nixpkgs/nixos/modules/services/monitoring/amazon-cloudwatch-agent.nix

214 lines
8.6 KiB
Nix

{
lib,
pkgs,
config,
...
}:
let
cfg = config.services.amazon-cloudwatch-agent;
tomlFormat = pkgs.formats.toml { };
jsonFormat = pkgs.formats.json { };
# See https://docs.aws.amazon.com/prescriptive-guidance/latest/implementing-logging-monitoring-cloudwatch/create-store-cloudwatch-configurations.html#store-cloudwatch-configuration-s3.
#
# We don't use the multiple JSON configuration files feature,
# but "config-translator" will log a benign error if the "-input-dir" option is omitted or is a non-existent directory.
#
# Create an empty directory to hide this benign error log. This prevents false-positives if users filter for "error" in the agent logs.
configurationDirectory = pkgs.runCommand "amazon-cloudwatch-agent.d" { } "mkdir $out";
in
{
options.services.amazon-cloudwatch-agent = {
enable = lib.mkEnableOption "Amazon CloudWatch Agent";
package = lib.mkPackageOption pkgs "amazon-cloudwatch-agent" { };
commonConfigurationFile = lib.mkOption {
type = lib.types.path;
default = tomlFormat.generate "common-config.toml" cfg.commonConfiguration;
defaultText = lib.literalExpression ''tomlFormat.generate "common-config.toml" cfg.commonConfiguration'';
description = ''
Amazon CloudWatch Agent common configuration. See
<https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/install-CloudWatch-Agent-commandline-fleet.html#CloudWatch-Agent-profile-instance-first>
for supported values.
{option}`commonConfigurationFile` takes precedence over {option}`commonConfiguration`.
Note: Restricted evaluation blocks access to paths outside the Nix store.
This means detecting content changes for mutable paths (i.e. not input or content-addressed) can't be done.
As a result, `nixos-rebuild` won't reload/restart the systemd unit when mutable path contents change.
`systemctl restart amazon-cloudwatch-agent.service` must be used instead.
'';
example = "/etc/amazon-cloudwatch-agent/amazon-cloudwatch-agent.json";
};
commonConfiguration = lib.mkOption {
type = tomlFormat.type;
default = { };
description = ''
See {option}`commonConfigurationFile`.
{option}`commonConfigurationFile` takes precedence over {option}`commonConfiguration`.
'';
example = {
credentials = {
shared_credential_profile = "profile_name";
shared_credential_file = "/path/to/credentials";
};
proxy = {
http_proxy = "http_url";
https_proxy = "https_url";
no_proxy = "domain";
};
};
};
configurationFile = lib.mkOption {
type = lib.types.path;
default = jsonFormat.generate "amazon-cloudwatch-agent.json" cfg.configuration;
defaultText = lib.literalExpression ''jsonFormat.generate "amazon-cloudwatch-agent.json" cfg.configuration'';
description = ''
Amazon CloudWatch Agent configuration file. See
<https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/CloudWatch-Agent-Configuration-File-Details.html>
for supported values.
The following options aren't supported:
* `agent.run_as_user`
* Use {option}`user` instead.
{option}`configurationFile` takes precedence over {option}`configuration`.
Note: Restricted evaluation blocks access to paths outside the Nix store.
This means detecting content changes for mutable paths (i.e. not input or content-addressed) can't be done.
As a result, `nixos-rebuild` won't reload/restart the systemd unit when mutable path contents change.
`systemctl restart amazon-cloudwatch-agent.service` must be used instead.
'';
example = "/etc/amazon-cloudwatch-agent/amazon-cloudwatch-agent.json";
};
configuration = lib.mkOption {
type = jsonFormat.type;
default = { };
description = ''
See {option}`configurationFile`.
{option}`configurationFile` takes precedence over {option}`configuration`.
'';
# Subset of "CloudWatch agent configuration file: Complete examples" and "CloudWatch agent configuration file: Traces section" in the description link.
