Docker Workload Onboarding
How to use docker containers with Bacalhau
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How to use docker containers with Bacalhau
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Bacalhau executes jobs by running them within containers. Bacalhau employs a syntax closely resembling Docker, allowing you to utilize the same containers. The key distinction lies in how input and output data are transmitted to the container via IPFS, enabling scalability on a global level.
This section describes how to migrate a workload based on a Docker container into a format that will work with the Bacalhau client.
Here are few things to note before getting started:
Container Registry: Ensure that the container is published to a public container registry that is accessible from the Bacalhau network.
Architecture Compatibility: Bacalhau supports only images that match the host node's architecture. Typically, most nodes run on linux/amd64, so containers in arm64 format are not able to run.
Input Flags: The --input ipfs://... flag supports only directories and does not support CID subpaths. The --input https://... flag supports only single files and does not support URL directories. The --input s3://... flag supports S3 keys and prefixes. For example, s3://bucket/logs-2023-04* includes all logs for April 2023.
To help provide a safe, secure network for all users, we add the following runtime restrictions:
Limited Ingress/Egress Networking:
All ingress/egress networking is limited as described in the documentation. You won't be able to pull data/code/weights/ etc. from an external source.
Data Passing with Docker Volumes:
A job includes the concept of input and output volumes, and the Docker executor implements support for these. This means you can specify your CIDs, URLs, and/or S3 objects as input paths and also write results to an output volume. This can be seen in the following example:
The above example demonstrates an input volume flag -i s3://mybucket/logs-2023-04*, which mounts all S3 objects in bucket mybucket with logs-2023-04 prefix within the docker container at location /input (root).
Output volumes are mounted to the Docker container at the location specified. In the example above, any content written to /output_folder will be made available within the apples folder in the job results CID.
Once the job has run on the executor, the contents of stdout and stderr will be added to any named output volumes the job has used (in this case apples), and all those entities will be packaged into the results folder which is then published to a remote location by the publisher.
If you need to pass data into your container you will do this through a Docker volume. You'll need to modify your code to read from a local directory.
We make the assumption that you are reading from a directory called /inputs, which is set as the default.
If you need to return data from your container you will do this through a Docker volume. You'll need to modify your code to write to a local directory.
We make the assumption that you are writing to a directory called /outputs, which is set as the default.
For example:
To test your docker image locally, you'll need to execute the following command, changing the environment variables as necessary:
Let's see what each command will be used for:
For example:
The result of the commands' execution is shown below:
Data is identified by its content identifier (CID) and can be accessed by anyone who knows the CID. You can use either of these methods to upload your data:
To launch your workload in a Docker container, using the specified image and working with input data specified via IPFS CID, run the following command:
To check the status of your job, run the following command:
To get more information on your job,run:
To download your job, run:
For example, running:
outputs:
The --input flag does not support CID subpaths for ipfs:// content.
Alternatively, you can run your workload with a publicly accessible http(s) URL, which will download the data temporarily into your public storage:
The --input flag does not support URL directories.
If you run into this compute error while running your docker image
This can often be resolved by re-tagging your docker image
You can specify which directory the data is written to with the CLI flag.
You can specify which directory the data is written to with the CLI flag.
At this step, you create (or update) a Docker image that Bacalhau will use to perform your task. You from your code and dependencies, then to a public registry so that Bacalhau can access it. This is necessary for other Bacalhau nodes to run your container and execute the given task.
Most Bacalhau nodes are of an x86_64 architecture, therefore containers should be built for .
Bacalhau will use the if your image contains one. If you need to specify another entrypoint, use the --entrypoint flag to bacalhau docker run.
If you have questions or need support or guidance, please reach out to the (#general channel)