Deploying an app that uses COS

Create a persistent volume claim (PVC) to provision IBM Cloud Object Storage for your cluster.

Depending on the settings that you choose in your PVC, you can provision IBM Cloud Object Storage in the following ways:

Dynamic provisioning: When you create the PVC, the matching persistent volume (PV) and the bucket in your IBM Cloud Object Storage service instance are automatically created.
Static provisioning: You can reference an existing bucket in your IBM Cloud Object Storage service instance in your PVC. When you create the PVC, only the matching PV is automatically created and linked to your existing bucket in IBM Cloud Object Storage.

Before you begin:

To add IBM Cloud Object Storage to your cluster:

Create a configuration file to define your persistent volume claim (PVC). If you add your IBM Cloud Object Storage credentials to the default storage classes, do not list your secret in the PVC.
```
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: <name> # Enter the name of the PVC.
  namespace: <namespace> # Enter the namespace where you want to create the PVC. The PVC must be created in the same namespace where you created the Kubernetes secret for your service credentials and where you want to run your pod.
  annotations:
    ibm.io/auto-create-bucket: "<true_or_false>"
    ibm.io/auto-delete-bucket: "<true_or_false>"
    ibm.io/bucket: "<bucket_name>"
    ibm.io/object-path: "<bucket_subdirectory>"
    ibm.io/quota-limit: "true/false" # Disable or enable a quota limit for your PVC. To use this annotation you must specify the -set quotaLimit=true option during installation.
    ibm.io/endpoint: "https://<s3fs_service_endpoint>"
    ibm.io/tls-cipher-suite: "default"
    ibm.io/secret-name: "<secret_name>" # The name of your Kubernetes secret that you created. 
    ibm.io/secret-namespace: "<secret-namespace>" # By default, the COS plug-in searches for your secret in the same namespace where you create the PVC. If you created your secret in a namespace other than the namespace where you want to create your PVC, enter the namespace where you created your secret.
    ibm.io/add-mount-param: "<option-1>,<option-2>" # s3fs mount options
    ibm.io/access-policy-allowed-ips: "XX.XXX.XX.XXX, XX.XX.XX.XXX, XX.XX.XX.XX" # A csv of allow listed IPs.
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: <size>
  storageClassName: <storage_class>
```
ibm.io/auto-create-bucket

Choose between the following options.

true: When you create the PVC, the PV and the bucket in your IBM Cloud Object Storage service instance are automatically created. Choose this option to create a new bucket in your IBM Cloud Object Storage service instance. Note that the service credentials must have Writer permissions to automatically create the bucket.

false: Choose this option if you want to access data in an existing bucket. When you create the PVC, the PV is automatically created and linked to the bucket that you specify in ibm.io/bucket.

ibm.io/auto-delete-bucket

Choose between the following options.

true: Your data, the bucket, and the PV is automatically removed when you delete the PVC. Your IBM Cloud Object Storage service instance remains and is not deleted. If you choose to set this option to true, then you must set ibm.io/auto-create-bucket: true and ibm.io/bucket: "" so that your bucket is automatically created with a name with the format tmp-s3fs-xxxx.

false: When you delete the PVC, the PV is deleted automatically, but your data and the bucket in your IBM Cloud Object Storage service instance remain. To access your data, you must create a new PVC with the name of your existing bucket.

ibm.io/bucket

Choose between the following options.

If ibm.io/auto-create-bucket is set to true: Enter the name of the bucket that you want to create in IBM Cloud Object Storage. If in addition ibm.io/auto-delete-bucket is set to true, you must leave this field blank to automatically assign your bucket a name with the format tmp-s3fs-xxxx. The name must be unique in IBM Cloud Object Storage.

