dSSM Database

Overview

The Service Proxy for Kubernetes (SPK) distributed Session State Management (dSSM) Pods provide centralized and persistent storage for the Service Proxy Traffic Management Microkernel (TMM) Pods. The dSSM Pods are Redis data structure stores that maintain application traffic data such as DNS/NAT46 translation mappings. The dSSM Pods bind to Kubernetes persistence volumes to persist data in the event of a container restart.

This document describes the dSSM Pods, and guides you through configuring and installing the f5-dssm-sentinel and f5-dssm-db containers.

Sentinels and DBs

The dSSM Pods integrate as a StatefulSet, containing three dSSM Sentinel Pods and three dSSM DB Pods to maintain high availability. The Sentinel Pods elect and monitor a primary dSSM DB Pod, and if the primary dSSM DB Pod fails, a secondary DB will assume the primary role.

Sentinel Service

The dSSM Sentinel Service receives data from TMM on TCP service port 26379, and forwards to the dSSM DB Pods using the same service port.

Example dSSM Service:

Name:              f5-dssm-sentinel
Namespace:         spk-utilities
IP:                10.106.99.127
Port:              sentinel  26379/TCP
Endpoints:         10.244.1.15:26379,10.244.1.20:26379,10.244.4.3:26379

Example dSSM deployment:

_images/dssm_database.png

Secure communication

The TMM, dSSM Sentinel and dSSM DB Pods communicate over a mesh of secure channels. These channels are secured using SSL/TLS keys and certificates stored as Secrets in the cluster. When deploying dSSM, the first step involves creating the SSL/TLS keys and certificates, and installing them as Secrets. Ensure you understand the key points in the following subsections:

Certificate Validity

SSL/TLS certificates are valid for a specific period of time, and once they expire, secure connections fail when validating the certificate. When creating new SSL/TLS certificates for the secure dSSM channels, choose a period of one year, or two years to avoid connection failures.

Example Certificate Validity:

Validity
    Not Before: Jan 1  10:30:00 2021 GMT
    Not After : Jan 1  10:30:00 2022 GMT

Updating Secrets

If you plan to replace a current set of Secrets with a new set, you must restart both the dSSM and Service Proxy TMM Pods to begin using the new Secrets. It is important to understand that restarting the TMM Pods causes a brief interruption to traffic processing, and should be performed during a planned maintenance window. To restart dSMM and the Service Proxy TMM Pods, refer to the Restarting procedure.

Requirements

Ensure you have:

Procedures

Install the Secrets

Use the following steps to create the required SSL/TLS keys and certificates, and install them as Secrets in both the TMM and dSSM Namespaces:

  1. Change into the directory with the SPK files:

    cd <directory>
    

    In this example, the SPK files are in the spkinstall directory:

    cd spkinstall
    
  2. Create a new directory for the dSSM Secret keys and certificates, and change into the directory:

    mkdir <directory>
    
    cd <directory>
    

    In this example, a new directory named dssm_secrets is created and changed into:

    mkdir dssm_secrets
    
    cd dssm_secrets
    
  3. Create the dSSM Certificate Authority (CA) key and certificate:

    In this example, the CA signing certificate is valid for one year.

    openssl genrsa -out dssm-ca.key 4096
    
    openssl req -x509 -new -nodes -sha384 \
        -key dssm-ca.key -days 365 \
        -subj '/O=Redis Test/CN=Certificate Authority' \
        -out dssm-ca.crt
    
  4. Create the dSSM client key and certificate:

    In this example, the dSSM client certificate is valid for one year.

    openssl genrsa -out dssm-key.key 4096
    
    openssl req -new -sha384 -key dssm-key.key \
        -subj '/O=Redis Test/CN=Server' | \
        openssl x509 -req -sha384 -CA dssm-ca.crt \
            -CAkey dssm-ca.key -CAserial dssm-ca.txt \
            -CAcreateserial  -days 365 \
            -out dssm-cert.crt
    
  5. Create the mTLS certificate for the TMM and dSSM communication channels:

    _images/spk_info.png Note: The mTLS certificate can take up to a minute to generate.

    openssl dhparam -out dhparam2048.pem 2048
    
  6. Encode the keys and certificates:

    cat dssm-ca.crt | base64 -w 0  > dssm-ca-encode.crt
    cat dssm-cert.crt | base64 -w 0 > dssm-cert-encode.crt
    cat dhparam2048.pem | base64 -w 0 > dhparam2048-encode.pem
    cat dssm-key.key | base64 -w 0 > dssm-key-encode.key
    
