slack: Send alerts and notifications to a Slack channel

The slack() destination driver sends messages to a Slack channel using the Slack Web API. For the list of available optional parameters, see Slack destination options.

Prerequisites

• AxoSyslog version 3.19 or later.

• Install the axosyslog-scl package on Debian/Ubuntu. On RHEL and compatible distributions, the SCL files are part of the axosyslog base package.

  Your configuration must also contain @include "scl.conf", which the default configuration file already does. If the SCL files are missing, AxoSyslog fails to start with an unexpected LL_IDENTIFIER error.

  @include "scl.conf"

  The slack() driver is a reusable configuration snippet (SCL). For details on using or writing such configuration snippets, see Reusing configuration blocks. You can find its source in scl/slack/slack.conf on GitHub.

• This feature requires a separate module. Install the axosyslog-mod-http package on Debian/Ubuntu, or the axosyslog-http package on RHEL and compatible distributions. If the module isn’t installed, AxoSyslog fails to start with an unexpected LL_IDENTIFIER error.

• Create a Slack app and a Webhook that AxoSyslog can use. For details, see the Slack documentation.

Declaration:

@include "scl.conf"
# ...

destination d_slack {
  slack(
    hook-url("https://hooks.slack.com/services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX")
  );
};

The driver allows you to modify nearly every field of the HTTP request. For details, see the Slack API documentation.

You can use the proxy() option to configure the HTTP driver in all HTTP-based destinations to use a specific HTTP proxy that is independent from the proxy configured for the system.

By default, the throttle() option is set to 1, because Slack has a 1 message/second limit on Webhooks. It can allow more message in short bursts, so you can set it to 0, if you only expect messages in a short period of time. For details, see the Web API rate limiting in the Slack documentation.

Example: Using the slack() driver

The following example sets the colors and the author of the message.

@include "scl.conf"

destination d_slack1 {
  slack(
    hook-url("https://hooks.slack.com/services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX")
    colors("#000000,#222222,#444444,#666666,#888888,#AAAAAA,#CCCCCC,#EEEEEE")
    color-chooser(7)
    author-name("Example BOT")
    author-link("https://www.syslog-ng.com/products/open-source-log-management")
    author-icon("https://raw.githubusercontent.com/MrAnno/vscode-syslog-ng/master/images/syslog-ng-icon.png")
  );
};