selector¶

Selectors make it possible to "pick" a value from the parsed content.

Structured content formats (ini, yaml, json) support selectors using - - slash-notation (eg: /foo/bar) - dot-notation (eg: foo.0.bar) - brace-notation (eg: foo[0]bar)

Text files support line-number selectors only; by default selector value is one (1) for text content type, thus if omitted the first line only will be selected.

NB: previous versions of env-alias supported a none/null selector that worked in teh same way as a none/null name, this has been dropped in favour of a name-is-null only mechanism for such functionality.

Example - dot-notation¶

Make a selection from a structured data source using dot-notation

env-alias:
    EXAMPLE:
        source: "https://ip-ranges.amazonaws.com/ip-ranges.json"
        selector: ".prefixes[1].ip_prefix"

Example - slash-notation¶

Make a selection from a structured data source using slash-notation

env-alias:
    EXAMPLE:
        source: "https://ip-ranges.amazonaws.com/ip-ranges.json"
        selector: "/prefixes[1]/ip_prefix"

Example - line-number¶

Make a selection from a flat text file by line number only

env-alias:
    EXAMPLE:
        source: "/proc/cpuinfo"
        selector: 5