Hcl2 input variables, local variables and functions (#8588)
Mainly redefine or reused what Terraform did.
* allow to used `variables`, `variable` and `local` blocks
* import the following functions and their docs from Terraform: abs, abspath, basename, base64decode, base64encode, bcrypt, can, ceil, chomp, chunklist, cidrhost, cidrnetmask, cidrsubnet, cidrsubnets, coalesce, coalescelist, compact, concat, contains, convert, csvdecode, dirname, distinct, element, file, fileexists, fileset, flatten, floor, format, formatdate, formatlist, indent, index, join, jsondecode, jsonencode, keys, length, log, lookup, lower, max, md5, merge, min, parseint, pathexpand, pow, range, reverse, rsadecrypt, setintersection, setproduct, setunion, sha1, sha256, sha512, signum, slice, sort, split, strrev, substr, timestamp, timeadd, title, trim, trimprefix, trimspace, trimsuffix, try, upper, urlencode, uuidv4, uuidv5, values, yamldecode, yamlencode, zipmap.
2020-02-06 11:49:21 +01:00
|
|
|
---
|
2020-03-18 18:46:47 -04:00
|
|
|
page_title: lookup - Functions - Configuration Language
|
|
|
|
|
description: The lookup function retrieves an element value from a map given its key.
|
Hcl2 input variables, local variables and functions (#8588)
Mainly redefine or reused what Terraform did.
* allow to used `variables`, `variable` and `local` blocks
* import the following functions and their docs from Terraform: abs, abspath, basename, base64decode, base64encode, bcrypt, can, ceil, chomp, chunklist, cidrhost, cidrnetmask, cidrsubnet, cidrsubnets, coalesce, coalescelist, compact, concat, contains, convert, csvdecode, dirname, distinct, element, file, fileexists, fileset, flatten, floor, format, formatdate, formatlist, indent, index, join, jsondecode, jsonencode, keys, length, log, lookup, lower, max, md5, merge, min, parseint, pathexpand, pow, range, reverse, rsadecrypt, setintersection, setproduct, setunion, sha1, sha256, sha512, signum, slice, sort, split, strrev, substr, timestamp, timeadd, title, trim, trimprefix, trimspace, trimsuffix, try, upper, urlencode, uuidv4, uuidv5, values, yamldecode, yamlencode, zipmap.
2020-02-06 11:49:21 +01:00
|
|
|
---
|
|
|
|
|
|
|
|
|
|
# `lookup` Function
|
|
|
|
|
|
|
|
|
|
`lookup` retrieves the value of a single element from a map, given its key.
|
|
|
|
|
If the given key does not exist, a the given default value is returned instead.
|
|
|
|
|
|
2020-03-31 18:47:06 -04:00
|
|
|
```hcl
|
Hcl2 input variables, local variables and functions (#8588)
Mainly redefine or reused what Terraform did.
* allow to used `variables`, `variable` and `local` blocks
* import the following functions and their docs from Terraform: abs, abspath, basename, base64decode, base64encode, bcrypt, can, ceil, chomp, chunklist, cidrhost, cidrnetmask, cidrsubnet, cidrsubnets, coalesce, coalescelist, compact, concat, contains, convert, csvdecode, dirname, distinct, element, file, fileexists, fileset, flatten, floor, format, formatdate, formatlist, indent, index, join, jsondecode, jsonencode, keys, length, log, lookup, lower, max, md5, merge, min, parseint, pathexpand, pow, range, reverse, rsadecrypt, setintersection, setproduct, setunion, sha1, sha256, sha512, signum, slice, sort, split, strrev, substr, timestamp, timeadd, title, trim, trimprefix, trimspace, trimsuffix, try, upper, urlencode, uuidv4, uuidv5, values, yamldecode, yamlencode, zipmap.
2020-02-06 11:49:21 +01:00
|
|
|
lookup(map, key, default)
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
-> For historical reasons, the `default` parameter is actually optional. However,
|
|
|
|
|
omitting `default` is deprecated since v0.7 because that would then be
|
|
|
|
|
equivalent to the native index syntax, `map[key]`.
|
|
|
|
|
|
|
|
|
|
## Examples
|
|
|
|
|
|
2020-05-29 17:12:05 -04:00
|
|
|
```shell-session
|
Hcl2 input variables, local variables and functions (#8588)
Mainly redefine or reused what Terraform did.
* allow to used `variables`, `variable` and `local` blocks
* import the following functions and their docs from Terraform: abs, abspath, basename, base64decode, base64encode, bcrypt, can, ceil, chomp, chunklist, cidrhost, cidrnetmask, cidrsubnet, cidrsubnets, coalesce, coalescelist, compact, concat, contains, convert, csvdecode, dirname, distinct, element, file, fileexists, fileset, flatten, floor, format, formatdate, formatlist, indent, index, join, jsondecode, jsonencode, keys, length, log, lookup, lower, max, md5, merge, min, parseint, pathexpand, pow, range, reverse, rsadecrypt, setintersection, setproduct, setunion, sha1, sha256, sha512, signum, slice, sort, split, strrev, substr, timestamp, timeadd, title, trim, trimprefix, trimspace, trimsuffix, try, upper, urlencode, uuidv4, uuidv5, values, yamldecode, yamlencode, zipmap.
2020-02-06 11:49:21 +01:00
|
|
|
> lookup({a="ay", b="bee"}, "a", "what?")
|
|
|
|
|
ay
|
|
|
|
|
> lookup({a="ay", b="bee"}, "c", "what?")
|
|
|
|
|
what?
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
## Related Functions
|
|
|
|
|
|
2021-01-15 09:18:39 -08:00
|
|
|
- [`element`](/docs/templates/hcl_templates/functions/collection/element) retrieves a value from a _list_ given its _index_.
|
