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|
{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.services.webhook;
defaultUser = "webhook";
hookFormat = pkgs.formats.json {};
hookType = types.submodule ({ name, ... }: {
freeformType = hookFormat.type;
options = {
id = mkOption {
type = types.str;
default = name;
description = mdDoc ''
The ID of your hook. This value is used to create the HTTP endpoint (`protocol://yourserver:port/prefix/''${id}`).
'';
};
execute-command = mkOption {
type = types.str;
description = mdDoc "The command that should be executed when the hook is triggered.";
};
};
});
hookFiles = mapAttrsToList (name: hook: hookFormat.generate "webhook-${name}.json" [ hook ]) cfg.hooks
++ mapAttrsToList (name: hook: pkgs.writeText "webhook-${name}.json.tmpl" "[${hook}]") cfg.hooksTemplated;
in {
options = {
services.webhook = {
enable = mkEnableOption (mdDoc ''
[Webhook](https://github.com/adnanh/webhook), a server written in Go that allows you to create HTTP endpoints (hooks),
which execute configured commands for any person or service that knows the URL
'');
package = mkPackageOption pkgs "webhook" {};
user = mkOption {
type = types.str;
default = defaultUser;
description = mdDoc ''
Webhook will be run under this user.
If set, you must create this user yourself!
'';
};
group = mkOption {
type = types.str;
default = defaultUser;
description = mdDoc ''
Webhook will be run under this group.
If set, you must create this group yourself!
'';
};
ip = mkOption {
type = types.str;
default = "0.0.0.0";
description = mdDoc ''
The IP webhook should serve hooks on.
The default means it can be reached on any interface if `openFirewall = true`.
'';
};
port = mkOption {
type = types.port;
default = 9000;
description = mdDoc "The port webhook should be reachable from.";
};
openFirewall = mkOption {
type = types.bool;
default = false;
description = lib.mdDoc ''
Open the configured port in the firewall for external ingress traffic.
Preferably the Webhook server is instead put behind a reverse proxy.
'';
};
enableTemplates = mkOption {
type = types.bool;
default = cfg.hooksTemplated != {};
defaultText = literalExpression "hooksTemplated != {}";
description = mdDoc ''
Enable the generated hooks file to be parsed as a Go template.
See [the documentation](https://github.com/adnanh/webhook/blob/master/docs/Templates.md) for more information.
'';
};
urlPrefix = mkOption {
type = types.str;
default = "hooks";
description = mdDoc ''
The URL path prefix to use for served hooks (`protocol://yourserver:port/''${prefix}/hook-id`).
'';
};
hooks = mkOption {
type = types.attrsOf hookType;
default = {};
example = {
echo = {
execute-command = "echo";
response-message = "Webhook is reachable!";
};
redeploy-webhook = {
execute-command = "/var/scripts/redeploy.sh";
command-working-directory = "/var/webhook";
};
};
description = mdDoc ''
The actual configuration of which hooks will be served.
Read more on the [project homepage] and on the [hook definition] page.
At least one hook needs to be configured.
[hook definition]: https://github.com/adnanh/webhook/blob/master/docs/Hook-Definition.md
[project homepage]: https://github.com/adnanh/webhook#configuration
'';
};
hooksTemplated = mkOption {
type = types.attrsOf types.str;
default = {};
example = {
echo-template = ''
{
"id": "echo-template",
"execute-command": "echo",
"response-message": "{{ getenv "MESSAGE" }}"
}
'';
};
description = mdDoc ''
Same as {option}`hooks`, but these hooks are specified as literal strings instead of Nix values,
and hence can include [template syntax](https://github.com/adnanh/webhook/blob/master/docs/Templates.md)
which might not be representable as JSON.
Template syntax requires the {option}`enableTemplates` option to be set to `true`, which is
done by default if this option is set.
'';
};
verbose = mkOption {
type = types.bool;
default = true;
description = mdDoc "Whether to show verbose output.";
};
extraArgs = mkOption {
type = types.listOf types.str;
default = [];
example = [ "-secure" ];
description = mdDoc ''
These are arguments passed to the webhook command in the systemd service.
You can find the available arguments and options in the [documentation][parameters].
[parameters]: https://github.com/adnanh/webhook/blob/master/docs/Webhook-Parameters.md
'';
};
environment = mkOption {
type = types.attrsOf types.str;
default = {};
description = mdDoc "Extra environment variables passed to webhook.";
};
};
};
config = mkIf cfg.enable {
assertions = let
overlappingHooks = builtins.intersectAttrs cfg.hooks cfg.hooksTemplated;
in [
{
assertion = hookFiles != [];
message = "At least one hook needs to be configured for webhook to run.";
}
{
assertion = overlappingHooks == {};
message = "`services.webhook.hooks` and `services.webhook.hooksTemplated` have overlapping attribute(s): ${concatStringsSep ", " (builtins.attrNames overlappingHooks)}";
}
];
users.users = mkIf (cfg.user == defaultUser) {
${defaultUser} =
{
isSystemUser = true;
group = cfg.group;
description = "Webhook daemon user";
};
};
users.groups = mkIf (cfg.user == defaultUser && cfg.group == defaultUser) {
${defaultUser} = {};
};
networking.firewall.allowedTCPPorts = mkIf cfg.openFirewall [ cfg.port ];
systemd.services.webhook = {
description = "Webhook service";
after = [ "network.target" ];
wantedBy = [ "multi-user.target" ];
environment = config.networking.proxy.envVars // cfg.environment;
script = let
args = [ "-ip" cfg.ip "-port" (toString cfg.port) "-urlprefix" cfg.urlPrefix ]
++ concatMap (hook: [ "-hooks" hook ]) hookFiles
++ optional cfg.enableTemplates "-template"
++ optional cfg.verbose "-verbose"
++ cfg.extraArgs;
in ''
${cfg.package}/bin/webhook ${escapeShellArgs args}
'';
serviceConfig = {
Restart = "on-failure";
User = cfg.user;
Group = cfg.group;
};
};
};
}
|