Merge pull request #673 from fmount/probes

Introduce configurable interface for probe management

Author: stuggi

modules/common/probes/probes.go

@@ -13,8 +13,11 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */
+// +kubebuilder:object:generate:=true
+
+// The probes package provides utilities for configuring Kubernetes liveness
+// and readiness probes
 
-// Package probes provides utilities for configuring Kubernetes liveness and readiness probes
 package probes
 
 import (
@@ -23,61 +26,172 @@ import (
 	"github.com/openstack-k8s-operators/lib-common/modules/common/util"
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/util/intstr"
+	"k8s.io/apimachinery/pkg/util/validation/field"
+	"strings"
 )
 
-// ProbeConfig - the configuration for liveness and readiness probes
-// LivenessPath - Endpoint path for the liveness probe
-// ReadinessPath - Endpoint path for the readiness probe
-// InitialDelaySeconds - Number of seconds after the container starts before liveness/readiness probes are initiated
-// TimeoutSeconds - Number of seconds after which the probe times out
-// PeriodSeconds - How often (in seconds) to perform the probe
-type ProbeConfig struct {
-	LivenessPath        string
-	ReadinessPath       string
-	InitialDelaySeconds int32
-	TimeoutSeconds      int32
-	PeriodSeconds       int32
+func (p *ProbeConf) merge(overrides ProbeConf) {
+	// Override path if provided
+	if overrides.Path != "" {
+		p.Path = overrides.Path
+	}
+	// Override timing values if they are non-zero
+	if overrides.InitialDelaySeconds > 0 {
+		p.InitialDelaySeconds = overrides.InitialDelaySeconds
+	}
+	if overrides.TimeoutSeconds > 0 {
+		p.TimeoutSeconds = overrides.TimeoutSeconds
+	}
+	if overrides.PeriodSeconds > 0 {
+		p.PeriodSeconds = overrides.PeriodSeconds
+	}
+	if overrides.FailureThreshold > 0 {
+		p.FailureThreshold = overrides.FailureThreshold
+	}
 }
 
-// SetProbes - configures and returns liveness and readiness probes based on the provided settings
-func SetProbes(port int, disableNonTLSListeners bool, config ProbeConfig) (*v1.Probe, *v1.Probe, error) {
+// CreateProbeSet - creates all probes at once using the interface
+func CreateProbeSet(
+	port int32,
+	scheme *v1.URIScheme,
+	overrides ProbeOverrides,
+	defaults OverrideSpec,
+) (*ProbeSet, error) {
 
-	if port < 1 || port > 65535 {
-		return nil, nil, fmt.Errorf("%w: %d", util.ErrInvalidPort, port)
+	livenessProbe, err := SetProbeConf(
+		port,
+		scheme,
+		func() ProbeConf {
+			if defaults.LivenessProbes == nil {
+				defaults.LivenessProbes = &ProbeConf{}
+			}
+			baseConf := *defaults.LivenessProbes
+			if p := overrides.GetLivenessProbes(); p != nil {
+				baseConf.merge(*p)
+			}
+			return baseConf
+		}(),
+	)
+
+	// Could not process probes config
+	if err != nil {
+		return nil, err
 	}
 
-	var scheme v1.URIScheme
-	if disableNonTLSListeners {
-		scheme = v1.URISchemeHTTPS
-	} else {
-		scheme = v1.URISchemeHTTP
+	readinessProbe, err := SetProbeConf(
+		port,
+		scheme,
+		func() ProbeConf {
+			if defaults.ReadinessProbes == nil {
+				defaults.ReadinessProbes = &ProbeConf{}
+			}
+			baseConf := *defaults.ReadinessProbes
+			if p := overrides.GetReadinessProbes(); p != nil {
+				baseConf.merge(*p)
+			}
+			return baseConf
+		}(),
+	)
+
+	// Could not process probes config
+	if err != nil {
+		return nil, err
 	}
 
