github.com/hugorut/terraform@v1.1.3/website/docs/language/functions/uuidv5.mdx (about) 1 --- 2 page_title: uuidv5 - Functions - Configuration Language 3 description: >- 4 The uuidv5 function generates a uuid v5 string representation of the value in 5 the specified namespace. 6 --- 7 8 # `uuidv5` Function 9 10 `uuidv5` generates a _name-based_ UUID, as described in 11 [RFC 4122 section 4.3](https://tools.ietf.org/html/rfc4122#section-4.3), 12 also known as a "version 5" UUID. 13 14 ``` 15 uuidv5(namespace, name) 16 ``` 17 18 Unlike the pseudo-random UUIDs generated by 19 [`uuid`](/language/functions/uuid), name-based UUIDs derive from namespace and an name, 20 producing the same UUID value every time if the namespace and name are 21 unchanged. 22 23 Name-based UUID namespaces are themselves UUIDs, but for readability this 24 function accepts some keywords as aliases for the namespaces that were 25 assigned by RFC 4122: 26 27 | Keyword | Namespace ID | Name format | 28 | -------- | -------------------------------------- | ---------------------------------------------------------------------------- | 29 | `"dns"` | `6ba7b810-9dad-11d1-80b4-00c04fd430c8` | A fully-qualified DNS domain name. | 30 | `"url"` | `6ba7b811-9dad-11d1-80b4-00c04fd430c8` | Any valid URL as defined in [RFC 3986](https://tools.ietf.org/html/rfc3986). | 31 | `"oid"` | `6ba7b812-9dad-11d1-80b4-00c04fd430c8` | An [ISO/IEC object identifier](https://oidref.com/) | 32 | `"x500"` | `6ba7b814-9dad-11d1-80b4-00c04fd430c8` | [X.500 Distinguished Name](https://tools.ietf.org/html/rfc1779) | 33 34 To use any other namespace not included in the above table, pass its assigned 35 namespace ID directly in the first argument in the usual UUID string format. 36 37 ## Examples 38 39 Use the namespace keywords where possible, to make the intent more obvious to 40 a future reader: 41 42 ``` 43 > uuidv5("dns", "www.terraform.io") 44 a5008fae-b28c-5ba5-96cd-82b4c53552d6 45 46 > uuidv5("url", "https://www.terraform.io/") 47 9db6f67c-dd95-5ea0-aa5b-e70e5c5f7cf5 48 49 > uuidv5("oid", "1.3.6.1.4") 50 af9d40a5-7a36-5c07-b23a-851cd99fbfa5 51 52 > uuidv5("x500", "CN=Example,C=GB") 53 84e09961-4aa4-57f8-95b7-03edb1073253 54 ``` 55 56 The namespace keywords treated as equivalent to their corresponding namespace 57 UUIDs, and in some special cases it may be more appropriate to use the 58 UUID form: 59 60 ``` 61 > uuidv5("6ba7b810-9dad-11d1-80b4-00c04fd430c8", "www.terraform.io") 62 a5008fae-b28c-5ba5-96cd-82b4c53552d6 63 ``` 64 65 If you wish to use a namespace defined outside of RFC 4122, using the namespace 66 UUID is required because no corresponding keyword is available: 67 68 ``` 69 > uuidv5("743ac3c0-3bf7-4a5b-9e6c-59360447c757", "LIBS:diskfont.library") 70 ede1a974-df7e-5f17-84b9-76208818b2c8 71 ``` 72 73 When using raw UUID namespaces, consider including a comment alongside the 74 expression that indicates which namespace this represents in a 75 human-significant manner, such as by reference to the standard that 76 defined it. 77 78 ## Related Functions 79 80 * [`uuid`](/language/functions/uuid), which generates pseudorandom UUIDs.