If ibm.io/auto-create-bucket is set to false: Enter the name of the existing bucket that you want to access in the cluster.

ibm.io/object-path

Optional: Enter the name of the existing subdirectory in your bucket that you want to mount. Use this option if you want to mount a subdirectory only and not the entire bucket. To mount a subdirectory, you must set ibm.io/auto-create-bucket: "false" and provide the name of the bucket in ibm.io/bucket.

ibm.io/quota-limit

To use this annotation, you must specify the --set quotaLimit=true option during installation. If you want to use this annotation, but didn't specify --set quotaLimit=true during installation, re-install the helm chart.

If ibm.io/quota-limit is set to true, your PVC will set a maximum amount of storage (in bytes) available for the bucket based on the size storage: <size> that you specify.

If ibm.io/quota-limit is set to false, the quota is not enforced on your PVC meaning that actual amount of storage in bytes might exceed the storage: <size> that you specified depending on your app.

ibm.io/endpoint

If you created your IBM Cloud Object Storage service instance in a location that is different from your cluster, enter the private or public cloud service endpoint of your IBM Cloud Object Storage service instance that you want to use. For more information and an overview of available service endpoints, see Additional endpoint information. By default, the ibmc Helm plug-in automatically retrieves your cluster location and creates the storage classes by using the IBM Cloud Object Storage private cloud service endpoint that matches your cluster location. If your classic cluster is in a multizone metro, such as dal10, the IBM Cloud Object Storage private cloud service endpoint for the multizone metro, for example Dallas. To verify that the service endpoint in your storage classes matches the service endpoint of your service instance, run kubectl describe storageclass < storageclassname>. Make sure that you enter your service endpoint in the format https://< s3fs_private_service_endpoint> for private cloud service endpoints, or http://< s3fs_public_service_endpoint> for public cloud service endpoints. If the service endpoint in your storage class matches the service endpoint of your IBM Cloud Object Storage service instance, don't include the ibm.io/endpoint option in your PVC YAML file.

ibm.io/add-mount-param

Enter mount options for your s3fs Fuse volumes. For example ibm.io/add-mount-param: "del_cache,retries=6". For a list of option, see the s3fs man pages

ibm.io/access-policy-allowed-ips

Enter a comma-separated list of IPs that can access your volumes. For example, ibm.io/access-policy-allowed-ips: "XX.XXX.XX.XXX, XX.XX.XX.XXX, XX.XX.XX.XX.

storage

In the spec resources requests section, enter a size for your IBM Cloud Object Storage bucket in gigabytes. The actual space that you use in IBM Cloud Object Storage might be different and is billed based on the pricing table. If you enabled quotas when you installed the plug-in , the quota for your bucket is equal to this size.

storageClassName

Choose between the following options.

If ibm.io/auto-create-bucket: "true": Enter the storage class that you want to use for your new bucket.

If ibm.io/auto-create-bucket: "false": Enter the storage class that you used to create your existing bucket.

If you manually created the bucket in your IBM Cloud Object Storage service instance or you can't remember the storage class that you used, find your service instance in the IBM Cloud dashboard and review the Class and Location of your existing bucket. Then, use the appropriate storage class. The IBM Cloud Object Storage API endpoint that is set in your storage class is based on the region that your cluster is in. If you want to access a bucket that is located in a different region than the one where your cluster is in, you must create your own storage class and use the appropriate API endpoint for your bucket.

ibm.io/secret-name

Enter the name of the secret that holds the IBM Cloud Object Storage credentials that you created earlier. If you add your IBM Cloud Object Storage credentials to the default storage classes, you must not list secrets in the PVC. If you want to integrate Key Protect encryption when creating new buckets from PVCs in your cluster, you must include the root key CRN when creating your IBM Cloud Object Storage secret. Note that you cannot add Key Protect encryption to existing buckets.

secret-namespace

By default, the COS plug-in searches for your secret in the same namespace where you create the PVC. If you created your secret in a namespace other than the namespace where you want to create your PVC, enter the namespace where you created your secret.
Create the PVC in your cluster.
```
kubectl apply -f filepath/pvc.yaml
```

Verify that your PVC is created and bound to the PV.

kubectl get pvc

Example output

NAME                  STATUS    VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS                     AGE
s3fs-test-pvc         Bound     pvc-b38b30f9-1234-11e8-ad2b-t910456jbe12   8Gi        RWO            ibmc-s3fs-standard-cross-region  1h

Optional: If you plan to access your data with a non-root user, or added files to an existing IBM Cloud Object Storage bucket by using the console or the API directly, make sure that the files have the correct permission assigned so that your app can successfully read and update the files as needed.

