vmod-hashids
This module makes Hashids encoding and decoding available in VCL. See https://hashids.org/ for details about the hashids library.
Functions
hashids.encode(salt, number) returns a hashid for number salted with
salt.
hashids.decode(salt, hashid) returns the decoded number for hashid
salted with salt.
Errors
hashids.decode() will return negative numbers between -1 and -5 if an error occurs during decoding.
The table below shows the meaning of the returned error codes:
| Error code | Description |
|---|---|
| -1 | Input hash is empty. |
| -2 | Input hash is larger than max allowed size (default: 64 bytes) |
| -3 | No numbers was returned. |
| -4 | Invalid hash / salt mismatch. |
| -5 | Hashids library initialization failed. |
hashids.encode() will return an empty string if an error occurs.
Example
import hashids;
sub vcl_deliver {
# Encodes 1234
set resp.http.Encoded-Hash = hashids.encode("mysalt", 1234);
# Decodes resp.http.Encoded-Hash
set resp.http.Decoded-Hash = hashids.decode("mysalt", resp.http.Encoded-Hash);
}
Installation
The source tree is based on autotools to configure the building, and
does also have the necessary bits in place to do functional unit tests
using the varnishtest tool.
Building requires the Varnish header files and uses pkg-config to find the necessary paths.
Usage
./autogen.sh ./configure
If you have installed Varnish to a non-standard directory, call
autogen.sh and configure with PKG_CONFIG_PATH pointing to the
appropriate path. For instance, when varnishd configure was called with
--prefix=$PREFIX, use
export PKG_CONFIG_PATH=({PREFIX}/lib/pkgconfig export ACLOCAL_PATH={PREFIX}/share/aclocal
The module will inherit its prefix from Varnish, unless you specify a
different --prefix when running the configure script for this
module.
Make targets:
- make - builds the vmod.
- make install - installs your vmod.
- make check - runs the unit tests in src/tests/*.vtc.
- make distcheck - run check and prepare a tarball of the vmod.
Installation directories
By default, the vmod configure script installs the built vmod in the
directory relevant to the prefix. The vmod installation directory can be
overridden by passing the vmoddir variable to make install.
Supported Varnish versions
At the time of writing the module is verified working with the latest releases of Varnish 4, 5 and 6.