nixpkgs/nixos/modules/services/monitoring/grafana-agent.nix
2022-06-19 11:50:32 +02:00

144 lines
4.6 KiB
Nix

{ lib, pkgs, config, generators, ... }:
with lib;
let
cfg = config.services.grafana-agent;
settingsFormat = pkgs.formats.yaml { };
configFile = settingsFormat.generate "grafana-agent.yaml" cfg.settings;
in
{
meta = {
maintainers = with maintainers; [ flokli zimbatm ];
};
options.services.grafana-agent = {
enable = mkEnableOption "grafana-agent";
package = mkOption {
type = types.package;
default = pkgs.grafana-agent;
defaultText = "pkgs.grafana-agent";
description = "The grafana-agent package to use.";
};
credentials = mkOption {
description = ''
Credentials to load at service startup. Keys that are UPPER_SNAKE will be loaded as env vars. Values are absolute paths to the credentials.
'';
type = types.attrsOf types.str;
default = { };
example = {
logs_remote_write_password = "/run/keys/grafana_agent_logs_remote_write_password";
LOGS_REMOTE_WRITE_URL = "/run/keys/grafana_agent_logs_remote_write_url";
LOGS_REMOTE_WRITE_USERNAME = "/run/keys/grafana_agent_logs_remote_write_username";
metrics_remote_write_password = "/run/keys/grafana_agent_metrics_remote_write_password";
METRICS_REMOTE_WRITE_URL = "/run/keys/grafana_agent_metrics_remote_write_url";
METRICS_REMOTE_WRITE_USERNAME = "/run/keys/grafana_agent_metrics_remote_write_username";
};
};
settings = mkOption {
description = ''
Configuration for <package>grafana-agent</package>.
See https://grafana.com/docs/agent/latest/configuration/
'';
type = types.submodule {
freeformType = settingsFormat.type;
};
default = {
metrics = {
wal_directory = "\${STATE_DIRECTORY}";
global.scrape_interval = "5s";
};
integrations = {
agent.enabled = true;
agent.scrape_integration = true;
node_exporter.enabled = true;
replace_instance_label = true;
};
};
example = {
metrics.global.remote_write = [{
url = "\${METRICS_REMOTE_WRITE_URL}";
basic_auth.username = "\${METRICS_REMOTE_WRITE_USERNAME}";
basic_auth.password_file = "\${CREDENTIALS_DIRECTORY}/metrics_remote_write_password";
}];
logs.configs = [{
name = "default";
scrape_configs = [
{
job_name = "journal";
journal = {
max_age = "12h";
labels.job = "systemd-journal";
};
relabel_configs = [
{
source_labels = [ "__journal__systemd_unit" ];
target_label = "systemd_unit";
}
{
source_labels = [ "__journal__hostname" ];
target_label = "nodename";
}
{
source_labels = [ "__journal_syslog_identifier" ];
target_label = "syslog_identifier";
}
];
}
];
positions.filename = "\${STATE_DIRECTORY}/loki_positions.yaml";
clients = [{
url = "\${LOGS_REMOTE_WRITE_URL}";
basic_auth.username = "\${LOGS_REMOTE_WRITE_USERNAME}";
basic_auth.password_file = "\${CREDENTIALS_DIRECTORY}/logs_remote_write_password";
}];
}];
};
};
};
config = mkIf cfg.enable {
systemd.services.grafana-agent = {
wantedBy = [ "multi-user.target" ];
script = ''
set -euo pipefail
shopt -u nullglob
# Load all credentials into env if they are in UPPER_SNAKE form.
if [[ -n "''${CREDENTIALS_DIRECTORY:-}" ]]; then
for file in "$CREDENTIALS_DIRECTORY"/*; do
key=$(basename "$file")
if [[ $key =~ ^[A-Z0-9_]+$ ]]; then
echo "Environ $key"
export "$key=$(< "$file")"
fi
done
fi
# We can't use Environment=HOSTNAME=%H, as it doesn't include the domain part.
export HOSTNAME=$(< /proc/sys/kernel/hostname)
exec ${cfg.package}/bin/agent -config.expand-env -config.file ${configFile}
'';
serviceConfig = {
Restart = "always";
DynamicUser = true;
RestartSec = 2;
SupplementaryGroups = [
# allow to read the systemd journal for loki log forwarding
"systemd-journal"
];
StateDirectory = "grafana-agent";
LoadCredential = lib.mapAttrsToList (key: value: "${key}:${value}") cfg.credentials;
Type = "simple";
};
};
};
}