Troubleshooting MarkLogic Docker Image Execution Issues With Podman

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Introduction

When working with MarkLogic in containerized environments, developers sometimes encounter issues when transitioning between different container runtimes. A common scenario involves a Docker image that functions correctly under Docker Desktop but fails to execute properly when deployed using Podman. This article addresses this specific problem, focusing on the error encountered when trying to run a MarkLogic Docker image with Podman, and provides a detailed guide to troubleshooting and resolving the issue.

This comprehensive guide will walk you through the error logs, potential causes, and step-by-step solutions to ensure a smooth transition from Docker to Podman for your MarkLogic instances. By the end of this article, you'll have a solid understanding of how to diagnose and fix common Podman-related issues when deploying MarkLogic, allowing you to leverage the benefits of Podman in your development and production environments.

Understanding the Problem

When attempting to run a MarkLogic Docker image using Podman, the process may fail with an error indicating an unexpected response code during the initialization phase. The error message typically looks like this:

2025-07-08 05:49:35.817 Error: Expected response code 202, got 000 from http://aa33618daee8:8001/admin/v1/instance-admin.

This error suggests that the MarkLogic instance is not initializing correctly within the Podman container. While the same image might work seamlessly with Docker, Podman's different architecture and security model can lead to this discrepancy. Understanding the root causes of this issue is crucial for effective troubleshooting.

To further clarify, let’s break down the error message. The log indicates that the MarkLogic server expected a response code of 202 from the http://aa33618daee8:8001/admin/v1/instance-admin endpoint, but instead received a 000 response. This typically means that the HTTP request either failed to reach the endpoint or did not receive a valid response. This can happen due to several reasons, including network configuration issues within the container, problems with the MarkLogic initialization process, or permission errors that prevent the server from starting correctly.

Examining the Error Logs

The provided error logs offer valuable clues about the failure. Key snippets include:

/opt/MarkLogic/mlcmd/bin/is-ec2.sh: line 6: sudo: command not found

This line indicates that the is-ec2.sh script, which likely checks if the environment is an EC2 instance, failed because the sudo command was not found. This suggests a potential issue with the container's environment or the script's dependencies.

2025-07-08 05:49:35.817 Error: Expected response code 202, got 000 from http://aa33618daee8:8001/admin/v1/instance-admin.

As mentioned earlier, this is the core error, pointing to a problem during the initialization of the MarkLogic instance.

By carefully examining these logs, we can start to form a hypothesis about the root cause of the problem and identify potential solutions.

Potential Causes

Several factors can contribute to this issue. Here are some of the most common:

  1. Differences in Container Runtimes: Podman and Docker, while both container runtimes, have architectural differences. Podman, being rootless by default, may encounter permission issues that Docker doesn't.
  2. Network Configuration: Podman's networking setup might differ from Docker's, leading to connectivity problems within the container.
  3. Missing Dependencies: The container might be missing dependencies required by MarkLogic or its initialization scripts, such as the sudo command in the is-ec2.sh script.
  4. Initialization Issues: Problems during the MarkLogic initialization process, such as incorrect environment variables or configuration errors, can also lead to this error.
  5. Resource Constraints: Insufficient resources allocated to the container, such as memory or CPU, can prevent MarkLogic from starting correctly.

Understanding these potential causes is the first step toward resolving the issue. In the following sections, we will explore each of these in detail and provide actionable solutions.

Troubleshooting Steps

To effectively resolve the issue of being unable to execute a MarkLogic Docker image with Podman, we need to follow a systematic troubleshooting approach. This involves examining the environment, configurations, and dependencies, and addressing any discrepancies that may be causing the failure.

1. Verify Podman Installation and Configuration

First, ensure that Podman is correctly installed and configured on your system. This includes checking the Podman version, verifying that the Podman service is running, and ensuring that your user has the necessary permissions to run Podman commands.

To check the Podman version, use the following command:

podman --version

This command will display the installed Podman version, which can help you determine if you are using a compatible version with your MarkLogic image. If Podman is not installed or the version is outdated, you may need to update or reinstall Podman.

Next, verify that the Podman service is running. You can check the status of the Podman service using the systemctl command (on systems that use systemd):

systemctl status podman.socket

If the Podman service is not running, you can start it using:

systemctl start podman.socket

It's also important to ensure that your user has the necessary permissions to run Podman commands. Podman is designed to be rootless, which means it can run without requiring root privileges. However, you may still encounter permission issues if your user does not have the appropriate rights to access the container storage or network resources. You can address permission issues by adding your user to the podman group or by configuring Podman's storage and network settings.

2. Check Network Configuration

Networking issues are a common cause of failures when running containerized applications. Podman's networking setup differs from Docker's, and this can sometimes lead to connectivity problems within the container. You need to ensure that the container can access the necessary network resources and that the ports are correctly exposed.

