resources/template.yaml"}' --output template.yaml
```

Rendered:

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curl '/builds/assets/resources/template.yaml' --output template.yaml

Source:

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```bash
curl ':assetUrl{path="/resources/template.yaml" source=s3}' --output template.yaml
```