-	livenessProbe := &v1.Probe{
-		ProbeHandler: v1.ProbeHandler{
-			HTTPGet: &v1.HTTPGetAction{
-				Path:   config.LivenessPath,
-				Port:   intstr.FromInt(port),
-				Scheme: scheme,
-			},
-		},
-		InitialDelaySeconds: config.InitialDelaySeconds,
-		TimeoutSeconds:      config.TimeoutSeconds,
-		PeriodSeconds:       config.PeriodSeconds,
+	startupProbe, err := SetProbeConf(
+		port,
+		scheme,
+		func() ProbeConf {
+			if defaults.StartupProbes == nil {
+				defaults.StartupProbes = &ProbeConf{}
+			}
+			baseConf := *defaults.StartupProbes
+			if p := overrides.GetStartupProbes(); p != nil {
+				baseConf.merge(*p)
+			}
+			return baseConf
+		}(),
+	)
+
+	// Could not process probes config
+	if err != nil {
+		return nil, err
 	}
 
-	readinessProbe := &v1.Probe{
+	return &ProbeSet{
+		Liveness:  livenessProbe,
+		Readiness: readinessProbe,
+		Startup:   startupProbe,
+	}, nil
+}
+
+// SetProbeConf configures and returns liveness and readiness probes based on
+// the provided settings
+func SetProbeConf(port int32, scheme *v1.URIScheme, config ProbeConf) (*v1.Probe, error) {
+	if port < 1 || port > 65535 {
+		return nil, fmt.Errorf("%w: %d", util.ErrInvalidPort, port)
+	}
+	probe := &v1.Probe{
 		ProbeHandler: v1.ProbeHandler{
 			HTTPGet: &v1.HTTPGetAction{
-				Path:   config.ReadinessPath,
-				Port:   intstr.FromInt(port),
-				Scheme: scheme,
+				Path: config.Path,
+				Port: intstr.FromInt32(port),
 			},
 		},
 		InitialDelaySeconds: config.InitialDelaySeconds,
 		TimeoutSeconds:      config.TimeoutSeconds,
 		PeriodSeconds:       config.PeriodSeconds,
+		FailureThreshold:    config.FailureThreshold,
+	}
+	if scheme != nil {
+		probe.HTTPGet.Scheme = *scheme
+	}
+	return probe, nil
+}
+
+// ValidateProbeConf - This function can be used at webhooks level to explicitly
+// validate the overrides
+func ValidateProbeConf(basePath *field.Path, config *ProbeConf) field.ErrorList {
+	errorList := field.ErrorList{}
+	// nothing to validate, return an empty errorList
+	if config == nil {
+		return errorList
+	}
+	// Path validation: fail is explicitly set as an empty string
+	// or the endpoint does't start with "/"
+	if config.Path != "" && !strings.HasPrefix(config.Path, "/") {
+		err := field.Invalid(basePath.Child("path"), config.Path,
+			"path must start with '/' if specified")
+		errorList = append(errorList, err)
+	}
+
+	// InitialDelaySeconds validation: must be > 0
+	if config.InitialDelaySeconds < 0 {
+		err := field.Invalid(basePath.Child("initialDelaySeconds"), config.InitialDelaySeconds,
+			"initialDelaySeconds must be non-negative")
+		errorList = append(errorList, err)
+	}
+
+	// TimeoutSeconds validation: fail if it's a negative number
+	if config.TimeoutSeconds != 0 && config.TimeoutSeconds < 1 {
+		err := field.Invalid(basePath.Child("timeoutSeconds"), config.TimeoutSeconds,
+			"timeoutSeconds must be at least 1 second when set")
+		errorList = append(errorList, err)
+	}
+
+	// PeriodSeconds validation: fail if it's set as a negative number
+	if config.PeriodSeconds != 0 && config.PeriodSeconds < 1 {
+		err := field.Invalid(basePath.Child("periodSeconds"), config.PeriodSeconds,
+			"periodSeconds must be at least 1 second when set")
+		errorList = append(errorList, err)
+	}
+
+	// FailureThreshold validation: fail if it's set as a negative number
+	if config.FailureThreshold != 0 && config.FailureThreshold < 1 {
+		err := field.Invalid(basePath.Child("failureThreshold"), config.FailureThreshold,
+			"failureThreshold must be at least 1 when set")
+		errorList = append(errorList, err)
 	}
 
-	return livenessProbe, readinessProbe, nil
+	return errorList
 }