To mount the PV to your deployment, create a configuration .yaml file and specify the PVC that binds the PV.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: <deployment_name>
  labels:
    app: <deployment_label>
spec:
  selector:
    matchLabels:
      app: <app_name>
  template:
    metadata:
      labels:
        app: <app_name>
    spec:
      containers:
      - image: <image_name>
        name: <container_name>
        securityContext:
          runAsUser: <non_root_user>
        volumeMounts:
        - name: <volume_name>
          mountPath: /<file_path>
      volumes:
      - name: <volume_name>
        persistentVolumeClaim:
          claimName: <pvc_name>

app: In the metadata section, enter label for the deployment.
matchLabels.app and labels.app: In the spec selector and in the spec template metadata sections, enter a label for your app.
image: The name of the container image that you want to use. To list available images in your IBM Cloud Container Registry account, run ibmcloud cr image-list.
name: The name of the container that you want to deploy to your cluster.
runAsUser: In the spec containers security context section, you can optionally set the run as user value.
mountPath: In the spec containers volume mounts section, enter the absolute path of the directory to where the volume is mounted inside the container. If you want to share a volume between different apps, you can specify volume sub paths for each of your apps.
volumeMounts.name: In the spec containers volume mounts section, enter the name of the volume to mount to your pod.
volumes.name: In the volumes section, enter the name of the volume to mount to your pod. Typically this name is the same as volumeMounts/name.
claimName: In the volumes persistent volume claim section, enter the name of the PVC that binds the PV that you want to use.

Creating a deployment

After you create PVC and deployment configuration files, create the deployment in your cluster.

Create the deployment.
```
kubectl apply -f <local_yaml_path>
```

Verify that the PV is successfully mounted.

kubectl describe deployment <deployment_name>

The mount point is in the Volume Mounts field and the volume is in the Volumes field.

Volume Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-tqp61 (ro)
      /volumemount from myvol (rw)
...
Volumes:
    myvol:
    Type:    PersistentVolumeClaim (a reference to a PersistentVolumeClaim in the same namespace)
    ClaimName:    mypvc
    ReadOnly:    false

Verify that you can write data to your IBM Cloud Object Storage service instance by logging in to the app pod and writing data. Log in to the pod that mounts your PV.
```
kubectl exec <pod_name> -it bash
```
Navigate to your volume mount path that you defined in your app deployment.
Create a text file.
```
echo "This is a test" > test.txt
```
From the IBM Cloud® dashboard, navigate to your IBM Cloud Object Storage service instance.
From the menu, select Buckets.
Open your bucket, and verify that you can see the test.txt that you created.

Using object storage in a stateful set

If you have a stateful app such as a database, you can create stateful sets that use IBM Cloud Object Storage to store your app's data. Alternatively, you can use an IBM Cloud database-as-a-service, such as IBM Cloudant and store your data in the cloud.

Before you begin:

To deploy a stateful set that uses object storage:

Create a configuration file for your stateful set and the service that you use to expose the stateful set. The following examples show how to deploy NGINX as a stateful set with three replicas, each replica with a separate bucket or sharing the same bucket.

