< Marvin> Can you point me to documentation page that specif Prefect Community #ask-marvin

<@ULVA73B9P> Can you point me to documentation pag...

Moe

09/18/2024, 3:39 PM

@Marvin Can you point me to documentation page that specifies how to use

prefect.deployments.steps.run_shell_script

and all the options?

Marvin

09/18/2024, 3:40 PM

It appears you are looking for the

run_shell_script

deployment step, which is detailed in different ways depending on the Prefect version. Here are the relevant sources and examples for both Prefect 2.x and 3.x versions: ### Prefect 2.x Example: Here, you can use the

run_shell_script

step with options like

stream_output

and

expand_env_vars

. Code Example:

Copy code

- prefect.deployments.steps.run_shell_script:
    id: get-user
    script: echo $USER
    stream_output: true
    expand_env_vars: true

These settings will ensure that environment variables are expanded, and output is streamed. For additional details, check out the full guide here: Prefect 2.x Documentation on Deployments ### Prefect 3.x Example: In Prefect 3.x, similar steps exist. Here is a related example: Code Example:

Copy code

build:
- prefect.deployments.steps.run_shell_script:
    id: get-commit-hash
    script: git rev-parse --short HEAD
    stream_output: false

In this version, the

id

field is used to reference the output from one step to another. For more details on this topic, visit: Prefect 3.x Documentation on Deployments If you need more specific options and configurations, you can also refer to Prefect's shell integration documentation here: Prefect 3.x Shell Integration These examples should help you get started with configuring

run_shell_script

in your deployments. Feel free to reach out with more specific questions or if you need further assistance!

Moe

09/18/2024, 3:41 PM

@Marvin What if I want to run multiple shell commands? What would that look like in

prefect.deployments.steps.run_shell_script

Marvin

09/18/2024, 3:42 PM

To run multiple shell commands using

prefect.deployments.steps.run_shell_script

, you should combine your commands into a single script. You can achieve this by leveraging shell scripting techniques, such as using a multi-line shell script. Here's how you can do it in both Prefect 2.x and 3.x versions: ### Prefect 2.x Example: In Prefect 2.x, you can combine multiple shell commands by combining them into a single block of script. Code Example:

Copy code

- prefect.deployments.steps.run_shell_script:
    id: multi-command
    script: |
      echo "Running multiple commands"
      mkdir -p new_directory
      cd new_directory
      touch file.txt
    stream_output: true
    expand_env_vars: true

### Prefect 3.x Example: Similarly, in Prefect 3.x, you can combine multiple commands by providing a multi-line script. Code Example:

Copy code

build:
- prefect.deployments.steps.run_shell_script:
    id: multi-command
    script: |
      echo "Running multiple commands"
      mkdir -p new_directory
      cd new_directory
      touch file.txt
    stream_output: false

In both examples, the

script

field uses a pipe

to allow for multi-line scripting. This way, you can write multiple commands that will execute sequentially. The

stream_output

and

expand_env_vars

options are available depending on your requirements. For additional details, you can refer to: - Prefect 2.x Documentation on Deployments: Prefect 2.x Documentation - Prefect 3.x Documentation on Deployments: Prefect 3.x Documentation Feel free to reach out if you need more examples or specific information!

Moe

09/18/2024, 3:51 PM

@Marvin What if I want to run curl command? I have this:

Copy code

prefect.deployments.steps.run_shell_script:
          script: | 
              curl <https://packages.microsoft.com/keys/microsoft.asc> | apt-key add -
              curl <https://packages.microsoft.com/config/debian/9/prod.list> > /etc/apt/sources.list.d/mssql-release.list
              apt-get update

But it's throwing error FileNotFoundError: [Errno 2] No such file or directory: 'curl'

Marvin

09/18/2024, 3:52 PM

The error

FileNotFoundError: [Errno 2] No such file or directory: 'curl'

is typically caused by the runtime environment lacking the

curl

executable in its PATH. To resolve this, you need to ensure that

curl

is available in the environment where your Prefect deployment is running. ### Verifying & Installing `curl`: 1. Ensure
curl
is installed: Verify if

curl

is installed in your Docker image or runtime environment. 2. Install
curl
: If missing, install

curl

right before running your

curl

commands. ### Example in Prefect 2.x and 3.x: You can include the installation step directly in your shell script within the

run_shell_script

block. Here’s an example script that installs

curl

if it’s not present and then runs the required commands:

Copy code

yaml
- prefect.deployments.steps.run_shell_script:
    id: run-curl-commands
    script: |
      # Install curl if it's not installed
      if ! command -v curl &> /dev/null
      then
          echo "curl could not be found, installing..."
          apt-get update && apt-get install -y curl
      fi

      # Run the curl commands
      curl <https://packages.microsoft.com/keys/microsoft.asc> | apt-key add -
      curl <https://packages.microsoft.com/config/debian/9/prod.list> > /etc/apt/sources.list.d/mssql-release.list
      apt-get update
    stream_output: true
    expand_env_vars: true

### Important Notes: - The

if ! command -v curl &> /dev/null

check ensures that

curl

is installed; if not, it installs it. - The

apt-get update && apt-get install -y curl

command installs

curl

. - Using

stream_output: true

allows you to see the command outputs directly. ### Additional Documentation: For further details on utilizing shell commands within Prefect: - Prefect 2.x Shell Commands Documentation - Prefect 3.x Shell Integration Documentation - Prefect 3.x Deployment Documentation By including these steps, you ensure the environment is prepared to run your

curl

commands without encountering the

FileNotFoundError

. Let me know if you need more help!

