Remove user provided liveness and readiness config (#129)

This PR removes user provided configuration for liveness and
readiness probes, since most of these fields are expected to be
constant and are known to us, we should not require users to
provide these. Instead, we simply use all known values and create
the probes - we only expect initialDelay and probe period from
users. If these fields are not provided, we do not create the
probe.

Additionally, this PR also adds steps on how to create local PV
before creating a MinIOInstance.

Fixes #124

.golangci.yml

@@ -23,5 +23,12 @@ issues:
   exclude:
       - should have a package comment
       - error strings should not be capitalized or end with punctuation or a newline
+  exclude-rules:
+    # Exclude linters from running on auto-generated files.
+    - path: pkg/client
+      linters:
+        - golint
+        - deadcode
+
 service:
   golangci-lint-version: 1.20.0 # use the fixed version to not introduce new linters unexpectedly

README.md

@@ -19,6 +19,7 @@ MinIO-Operator brings native MinIO, [MCS](https://github.com/minio/mcs), [KES](h
 
 - Kubernetes version v1.17.0 and above for compatibility. MinIO Operator uses `k8s/client-go` v0.18.0.
 - `kubectl` configured to refer to a Kubernetes cluster.
+- Create the required PVs as [explained here](https://github.com/minio/minio-operator/blob/master/docs/creating-pv-manually.md).
 
 ### Create Operator and related resources
 
@@ -30,7 +31,7 @@ kubectl apply -f https://raw.githubusercontent.com/minio/minio-operator/master/m
 
 This will create all relevant resources required for the Operator to work.
 
