The “server gave HTTP response to HTTPS client” error in Docker usually indicates that there is a mismatch between the expected protocol (HTTPS) and the server’s response (HTTP). This article offers the troubleshooting tips for this issue. As part of our Docker Hosting Support Service, we assist our customers with several Docker queries.

Overview

1. Understanding Docker Error “server gave HTTP response to HTTPS client”
2. Causes & Fixes of the Docker Error
   • Cause 1 & Fix
   • Cause 2 & Fix
   • Cause 3 & Fix
   • Cause 4 & Fix
   • Cause 5 & Fix
3. Key Considerations
4. Benefits of Fixing the Error
5. Conclusion

Understanding Docker Error “server gave HTTP response to HTTPS client”

Docker is a platform that automates the deployment, scaling, and management of programs within lightweight containers. Containers combine the program with its dependencies, libraries, and factors to provide consistent behavior across several environments.

By default, Docker communicates with Docker registries (like Docker Hub or private registries) over HTTPS for secure transmission. When we pull or push images, Docker expects the registry to support HTTPS. However, if we use a private Docker registry that only supports HTTP, we need to configure Docker to treat the registry as an insecure registry by adding it to the insecure-registries list in the Docker daemon configuration file (daemon.json). This allows Docker to communicate over HTTP.

The “server gave HTTP response to HTTPS client” error in Docker often signifies that the protocol that the server is responding with (HTTP) and the one that is anticipated (HTTPS) are not matching. This issue usually appears when Docker tries to use HTTPS to connect to a registry, but HTTP is the only protocol that the registry supports. This mismatch in protocols causes the connection to fail.

In this post, we’ll see some of the common reasons of the error, along with its fixes.

Causes & Fixes of the Docker Error

1. Insecure Registry Configuration

We must set up the Docker daemon to treat a private Docker registry that is only reachable over HTTP as an insecure registry. Let’s see the steps:

1. Initially, add this to /etc/docker/daemon.json on Linux or C:\ProgramData\docker\config\daemon.json on Windows:

json

{
"insecure-registries" : ["XXX.XXX.X.XX:PPPP"]
}

2. Now, restart Docker:

Linux: sudo systemctl restart docker

Windows: Restart Docker Desktop.

2. Buildkit Configuration

If insecure-registries didn’t fix it, we must disable Buildkit by adding:

json

{
"features": {
"buildkit": false
}
}

Or, disable it with:

bash

export DOCKER_BUILDKIT=0

3. Incorrect Registry URL

We must ensure the registry URL is correct. We can use http:// instead of https:// for HTTP-only registries

4. Pulling Base Image First

We can also try pulling the base image first to resolve the issue:

bash

docker pull base-image

5. Restarting Docker Service

We can restart Docker to resolve the issue:

Linux: sudo systemctl restart docker

If needed, use:

bash

sudo systemctl stop docker
sudo systemctl start docker

If none of these work, we must make sure the registry is running and accessible via HTTP.

Key Considerations

When addressing the “server gave HTTP response to HTTPS client” error in Docker, consider the following key points:

1. Registry Protocol: Ensure we are using the correct protocol (http:// for HTTP-only registries) in the Docker commands and configurations.

2. Insecure Registry Configuration: If the registry is HTTP-only, configure Docker to treat it as an insecure registry by adding it to the insecure-registries list in the Docker daemon configuration file.

3. Buildkit Compatibility: If Buildkit is enabled, it may cause issues with insecure registries. Consider disabling Buildkit or adjusting the configuration to include the http:// protocol.

4. Docker Service Management: Restart Docker after making configuration changes to apply them effectively.

5. Network and Registry Accessibility: Verify that the private registry is running and accessible over the specified IP and port.

6. Correct Registry URL: Double-check that the registry URL is correct and consistent with the protocol supported by the registry.

Benefits of Fixing the Error

Fixing the “server gave HTTP response to HTTPS client” issue in Docker offers several benefits:

1. Smooth Docker Operations: Ensures seamless image pulls, pushes, and interactions with private or public Docker registries.

2. Improved Efficiency: Eliminates interruptions caused by the error, enabling faster development and deployment cycles.

3. Enhanced Compatibility: Ensures that Docker can communicate correctly with various registries, whether they use HTTP or HTTPS.

4. Security Compliance: Allows proper configuration of secure (HTTPS) communication where necessary, or safe handling of HTTP-only registries.

5. Minimized Downtime: Prevents delays in containerized application development and deployment due to registry access issues.

6. Better Resource Management: Reduces the need for repeated attempts to pull or push images, saving bandwidth and time.

7. Flexibility in Registry Usage: Enables the use of both secure and insecure registries, depending on project requirements.

[Need to know more? Get in touch with us if you have any further inquiries.]

Conclusion

For reliable and continuous operations, the Docker error “server gave HTTP response to HTTPS client” must be fixed. By fixing this issue, we may increase workflow speed, make sure Docker can interact with registries without any issues, and keep the flexibility to work with both safe and vulnerable registries as needed. This provides improved resource management and security procedures in the containerized settings in addition to increasing productivity.

To sum up, our Support team went over the Docker error “server gave HTTP response to HTTPS client” details.