FAQs for rules and naming conventions

What are the rules for the CDN hostname?

The CDN Hostname input string must:

• Consist of alphanumeric characters
• Be fewer than 254 characters
• End with a valid top-level domain name
• Must not contain more than 10 labels
• Must not end in cdn.appdomain.cloud. or cdnedge.bluemix.net. (that ending is used for CNAMES and is reserved)

Refer to RFC 1035, section 2.3.4 for more details.

Furthermore, we highly recommend the use of a fully qualified domain name as your CDN hostname. Choose a name of the form www.example.com rather than a root domain name (also referred as Zone Apex or Naked domain), of the form example.com. You must create a CNAME Record for the CDN hostname you use, and the DNS RFC 1033 requires the root domain record to be an A Record, not a CNAME. Further clarification is provided in RFC 2181, section 10.1

What are the custom CNAME naming conventions?

The CNAME input string must adhere to the following rules:

• Must be unique (it cannot be in use by any other IBM Cloud CDN)
• Less than 64 alphanumeric characters
• Special characters ! @ # $ % ^ & * are not allowed
• Underscores _ are not allowed
• Periods . are not allowed
• Dashes - are allowed, but the CNAME cannot begin or end with a dash

What are the rules for Bucket names?

Bucket names:

• Must be at least one character
• Must be fewer than 200 characters
• Can contain letters (both uppercase and lowercase letters are allowed), numbers, and hyphens
• Must not be formatted as an IP address (for example, 127.0.0.1)
• Cannot start with a period (.)
• Can end with a period (.)
• Only one period (.) is allowed between labels (for example, my..ibmcloud.bucket is not allowed).

Although uppercase letters and periods can pass validation, we suggest that you always use DNS-compliant Bucket names.

What are the rules for the Path string for the origin?

The Path is optional when creating your CDN. However, if provided, the Path:

• Must be less than 1000 characters in length
• Must begin with /

What are the rules for the Path string for Purge?

The purge path:

• Cannot contain *
• Cannot contain spaces
• Cannot end with a period (.)
• Must begin with /
• Must be English characters
• Must be separated by line breaks
• Must be less than 1000 characters in length
• Must be less than 2 M characters in total
• No duplicate paths

For the imported purge file, it is recommended to use a txt file extension, and all paths in the file follow these rules.

For the Add Origin command, are there any rules to follow for the Path string?

For Add Origin, the path is mandatory. Also, if your CDN was created with a path, the path for Add Origin must start with the CDN path as the prefix. For example, if the CDN path was specified as /storage, to invoke Add Origin with a path called /examplePath, the path that is provided would be /storage/examplePath.

What are the rules for providing file extensions?

When creating an origin with Object Storage, file extensions should be comma that is separated. For example, txt, jpg, xml is a valid list. Any one particular extension cannot be longer than 10 characters.