Example to create a stateful set with three replicas, with each replica using a separate bucket.

apiVersion: v1
kind: Service
metadata:
  name: nginx-v01
  namespace: default
  labels:
    app: nginx-v01 # must match spec.template.metadata.labels and spec.selector.matchLabels in stateful set YAML
spec:
  ports:
  - port: 80
    name: web
  clusterIP: None
  selector:
    app: nginx-v01 # must match spec.template.metadata.labels and spec.selector.matchLabels in stateful set YAML
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: web-v01
  namespace: default
spec:
  selector:
    matchLabels:
      app: nginx-v01 # must match spec.template.metadata.labels in stateful set YAML and metadata.labels in service YAML
  serviceName: "nginx-v01"
  replicas: 3
  template:
    metadata:
      labels:
        app: nginx-v01 # must match spec.selector.matchLabels in stateful set YAML and metadata.labels in service YAML
    spec:
      terminationGracePeriodSeconds: 10
      containers:
      - name: nginx
        image: k8s.gcr.io/nginx-slim:0.8
        ports:
        - containerPort: 80
          name: web
        volumeMounts:
        - name: mypvc
          mountPath: /usr/share/nginx/html
  volumeClaimTemplates:
  - metadata:
      name: mypvc
      annotations:
        ibm.io/auto-create-bucket: "true"
        ibm.io/auto-delete-bucket: "true"
        ibm.io/bucket: ""
        ibm.io/secret-name: mysecret
        volume.beta.kubernetes.io/storage-class: ibmc-s3fs-standard-perf-cross-region
        volume.beta.kubernetes.io/storage-provisioner: ibm.io/ibmc-s3fs
    spec:
      accessModes: [ "ReadWriteOnce" ]
      storageClassName: "ibmc-s3fs-standard-perf-cross-region"
      resources:
        requests:
          storage: 1Gi

Example to create a stateful set with three replicas that share the same bucket mybucket.

apiVersion: v1
kind: Service
metadata:
  name: nginx-v01
  namespace: default
  labels:
    app: nginx-v01 # must match spec.template.metadata.labels and spec.selector.matchLabels in stateful set YAML
spec:
  ports:
  - port: 80
    name: web
  clusterIP: None
  selector:
    app: nginx-v01 # must match spec.template.metadata.labels and spec.selector.matchLabels in stateful set YAML
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: web-v01
  namespace: default
spec:
  selector:
    matchLabels:
      app: nginx-v01 # must match spec.template.metadata.labels in stateful set YAML and metadata.labels in service YAML
  serviceName: "nginx-v01"
  replicas: 3
  template:
    metadata:
      labels:
        app: nginx-v01 # must match spec.selector.matchLabels in stateful set YAML and metadata.labels in service YAML
    spec:
      terminationGracePeriodSeconds: 10
      containers:
      - name: nginx
        image: k8s.gcr.io/nginx-slim:0.8
        ports:
        - containerPort: 80
          name: web
        volumeMounts:
        - name: mypvc
          mountPath: /usr/share/nginx/html
  volumeClaimTemplates:
  - metadata:
      name: mypvc
      annotations:
        ibm.io/auto-create-bucket: "false"
        ibm.io/auto-delete-bucket: "false"
        ibm.io/bucket: mybucket
        ibm.io/secret-name: mysecret
        volume.beta.kubernetes.io/storage-class: ibmc-s3fs-standard-perf-cross-region
        volume.beta.kubernetes.io/storage-provisioner: ibm.io/ibmc-s3fs
    spec:
      accessModes: [ "ReadOnlyMany" ]
      storageClassName: "ibmc-s3fs-standard-perf-cross-region"
      resources:
        requests:
          storage: 1Gi

name

Enter a name for your stateful set. The name that you enter is used to create the name for your PVC in the format: <volume_name>-< statefulset_name>-<replica_number>.

serviceName

Enter the name of the service that you want to use to expose your stateful set.

replicas

Enter the number of replicas for your stateful set.

matchLabels

In the spec selector match labels section, enter all labels that you want to include in your stateful set and your PVC. Labels that you include in the volumeClaimTemplates of your stateful set are not recognized by Kubernetes. Instead, you must define these labels in the spec.selector.matchLabels and spec.template.metadata.labels section of your stateful set YAML. To make sure that all your stateful set replicas are into the load balancing of your service, include the same label that you used in the spec.selector section of your service YAML.

labels

In the spec metadata labels section, enter the same labels that you added to the spec.selector.matchLabels section of your stateful set YAML.

terminationGracePeriodSeconds

Enter the number of seconds to give the kubelet to safely terminate the pod that runs your stateful set replica. For more information, see Delete Pods.

