Josh Phillips
03/09/2024, 2:09 PMScout
03/09/2024, 2:09 PMdeploy_dagster
example project. This project provides a Docker-based deployment example that you can use as a starting point.
For hot reloading, you'll want to ensure that your development environment is set up in such a way that changes to your code are automatically picked up without needing to rebuild your Docker images or restart your services manually. This typically involves mounting your code as a volume in your Docker container so that changes on your host machine are reflected inside the container.
Here are some steps you can follow to modify the deploy_dagster
example to work with hot reloading:
1. Mount Code as a Volume: Modify the docker-compose.yml
file to mount your Dagster project code as a volume inside the container. This allows the running services to see changes made to the code on the host filesystem.
2. Use Development Servers: Ensure that you are using development servers that support hot reloading. For example, Dagit, the web interface for Dagster, automatically reloads when it detects changes to your code.
3. Configure dagster.yaml
: The dagster.yaml
file is used to configure your Dagster instance. For development purposes, you may want to set up different run storage, event log storage, or compute log storage that makes it easier to iterate on your code.
4. Use the watch
Command: Dagster provides a dagster-daemon
service that can be run in watch mode during development. This service will automatically pick up changes to your repository and workspace definitions.
5. Set Up Development Tools: If you're using Dagster Cloud, you might want to use the dagster dev
command, which is designed to streamline local development. It can be used to start up all the necessary components for local development, including Dagit and the Dagster daemon.
6. Test Your Setup: Before using this setup in a production environment, thoroughly test it to ensure that hot reloading works as expected and that there are no issues with the development workflow.
Remember that the exact steps may vary depending on the specifics of your project and the cloud environment you are using. The documentation provides guidance on configuring your Dagster instance and setting up your development environment, but it may not cover all scenarios for hot reloading or development-specific configurations.
For more detailed instructions and best practices, you should refer to the Dagster documentation, particularly the sections on [Dagster instance configuration](https://docs.dagster.io/deployment/dagster-instance) and [development workflows](https://docs.dagster.io/development/workflows). IScout
03/09/2024, 2:09 PMJosh Phillips
03/09/2024, 5:05 PMScout
03/09/2024, 5:05 PM.py
added.
2. Start the gRPC Server: Use the dagster api grpc
command to start a gRPC server that loads your repository or job from the specified module. You can use the --module-name
or -m
flag to specify the module where your definitions reside.
Here's an example command to start a gRPC server with a module named `my_module`:
shell
dagster api grpc -m my_module
This command assumes that my_module
is a Python module accessible in your Python environment and contains your repository or job definitions as top-level symbols.
3. Configure Your Workspace: In your workspace.yaml
file, you will need to configure the gRPC server as a code location. Here's an example of what that might look like:
yaml
load_from:
- grpc_server:
host: localhost
port: 4000
location_name: "my_repository_location"
This configuration tells Dagit where to find the gRPC server hosting your repository or job definitions.
4. Ensure Network Accessibility: Make sure that the gRPC server is accessible from wherever Dagit is running. If they are running on different machines, you will need to ensure that the network is configured to allow traffic between them on the specified port.
5. Use Environment Variables (Optional): If you prefer, you can also use environment variables to provide defaults for the gRPC server options. For example, you can set DAGSTER_GRPC_PORT
to specify the default port for the gRPC server.
By following these steps, you can set up a gRPC server that serves your Dagster repository or job definitions from a Python module. This setup is useful for development and production environments where you want to separate the execution of pipelines from the Dagit interface.