-You could install the MinIO Operator a custom namespace by customizing the `minio-operator.yaml` file or using [kustomize](https://github.com/kubernetes-sigs/kustomize) 
+You could install the MinIO Operator a custom namespace by customizing the `minio-operator.yaml` file or using [kustomize](https://github.com/kubernetes-sigs/kustomize)
 
 ```bash
 kustomize build | kubectl apply -f -

docs/creating-pv-manually.md

@@ -0,0 +1,48 @@
+# Creating PersistentVolumes
+
+[![Slack](https://slack.min.io/slack?type=svg)](https://slack.min.io)
+[![Docker Pulls](https://img.shields.io/docker/pulls/minio/k8s-operator.svg?maxAge=604800)](https://hub.docker.com/r/minio/k8s-operator)
+
+We recommend using [`local` Persistent Volumes](https://kubernetes.io/docs/concepts/storage/volumes/#local) as the backing storage for MinIO StatefulSets. MinIO
+creates a distributed, resilient, failure tolerant storage system on `local` PVs. There is no explicit dependency on external distributed file systems or CSI vendors.
+
+This document explains how to create `local` PVs. Once you create these PVs, MinIOInstance PVCs should automatically bind to these PVs.
+
+## Getting Started
+
+A `local` volume represents a mounted local storage device such as a disk, partition or directory.
+
+Currently, `local` volumes can only be used as a statically created PersistentVolume. Dynamic provisioning is not supported yet. Compared to `hostPath` volumes, `local` volumes can be used in a durable and portable manner without manually scheduling Pods to nodes, as the system is aware of the volume’s node constraints by looking at the node affinity on the PersistentVolume.
+
+Total number of `local` PVs required for a MinIOInstance is equal to Total Servers (across all zones) x Total Volumes Per Server. For example, if you have 4 zones, with 4 servers per zone and each server has 4 volumes, then total PVs required is 64. Since each server has 4 volumes, you'll need to create 4 `local` PVs, on all 16 Servers.
+
+## Sample PV
+
+This is a sample PV configuration. Note that `storageClassName` and `capacity` specified here should match the `storageClassName` and `capacity` specified in MinIOInstance `volumeClaimTemplate` for the PV and PVC to bind. Additionally, please change `capacity`, `path`, and `nodeAffinity` as per your specific requirements.
+
+```yaml
+apiVersion: v1
+kind: PersistentVolume
+metadata:
+  name: minio-pv
+spec:
+  capacity:
+    storage: 1Ti
+  volumeMode: Filesystem
+  accessModes:
+  - ReadWriteOnce
+  persistentVolumeReclaimPolicy: Retain
+  storageClassName: ""
+  local:
+    path: /mnt/disks/ssd1
+  nodeAffinity:
+    required:
+    nodeSelectorTerms:
+    - matchExpressions:
+      - key: kubernetes.io/hostname
+        operator: In
+        values:
+        - example-node
+```
+
+After configuring the PV details, use `kubectl` to create the requisite number of PVs.

examples/minioinstance-kes.yaml

@@ -150,9 +150,6 @@ spec:
   ## is not working properly and needs restart. Kubernetes automatically
   ## restarts the pods if liveness checks fail.
   liveness:
-    httpGet:
-      path: /minio/health/live
-      port: 9000
     initialDelaySeconds: 120
     periodSeconds: 60
   ## Readiness probe detects situations when MinIO server instance
@@ -161,9 +158,6 @@ spec:
   ## Readiness check will only work if PodManagementPolicy is set to "Parallel".
   ## Disable this check if you're setting PodManagementPolicy to "OrderedReady".
   readiness:
-    httpGet:
-      path: /minio/health/ready
-      port: 9000
     initialDelaySeconds: 120
     periodSeconds: 60
   ## nodeSelector parameters for MinIO Pods. It specifies a map of key-value pairs. For the pod to be

examples/minioinstance-mcs.yaml

@@ -138,9 +138,6 @@ spec:
   ## is not working properly and needs restart. Kubernetes automatically
   ## restarts the pods if liveness checks fail.
   liveness:
-    httpGet:
-      path: /minio/health/live
-      port: 9000
     initialDelaySeconds: 120
     periodSeconds: 60
   ## Readiness probe detects situations when MinIO server instance
@@ -149,9 +146,6 @@ spec:
   ## Readiness check will only work if PodManagementPolicy is set to "Parallel".
   ## Disable this check if you're setting PodManagementPolicy to "OrderedReady".
   readiness:
-    httpGet:
-      path: /minio/health/ready
-      port: 9000
     initialDelaySeconds: 120
     periodSeconds: 60
   ## nodeSelector parameters for MinIO Pods. It specifies a map of key-value pairs. For the pod to be

examples/minioinstance.yaml

@@ -112,9 +112,6 @@ spec:
   ## is not working properly and needs restart. Kubernetes automatically
   ## restarts the pods if liveness checks fail.
   liveness:
-    httpGet:
-      path: /minio/health/live
-      port: 9000
     initialDelaySeconds: 120
     periodSeconds: 60
   ## Readiness probe detects situations when MinIO server instance
@@ -123,9 +120,6 @@ spec:
   ## Readiness check will only work if PodManagementPolicy is set to "Parallel".
   ## Disable this check if you're setting PodManagementPolicy to "OrderedReady".
   readiness:
-    httpGet:
-      path: /minio/health/ready
