Fastly's Varnish is based on Varnish 2.1 and our Varnish syntax is specifically compatible with Varnish 2.1.5. We run a custom version with added functionality.
The official Varnish documentation is a good place to start when looking for online information:
In addition, Varnish Software, who provides commercial support for Varnish, has written a free book:
Specifically, the VCL references are located here:
Roberto Moutinho has written a book on using Varnish that may help:
In addition, Fastly has included a number of extensions to VCL that won't be covered by any other documentation. Specifically:
|cryptographic and hashing functions||Supports Hash-based Message Authentication Code (HMAC), a message authentication code that uses a cryptographic key in conjunction with a hash function.|
|date- and time-related features||Supports the default VCL “now” variable that provides the current time as an RFC 850 formatted date (e.g., Tuesday, 29-Apr-14 08:41:55), as well as several new functions that allow you to have more flexibility when dealing with dates and times.|
|GeoIP features||Provides the ability to search a database from MaxMind.com for a given host or IP address, and return information about the country, city or Internet Service Provider (ISP) for that IP address.|
|randomness features||Supports the insertion of random strings, content cookies, and decisions into requests.|
|size-related variables||Supports reporting variables that offer insight into what happened in a request.|
|miscellaneous features and variables||Provides miscellaneous VCL extensions not easily grouped into other categories.|
Have feedback? Want to go deeper? Check out community.fastly.com.