Docker Config Examples: Windows Service, Templated Config, and Advanced Nginx Usage

fzwcfuqjkvo5foqu7ts7ls578 hello 31 minutes ago 31 minutes ago $ docker config rm my-config Error response from daemon: rpc error: code = 3 desc = config 'my-config' is in use by the following service: redis ``` 6. Remove access to the config from the running `redis` service by updating the service. ```console $ docker service update --config-rm my-config redis ``` 7. Repeat steps 3 and 4 again, verifying that the service no longer has access to the config. The container ID is different, because the `service update` command redeploys the service. ```none $ docker container exec -it $(docker ps --filter name=redis -q) cat /my-config cat: can't open '/my-config': No such file or directory ``` 8. Stop and remove the service, and remove the config from Docker. ```console $ docker service rm redis $ docker config rm my-config ``` ### Simple example: Use configs in a Windows service This is a very simple example which shows how to use configs with a Microsoft IIS service running on Docker for Windows running Windows containers on Microsoft Windows 10. It is a naive example that stores the webpage in a config. This example assumes that you have PowerShell installed. 1. Save the following into a new file `index.html`. ```html <html lang="en"> <head><title>Hello Docker</title></head> <body> Hello Docker! You have deployed a HTML page. </body> </html> ``` 2. If you have not already done so, initialize or join the swarm. ```powershell docker swarm init ``` 3. Save the `index.html` file as a swarm config named `homepage`. ```powershell docker config create homepage index.html ``` 4. Create an IIS service and grant it access to the `homepage` config. ```powershell docker service create --name my-iis --publish published=8000,target=8000 --config src=homepage,target="\inetpub\wwwroot\index.html" microsoft/iis:nanoserver ``` 5. Access the IIS service at `http://localhost:8000/`. It should serve the HTML content from the first step. 6. Remove the service and the config. ```powershell docker service rm my-iis docker config rm homepage ``` ### Example: Use a templated config To create a configuration in which the content will be generated using a template engine, use the `--template-driver` parameter and specify the engine name as its argument. The template will be rendered when container is created. 1. Save the following into a new file `index.html.tmpl`. ```html <html lang="en"> <head><title>Hello Docker</title></head> <body> Hello {{ env "HELLO" }}! I'm service {{ .Service.Name }}. </body> </html> ``` 2. Save the `index.html.tmpl` file as a swarm config named `homepage`. Provide parameter `--template-driver` and specify `golang` as template engine. ```console $ docker config create --template-driver golang homepage index.html.tmpl ``` 3. Create a service that runs Nginx and has access to the environment variable HELLO and to the config. ```console $ docker service create \ --name hello-template \ --env HELLO="Docker" \ --config source=homepage,target=/usr/share/nginx/html/index.html \ --publish published=3000,target=80 \ nginx:alpine ``` 4. Verify that the service is operational: you can reach the Nginx server, and that the correct output is being served. ```console $ curl http://0.0.0.0:3000 <html lang="en"> <head><title>Hello Docker</title></head> <body> Hello Docker! I'm service hello-template. </body> </html> ``` ### Advanced example: Use configs with a Nginx service This example is divided into two parts. [The first part](#generate-the-site-certificate) is all about generating

This section continues with Docker config examples, including a simple demonstration of using configs with a Windows IIS service, creating a templated config, and a setup for using configs with an Nginx service. The Windows example covers creating an HTML file, initializing the swarm, saving the HTML as a config, creating an IIS service with access to the config, accessing the service, and removing the service and config. The templated config example shows how to create a dynamic configuration using a template engine, create a service with access to the config and environment variables, and verify the service's output. The last example mentions being divided into two parts and focuses on generating a site certificate for Nginx.