-      port: 9000
     initialDelaySeconds: 120
     periodSeconds: 60
   ## nodeSelector parameters for MinIO Pods. It specifies a map of key-value pairs. For the pod to be

pkg/apis/operator.min.io/v1/constants.go

@@ -87,6 +87,24 @@ const DefaultVolumesPerServer = 1
 // DefaultZoneName specifies the default zone name
 const DefaultZoneName = "zone-0"
 
+// ReadinessPath specifies the endpoint for readiness check
+const ReadinessPath = "/minio/health/ready"
+
+// ReadinessInitialDelay specifies the initial delay in calling the readiness endpoint
+const ReadinessInitialDelay = 120
+
+// ReadinessPeriod specifies the interval in calling the readiness endpoint
+const ReadinessPeriod = 60
+
+// LivenessPath specifies the endpoint for liveness check
+const LivenessPath = "/minio/health/live"
+
+// LivenessInitialDelay specifies the initial delay in calling the liveness endpoint
+const LivenessInitialDelay = 120
+
+// LivenessPeriod specifies the interval in calling the liveness endpoint
+const LivenessPeriod = 60
+
 // MC Mirror Related Constants
 
 // DefaultMCImage specifies the default mc Docker hub image

pkg/apis/operator.min.io/v1/helper.go

@@ -169,6 +169,24 @@ func (mi *MinIOInstance) EnsureDefaults() *MinIOInstance {
 		}
 	}
 
+	if mi.Spec.Readiness != nil {
+		if mi.Spec.Readiness.InitialDelaySeconds == 0 {
+			mi.Spec.Readiness.InitialDelaySeconds = ReadinessInitialDelay
+		}
+		if mi.Spec.Readiness.PeriodSeconds == 0 {
+			mi.Spec.Readiness.PeriodSeconds = ReadinessPeriod
+		}
+	}
+
+	if mi.Spec.Liveness != nil {
+		if mi.Spec.Liveness.InitialDelaySeconds == 0 {
+			mi.Spec.Liveness.InitialDelaySeconds = LivenessInitialDelay
+		}
+		if mi.Spec.Liveness.PeriodSeconds == 0 {
+			mi.Spec.Liveness.PeriodSeconds = LivenessPeriod
+		}
+	}
+
 	if mi.HasMCSEnabled() {
 		if mi.Spec.MCS.Image == "" {
 			mi.Spec.MCS.Image = DefaultMCSImage

pkg/apis/operator.min.io/v1/types.go

@@ -100,10 +100,10 @@ type MinIOInstanceSpec struct {
 	Subpath string `json:"subPath,omitempty"`
 	// Liveness Probe for container liveness. Container will be restarted if the probe fails.
 	// +optional
-	Liveness *corev1.Probe `json:"liveness,omitempty"`
+	Liveness *Liveness `json:"liveness,omitempty"`
 	// Readiness Probe for container readiness. Container will be removed from service endpoints if the probe fails.
 	// +optional
-	Readiness *corev1.Probe `json:"readiness,omitempty"`
+	Readiness *Readiness `json:"readiness,omitempty"`
 	// RequestAutoCert allows user to enable Kubernetes based TLS cert generation and signing as explained here:
 	// https://kubernetes.io/docs/tasks/tls/managing-tls-in-a-cluster/
 	// +optional
@@ -157,6 +157,18 @@ type Zone struct {
 	Servers int32  `json:"servers"`
 }
 
+// Liveness specifies the spec for liveness probe
+type Liveness struct {
+	InitialDelaySeconds int32 `json:"initialDelaySeconds"`
+	PeriodSeconds       int32 `json:"periodSeconds"`
+}
+
+// Readiness specifies the spec for liveness probe
+type Readiness struct {
+	InitialDelaySeconds int32 `json:"initialDelaySeconds"`
+	PeriodSeconds       int32 `json:"periodSeconds"`
+}
+
 // MCSConfig defines the credentials for mcs
 type MCSConfig struct {
 	// Replicas defines number of pods for KES StatefulSet.

pkg/resources/statefulsets/minio-statefulset.go

@@ -28,6 +28,7 @@ import (
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/util/intstr"
 )
 
 // Returns the MinIO environment variables set in configuration.
@@ -149,6 +150,43 @@ func volumeMounts(mi *miniov1.MinIOInstance) []corev1.VolumeMount {
 	return mounts
 }
 
+func probes(mi *miniov1.MinIOInstance) (readiness, liveness *corev1.Probe) {
+	scheme := corev1.URIScheme(strings.ToUpper(miniov1.Scheme))
+	port := intstr.IntOrString{
+		IntVal: int32(miniov1.MinIOPort),
+	}
+
+	if mi.Spec.Readiness != nil {
+		readiness = &corev1.Probe{
+			Handler: corev1.Handler{
+				HTTPGet: &corev1.HTTPGetAction{
+					Path:   miniov1.ReadinessPath,
+					Port:   port,
+					Scheme: scheme,
+				},
+			},
+			InitialDelaySeconds: mi.Spec.Readiness.InitialDelaySeconds,
+			PeriodSeconds:       mi.Spec.Readiness.PeriodSeconds,
+		}
+	}
+
+	if mi.Spec.Liveness != nil {
+		liveness = &corev1.Probe{
+			Handler: corev1.Handler{
+				HTTPGet: &corev1.HTTPGetAction{
+					Path:   miniov1.LivenessPath,
+					Port:   port,
+					Scheme: scheme,
+				},
+			},
+			InitialDelaySeconds: mi.Spec.Liveness.InitialDelaySeconds,
+			PeriodSeconds:       mi.Spec.Liveness.PeriodSeconds,
+		}
+	}
+
+	return readiness, liveness
+}
+
 // Builds the MinIO container for a MinIOInstance.
 func minioServerContainer(mi *miniov1.MinIOInstance, serviceName string) corev1.Container {
 	args := []string{"server"}
@@ -164,11 +202,7 @@ func minioServerContainer(mi *miniov1.MinIOInstance, serviceName string) corev1.
 		}
 	}
 
-	readyProbe := mi.Spec.Readiness
-	readyProbe.HTTPGet.Scheme = corev1.URIScheme(strings.ToUpper(miniov1.Scheme))
-
-	liveProbe := mi.Spec.Liveness
-	liveProbe.HTTPGet.Scheme = corev1.URIScheme(strings.ToUpper(miniov1.Scheme))
+	readyProbe, liveProbe := probes(mi)
 
 	return corev1.Container{
 		Name:  miniov1.MinIOServerName,