Config schema reference

This page is a systematic reference, one section per top-level CUE definition in config/schema.cue. For a guided, example-driven walkthrough of building a config against this schema, see CUE in practice instead.

#Host

Field	Type	Default	Constraint
address	string	—	required, non-empty
parents	[...string]	[]	—
vars	#Vars	{}	see #Vars
check	#Check	—	required
services	{[Name=string]: #Service}	{}	—
notification	string	""	empty means the host never notifies
zone	string	"default"	non-empty
labels	#Labels	{}	see #Labels

#Service

Field	Type	Default	Constraint
vars	#Vars	{}	see #Vars
check	#Check	—	required
notification	string	""	empty means the service never notifies
zone	string	""	empty inherits the host’s zone
labels	#Labels	{}	see #Labels

#Schedule

Embedded by every branch of #Checks.

Field	Type	Default	Constraint
check_interval	time.Duration	"60s"	—
retry_interval	time.Duration	"15s"	—
timeout	time.Duration	"10s"	—
max_attempts	int	3	>=1
flap	#Flap	—	required, see #Flap

#Flap

Field	Type	Default	Constraint
enabled	bool	true	—
alpha	number	0.1	>0 & <=1
high_threshold	number	0.3	>=0 & <=1
low_threshold	number	0.15	>=0 & <=high_threshold

The #Checks branches

Every branch unifies #Schedule with its own type-specific fields; type is the discriminator and matches the branch’s key in #Checks.

tcp (#TCPCheck)

Field	Type	Default	Constraint
type	string	—	fixed "tcp"
address	string	—	required, non-empty ("host:port")

http (#HTTPCheck)

Field	Type	Default	Constraint
type	string	—	fixed "http"
url	string	—	required, non-empty

dns (#DNSCheck)

Field	Type	Default	Constraint
type	string	—	fixed "dns"
server	string	—	required, non-empty ("host:port")
name	string	—	required, non-empty (record to resolve)

icmp (#ICMPCheck)

Field	Type	Default	Constraint
type	string	—	fixed "icmp"
host	string	—	required, non-empty

tls (#TLSCheck)

Field	Type	Default	Constraint
type	string	—	fixed "tls"
address	string	—	required, non-empty
warn_within	time.Duration	"336h"	—
crit_within	time.Duration	"72h"	—

snmp (#SNMPCheck)

Field	Type	Default	Constraint
type	string	—	fixed "snmp"
address	string	—	required, non-empty
oid	string	—	required, non-empty
community	string	—	v2c; required, non-empty when set
user	string	—	v3 USM; required, non-empty when set
auth_proto	string	""	"", "MD5", "SHA", "SHA224", "SHA256", "SHA384", "SHA512"
auth_pass	string	""	—
priv_proto	string	""	"", "DES", "AES", "AES192", "AES256", "AES192C", "AES256C"
priv_pass	string	""	—
warn	string	""	Nagios threshold range; mutually exclusive with expect
crit	string	""	Nagios threshold range; mutually exclusive with expect
expect	string	""	exact-match string; mutually exclusive with warn/crit

Exactly one of community or user must be set — the schema enforces this as a disjunction. auth_proto/auth_pass/priv_proto/priv_pass are only meaningful alongside user.

legacy (#LegacyCheck)

Field	Type	Default	Constraint
type	string	—	fixed "legacy"
path	string	—	required, non-empty
args	[...string]	[]	—

wasm (#WASMCheck)

Field	Type	Default	Constraint
type	string	—	fixed "wasm"
module	string	—	required, non-empty (path to a .wasm file)
args	[...string]	[]	—

command (#CommandCheck)

Field	Type	Default	Constraint
type	string	—	fixed "command"
command	string	—	required, non-empty; key into the top-level commands map
args	[...string]	[]	—

passive (#PassiveCheck)

Field	Type	Default	Constraint
type	string	—	fixed "passive"
freshness_threshold	time.Duration	—	required, no default
stale_status	string	"UNKNOWN"	"UNKNOWN", "WARNING", "CRITICAL"

timeout (from #Schedule) has no meaning for passive.

