How to use docker plugin inspect command to view plugin details

Introduction

In this lab, you will learn how to use the docker plugin inspect command to view detailed information about Docker plugins. We will start by inspecting a specific plugin to see the default JSON output, which provides comprehensive details about its configuration and state.

Following that, you will discover how to format the output of the docker plugin inspect command using the --format flag and Go's text/template package. This allows you to extract and display specific pieces of information from the plugin details in a more readable and customized way.

Skills Graph

Inspect a specific plugin

In this step, we will learn how to inspect a specific Docker plugin. The docker plugin inspect command allows you to view detailed information about a plugin, including its configuration, settings, and state.

First, let's list the available plugins to see which ones we can inspect. We can use the docker plugin ls command for this.

docker plugin ls

You should see a list of installed plugins. For this example, we will inspect the vieux/sshfs:latest plugin. If this plugin is not listed, you can install it first using docker plugin install vieux/sshfs:latest.

Now, let's inspect the vieux/sshfs:latest plugin using the docker plugin inspect command followed by the plugin name.

docker plugin inspect vieux/sshfs:latest

This command will output a large JSON object containing all the details about the vieux/sshfs:latest plugin. This output includes information like the plugin ID, name, enabled status, configuration, and more.

Format the output of plugin inspection

In the previous step, we saw that the default output of docker plugin inspect is a large JSON object. While this is useful for detailed analysis, it can be difficult to read quickly. Docker provides a --format flag that allows you to format the output using Go's text/template package. This is very powerful and allows you to extract specific pieces of information or display the output in a custom way.

Let's try to extract just the plugin ID and name using the --format flag. We will use the {{.ID}} and {{.Name}} template fields to access these properties from the JSON output.

docker plugin inspect --format 'ID: {{.ID}}, Name: {{.Name}}' vieux/sshfs:latest

This command will output a string like ID: <plugin_id>, Name: vieux/sshfs:latest, where <plugin_id> is the actual ID of the plugin. This is much more concise and easier to read if you only need specific information.

You can also use the --format flag to create more complex output. For example, let's display the plugin name and its enabled status. The enabled status is a boolean value, and we can access it using {{.Enabled}}.

docker plugin inspect --format 'Plugin: {{.Name}}, Enabled: {{.Enabled}}' vieux/sshfs:latest

This will output something like Plugin: vieux/sshfs:latest, Enabled: true or Plugin: vieux/sshfs:latest, Enabled: false depending on the plugin's state.

The --format flag is a very flexible tool for customizing the output of Docker commands. You can explore the structure of the JSON output from the default inspect command to find other fields you might want to include in your formatted output.

Summary

In this lab, we learned how to use the docker plugin inspect command to view detailed information about a Docker plugin. We first explored the default output of the command, which provides a comprehensive JSON object containing various plugin details such as ID, name, and configuration.

We then discovered how to format the output of docker plugin inspect using the --format flag and Go's text/template package. This powerful feature allows us to extract specific information, such as the plugin ID and name, and display it in a more readable and customized format, making it easier to quickly access the desired details.