Setting a Backup Target

A backup target is the endpoint used to access a backupstore in Longhorn. A backupstore is a NFS server or S3 compatible server that stores the backups of Longhorn volumes. The backup target can be set at Settings/General/BackupTarget.

For more information about how the backupstore works in Longhorn, see the concepts section.

If you don’t have access to AWS S3 or want to give the backupstore a try first, we’ve also provided a way to setup a local S3 testing backupstore using MinIO.

Longhorn also supports setting up recurring snapshot/backup jobs for volumes, via Longhorn UI or Kubernetes Storage Class. See here for details.

This page covers the following topics:

Set up AWS S3 Backupstore

  1. Create a new bucket in AWS S3.

  2. Set permissions for Longhorn. There are two options for setting up the credentials. The first is that you can set up a Kubernetes secret with the credentials of an AWS IAM user. The second is that you can use a third-party application to manage temporary AWS IAM permissions for a Pod via annotations rather than operating with AWS credentials.

    • Option 1: Create a Kubernetes secret with IAM user credentials

      1. Follow the guide to create a new AWS IAM user, with the following permissions set. Edit the Resource section to use your S3 bucket name:

        {
          "Version": "2012-10-17",
          "Statement": [
            {
              "Sid": "GrantLonghornBackupstoreAccess0",
              "Effect": "Allow",
              "Action": [
                "s3:PutObject",
                "s3:GetObject",
                "s3:ListBucket",
                "s3:DeleteObject"
              ],
              "Resource": [
                "arn:aws:s3:::<your-bucket-name>",
                "arn:aws:s3:::<your-bucket-name>/*"
              ]
            }
          ]
        }
        
      2. Create a Kubernetes secret with a name such as aws-secret in the namespace where Longhorn is placed (longhorn-system by default). The secret must be created in the longhorn-system namespace for Longhorn to access it:

        kubectl create secret generic <aws-secret> \
            --from-literal=AWS_ACCESS_KEY_ID=<your-aws-access-key-id> \
            --from-literal=AWS_SECRET_ACCESS_KEY=<your-aws-secret-access-key> \
            -n longhorn-system
        
    • Option 2: Set permissions with IAM temporary credentials by AWS STS AssumeRole (kube2iam or kiam)

      kube2iam or kiam is a Kubernetes application that allows managing AWS IAM permissions for Pod via annotations rather than operating on AWS credentials. Follow the instructions in the GitHub repository for kube2iam or kiam to install it into the Kubernetes cluster.

      1. Follow the guide to create a new AWS IAM role for AWS S3 service, with the following permissions set:

        {
          "Version": "2012-10-17",
          "Statement": [
            {
              "Sid": "GrantLonghornBackupstoreAccess0",
              "Effect": "Allow",
              "Action": [
                "s3:PutObject",
                "s3:GetObject",
                "s3:ListBucket",
                "s3:DeleteObject"
              ],
              "Resource": [
                "arn:aws:s3:::<your-bucket-name>",
                "arn:aws:s3:::<your-bucket-name>/*"
              ]
            }
          ]
        }
        
      2. Edit the AWS IAM role with the following trust relationship:

        {
          "Version": "2012-10-17",
          "Statement": [
            {
              "Effect": "Allow",
              "Principal": {
                  "Service": "ec2.amazonaws.com"
              },
              "Action": "sts:AssumeRole"
            },
            {
              "Effect": "Allow",
              "Principal": {
                "AWS": "arn:aws:iam::<AWS_ACCOUNT_ID>:role/<AWS_EC2_NODE_INSTANCE_ROLE>"
              },
              "Action": "sts:AssumeRole"
            }
          ]
        }
        
      3. Create a Kubernetes secret with a name such as aws-secret in the namespace where Longhorn is placed (longhorn-system by default). The secret must be created in the longhorn-system namespace for Longhorn to access it:

        kubectl create secret generic <aws-secret> \
            --from-literal=AWS_IAM_ROLE_ARN=<your-aws-iam-role-arn> \
            -n longhorn-system
        
  3. Go to the Longhorn UI. In the top navigation bar, click Settings. In the Backup section, set Backup Target to:

    s3://<your-bucket-name>@<your-aws-region>/
    

    Make sure that you have / at the end, otherwise you will get an error. A subdirectory (prefix) may be used:

    s3://<your-bucket-name>@<your-aws-region>/mypath/
    

    Also make sure you’ve set <your-aws-region> in the URL.

    For example, For AWS, you can find the region codes here.

