How to use docker secret inspect command to view secret details

Introduction

In this lab, you will learn how to use the docker secret inspect command to view detailed information about Docker secrets. You will begin by creating a Docker secret to manage sensitive data. Then, you will explore how to inspect this secret using both its name and its unique ID. Finally, you will learn how to format the output of the inspect command using a Go template to extract specific information. This hands-on experience will equip you with the skills to effectively manage and troubleshoot Docker secrets.

Skills Graph

%%%%{init: {'theme':'neutral'}}%%%% flowchart RL docker(("Docker")) -.-> docker/ContainerOperationsGroup(["Container Operations"]) docker/ContainerOperationsGroup -.-> docker/ls("List Containers") docker/ContainerOperationsGroup -.-> docker/inspect("Inspect Container") docker/ContainerOperationsGroup -.-> docker/create("Create Container") subgraph Lab Skills docker/ls -.-> lab-555221{{"How to use docker secret inspect command to view secret details"}} docker/inspect -.-> lab-555221{{"How to use docker secret inspect command to view secret details"}} docker/create -.-> lab-555221{{"How to use docker secret inspect command to view secret details"}} end

Create a Docker secret

In this step, you will learn how to create a Docker secret. Docker secrets are used to manage sensitive data, such as passwords, SSH keys, and TLS certificates. Secrets are encrypted at rest and in transit, and they are only accessible to services that have been granted access.

To create a Docker secret, you use the docker secret create command. This command takes two arguments: the name of the secret and the path to the file containing the secret data.

Let's create a simple secret named my_secret with the content "thisisasecret". First, create a file named secret.txt in your ~/project directory with the secret content.

echo "thisisasecret" > ~/project/secret.txt

Now, create the Docker secret using the docker secret create command.

docker secret create my_secret ~/project/secret.txt

You should see the ID of the newly created secret printed to the console. This indicates that the secret was created successfully.

Inspect a secret by name

In this step, you will learn how to inspect a Docker secret using its name. The docker secret inspect command allows you to view detailed information about a secret, such as its ID, creation date, and labels.

To inspect a secret by name, you use the docker secret inspect command followed by the name of the secret. In the previous step, we created a secret named my_secret. Let's inspect this secret.

docker secret inspect my_secret

The output of this command will be a JSON object containing detailed information about the my_secret secret. You will see fields like ID, Name, CreatedAt, UpdatedAt, and Spec.

This command is useful for verifying the details of a secret after it has been created or for troubleshooting issues related to secrets.

Inspect a secret by ID

In this step, you will learn how to inspect a Docker secret using its ID. While inspecting by name is convenient, sometimes you might only have the secret's ID, especially when working with automated scripts or logs.

To inspect a secret by ID, you use the docker secret inspect command followed by the ID of the secret. You can get the secret ID from the output of the docker secret create command or by listing secrets using docker secret ls.

Let's get the ID of the my_secret we created in the first step.

docker secret ls

The output will show a table with the secret ID and name. Copy the ID of the my_secret. It will look something like abcdef1234567890.

Now, replace YOUR_SECRET_ID with the actual ID you copied and run the inspect command:

docker secret inspect YOUR_SECRET_ID

You will see the same detailed JSON output as when inspecting by name. This demonstrates that you can use either the name or the ID to inspect a secret.

Format the output using a Go template

In this step, you will learn how to format the output of the docker secret inspect command using a Go template. This is a powerful feature that allows you to extract specific information from the JSON output and display it in a custom format.

Go templates use a simple syntax to access fields within the JSON structure. You can refer to fields using dot notation, for example, .ID to access the ID field or .Spec.Name to access the name within the Spec object.

To format the output, you use the --format flag followed by the Go template string. Let's try to extract just the ID and the name of the my_secret using a Go template.

docker secret inspect my_secret --format 'ID: {{.ID}}, Name: {{.Spec.Name}}'

The output will be:

ID: <secret_id>, Name: my_secret

Replace <secret_id> with the actual ID of your secret.

You can use various functions and control structures within Go templates to create more complex output formats. For example, you could iterate over labels or conditionally display information.

This formatting capability is particularly useful when you need to process the output of Docker commands in scripts or integrate it with other tools.

Summary

In this lab, you learned how to manage sensitive data in Docker using secrets. You started by creating a Docker secret named my_secret from a file, understanding that secrets are encrypted and only accessible to authorized services.

Following the creation, you explored how to view the details of a secret using the docker secret inspect command. You practiced inspecting the secret by its name (my_secret), which provided a JSON output containing information like the secret's ID, creation date, and other specifications. This demonstrated the basic usage of the inspect command for verifying secret details.