  7. Create the Secret certificate object file:

    echo "apiVersion: v1" > certs-secret.yaml
    echo "kind: Secret" >> certs-secret.yaml
    echo "metadata:" >> certs-secret.yaml
    echo " name: dssm-certs-secret" >> certs-secret.yaml
    echo "data:" >> certs-secret.yaml
    echo " dssm-ca.crt: `cat dssm-ca-encode.crt`"  >> certs-secret.yaml
    echo " dssm-cert.crt: `cat dssm-cert-encode.crt`" >> certs-secret.yaml
    echo " dhparam2048.pem: `cat dhparam2048-encode.pem`" >> certs-secret.yaml
    
  8. Create the Secret key object file:

    echo "apiVersion: v1" > keys-secret.yaml
    echo "kind: Secret" >> keys-secret.yaml
    echo "metadata:" >> keys-secret.yaml
    echo " name: dssm-keys-secret" >> keys-secret.yaml
    echo "data:" >> keys-secret.yaml
    echo " dssm-key.key: `cat dssm-key-encode.key`" >> keys-secret.yaml
    
  9. Create a new Project for the dSSM Pods:

    _images/spk_info.png Note: If you created a Project for the Fluentd Pod, switch to the project with oc project spk-utilities.

    oc new-project <project>
    

    In this example, a new Project named spk-utilities is created:

    oc new-project spk-utilities
    
  10. Install the Secret key and certificate files to the dSSM Project:

    oc apply -f keys-secret.yaml -n <project>
    oc apply -f certs-secret.yaml -n <project>
    

    In this example, the Secrets install to the spk-utilities Project:

    oc apply -f keys-secret.yaml -n spk-utilities
    oc apply -f certs-secret.yaml -n spk-utilities
    

    The command response should state the Secrets have been created:

    secret/dssm-keys-secret created
    secret/dssm-certs-secret created
    
  11. Install the Secret key and certificate files to the Ingress Controller Project:

    _images/spk_info.png Note: The Ingress Controller Project was created during the gRPC Secrets installation.

    oc apply -f keys-secret.yaml -n <project>
    oc apply -f certs-secret.yaml -n <project>
    

    In the example, the Secrets install to the spk-ingress Project:

    kubectl apply -f keys-secret.yaml -n spk-ingress
    kubectl apply -f certs-secret.yaml -n spk-ingress
    

    The command response should state the Secrets have been created:

    secret/dssm-keys-secret created
    secret/dssm-certs-secret created
    

Install the Pods

Use the following steps to deploy the dSSM Pods with persistence.

  1. Change into local directory with the SPK TAR files, and ensure the Helm charts have been extracted:

    cd <directory>
    
    ls -1 tar
    

    In this example, the SPK files are in the spkinstall directory:

    cd spkinstall
    
    ls -1 tar
    

    In this example, the dSSM Helm chart is named f5-dssm-0.3.3.tgz:

    f5-dssm-0.16.3.tgz
    f5-toda-fluentd-1.7.7.tgz
    f5ingress-2.0.19.tgz
    spk-docker-images.tgz
    
  2. Add the dSSM serviceAccount to the Project’s privileged security context constraint (SCC):

    _images/spk_info.png Note: The f5-dssm serviceAccount name is based on the Helm release name. See Steps 7 and 8.

    oc adm policy add-scc-to-user privileged -n <project> -z <serviceaccount>
    

    In this example, the f5-dssm serviceAccount is added to the spk-utilities Project’s privileged SCC:

    oc adm policy add-scc-to-user privileged -n spk-utilities -z f5-dssm
    
  3. Create a Helm values file named dssm-values, and set the image.repository parameter:

    image:
      repository: <registry>
    

    In this example, Helm pulls the f5-dssm-store images from registry.com:

    image:
      repository: registry.com
    
  4. Optional: If you deployed the Fluentd Logging Pod, you can send logging data to the f5-fluentd container by adding the following parameters to the values file:

    sentinel:
      fluentbit_sidecar:
        fluentd:
          host: '<fluentd hostname>'
    
    db:
      fluentbit_sidecar:
        fluentd:
          host: '<fluentd hostname>'
    

    In this example, the Fluentd container is deployed to the spk-utilities Project:

    sentinel:
      fluentbit_sidecar:
        fluentd:
          host: 'f5-toda-fluentd.spk-utilities.svc.cluster.local.'
    
    db:
      fluentbit_sidecar:
        fluentd:
          host: 'f5-toda-fluentd.spk-utilities.svc.cluster.local.'
    
