System limitations on KurocoEdge

Potential Major Impact

• You must have ownership of the domain you want to use
• The IP address of the source is set to X-forwarded-for
• Maximum response timeout is 60 seconds
• All responses from KurocoEdge are always in UTF-8
• HTTPS is used by default. Requests made via HTTP are redirected to HTTPS
• If the HTML is malformed, the CSS selector may not work properly

List of responses

Issue	Impact	Response
Unable to change the DNS records of the target domain	Cannot apply KurocoEdge	Not available for use
IP restriction is applied at the backend server	Access to the backend server comes from the IP address of KurocoEdge	Use X-forwarded-for, apply IP address restriction in KurocoEdge
There are pages that take more than 60 seconds to respond	Response times out and an error occurs	Process the page on a domain that does not use KurocoEdge
Pages are displayed in SJIS or EUC-JP	Pages are displayed with UTF-8 encoding	Change the encoding description in HTML in KurocoEdge
There are pages that only operate on HTTP	Redirected to HTTPS but not displayed properly	The relevant page cannot be used
There are pages with broken HTML	CSS selectors are not functioning properly	Substitute with text replacements

Potentially Affected Areas

• For files with .png, .jpg, .jpeg, or .gif extensions, when caching is enabled, responses to clients that support WebP are automatically converted to WebP
• If cache is enabled for files with png/jpg/jpeg/gif extensions and the parameters for automatic image conversion are automatically enabled
• Only TLS 1.2 and TLS 1.3 are supported
• If the cache settings are not set in the rules, cache-control: private, no-store is automatically set in the response header
• In the following cases, gzip/Brotli compressed responses are automatically applied:
• • If you are trying to use KurocoEdge in conjunction with another Fastly service you are already using, Service chaining will be applied, but you may encounter errors with Loop detection, etc. In this case, please contact support

File extensions:  
css js html eot ico otf ttf json svg

Content types:  
text/html application/x-javascript text/css application/javascript text/javascript application/json application/vnd.ms-fontobject application/x-font-opentype application/x-font-truetype application/x-font-ttf application/xml font/eot font/opentype font/otf image/svg+xml image/vnd.microsoft.icon text/plain text/xml

• The response headers from the following backend servers will be automatically converted as follows. However, it is possible to reset them using rules

Original Header Name	Converted Header Name	Description
x-cache-hits	x-kuroco-backend-x-cache-hits	Number of cache hits
x-cache	x-kuroco-backend-x-cache	Whether the cache was hit or not, etc.
last-modified	x-kuroco-backend-last-modified	Last modified date of the content
age	x-kuroco-backend-age	Cache lifespan (in seconds)
cache-control	x-kuroco-backend-cache-control	Cache settings such as the validity period
etag	x-kuroco-backend-etag	Identifier for identifying the content