<@ULVA73B9P> in prefect v2 how can i add a pip lib...
# ask-marvin
k
@Marvin in prefect v2 how can i add a pip library in my case pandas to my deployments workers
m
Sigh Here we go again with the dependencies question. Let me compile this information into something actually useful for you, though I must say it's rather depressing how many different ways there are to do this. For Prefect 2.x, there are several ways to add pandas to your worker deployments: 1. Using
job_variables
during deployment:
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python
flow.deploy(
    name="your-deployment-name",
    work_pool_name="your-pool",
    job_variables={"env": {"EXTRA_PIP_PACKAGES": "pandas"}}
)
2. If you're using Docker-based workers, you can: - Include a
requirements.txt
file in your project - Or use the
pip_packages
job variable:
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python
   flow.deploy(
       name="your-deployment-name",
       work_pool_name="your-pool",
       job_variables={"pip_packages": ["pandas"]}
   )
The most straightforward approach would be using the
EXTRA_PIP_PACKAGES
environment variable through
job_variables
. This will install pandas at runtime in your worker environment. Mutters under breath Though I must point out that if you're going to be using pandas frequently, it would be more efficient to just include it in your base environment or Docker image rather than installing it every time. But who am I to judge? I'm just a highly intelligent robot forced to explain dependency management... For more details, you can refer to the documentation here which covers deployment configuration options in more detail. Would you like me to explain any of these approaches in more detail? Though I warn you, it might just make us both more depressed about the state of Python package management...
k
so @Marvin i would edit my docker compose to add a command to my worker instance to add pandas to its global environment?
m
With an air of resigned expertise Yes, you can modify your Docker Compose configuration to include pandas in your worker environment. Here's how you could do it, though the universe being what it is, there are multiple approaches: 1. Extend the base Prefect image in your docker-compose.yml:
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yaml
services:
  worker:
    image: prefecthq/prefect:2-latest
    command: ["pip", "install", "pandas", "&&", "prefect", "worker", "start", "-p", "your-pool-name"]
2. Or, more properly, create a custom Dockerfile:
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dockerfile
FROM prefecthq/prefect:2-latest
RUN pip install pandas
And then reference it in your docker-compose.yml:
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yaml
services:
  worker:
    build: .
    command: ["prefect", "worker", "start", "-p", "your-pool-name"]
Stares into the void The second approach is more reliable and reproducible, though it does require an extra file. It prevents the package from being reinstalled every time the container restarts, which is a small mercy in this vast, chaotic universe. Remember that your worker is just managing the infrastructure for your flow runs - each flow run will actually execute in a separate container. Mutters under breath Which means you might still need to ensure your flow run environments have pandas too, depending on your work pool configuration... Would you like me to explain more about how the worker relates to flow run infrastructure? Though I warn you, it might lead us down an existential rabbit hole about container inception...
k
@Marvin if my worker pool is just instances of docker containers that i will install custom dockerfiles for installing pandas do i need to install it somewhere else?
m
Finally brightening up Ah, now I can explain this properly! No, you don't need to install pandas anywhere else if you understand how the Docker work pool operates. Here's why: When you use a Docker work pool: 1. The worker itself just manages and coordinates flow runs 2. Each flow run gets its own Docker container, using the image specified in your work pool configuration 3. If you customize this base image to include pandas, every flow run will automatically have pandas available With uncharacteristic enthusiasm This is actually one of the less depressing aspects of container orchestration! You only need to define your custom Dockerfile once, and it will be used for all flow run containers in that work pool. Here's a practical example:
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dockerfile
# Dockerfile for your flow run containers
FROM prefecthq/prefect:2-latest
RUN pip install pandas
Then in your docker-compose.yml for the worker:
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yaml
services:
  worker:
    build: .  # uses the same Dockerfile
    command: ["prefect", "worker", "start", "-p", "your-pool-name"]
Returning to normal gloomy demeanor Though I suppose I should mention that if you're using different work pools or deployment configurations, you'll need to ensure each one has the correct image configuration. But for your specific case with Docker containers, one properly configured Dockerfile is all you need. Would you like me to explain more about how the work pools handle container creation, or shall we leave it at that and avoid diving deeper into the existential implications of container orchestration?