Installing Flow Enterprise Server 2021.3.1

Tags: Flow on-prem

Before you begin your Flow Enterprise Server 2021.3.1 installation, carefully read through the system requirements.

This article covers installing Flow Enterprise for the first time. Read more about upgrading Flow if you want to upgrade to 2021.3.1 from a previous version.

The Flow application is based on two components: Replicated’s KOTS platform and the Pluralsight Flow application stack which runs on top of it. During installation, KOTS is installed first, then Flow is added as an application on this platform.

Preinstallation instructions

  • If you’re using an external database, have your database administrator complete the necessary steps to prepare the database

  • Download the latest copy of the flow-enterprise-tools package. Version 2.1.x is required. This is provided by your Pluralsight support representative. Install this package on each node of the Flow cluster. 

  • For the host server, copy flow-enterprise-tools-<channel>[-airgap]-<version>.tar.gz to the home directory of the user account used for the installation on the host server.

  • Extract the tools file using tar xvf flow-enterprise-tools-<channel>[-airgap]-<version>.tar.gz.

    Note: You can run any tool from the bin directory by running cd /path/to/flow-enterprise-tools/bin ./[tool name]. Install the tools package with the script cd /path/to/flow-enterprise-tools ./ The script will ask where to install the components. The default is /usr/local/share/flow-enterprise-tools.
  • Install the flow-enterprise-tools package using the script This allows installation of the scripts and binaries in the system where users can access them from standard PATHsettings. You can also run the scripts of this package in-place.
    Note: For the root user, /usr/local/bin must be in the PATH environment variable. The root user should be set up as a Flow user after the installation of Flow. This is critical if your OS is hardened.
  • Create the following directories. These can all be bundled in a single volume
    app directory (default: /opt/flow)
    mkdir -p [app_directory]
    chmod 755 [app_directory]
    Once the app directory is created, change the ownership of the directory to the following:
    chown -R 37355:37355 [app_directory]
  • If you're using an embedded database, make a database directory (default /opt/flow/database) on the primary host server only:
    mkdir -p [database_directory]
    chmod 725 [database_directory]
    Once the database directory is created, change the ownership of the directory to the following:
    chown -R 1000:1000 [database_directory]

If your version of Flow Enterprise Server is airgapped, download the airgap bundle from Replicated. A password is required. If you can't access Replicated, contact Support for assistance.

Tip: Depending on how you install Flow, you need to download a few different packages. flow-enterprise-tools contains the tools for installation and maintenance of the Kubernetes framework. Download the airgap version for airgapped installations. The app airgap bundle, only for airgap installations, is downloaded from Replicated. It contains the Flow application files, which are installed into the Kubernetes framework provided by flow-enterprise-tools.     

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Install Flow Enterprise

Now we are ready to install Flow Enterprise 2021.3.1. For an online installation, run sudo flow-tools install. For an airgapped installation, run sudo flow-tools install -a. This only needs to be done on the primary node.

Important: A raw block device for each node is required for new Flow installations.

The device filter is in golang regular expression format. Device names vary between distributions. Add multiple filters if the devices are named differently in worker nodes. An example of such a case may look like sd[b-z]|nvme[1-3]|xvd[b-c].

admin-user@primary-node:~$ sudo flow-tools install

[INFO] Verifying installation environment...

[INFO] HTTP command (curl): OK

[INFO] Archive command (tar): OK

[INFO] Swarm does not exist: OK

[INFO] Verifying system requirements...

[INFO] Checking networking...

[INFO] sysctl command : OK

[INFO] IPV6 Kernel module: LOADED

[INFO] IPV6 Check : OK

[INFO] IPv4 Forwarding: ENABLED

[INFO] Check IPtable Rules: OK

[INFO] Checking ufw firewall: INACTIVE

[INFO] Detecting proxy: NOT DETECTED

[INFO] site check : OK

[INFO] Checking hardware...


[INFO] Memory: OK

[INFO] Space check in /var/lib/containerd: OK

[INFO] Space check in /var/lib/kubelet: OK

[INFO] Space check in /opt/replicated: OK

[INFO] Space for Repo cache in /opt/flow: 149 GB

[INFO] Disk Space Check: OK


[INFO] Checking filesystem and permissions...

[INFO] Login restrictions check: OK

[INFO] bash Umask setting: OK

[INFO] /etc/profile Umask setting: OK

[INFO] Checking PATH for /usr/local/bin: OK

[INFO] Checking distro...

[INFO] No existing ceph raw disks detected

[INFO] Installation type is : NEW

=== Discovered Block Devices ===


Above is the list of block devices found during valid device discovery

Please provide pattern to match devices that should be used for K8s volume storage: nvme[1-9]n1

[INFO] Validating block storage device filter...