#Window

Field	Type	Default	Constraint
weekday	string	—	"sunday", "monday", "tuesday", "wednesday", "thursday", "friday", "saturday"
start	string	—	=~"^([01][0-9]|2[0-3]):[0-5][0-9]$"
end	string	—	=~"^([01][0-9]|2[0-3]|24):[0-5][0-9]$"

A window does not wrap past midnight; an overnight period is two windows. end may be "24:00"; start may not.

#View

Field	Type	Default	Constraint
selector	string	—	required; parsed with labels.NewSelector at decode time
description	string	""	free text, not parsed

The map key under views: is the display name and is deliberately unconstrained — no pattern, unlike #Labels’ keys — because it is never parsed.

#Labels

Position	Pattern
key	=~"^[a-z][a-z0-9_.-]*$"
value	=~"^[a-zA-Z0-9][a-zA-Z0-9_.:/-]*$"

Duplicated from labels.KeyPattern/labels.ValuePattern in labels/pattern.go, the single source of truth; a test pins the two copies together so drift fails the build.

#Vars

Position	Pattern
key	=~"^[A-Z][A-Z0-9_]*$"
value	string

A key PASSWORD on a host is referenced as $_HOSTPASSWORD$; on a service, as $_SERVICEPASSWORD$.

#Resources

Position	Pattern
key	=~"^USER[0-9]+$"
value	string

A key that is not USER<digits> is a config error, not a silently unreachable value.

#Contact and the contact types

Four discriminated variants of #Contact, each also carrying labels (#Labels, default {}).

email

Field	Type	Default	Constraint
type	string	—	fixed "email"
address	string	—	required, non-empty

webhook

Field	Type	Default	Constraint
type	string	—	fixed "webhook"
url	string	—	required, non-empty

command

Field	Type	Default	Constraint
type	string	—	fixed "command"
command	string	—	required, non-empty; key into the top-level commands map
args	[...string]	[]	—
address	string	""	what $CONTACTEMAIL$ expands to for this contact

telegram

Field	Type	Default	Constraint
type	string	—	fixed "telegram"
chat_id	string	—	required, non-empty

#NotificationPolicy

Field	Type	Default	Constraint
period	[...#Window]	[]	empty means “always notify”
levels	[...#EscalationLevel]	—	required, non-empty

#EscalationLevel

Field	Type	Default	Constraint
contacts	[...string]	—	required, non-empty
threshold	int	0	>=0; 0 means never escalate past this level
renotify_interval	time.Duration	"1h"	—
disabled_kinds	[...string]	[]	each one of "PROBLEM", "RECOVERY", "STATUS_CHANGE", "FLAPPING_START", "FLAPPING_STOP"

#Sinks

Every sink shares #SinkCommon, then adds its own type-specific fields. The map key under sinks: matches =~"^[a-z][a-z0-9_-]*$".

#SinkCommon (shared by every sink type)

Field	Type	Default	Constraint
input	string	"metrics"	"metrics" or "events"
selector	string	""	a labels selector expression
batch_size	int	1000	>0
flush_interval	time.Duration	"5s"	—

Per-type fields

Type	Field	Type	Default	Constraint
clickhouse	url	string	—	required, non-empty
clickhouse	table	string	"perfdata"	=~"^[A-Za-z_][A-Za-z0-9_]*$"
remote_write	url	string	—	required, non-empty
remote_write	cursor	string	""	—
archive	url	string	—	required, non-empty
archive	segment_bytes	int	67108864	>0
archive	input	string	—	fixed "events"
http	url	string	—	required, non-empty
http	headers	{[string]: string}	{}	—
http	cursor	string	""	—
exec	command	[string, ...string]	—	required, non-empty
exec	cursor	string	""	—
file	path	string	—	required, non-empty
file	rotate_bytes	int	67108864	>0
file	cursor	string	""	—
otlp	url	string	—	required, non-empty
otlp	headers	{[string]: string}	{}	—
otlp	cursor	string	""	—