    For Google Cloud Storage, you can find the region codes here.

  4. In the Backup section set Backup Target Credential Secret to:

    aws-secret
    

    This is the secret name with AWS credentials or AWS IAM role.

Result: Longhorn can store backups in S3. To create a backup, see this section.

Note: If you operate Longhorn behind a proxy and you want to use AWS S3 as the backupstore, you must provide Longhorn information about your proxy in the aws-secret as below:

kubectl create secret generic <aws-secret> \
    --from-literal=AWS_ACCESS_KEY_ID=<your-aws-access-key-id> \
    --from-literal=AWS_SECRET_ACCESS_KEY=<your-aws-secret-access-key> \
    --from-literal=HTTP_PROXY=<your-proxy-ip-and-port> \
    --from-literal=HTTPS_PROXY=<your-proxy-ip-and-port> \
    --from-literal=NO_PROXY=<excluded-ip-list> \
    -n longhorn-system

Make sure NO_PROXY contains the network addresses, network address ranges and domains that should be excluded from using the proxy. In order for Longhorn to operate, the minimum required values for NO_PROXY are:

  • localhost
  • 127.0.0.1
  • 0.0.0.0
  • 10.0.0.0/8 (K8s components’ IPs)
  • 192.168.0.0/16 (internal IPs in the cluster)

Set up a Local Testing Backupstore

We provides two testing purpose backupstore based on NFS server and MinIO S3 server for testing, in ./deploy/backupstores.

  1. Use following command to setup a MinIO S3 server for the backupstore after longhorn-system was created.

    kubectl create -f https://raw.githubusercontent.com/longhorn/longhorn/master/deploy/backupstores/minio-backupstore.yaml
    
  2. Go to the Longhorn UI. In the top navigation bar, click Settings. In the Backup section, set Backup Target to

    s3://backupbucket@us-east-1/
    

    And set Backup Target Credential Secret to:

    minio-secret
    

    The minio-secret yaml looks like this:

    apiVersion: v1
    kind: Secret
    metadata:
      name: minio-secret
      namespace: longhorn-system
    type: Opaque
    data:
      AWS_ACCESS_KEY_ID: bG9uZ2hvcm4tdGVzdC1hY2Nlc3Mta2V5 # longhorn-test-access-key
      AWS_SECRET_ACCESS_KEY: bG9uZ2hvcm4tdGVzdC1zZWNyZXQta2V5 # longhorn-test-secret-key
      AWS_ENDPOINTS: aHR0cHM6Ly9taW5pby1zZXJ2aWNlLmRlZmF1bHQ6OTAwMA== # https://minio-service.default:9000
      AWS_CERT: LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0tCk1JSURMRENDQWhTZ0F3SUJBZ0lSQU1kbzQycGhUZXlrMTcvYkxyWjVZRHN3RFFZSktvWklodmNOQVFFTEJRQXcKR2pFWU1CWUdBMVVFQ2hNUFRHOXVaMmh2Y200Z0xTQlVaWE4wTUNBWERUSXdNRFF5TnpJek1EQXhNVm9ZRHpJeApNakF3TkRBek1qTXdNREV4V2pBYU1SZ3dGZ1lEVlFRS0V3OU1iMjVuYUc5eWJpQXRJRlJsYzNRd2dnRWlNQTBHCkNTcUdTSWIzRFFFQkFRVUFBNElCRHdBd2dnRUtBb0lCQVFEWHpVdXJnUFpEZ3pUM0RZdWFlYmdld3Fvd2RlQUQKODRWWWF6ZlN1USs3K21Oa2lpUVBvelVVMmZvUWFGL1BxekJiUW1lZ29hT3l5NVhqM1VFeG1GcmV0eDBaRjVOVgpKTi85ZWFJNWRXRk9teHhpMElPUGI2T0RpbE1qcXVEbUVPSXljdjRTaCsvSWo5Zk1nS0tXUDdJZGxDNUJPeThkCncwOVdkckxxaE9WY3BKamNxYjN6K3hISHd5Q05YeGhoRm9tb2xQVnpJbnlUUEJTZkRuSDBuS0lHUXl2bGhCMGsKVHBHSzYxc2prZnFTK3hpNTlJeHVrbHZIRXNQcjFXblRzYU9oaVh6N3lQSlorcTNBMWZoVzBVa1JaRFlnWnNFbQovZ05KM3JwOFhZdURna2kzZ0UrOElXQWRBWHExeWhqRDdSSkI4VFNJYTV0SGpKUUtqZ0NlSG5HekFnTUJBQUdqCmF6QnBNQTRHQTFVZER3RUIvd1FFQXdJQ3BEQVRCZ05WSFNVRUREQUtCZ2dyQmdFRkJRY0RBVEFQQmdOVkhSTUIKQWY4RUJUQURBUUgvTURFR0ExVWRFUVFxTUNpQ0NXeHZZMkZzYUc5emRJSVZiV2x1YVc4dGMyVnlkbWxqWlM1awpaV1poZFd4MGh3Ui9BQUFCTUEwR0NTcUdTSWIzRFFFQkN3VUFBNElCQVFDbUZMMzlNSHVZMzFhMTFEajRwMjVjCnFQRUM0RHZJUWozTk9kU0dWMmQrZjZzZ3pGejFXTDhWcnF2QjFCMVM2cjRKYjJQRXVJQkQ4NFlwVXJIT1JNU2MKd3ViTEppSEtEa0Jmb2U5QWI1cC9VakpyS0tuajM0RGx2c1cvR3AwWTZYc1BWaVdpVWorb1JLbUdWSTI0Q0JIdgpnK0JtVzNDeU5RR1RLajk0eE02czNBV2xHRW95YXFXUGU1eHllVWUzZjFBWkY5N3RDaklKUmVWbENtaENGK0JtCmFUY1RSUWN3cVdvQ3AwYmJZcHlERFlwUmxxOEdQbElFOW8yWjZBc05mTHJVcGFtZ3FYMmtYa2gxa3lzSlEralAKelFadHJSMG1tdHVyM0RuRW0yYmk0TktIQVFIcFc5TXUxNkdRakUxTmJYcVF0VEI4OGpLNzZjdEg5MzRDYWw2VgotLS0tLUVORCBDRVJUSUZJQ0FURS0tLS0tCg==
    