  5. Install the dSSM Pods:

    _images/spk_warn.png Important: The string f5-dssm is the Helm release name. If a different release name is used, ensure the name is added to the privileged SCC.

    helm install f5-dssm tar/f5-dssm-<tag>.tgz -f <values>.yaml 
    

    For example:

    helm install f5-dssm tar/f5-dssm-0.16.3.tgz -f dssm-values.yaml 
    
  6. All dSSM Pods will be available after the election process, which can take up to a minute.

    _images/spk_warn.png Important: DB entries may fail to be created during the election process if TMM installs prior to completion. TMM will connect after the process completes.

    oc get pods
    

    In this example, the dSSM Pods in the spk-utilities Project have completed the election process, and the Pod STATUS is Running:

    NAME                              READY   STATUS   
    f5-dssm-db-0                      1/1     Running   
    f5-dssm-db-1                      1/1     Running   
    f5-dssm-db-2                      1/1     Running   
    f5-dssm-sentinel-0                1/1     Running   
    f5-dssm-sentinel-1                1/1     Running   
    f5-dssm-sentinel-2                1/1     Running  
    
  7. The dSSM DB Pods should be bound to the persistent volumes:

    oc get pvc
    

    In this example, the dSSM Pod’s PVC STATUS is Bound:

    NAME                STATUS   VOLUME                                     
    data-f5-dssm-db-0   Bound    pvc-c7060354-64d2-456b-9328-aa38f19b44b5   
    data-f5-dssm-db-1   Bound    pvc-8358b993-bf21-4fd7-a0fa-ee84ec420aac  
    data-f5-dssm-db-2   Bound    pvc-de65ed0f-f616-4021-a158-e0e78ed4539e   
    

Next step

Continue to the Ingress Controller and Service Proxy TMM installation guide. To securely connect the TMM and dSSM Pods, add the following parameters to the Ingress Controller’s Helm values file:

_images/spk_warn.png Important: Set the SESSIONDB_EXTERNAL_SERVICE parameter to the Project of the dSSM Pod.

tmm:

  sessiondb:
    useExternalStorage: "true"

  customEnvVars:
  - name: REDIS_CA_FILE
    value: "/etc/ssl/certs/dssm-ca.crt"
  - name: REDIS_AUTH_CERT
    value: "/etc/ssl/certs/dssm-cert.crt"
  - name: REDIS_AUTH_KEY
    value: "/etc/ssl/private/dssm-key.key"
  - name: SESSIONDB_EXTERNAL_STORAGE
    value: "true"
  - name: SESSIONDB_DISCOVERY_SENTINEL
    value: "true"
  - name: SESSIONDB_EXTERNAL_SERVICE
    value: "f5-dssm-sentinel.spk-utilities"

Restarting

This procedure assumes that you have deployed the dSSM Pods, and have created a new set of Secrets to replace the existing Secrets. The new Secrets will not be used until the dSSM and TMM Pods have been restarted.

_images/spk_warn.png Important: Restarting the Service Proxy TMM Pods impacts traffic processing.

  1. Obtain the name and number of Service Proxy TMM Pods:

    oc get deploy -n <project> | grep tmm 
    

    In this example, there are 3 Service Proxy TMM Pods in the spk-ingress Project:

    oc get deploy -n spk-ingress | grep f5-tmm
    
    f5-tmm                 3/3     3       3      
    
  2. Scale the number of Service Proxy Pods to 0:

    oc scale deploy/f5-tmm --replicas=0 -n <project>
    

    In this example the TMM Pods are in the spk-ingress Project:

    oc scale deploy/f5-tmm --replicas=0 -n spk-ingress
    
  3. Wait 5 or 10 seconds for the TMM Pods to terminate, and scale the TMM Pods back to the previous number:

    oc scale deploy/f5-tmm --replicas=<number> -n <project>
    

    In this example the TMM Pods are scaled back to 3 in the spk-ingress Namespace:

    oc scale deploy/f5-tmm --replicas=3 -n spk-ingress
    
  4. Restart the dSSM Sentinel and DB Pods:

    The dSSM Sentinel and DB Pods run as StatefulSets, and will be restarted automatically.

    oc delete pods -l 'app in (f5-dssm-db, f5-dssm-sentinel)' -n <project>
    

    In this example, the Sentinel and DB Pods are in the spk-utilities Namespace:

    oc delete pods -l 'app in (f5-dssm-db, f5-dssm-sentinel)' -n spk-utilities
    
    pod "f5-dssm-db-0" deleted
    pod "f5-dssm-db-1" deleted
    pod "f5-dssm-db-2" deleted
    pod "f5-dssm-sentinel-0" deleted
    pod "f5-dssm-sentinel-1" deleted
    pod "f5-dssm-sentinel-2" deleted
    
  5. Verify the dSSM Pods STATUS is Running:

    oc get pods -n spk-utilities
    

    NAME READY STATUS f5-dssm-db-0 2/2 Running f5-dssm-db-1 2/2 Running f5-dssm-db-2 2/2 Running f5-dssm-sentinel-0 2/2 Running f5-dssm-sentinel-1 2/2 Running f5-dssm-sentinel-2 2/2 Running

    
    
  6. The new Secrets should now be used to secure the dSSM channels.

Feedback

Provide feedback to improve this document by emailing spkdocs@f5.com.