For more detailed instructions and best practices, refer to the Dagster documentation, particularly the sections on [gRPC servers](https://docs.dagster.io/deployment/grpc) and [workspace configuration](https://docs.dagster.io/deployment/workspaces). If you encounter any issues or have specific requirements, you may also find it helpful to look at discussions and issues in the Dagster GitHub repository forScout
03/09/2024, 5:05 PMJosh Phillips
03/09/2024, 9:16 PM## start_user_code.sh
#!/bin/bash
cd /code
# check if venv already exists
if [ -d "/environments/pipelines" ]; then
echo "pipelines venv already exists"
else
echo "pipelines venv does not exist, creating"
python3 -m venv /environments/pipelines
fi
source /environments/pipelines/bin/activate
pip install -e /code/pipelines
dagster code-server start -h 0.0.0.0 -p 4000 -m pipelines.definitions
It is able to load fine, but when I get to a job and launch it in the ui (indicating it is definitely loaded somewhere) I get this error :
Could not load job definition.
dagster._core.errors.DagsterImportError: Encountered ImportError: No module named 'pipelines'
while importing module pipelines.definitions. Local modules were resolved using the working directory /code
. If another working directory should be used, please explicitly specify the appropriate path using the -d
or --working-directory
for CLI based targets or the working_directory
configuration option for workspace targets.Scout
03/09/2024, 9:16 PMpipelines
module when attempting to load the job definition. This could be due to a few reasons, such as the module not being installed correctly, the Python environment not being activated, or the working directory not being set correctly.
Here are some steps to troubleshoot and resolve the issue:
1. Check Module Installation: Ensure that the pipelines
module is installed correctly in the virtual environment. Since you're using the -e
flag with pip install
, it should install the module in editable mode, which means changes to the code will immediately affect the installed package without needing a reinstall. Verify that the installation process completes without errors.
2. Activate Virtual Environment: It looks like you're correctly activating the virtual environment with source /environments/pipelines/bin/activate
. Make sure that this step is successful and that the subsequent pip install
command is running within the activated environment.
3. Working Directory: The error message suggests that the working directory might be incorrect. You're already using cd /code
to set the working directory to /code
. Ensure that the pipelines
module is indeed located in the /code/pipelines
directory and that it is structured as a Python package (i.e., it contains an __init__.py
file).
4. Use the Working Directory Flag: If the pipelines
module is in a different directory or if there's any ambiguity about the working directory, you can explicitly set it using the -d
or --working-directory
flag when starting the code server. For example:
shell
dagster code-server start -h 0.0.0.0 -p 4000 -m pipelines.definitions -d /path/to/module
Replace /path/to/module
with the actual path to the directory containing your pipelines
module.
5. Check Python Path: Ensure that the PYTHONPATH
environment variable includes the directory where your pipelines
module is located. If it's not included, you can set it in your start_user_code.sh
script before starting the code server:
shell
export PYTHONPATH="/code:$PYTHONPATH"
6. Check Container Logs: Look at the logs of your Docker container to see if there are any other error messages that might give you clues about what's going wrong.
7. Workspace Configuration: Double-check your workspace.yaml
file to ensure that it's correctly pointing to the gRPC server and that the location_name
matches the name you expect.
If you've gone through these steps and the issue persists, you may want to verify the entire setup step by step, ensuring that each part of the system is configured correctly. If necessary, consult the Dagster documentatScout
03/09/2024, 9:17 PMJosh Phillips
03/09/2024, 9:22 PMScout
03/09/2024, 9:22 PMNo module named 'pipelines'
while importing module pipelines.definitions.` indicates an issue with loading the user code, specifically the pipelines
module. In the provided docker-compose.yml
file, the service responsible for loading and running user code is docker_example_user_code
. This service builds an image from Dockerfile_user_code
and is likely where the dagster code-server
command is executed to start the gRPC server that serves the user code to the Dagster instance. The docker_example_webserver
service runs the Dagit web interface (dagster-webserver
), which allows you to view and interact with your Dagster instance, including launching jobs. However, the actual loading of the user code definitions happens in the docker_example_user_code
service. The docker_example_daemon
service runs the dagster-daemon
process, which is responsible for scheduling and executing runs, but it also relies on the user code being accessible and correctly loaded by the gRPC server. To resolve the issue, you should check the docker_example_user_code
service's build context and Dockerfile_user_code
to ensure that the pipelines
module is correctly installed and accessible. Make sure that the pipelines
module is structured as a Python package and that the working directory is set correctly when starting the gRPC server. If necessary, you may need to adjust the volume mounts or the PYTHONPATH
environment variable to ensure that the pipelines
module can be found by Python.