#
# Log file path changed from "/opt/aws/amazon-cloudwatch-agent/logs" to "/var/log/amazon-cloudwatch-agent" to follow the FHS.
example = {
agent = {
metrics_collection_interval = 10;
logfile = "/var/log/amazon-cloudwatch-agent/amazon-cloudwatch-agent.log";
};
metrics = {
namespace = "MyCustomNamespace";
metrics_collected = {
cpu = {
resource = [ "*" ];
measurement = [
{
name = "cpu_usage_idle";
rename = "CPU_USAGE_IDLE";
unit = "Percent";
}
{
name = "cpu_usage_nice";
unit = "Percent";
}
"cpu_usage_guest"
];
totalcpu = false;
metrics_collection_interval = 10;
append_dimensions = {
customized_dimension_key_1 = "customized_dimension_value_1";
customized_dimension_key_2 = "customized_dimension_value_2";
};
};
};
};
logs = {
logs_collected = {
files = {
collect_list = [
{
file_path = "/var/log/amazon-cloudwatch-agent/amazon-cloudwatch-agent.log";
log_group_name = "amazon-cloudwatch-agent.log";
log_stream_name = "{instance_id}";
timezone = "UTC";
}
];
};
};
log_stream_name = "log_stream_name";
force_flush_interval = 15;
};
traces = {
traces_collected = {
xray = { };
oltp = { };
};
};
};
};
# Replaces "agent.run_as_user" from the configuration file.
user = lib.mkOption {
type = lib.types.str;
default = "root";
description = ''
The user that runs the Amazon CloudWatch Agent.
'';
example = "amazon-cloudwatch-agent";
};
mode = lib.mkOption {
type = lib.types.str;
default = "auto";
description = ''
Amazon CloudWatch Agent mode. Indicates whether the agent is running in EC2 ("ec2"), on-premises ("onPremise"),
or if it should guess based on metadata endpoints like IMDS or the ECS task metadata endpoint ("auto").
'';
example = "onPremise";
};
};
config = lib.mkIf cfg.enable {
# See https://github.com/aws/amazon-cloudwatch-agent/blob/v1.300049.1/packaging/dependencies/amazon-cloudwatch-agent.service.
systemd.services.amazon-cloudwatch-agent = {
description = "Amazon CloudWatch Agent";
after = [ "network.target" ];
wantedBy = [ "multi-user.target" ];
serviceConfig = {
Type = "simple";
# "start-amazon-cloudwatch-agent" assumes the package is installed at "/opt/aws/amazon-cloudwatch-agent" so we can't use it.
#
# See https://github.com/aws/amazon-cloudwatch-agent/issues/1319.
#
# This program:
# 1. Switches to a non-root user if configured.
# 2. Runs "config-translator" to translate the input JSON configuration files into separate TOML (for CloudWatch Logs + Metrics),
# YAML (for X-Ray + OpenTelemetry), and JSON (for environment variables) configuration files.
# 3. Runs "amazon-cloudwatch-agent" with the paths to these generated files.
#
# Re-implementing with systemd options.
User = cfg.user;
RuntimeDirectory = "amazon-cloudwatch-agent";
LogsDirectory = "amazon-cloudwatch-agent";
ExecStartPre = builtins.concatStringsSep " " [
"${cfg.package}/bin/config-translator"
"-config ${cfg.commonConfigurationFile}"
"-input ${cfg.configurationFile}"
"-input-dir ${configurationDirectory}"
"-mode ${cfg.mode}"
"-output \${RUNTIME_DIRECTORY}/amazon-cloudwatch-agent.toml"
];
ExecStart = builtins.concatStringsSep " " [
"${cfg.package}/bin/amazon-cloudwatch-agent"
"-config \${RUNTIME_DIRECTORY}/amazon-cloudwatch-agent.toml"
"-envconfig \${RUNTIME_DIRECTORY}/env-config.json"
"-otelconfig \${RUNTIME_DIRECTORY}/amazon-cloudwatch-agent.yaml"
"-pidfile \${RUNTIME_DIRECTORY}/amazon-cloudwatch-agent.pid"
];
KillMode = "process";
Restart = "on-failure";
RestartSec = 60;
};
};
};
}