To inspect the network configuration of your Podman container, you can use the podman inspect command:

podman inspect <container_name_or_id>

This command will display detailed information about the container, including its network settings. Look for the NetworkSettings section to examine the container's IP address, gateway, and DNS configuration. Verify that the container has a valid IP address and that it can communicate with other containers or services on the network.

If you are using port mappings to expose ports from the container to the host, ensure that the mappings are correctly configured. You can specify port mappings using the -p option when running the podman run command. For example, to map port 8001 on the host to port 8001 in the container, you would use:

podman run -p 8001:8001 ...

It's also important to check for any firewall rules that may be blocking traffic to the container. If you are using a firewall, ensure that it allows traffic on the ports that you are using for your MarkLogic instance. You may need to add rules to your firewall to allow traffic on ports 8000, 8001, and other ports used by MarkLogic.

3. Verify Environment Variables

Environment variables play a crucial role in configuring MarkLogic instances within containers. Incorrect or missing environment variables can lead to initialization failures. You need to ensure that all required environment variables are set correctly when running the Podman container. Common environment variables for MarkLogic include:

  • MARKLOGIC_ADMIN_USERNAME: The username for the MarkLogic administrator account.
  • MARKLOGIC_ADMIN_PASSWORD: The password for the MarkLogic administrator account.
  • MARKLOGIC_INIT: A flag indicating whether to initialize the MarkLogic server.
  • MARKLOGIC_WALLET_PASSWORD: The password for the MarkLogic wallet.

To check the environment variables that are being passed to the container, you can use the podman inspect command:

podman inspect <container_name_or_id>

This command will display detailed information about the container, including its environment variables. Look for the Env section to examine the environment variables that are set for the container. Verify that all required environment variables are present and that their values are correct.

You can set environment variables when running the podman run command using the -e option. For example, to set the MARKLOGIC_ADMIN_USERNAME and MARKLOGIC_ADMIN_PASSWORD environment variables, you would use:

podman run -e MARKLOGIC_ADMIN_USERNAME=admin -e MARKLOGIC_ADMIN_PASSWORD=password ...

It's also important to ensure that the environment variables are being set correctly within the container. You can log into the container using podman exec and check the environment variables using the env command:

podman exec -it <container_name_or_id> bash
env

This will display the environment variables that are set within the container, allowing you to verify that they are being set correctly.

4. Address Missing Dependencies

The error log snippet /opt/MarkLogic/mlcmd/bin/is-ec2.sh: line 6: sudo: command not found indicates that the sudo command is missing from the container. This is a common issue in minimal container images, where certain utilities are not included by default. To resolve this, you need to install the missing dependencies within the container.

There are two main ways to address this issue:

  1. Modify the Dockerfile: If you have control over the Dockerfile used to build the image, you can add a step to install the missing dependencies. For example, if you are using a Debian-based image, you can add the following line to your Dockerfile:
RUN apt-get update && apt-get install -y sudo

This will install the sudo command in the container when the image is built. You will then need to rebuild the image using podman build.

  1. Install Dependencies at Runtime: If you cannot modify the Dockerfile, you can install the missing dependencies at runtime by logging into the container and using the package manager. For example, if you are using a Debian-based image, you can use the following commands:
podman exec -it <container_name_or_id> bash
apt-get update
apt-get install -y sudo
exit

This will install the sudo command in the running container. However, this change will not persist if the container is restarted. To make the change permanent, you would need to commit the changes to a new image using podman commit.

It's important to identify all missing dependencies and install them using the appropriate method. You can examine the error logs and the scripts that are being executed within the container to determine which dependencies are required.

5. Check Resource Limits

Insufficient resources, such as memory or CPU, can prevent MarkLogic from starting correctly within a Podman container. If the container does not have enough resources, it may crash or fail to initialize properly. You need to ensure that the container has sufficient resources allocated to it.

You can set resource limits when running the podman run command using the --memory and --cpus options. For example, to allocate 4GB of memory and 2 CPUs to the container, you would use:

podman run --memory=4g --cpus=2 ...

It's important to determine the appropriate resource limits for your MarkLogic instance based on its workload and requirements. You can monitor the container's resource usage using the podman stats command:

podman stats <container_name_or_id>

This command will display real-time statistics about the container's resource usage, including CPU usage, memory usage, and network I/O. You can use this information to identify if the container is running out of resources and adjust the resource limits accordingly.

If you are running multiple containers on the same host, it's important to ensure that the total resource usage of all containers does not exceed the host's capacity. Overcommitting resources can lead to performance issues and instability.

6. Review MarkLogic Configuration

Incorrect MarkLogic configuration settings can also cause initialization failures. You need to review the MarkLogic configuration files and ensure that they are correctly set up for the Podman environment. This includes checking the marklogic.conf file and any other configuration files that may be used by MarkLogic.