VolumeClaimTemplates.name

In the spec volume claim templates metadata section, enter a name for your volume. Use the same name that you defined in the spec.containers.volumeMount.name section. The name that you enter here is used to create the name for your PVC in the format: <volume_name>-<statefulset_name>-<replica_number>.

ibm.io/auto-create-bucket

In the spec volume claim templates metadata section, set an annotation to configure how buckets are created. Choose between the following options:

true: Choose this option to automatically create a bucket for each stateful set replica. Note that the service credentials must have Writer permissions to automatically create the bucket.
false: Choose this option if you want to share an existing bucket across your stateful set replicas. Make sure to define the name of the bucket in the spec.volumeClaimTemplates.metadata.annotions.ibm.io/bucket section of your stateful set YAML.

ibm.io/auto-delete-bucket

In the spec volume claim templates metadata section, set an annotation to configure how buckets are deleted. Choose between the following options:

true: Your data, the bucket, and the PV is automatically removed when you delete the PVC. Your IBM Cloud Object Storage service instance remains and is not deleted. If you choose to set this option to true, then you must set ibm.io/auto-create-bucket: true and ibm.io/bucket: ""so that your bucket is automatically created with a name with the format tmp-s3fs-xxxx.
false: When you delete the PVC, the PV is deleted automatically, but your data and the bucket in your IBM Cloud Object Storage service instance remain. To access your data, you must create a new PVC with the name of your existing bucket.

ibm.io/bucket

In the spec volume claim templates metadata section, set an annotation for the bucket details. Choose between the following options:

If ibm.io/auto-create-bucket is set to true: Enter the name of the bucket that you want to create in IBM Cloud Object Storage. If in addition ibm.io/auto-delete-bucket is set to true, you must leave this field blank to automatically assign your bucket a name with the format tmp-s3fs-xxxx. The name must be unique in IBM Cloud Object Storage.
If ibm.io/auto-create-bucket is set to false: Enter the name of the existing bucket that you want to access in the cluster.

ibm.io/secret-name

In the spec volume claim templates metadata annotations section, enter the name of the secret that holds the IBM Cloud Object Storage credentials that you created earlier. If you add your IBM Cloud Object Storage credentials to the default storage classes, you must not list the secret in the PVC.

kubernetes.io/storage-class

In the spec volume claim templates metadata annotations section, enter the storage class that you want to use. Choose between the following options:

If ibm.io/auto-create-bucket: "true": Enter the storage class that you want to use for your new bucket.
If ibm.io/auto-create-bucket: "false": Enter the storage class that you used to create your existing bucket.

To list existing storage classes, runkubectl get sc | grep s3. If you don't specify a storage class, the PVC is created with the default storage class that is set in your cluster. Make sure that the default storage class uses the ibm.io/ibmc-s3fs provisioner so that your stateful set is provisioned with object storage.

storageClassName

In the spec volume claim templates spec section, enter the same storage class that you entered in the spec.volumeClaimTemplates.metadata.annotations.volume.beta.kubernetes.io/storage-class section of your stateful set YAML.

storage

In the spec volume claim templates spec resource requests section, enter a fictitious size for your IBM Cloud Object Storage bucket in gigabytes. The size is required by Kubernetes, but not respected in IBM Cloud Object Storage. You can enter any size that you want. The actual space that you use in IBM Cloud Object Storage might be different and is billed based on the pricing table.