stockholm/lass/2configs/monitoring/telegraf.nix
2023-09-03 11:57:38 +02:00

164 lines
5.2 KiB
Nix

{ pkgs, lib, config, ... }:
# To use this module you also need to allow port 9273 either on the internet or on a vpn interface
# i.e. networking.firewall.interfaces."vpn0".allowedTCPPorts = [ 9273 ];
# Example prometheus alert rules:
# - https://github.com/Mic92/dotfiles/blob/master/nixos/eva/modules/prometheus/alert-rules.nix
let
isVM = lib.any (mod: mod == "xen-blkfront" || mod == "virtio_console") config.boot.initrd.kernelModules;
# potentially wrong if the nvme is not used at boot...
hasNvme = lib.any (m: m == "nvme") config.boot.initrd.availableKernelModules;
ipv6DadCheck = pkgs.writeShellScript "ipv6-dad-check" ''
${pkgs.iproute2}/bin/ip --json addr | \
${pkgs.jq}/bin/jq -r 'map(.addr_info) | flatten(1) | map(select(.dadfailed == true)) | map(.local) | @text "ipv6_dad_failures count=\(length)i"'
'';
zfsChecks = lib.optional
(lib.any (fs: fs == "zfs") config.boot.supportedFilesystems)
(pkgs.writeScript "zpool-health" ''
#!${pkgs.gawk}/bin/awk -f
BEGIN {
while ("${pkgs.zfs}/bin/zpool status" | getline) {
if ($1 ~ /pool:/) { printf "zpool_status,name=%s ", $2 }
if ($1 ~ /state:/) { printf " state=\"%s\",", $2 }
if ($1 ~ /errors:/) {
if (index($2, "No")) printf "errors=0i\n"; else printf "errors=%di\n", $2
}
}
}
'');
nfsChecks =
let
collectHosts = shares: fs:
if builtins.elem fs.fsType [ "nfs" "nfs3" "nfs4" ]
then
shares
// (
let
# also match ipv6 addresses
group = builtins.match "\\[?([^\]]+)]?:([^:]+)$" fs.device;
host = builtins.head group;
path = builtins.elemAt group 1;
in
{
${host} = (shares.${host} or [ ]) ++ [ path ];
}
)
else shares;
nfsHosts = lib.foldl collectHosts { } (builtins.attrValues config.fileSystems);
in
lib.mapAttrsToList
(
host: args:
(pkgs.writeScript "nfs-health" ''
#!${pkgs.gawk}/bin/awk -f
BEGIN {
for (i = 2; i < ARGC; i++) {
mounts[ARGV[i]] = 1
}
while ("${pkgs.nfs-utils}/bin/showmount -e " ARGV[1] | getline) {
if (NR == 1) { continue }
if (mounts[$1] == 1) {
printf "nfs_export,host=%s,path=%s present=1\n", ARGV[1], $1
}
delete mounts[$1]
}
for (mount in mounts) {
printf "nfs_export,host=%s,path=%s present=0\n", ARGV[1], $1
}
}
'')
+ " ${host} ${builtins.concatStringsSep " " args}"
)
nfsHosts;
in
{
systemd.services.telegraf.path = lib.optional (!isVM && hasNvme) pkgs.nvme-cli;
services.telegraf = {
enable = true;
extraConfig = {
agent.interval = "60s";
inputs = {
prometheus.urls = lib.mkIf config.services.promtail.enable [
# default promtail port
"http://localhost:9080/metrics"
];
prometheus.metric_version = 2;
kernel_vmstat = { };
nginx.urls = lib.mkIf config.services.nginx.statusPage [
"http://localhost/nginx_status"
];
smart = lib.mkIf (!isVM) {
path_smartctl = pkgs.writeShellScript "smartctl" ''
exec /run/wrappers/bin/sudo ${pkgs.smartmontools}/bin/smartctl "$@"
'';
};
system = { };
mem = { };
file =
[
{
data_format = "influx";
file_tag = "name";
files = [ "/var/log/telegraf/*" ];
}
]
++ lib.optional (lib.any (fs: fs == "ext4") config.boot.supportedFilesystems) {
name_override = "ext4_errors";
files = [ "/sys/fs/ext4/*/errors_count" ];
data_format = "value";
};
exec = [
{
## Commands array
commands =
[ ipv6DadCheck ]
++ zfsChecks
++ nfsChecks;
data_format = "influx";
}
];
systemd_units = { };
swap = { };
disk.tagdrop = {
fstype = [ "tmpfs" "ramfs" "devtmpfs" "devfs" "iso9660" "overlay" "aufs" "squashfs" ];
device = [ "rpc_pipefs" "lxcfs" "nsfs" "borgfs" ];
};
diskio = { };
zfs = {
poolMetrics = true;
};
} // lib.optionalAttrs (if lib.versionAtLeast (lib.versions.majorMinor lib.version) "23.11" then config.boot.swraid.enable else config.boot.initrd.services.swraid.enable) {
mdstat = { };
};
outputs.prometheus_client = {
listen = ":9273";
metric_version = 2;
};
};
};
security.sudo.extraRules = lib.mkIf (!isVM) [
{
users = [ "telegraf" ];
commands = [
{
command = "${pkgs.smartmontools}/bin/smartctl";
options = [ "NOPASSWD" ];
}
];
}
];
# avoid logging sudo use
security.sudo.configFile = ''
Defaults:telegraf !syslog,!pam_session
'';
# create dummy file to avoid telegraf errors
systemd.tmpfiles.rules = [
"f /var/log/telegraf/dummy 0444 root root - -"
];
}