    For more information on creating a secret, see the Kubernetes documentation. The secret must be created in the longhorn-system namespace for Longhorn to access it.

    Note: Make sure to use echo -n when generating the base64 encoding, otherwise an new line will be added at the end of the string and it will cause error when accessing the S3.

  3. Click the Backup tab in the UI. It should report an empty list without any errors.

Result: Longhorn can store backups in S3. To create a backup, see this section.

Using a self-signed SSL certificate for S3 communication

If you want to use a self-signed SSL certificate, you can specify AWS_CERT in the Kubernetes secret you provided to Longhorn. See the example in Set up a Local Testing Backupstore. It’s important to note that the certificate needs to be in PEM format, and must be its own CA. Or one must include a certificate chain that contains the CA certificate. To include multiple certificates, one can just concatenate the different certificates (PEM files).

Enable virtual-hosted-style access for S3 compatible Backupstore

You may need to enable this new addressing approach for your S3 compatible Backupstore when

  1. you want to switch to this new access style right now so that you won’t need to worry about Amazon S3 Path Deprecation Plan;
  2. the backupstore you are using supports virtual-hosted-style access only, e.g., Alibaba Cloud(Aliyun) OSS;
  3. you have configurated MINIO_DOMAIN environment variable to enable virtual-host-style requests for the MinIO server;
  4. the error ...... error: AWS Error: SecondLevelDomainForbidden Please use virtual hosted style to access. ..... is triggered.

The way to enable virtual-hosted-style access

  1. Add a new field VIRTUAL_HOSTED_STYLE with value true to your backup target secret. e.g.:
    apiVersion: v1
    kind: Secret
    metadata:
      name: s3-compatible-backup-target-secret
      namespace: longhorn-system
    type: Opaque
    data:
      AWS_ACCESS_KEY_ID: bG9uZ2hvcm4tdGVzdC1hY2Nlc3Mta2V5
      AWS_SECRET_ACCESS_KEY: bG9uZ2hvcm4tdGVzdC1zZWNyZXQta2V5
      AWS_ENDPOINTS: aHR0cHM6Ly9taW5pby1zZXJ2aWNlLmRlZmF1bHQ6OTAwMA==
      VIRTUAL_HOSTED_STYLE: dHJ1ZQ== # true
    
  2. Deploy/update the secret and set it in Settings/General/BackupTargetSecret.

NFS Backupstore

For using NFS server as backupstore, NFS server must support NFSv4.

The target URL should look like this:

nfs://longhorn-test-nfs-svc.default:/opt/backupstore

You can find an example NFS backupstore for testing purpose here.

Result: Longhorn can store backups in NFS. To create a backup, see this section.


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