Based on the error message you've provided, it appears that there are issues with the configuration of the header mutator in Ory Oathkeeper. Let me explain the problem and suggest a solution: 1. The error indicates that the

mutators.header.config

is

<nil>

, which means it's missing or not properly set. 2. The configuration you're trying to set via the environment variable is for a specific header within the mutator's config, but the overall structure of the mutator configuration is not correct. To fix this issue, you need to properly structure the configuration for the header mutator. Here's how you can do it: 1. First, enable the header mutator:

MUTATORS_HEADER_ENABLED=true

2. Then, set the configuration for the headers:

MUTATORS_HEADER_CONFIG_HEADERS_X-USER="{{ print .Subject }}"

Make sure both of these environment variables are set correctly. The reason for the failure is that the configuration is expecting a specific structure, and setting just the header value without properly enabling and configuring the mutator causes these validation errors. For reference, here's how the configuration should look in the YAML format, as shown in the [Oathkeeper Mutator documentation](https://www.ory.sh/docs/oathkeeper/pipeline/mutator#header):

yaml mutators:   header:     enabled: true     config:       headers:         X-User: "{{ print .Subject }}"

When translating this to environment variables, you need to ensure all parts of this structure are represented. If you continue to face issues, you might want to double-check your overall Oathkeeper configuration and ensure that all necessary parts of the mutator configuration are properly set.

@chilly-king-10285 both vars are already set

MUTATORS_HEADER_ENABLED="true"
MUTATORS_HEADER_CONFIG_HEADERS_X-USER="{{ print .Subject }}"

Thank you for providing that additional information. If both environment variables are already set as you've shown, but you're still encountering the error, there might be a few other issues at play. Let's explore some possibilities: 1. Environment Variable Format: The format of your environment variables looks correct, but sometimes quotation marks can cause issues. Try setting them without quotes:

MUTATORS_HEADER_ENABLED=true    MUTATORS_HEADER_CONFIG_HEADERS_X-USER={{ print .Subject }}

2. Configuration Precedence: Ory Oathkeeper uses a specific [configuration loading order](https://www.ory.sh/docs/oathkeeper/reference/configuration). Make sure that these environment variables are not being overridden by configuration files or other environment variables. 3. Version Compatibility: Ensure that you're using a version of Oathkeeper that supports this configuration method. Some older versions might have different requirements for setting up mutators. 4. Full Configuration: The error message suggests that the

mutators.header.config

is

<nil>

. This could indicate that other required configuration elements are missing. You might need to set additional configuration values for the header mutator. 5. Syntax in Docker Compose or Kubernetes: If you're using Docker Compose or Kubernetes, make sure the environment variables are properly escaped in your YAML files. 6. Logging and Debugging: Try running Oathkeeper with increased log verbosity to get more detailed error messages. This might provide more insight into why the configuration is not being recognized correctly. If none of these suggestions resolve the issue, it would be helpful to see your full Oathkeeper configuration (with sensitive information redacted) and the exact version of Oathkeeper you're using. This would allow for a more precise diagnosis of the problem. You might also want to consider opening an issue on the [Ory Oathkeeper GitHub repository](https://github.com/ory/oathkeeper) if you believe this might be a bug or an undocumented behavior.

@chilly-king-10285 still failing

I apologize that you're still experiencing issues with the Ory Oathkeeper configuration. Since the problem persists, we need to dig deeper into the configuration and potential causes. However, based on the limited information in the knowledge sources and our conversation history, I don't have enough specific details to pinpoint the exact cause of your ongoing issue. To better assist you, I would recommend the following steps: 1. Double-check your entire Oathkeeper configuration, not just the mutator settings. There might be conflicts or issues in other parts of the config affecting the mutator setup. 2. Verify the Oathkeeper version you're using, as configuration methods can vary between versions. 3. If possible, try setting up the configuration using a YAML file instead of environment variables to rule out any environment-related issues. 4. Enable debug logging in Oathkeeper to get more detailed error messages that could provide clues about the root cause. 5. If you're using Docker or Kubernetes, ensure that the environment variables are being properly passed to the Oathkeeper container. If you continue to face problems after trying these steps, I strongly recommend reaching out to the Ory community or support channels for more personalized assistance. You could: 1. Open an issue on the [Ory Oathkeeper GitHub repository](https://github.com/ory/oathkeeper), providing detailed information about your setup, configuration, and the full error messages you're receiving. 2. Join the [Ory Community Slack](https://slack.ory.sh) to discuss the issue with other users and Ory developers who might have encountered similar problems. 3. If you're using Ory's commercial offerings, consider contacting their support team directly. I apologize that I couldn't provide a direct solution to your problem. The issue seems to be specific to your setup, and without more detailed information about your configuration and environment, it's challenging to diagnose the root cause accurately.

I understand that you want to configure Ory Oathkeeper using environment variables instead of YAML, even though the YAML configuration is working fine for you. This is a common requirement, especially in containerized environments. Let's go through how you can properly set up Oathkeeper configuration using environment variables. According to the [Ory ecosystem configuration documentation](https://www.ory.sh/docs/ecosystem/configuring), you can set any configuration value using environment variables. Here's how you can translate your YAML configuration to environment variables: 1. Use uppercase letters for all keys. 2. Replace nested keys with underscores (_). 3. For array items, use the index number after the key. For the header mutator configuration, you would set the following environment variables:

MUTATORS_HEADER_ENABLED=true MUTATORS_HEADER_CONFIG_HEADERS_X-USER="{{ print .Subject }}"

However, there are a few things to keep in mind: 1. Ensure that you're not mixing configuration methods. If you're using environment variables, make sure you're not also loading a config file that might override these settings. 2. Be careful with quoting and escaping, especially if you're setting these variables in a shell script or Docker/Kubernetes configuration. 3. For complex values (like JSON objects or arrays), you can use JSON strings. For example:

MUTATORS_HEADER_CONFIG_HEADERS='{"X-User": "{{ print .Subject }}"}'

4. Remember that Oathkeeper uses a specific [configuration loading order](https://www.ory.sh/docs/oathkeeper/reference/configuration). Environment variables typically take precedence over config files, but it's good to be aware of this hierarchy. 5. If you're setting many configuration values, consider using an

.env

file or a similar method to manage your environment variables more easily. If you're still encountering issues after setting these environment variables correctly, it might be helpful to: 1. Double-check that the environment variables are actually being set and picked up by the Oathkeeper process. 2. Run Oathkeeper with increased verbosity to see how it's interpreting your configuration. 3. Ensure you're using a recent version of Oathkeeper that fully supports environment variable configuration. If problems persist, consider sharing more details about your setup and the specific error messages you're seeing with the Ory community through their [GitHub issues](https://github.com/ory/oathkeeper/issues) or [Community Slack](https://slack.ory.sh).