reaction/config/example.jsonnet

92 lines
3.7 KiB
Plaintext

// This file is using JSONNET, a complete configuration language based on JSON
// See https://jsonnet.org
// JSONNET is a superset of JSON, so one can write plain JSON files if wanted.
// Note that YAML is also supported.
// variables defined for later use.
local iptablesban = ['ip46tables', '-w', '-A', 'reaction', '1', '-s', '<ip>', '-j', 'DROP'];
local iptablesunban = ['ip46tables', '-w', '-D', 'reaction', '1', '-s', '<ip>', '-j', 'DROP'];
// ip46tables is a minimal C program (only POSIX dependencies) present as a subdirectory.
// it permits to handle both ipv4/iptables and ipv6/ip6tables commands
{
// patterns are substitued in regexes.
// when a filter performs an action, it replaces the found pattern
patterns: {
ip: {
// reaction regex syntax is defined here: https://github.com/google/re2/wiki/Syntax
// jsonnet's @'string' is for verbatim strings
regex: @'(?:(?:[0-9]{1,3}\.){3}[0-9]{1,3})|(?:[0-9a-fA-F:]{2,90})',
ignore: ['127.0.0.1', '::1'],
},
},
// streams are commands
// they're run and their ouptut is captured
// *example:* `tail -f /var/log/nginx/access.log`
// their output will be used by one or more filters
streams: {
// streams have a user-defined name
ssh: {
// note that if the command is not in environment's `PATH`
// its full path must be given.
cmd: ['journalctl', '-n0', '-fu', 'sshd.service'],
// filters run actions when they match regexes on a stream
filters: {
// filters have a user-defined name
failedlogin: {
// reaction's regex syntax is defined here: https://github.com/google/re2/wiki/Syntax
regex: [
// <ip> is predefined in the patterns section
// ip's regex is inserted in the following regex
'authentication failure;.*rhost=<ip>',
],
// if retry and retryperiod are defined,
// the actions will only take place if a same pattern is
// found `retry` times in a `retryperiod` interval
retry: 3,
// format is defined here: https://pkg.go.dev/time#ParseDuration
retryperiod: '6h',
// actions are run by the filter when regexes are matched
actions: {
// actions have a user-defined name
ban: {
// JSONNET substitutes the variable (defined at the beginning of the file)
cmd: iptablesban,
},
unban: {
cmd: iptablesunban,
// if after is defined, the action will not take place immediately, but after a specified duration
// same format as retryperiod
after: '48h',
// let's say reaction is quitting. does it run all those pending commands which had an `after` duration set?
// if you want reaction to run those pending commands before exiting, you can set this:
onexit: true,
// (defaults to false)
// here it is not useful because we will flush the chain containing the bans anyway
// (see /conf/reaction.service)
},
},
},
},
},
},
}
// persistence
// tldr; when an `after` action is set in a filter, such filter acts as a 'jail',
// which is persisted after reboots.
// full;
// when a filter is triggered, there are 2 flows:
//
// if none of its actions have an `after` directive set:
// no action will be replayed.
//
// else (if at least one action has an `after` directive set):
// if reaction stops while `after` actions are pending:
// and reaction starts again while those actions would still be pending:
// reaction executes the past actions (actions without after or with then+after < now)
// and plans the execution of future actions (actions with then+after > now)