SLO (v2alpha)

SLO defines a target for an SLI over a time window.

Properties

apiVersion

string required

Version represents a version of the OpenSLO specification.

Allowed values: openslo.com/v2alpha

Validation rules

Rule
property is required
must be equal to openslo.com/v2alpha

kind

string required

Kind represents all the object kinds defined by OpenSLO specification. Keep in mind not all specification versions support every Kind.

Allowed values: SLO

Validation rules

Rule
property is required
must be equal to SLO

metadata

struct required reference

See the metadata definition in the overview.

Validation rules

Rule
property is required

spec

struct required

SLOSpec defines an SLO's service, SLI, time window, budgeting method, objectives, and alert policies. A standard SLO applies one SLI to all objectives. A composite SLO can select a different SLI per objective.

Validation rules

Rule	Applies when
property is required
sli or sliRef fields must either be defined on the spec level (standard SLOs) or on the spec.objectives[*] level (composite SLOs)
exactly one of sli and sliRef must be set	sli or sliRef is set

spec.description

string

Description summarizes the SLO.

Validation rules

Rule
property is optional
length must be less than or equal to 1050

spec.serviceRef

string required

ServiceRef names the service associated with this SLO. The SDK serializes the field as "serviceRef". The living v2alpha proposal calls it "service".

Validation rules

Rule
property is required

spec.sli

struct reference

SLI embeds the service level indicator for a standard SLO.

Use the metadata and spec properties from the SLI definition. The inline form omits apiVersion and kind.

Validation rules

Rule	Applies when
property is optional	sli or sliRef is set

spec.sliRef

string

SLIRef names an existing SLI for a standard SLO.

Validation rules

Rule	Applies when	Details	Examples
property is optional	sli or sliRef is set
length must be between 1 and 63	sli or sliRef is set
string must match regular expression: ^[a-z0-9]([-a-z0-9]*[a-z0-9])?$	sli or sliRef is set	an RFC-1123 compliant label name must consist of lower case alphanumeric characters or -, and must start and end with an alphanumeric character	my-name 123-abc

spec.budgetingMethod

string required

BudgetingMethod applies the selected error-budget calculation to every objective.

SLOBudgetingMethod selects how an SLO consumes its error budget. Occurrences uses good events over total events, Timeslices uses good slices over total slices, and RatioTimeslices averages slice success ratios.

Allowed values: Occurrences, Timeslices, RatioTimeslices

Validation rules

Rule
property is required
must be one of: Occurrences, Timeslices, RatioTimeslices

spec.timeWindow

[]struct

TimeWindow defines the period over which the SLO is evaluated.

Validation rules

Rule
length must be between 1 and 1

spec.timeWindow[*]

struct

SLOTimeWindow describes one rolling or calendar-aligned evaluation window.

Validation rules

Rule
calendar must be set when isRolling is false and cannot be set when isRolling is true

spec.timeWindow[*].duration

string required

Duration is the length of the evaluation window.

DurationShorthand represents a duration as an integer and a DurationShorthandUnit, such as "1m" or "10d". A zero value encodes as empty text.

Validation rules

Rule
property is required

Validation of value components

These rules apply to parts of this value.

Component: unit

Possible values: m, h, d, w

Rule
property is required
must be one of: m, h, d, w

Component: value

Rule
must be greater than or equal to 0

spec.timeWindow[*].isRolling

bool

IsRolling selects a rolling window when true and a calendar-aligned window when false.

spec.timeWindow[*].calendar

struct

Calendar defines the alignment of a calendar window.

SLOCalendar defines the starting wall-clock time and time zone for a calendar-aligned SLOTimeWindow.

Validation rules

Rule
property is optional

spec.timeWindow[*].calendar.startTime

string

StartTime is the local date and time when calendar alignment starts.

Validation rules

Rule	Details
string must be a valid date and time in 2006-01-02 15:04:05 format	date and time format follows Go's time layout, see https://pkg.go.dev/time#Layout for more details

spec.timeWindow[*].calendar.timeZone

string

TimeZone determines how StartTime maps to an instant.

Validation rules

Rule	Examples
string must be a valid IANA Time Zone Database code	UTC America/New_York Europe/Warsaw

spec.objectives

[]struct

Objectives contains the SLO's budget targets and metric thresholds.

spec.objectives[*]

struct

SLOObjective defines one error-budget target and, for a threshold SLI, its metric comparison. The living v2alpha proposal also defines objective labels, which this SDK does not model.

Validation rules

Rule	Applies when
exactly one of target and targetPercent must be set
exactly one of sli and sliRef must be set	is composite SLO and sli or sliRef is set

spec.objectives[*].displayName

string

DisplayName is a human-readable name for this objective. It is not part of the enclosing object's Metadata.

spec.objectives[*].op

string conditionally required

Operator compares a threshold metric with Value.

