> ## Documentation Index
> Fetch the complete documentation index at: https://infisical-groups-phase-3.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Docker Swarm

> Learn how to manage secrets in Docker Swarm services.

In this guide, we'll demonstrate how to use Infisical for managing secrets within Docker Swarm.
Specifically, we'll set up a sidecar container using the [Infisical Agent](/infisical-agent/overview), which authenticates with Infisical to retrieve secrets and access tokens.
These secrets are then stored in a shared volume accessible by other services in your Docker Swarm.

## Prerequisites

* Infisical account
* Docker version 20.10.24 or newer
* Basic knowledge of Docker Swarm
* [Git](https://git-scm.com/book/en/v2/Getting-Started-Installing-Git) installed on your system
* Familiarity with the [Infisical Agent](/infisical-agent/overview)

## Objective

Our goal is to deploy an Nginx instance in your Docker Swarm cluster, configured to display Infisical secrets on its landing page. This will provide hands-on experience in fetching and utilizing secrets from Infisical within Docker Swarm. The principles demonstrated here are also applicable to Docker Compose deployments.

<Steps>
  <Step title="Cloning the Guide Assets Repository">
    Start by cloning the [Infisical guide assets repository](https://github.com/Infisical/infisical-guides.git) from Github. This repository includes necessary assets for this and other Infisical guides. Focus on the `docker-swarm-with-agent` sub-directory, which we'll use as our working directory.
  </Step>

  <Step title="Setting Up Authentication with Infisical">
    To allow the agent to fetch your Infisical secrets, choose an authentication method for the agent. For this guide, we will use [Universal Auth](/documentation/platform/identities/universal-auth) for authentication. Follow the instructions [here](/documentation/platform/identities/universal-auth) to generate a client ID and client secret.
  </Step>

  <Step title="Entering Universal Auth Credentials">
    Copy the client ID and client secret obtained in the previous step into the `client-id` and `client-secret` text files, respectively.
  </Step>

  <Step title="Configuring the Infisical Agent">
    The Infisical Agent will authenticate using Universal Auth and retrieve secrets for rendering as specified in the template(s).
    Adjust the `polling-interval` to control the frequency of secret updates.

    In the example template, the secrets are rendered as an HTML page, which will be set as Nginx's home page to demonstrate successful secret retrieval and utilization.

    <Tip>
      Remember to add your project id, environment slug and path of corresponding Infisical project to the secret template.
    </Tip>

    <Tabs>
      <Tab title="Agent Configuration">
        ```yaml infisical-agent-config
        infisical:
        address: "https://app.infisical.com"
        auth:
          type: "universal-auth"
          config:
            client-id: "/run/secrets/infisical-universal-auth-client-id"
            client-secret: "/run/secrets/infisical-universal-auth-client-secret"
            remove_client_secret_on_read: false
        sinks:
          - type: "file"
            config:
              path: "/infisical-secrets/access-token"
        templates:
          - source-path: /run/secrets/nginx-home-page-template
            destination-path: /infisical-secrets/index.html
            config:
              polling-interval: 60s
        ```

        <Info>
          Some paths contain `/run/secrets/` because the contents of those files reside in a [Docker secret](https://docs.docker.com/engine/swarm/secrets/#how-docker-manages-secrets).
        </Info>
      </Tab>

      <Tab title="Secret Template for Agent">
        ```html nginx-home-page-template
        <!DOCTYPE html>
        <html lang="en">
        <body>
            <h1>This file is rendered by Infisical agent template engine</h1>
            <p>Here are the secrets that have been fetched from Infisical and stored in your volume mount</p>
            <ol>
              {{- with secret "7df67a5f-d26a-4988-a375-7153c08149da" "dev" "/" }}
              {{- range . }}
              <li>{{ .Key }}={{ .Value }}</li>
              {{- end }}
              {{- end }}
            </ol>
        </body>
        </html>
        ```
      </Tab>
    </Tabs>
  </Step>

  <Step title="Creating the Docker Compose File">
    Define the `infisical-agent` and `nginx` services in your Docker Compose file. `infisical-agent` will handle secret retrieval and storage. These secrets are stored in a volume, accessible by other services like Nginx.

    ```yaml docker-compose.yaml
    version: "3.1"

    services:
      infisical-agent:
        container_name: infisical-agnet
        image: infisical/cli:0.18.0
        command: agent --config=/run/secrets/infisical-agent-config
        volumes:
          - infisical-agent:/infisical-secrets
        secrets:
          - infisical-universal-auth-client-id
          - infisical-universal-auth-client-secret
          - infisical-agent-config
          - nginx-home-page-template
        networks:
          - infisical_network

      nginx:
        image: nginx:latest
        ports:
          - "80:80"
        volumes:
          - infisical-agent:/usr/share/nginx/html
        networks:
          - infisical_network

    volumes:
      infisical-agent: 

    secrets:
      infisical-universal-auth-client-id:
        file: ./client-id
      infisical-universal-auth-client-secret:
        file: ./client-secret
      infisical-agent-config:
        file: ./infisical-agent-config
      nginx-home-page-template:
        file: ./nginx-home-page-template
        

    networks:
      infisical_network:
    ```
  </Step>

  <Step title="Initializing Docker Swarm">
    ```
    docker swarm init
    ```
  </Step>

  <Step title="Deploying the Docker Stack">
    ```
    docker stack deploy -c docker-compose.yaml agent-demo
    ```
  </Step>

  <Step title="Verifying Secret Consumption">
    To confirm that secrets are properly rendered and accessible, navigate to `http://localhost`. You should see the Infisical secrets displayed on the Nginx landing page.

    ![Nginx displaying Infisical secrets](https://mintlify.s3-us-west-1.amazonaws.com/infisical-groups-phase-3/images/docker-swarm-secrets-complete.png)
  </Step>

  <Step title="Clean up">
    ```
    docker stack rm agent-demo
    ```
  </Step>
</Steps>

## Considerations

* Secret Updates: Applications that access secrets directly from the volume mount will receive updates in real-time, in accordance with the `polling-interval` set in agent config.
* In-Memory Secrets: If your application loads secrets into memory, the new secrets will be available to the application on the next deployment.