The marklogic.conf file contains important configuration settings for MarkLogic, such as the port numbers, data directories, and security settings. You can check the contents of the marklogic.conf file within the container using the podman exec command:

podman exec -it <container_name_or_id> cat /etc/marklogic.conf

Verify that the settings in the marklogic.conf file are appropriate for your environment. Pay close attention to the port numbers, data directories, and any other settings that may affect the initialization of MarkLogic.

If you are using environment variables to configure MarkLogic, ensure that the environment variables are being correctly applied to the marklogic.conf file. The MarkLogic initialization scripts typically append environment variables to the marklogic.conf file, but you should verify that this process is working as expected.

It's also important to check for any errors or warnings in the MarkLogic logs. The logs can provide valuable clues about configuration issues or other problems that may be preventing MarkLogic from starting correctly. You can access the MarkLogic logs within the container using the podman exec command:

podman exec -it <container_name_or_id> tail -f /var/log/MarkLogic/ErrorLog.txt

This command will display the contents of the MarkLogic error log in real-time, allowing you to monitor for any errors or warnings.

7. Try a Different Image Tag or Version

Sometimes, the issue might be specific to a particular image tag or version. If you are encountering problems with a specific image, try using a different tag or version to see if it resolves the issue. For example, you can try using the latest tag or a specific version tag.

To use a different image tag, specify the tag when running the podman run command:

podman run progressofficial/marklogic-db:11.3.1-ubi9-rootless-2.1.3 ...

If you are using a custom image, you can try rebuilding the image with a different base image or with different dependencies. This can help you identify if the issue is related to the image itself.

It's also a good practice to keep your images up-to-date with the latest security patches and bug fixes. Using an outdated image can sometimes lead to compatibility issues or other problems.

8. Examine Podman Logs

Podman itself generates logs that can provide insights into container execution issues. Examining these logs can reveal underlying problems that are not immediately apparent from the container logs.

The Podman logs are typically located in the /var/log/pods/ directory on the host system. You can access the Podman logs using the journalctl command or by directly examining the log files.

To view the Podman logs using journalctl, you can use the following command:

journalctl -u podman.service

This will display the logs for the Podman service, which can include information about container creation, execution, and any errors that may have occurred.

You can also examine the log files directly by navigating to the /var/log/pods/ directory and opening the log files for your container. The log files are typically named using the container ID or name.

When examining the Podman logs, look for any error messages, warnings, or other indicators of problems. Pay close attention to the timestamps and correlate them with the events that occurred within the container.

The Podman logs can provide valuable information about issues such as network configuration errors, storage problems, or other low-level problems that may be affecting the container's execution.

Workarounds and Solutions

Based on the troubleshooting steps, here are some potential workarounds and solutions to the issue of being unable to execute a MarkLogic Docker image with Podman:

  1. Install Missing Dependencies: As indicated by the error log, the sudo command was missing. Install it within the container by either modifying the Dockerfile or installing it at runtime.
  2. Adjust Network Configuration: Ensure that the container can access the necessary network resources and that the ports are correctly exposed. Check for any firewall rules that may be blocking traffic to the container.
  3. Verify and Set Environment Variables: Ensure that all required environment variables, such as MARKLOGIC_ADMIN_USERNAME, MARKLOGIC_ADMIN_PASSWORD, and MARKLOGIC_INIT, are set correctly when running the Podman container.
  4. Allocate Sufficient Resources: Ensure that the container has sufficient resources allocated to it, such as memory and CPU. Use the --memory and --cpus options when running the podman run command.
  5. Review MarkLogic Configuration: Check the marklogic.conf file and any other configuration files to ensure that they are correctly set up for the Podman environment.
  6. Try a Different Image Tag or Version: If you are encountering problems with a specific image, try using a different tag or version to see if it resolves the issue.
  7. Use Rootless Mode: If you are not already using Podman in rootless mode, try running the container in rootless mode. This can help avoid permission issues that may occur when running containers as root.
  8. Check Storage Driver: Ensure that the storage driver used by Podman is compatible with the MarkLogic image. The overlay2 storage driver is generally recommended for performance reasons.

By implementing these workarounds and solutions, you should be able to resolve the issue and successfully execute your MarkLogic Docker image with Podman.

Conclusion

Troubleshooting issues when running MarkLogic Docker images with Podman requires a systematic approach. By examining error logs, verifying configurations, and addressing potential dependency issues, you can identify and resolve the root cause of the problem. This article has provided a comprehensive guide to troubleshooting common issues, including network configuration, missing dependencies, environment variables, and resource limits.

By following the steps outlined in this article, you can ensure a smooth transition from Docker to Podman for your MarkLogic deployments, leveraging the benefits of Podman's rootless architecture and enhanced security features. Remember to always check the Podman logs and MarkLogic logs for detailed error messages and warnings, and adjust your configurations accordingly.

By understanding the potential causes of failures and implementing the appropriate solutions, you can confidently deploy and manage MarkLogic instances in Podman containers, ensuring a stable and reliable environment for your applications.