Operator specifies a comparison operation for an SLO objective or alert condition.

Possible values: gt, lt, gte, lte

The applicable values depend on the conditions in the validation rules below.

Validation rules

Rule	Applies when
property is forbidden	sli.spec.ratioMetric is set
property is required	sli.spec.thresholdMetric is set
must be one of: gt, lt, gte, lte	sli.spec.thresholdMetric is set

spec.objectives[*].value

float64 conditionally required

Value is the comparison threshold for a threshold metric.

Validation rules

Rule	Applies when
property is forbidden	sli.spec.ratioMetric is set
property is required	sli.spec.thresholdMetric is set

spec.objectives[*].target

float64

Target is the desired success proportion. For example, 0.995 means 99.5 percent.

Validation rules

Rule
property is optional
must be greater than or equal to 0
must be less than 1

spec.objectives[*].targetPercent

float64

TargetPercent is the desired success percentage.

Validation rules

Rule
property is optional
must be greater than or equal to 0
must be less than 100

spec.objectives[*].timeSliceTarget

float64 conditionally required

TimeSliceTarget sets the per-slice success threshold for Timeslices.

Validation rules

Rule	Applies when
property is required	budgetingMethod is Timeslices
must be greater than 0	budgetingMethod is Timeslices
must be less than or equal to 1	budgetingMethod is Timeslices

spec.objectives[*].timeSliceWindow

string conditionally required

TimeSliceWindow sets the size of each slice for Timeslices and RatioTimeslices. OpenSLO also accepts a number interpreted as minutes. This SDK represents only duration shorthand.

DurationShorthand represents a duration as an integer and a DurationShorthandUnit, such as "1m" or "10d". A zero value encodes as empty text.

Validation rules

Rule	Applies when
property is required	budgetingMethod is Timeslices
property is required	budgetingMethod is RatioTimeslices

Validation of value components

These rules apply to parts of this value.

Component: unit

Possible values: d, h, m, w

Rule	Applies when
property is required	budgetingMethod is Timeslices
must be one of: m, h, d, w	budgetingMethod is Timeslices
property is required	budgetingMethod is RatioTimeslices
must be one of: m, h, d, w	budgetingMethod is RatioTimeslices

Component: value

Rule	Applies when
must be greater than or equal to 0	budgetingMethod is Timeslices
must be greater than or equal to 0	budgetingMethod is RatioTimeslices

spec.objectives[*].sli

struct reference

SLI embeds this objective's service level indicator for a composite SLO.

Use the metadata and spec properties from the SLI definition. The inline form omits apiVersion and kind.

Validation rules

Rule	Applies when
property is optional	is composite SLO and sli or sliRef is set

spec.objectives[*].sliRef

string

SLIRef names this objective's existing SLI for a composite SLO.

Validation rules

Rule	Applies when	Details	Examples
property is optional	is composite SLO and sli or sliRef is set
length must be between 1 and 63	is composite SLO and sli or sliRef is set
string must match regular expression: ^[a-z0-9]([-a-z0-9]*[a-z0-9])?$	is composite SLO and sli or sliRef is set	an RFC-1123 compliant label name must consist of lower case alphanumeric characters or -, and must start and end with an alphanumeric character	my-name 123-abc

spec.objectives[*].compositeWeight

float64

CompositeWeight scales this objective's contribution to a composite SLO. The living v2alpha proposal defaults it to 1, but this SDK preserves an omitted value as nil.

Validation rules

Rule	Applies when
property is optional	is composite SLO
must be greater than 0	is composite SLO

spec.alertPolicies

[]struct

AlertPolicies contains inline alert policies or references to existing AlertPolicy objects.

spec.alertPolicies[*]

struct

SLOAlertPolicy associates an inline or referenced alert policy with an SLO.

Validation rules

Rule
exactly one of alertPolicyRef and spec must be set
property is optional

spec.alertPolicies[*].kind

string required

Kind represents all the object kinds defined by OpenSLO specification. Keep in mind not all specification versions support every Kind.

Allowed values: AlertPolicy

Validation rules

Rule
property is required
must be equal to AlertPolicy

spec.alertPolicies[*].metadata

struct required reference

See the metadata definition in the overview.

Validation rules

Rule
property is required

spec.alertPolicies[*].spec

struct required reference

See the AlertPolicy specification.

Validation rules

Rule
property is required

spec.alertPolicies[*].alertPolicyRef

string required

AlertPolicyRef is the metadata name of the alert policy to use.

Validation rules

Rule	Details	Examples
property is required
length must be between 1 and 63
string must match regular expression: ^[a-z0-9]([-a-z0-9]*[a-z0-9])?$	an RFC-1123 compliant label name must consist of lower case alphanumeric characters or -, and must start and end with an alphanumeric character	my-name 123-abc