Device match:    /dev/nvme1n1

Device size:    500G

Device status:    valid

[INFO] Total valid block storage: 500G

[INFO] Block storage: OK

[INFO] Adding patch to use raw ceph block devices for installation

[INFO] Installing KOTS application

[INFO] Saving environment

[INFO] Fetching installation script from:

[INFO] Fetching join script from:



          Complete ✔

The UIs of Prometheus, Grafana and Alertmanager have been exposed on NodePorts 30900, 30902 and 30903 respectively.

To access Grafana use the generated user:password of admin:yJ8faebKRe .


Login with password (will not be shown again): 3fwbTdGgj

To access the cluster with kubectl, reload your shell:

    bash -l

[INFO] Loading environment

node/primary-node labeled

[INFO] Primary node has been labelled with



    If adding an additional node, please run the following,

    after adding a worker node:

        kubectl label nodes worker- --selector=''

[INFO] Existing ceph disk found : /dev/nvme1n1

Kubernetes connection credentials for worker node. Expires in 24 hours

Kubernetes Connection String :  kubernetes-master-address= kubeadm-token=e8sj6l.4h2oha16vr7zeths kubeadm-token-ca-hash=sha256:4373659bec1eafea7e91f13f75a91319dbdeeb6e52422e8af4caff4eab299f08 kubernetes-version=1.19.7 docker-registry-ip=

You may add additional command line options to the flow-tools join command.

Run ./flow-tools join --help for all available flags and options like [ -a|-f|-k|-n|--proxy ] etc.

Node join command for this cluster is below:

sudo ./flow-tools join kubernetes-master-address= kubeadm-token=e8sj6l.4h2oha16vr7zeths kubeadm-token-ca-hash=sha256:4373659bec1eafea7e91f13f75a91319dbdeeb6e52422e8af4caff4eab299f08 kubernetes-version=1.19.7 docker-registry-ip=


[INFO] To change the admin console password, run the following command:

    kubectl kots reset-password -n default

[INFO] Setting up kubectl command for current user

[INFO] Processing home directory: /home/admin-user

[INFO] Setting up kube-config for user: admin-user

On a single-node cluster, the installation labels the primary node appropriately by default. However, in a multi-node installation, label the worker nodes as directed from the output of the installation command as seen above.

Reset the console password by running kubectl kots reset-password -n default if desired.

Next, install Flow Enterprise on each of the worker nodes using the join command output at the end of the installation of the primary node. Read more about joining a node to the cluster.

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Configure the KOTS app

Configure TLS

  1. Open your Chrome browser and go the URL provided at the end of the installation on the primary node. It will look like http://<ip address of server>:8800).

    Note: You will receive an error saying your connection is not private. Flow uses a self-signed SSL/TLS Certificate to secure the communication between your local machine and the admin console during setup. This is secure.
    Click Advanced, then click Proceed to continue to the admin console.

  2. On the next screen, enter the following information from the Before you begin steps:

    1. Enter your hostname

    2. Upload your key and certificate

  3. Click Upload & Continue

Log in to the KOTS admin console

Note: The browser should redirect to the main KOTS admin console, where there is a prompt for login. If not, navigate to https://[hostname]:8800.

  1. Enter the password provided during installation at the end of the installation script output

  2. Upload the license file provided by your Flow representative.

  3. On the following screen, there are two options for installing Flow. If your server doesn’t have internet access, choose the airgapped environment option and upload the pre-downloaded airgapped binary zip file. Otherwise, click on the download from the internet link to continue.

Set up Flow configurations

Once the license is validated, the configuration screen appears as shown below. 

The following configuration changes are recommended:

  • The Flow URL must match the fully qualified domain name registered earlier.

  • Provide a valid email address to receive email alerts.

  • Click Email settings and provide the details of the SMTP/Email server port, credentials, protocol, and other details.

  • If there is a proxy involved, check Use an outbound HTTP/HTTPS Proxy and add in the details.

  • Enter the details for your external Postgres database.

Once this screen is configured, scroll to the bottom of the screen and click Save config.

Deploy Flow

To deploy Flow, on the next screen, click Deploy

Confirm the pop-up window by clicking Yes, deploy.

To monitor the deployment process, run kubectl get pods on the primary node to see each pod’s status. Wait until all pods are in a running state. Once all pods are running, start Flow.

Then proceed to log in to the Flow Enterprise Application using the original URL for the application.

Log in to Flow

Navigate to your Flow URL. Enter your organization name and the primary email. Choose a password to log in.

Connect with your Pluralsight Flow representative to talk about next steps for your onboarding experience. For steps to get started with Flow, check out our Getting Started guide.

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If you need help, please email for 24/7 assistance.