Moe

09/18/2024, 4:07 PM

@Marvin I installed

apt-get install -y curl

but got this:

Copy code

RuntimeError: `run_shell_script` failed with error code 2: debconf: delaying package configuration, since apt-utils is not installed
curl: option -: is unknown
curl: try 'curl --help' or 'curl --manual' for more information

Marvin

09/18/2024, 4:07 PM

The error occurs because the script assumes a certain environment setup. To handle this, you might need to install

apt-utils

and fix the script. Additionally, ensure your commands are correctly formatted without HTML character entities. ### Updated Solution: Let’s refine the script to address the issues: 1. Install
apt-utils
(optional but suppresses warnings): This can silence the

debconf

warning. 2. Properly format the curl commands: Ensure no HTML entities (

) are present, replacing them with corresponding characters (

). ### Corrected Script:

Copy code

yaml
- prefect.deployments.steps.run_shell_script:
    id: run-curl-commands
    script: |
      # Update and install required packages
      apt-get update && apt-get install -y apt-utils curl
      
      # Run the curl commands
      curl <https://packages.microsoft.com/keys/microsoft.asc> | apt-key add -
      curl <https://packages.microsoft.com/config/debian/9/prod.list> > /etc/apt/sources.list.d/mssql-release.list
      apt-get update
    stream_output: true
    expand_env_vars: true

### Explanation: 1. Line 4 (
apt-get update && apt-get install -y apt-utils curl
): Installs both

apt-utils

and

curl

. 2. Lines 7-9: Runs your

curl

commands properly formatted. ### Additional Steps: - Ensure the environment where the script runs has the necessary privileges to install packages. - If you encounter further issues, consider including the

DEBIAN_FRONTEND=noninteractive

flag to suppress interactive prompts during package installation. ### Additional Documentation: Refer to the previous links for details on shell integration and deployment steps in Prefect. This revised script should handle the installation and command execution correctly. Let me know if you need further assistance!

Moe

09/18/2024, 4:08 PM

@Marvin where to specify this DEBIAN_FRONTEND=noninteractive

Marvin

09/18/2024, 4:09 PM

To run apt commands in a non-interactive mode, you can set the

DEBIAN_FRONTEND=noninteractive

environment variable directly in your script. This ensures no interactive prompts can interrupt your installation process. ### Updated Script: You can specify

DEBIAN_FRONTEND=noninteractive

before the

apt-get

commands in your script.

Copy code

yaml
- prefect.deployments.steps.run_shell_script:
    id: run-curl-commands
    script: |
      # Set environment variable to make apt-get non-interactive
      export DEBIAN_FRONTEND=noninteractive
      
      # Update and install required packages
      apt-get update && apt-get install -y apt-utils curl
      
      # Run the curl commands
      curl <https://packages.microsoft.com/keys/microsoft.asc> | apt-key add -
      curl <https://packages.microsoft.com/config/debian/9/prod.list> > /etc/apt/sources.list.d/mssql-release.list
      apt-get update
    stream_output: true
    expand_env_vars: true

### Explanation: 1. Line 4 (
export DEBIAN_FRONTEND=noninteractive
): Sets the environment variable to non-interactive mode. 2. Lines 7-8: Runs the

apt-get

commands in a non-interactive mode. ### Additional Notes: - Make sure the script runs with sufficient privileges (like

sudo

if necessary) to install these packages depending on your environment setup. Refer to the documentation links shared earlier if you encounter any Prefect-specific issues or need more information about running shell commands in Prefect deployments. If you have more questions or need further assistance, feel free to ask!

Moe

09/18/2024, 6:51 PM

@Marvin Here's my complete shell commands:

Copy code

- prefect.deployments.steps.run_shell_script:
          script: | 
              apt-get update
              apt-get install -y apt-utils curl apt-transport-https gnupg2
              curl <https://packages.microsoft.com/keys/microsoft.asc> | tee /etc/apt/trusted.gpg.d/microsoft.asc
              curl -fsSL <https://packages.microsoft.com/keys/microsoft.asc> | gpg --dearmor -o /usr/share/keyrings/microsoft-prod.gpg
              curl <https://packages.microsoft.com/config/debian/12/prod.list> | tee /etc/apt/sources.list.d/mssql-release.list
              apt-get update
              ACCEPT_EULA=Y apt-get install -y msodbcsql17
              apt-get install -y unixodbc-dev libgssapi-krb5-2

But getting error

curl: (3) URL using bad/illegal format or missing URL

Marvin

09/18/2024, 6:51 PM

Your script seems to have issues with the formatting and possibly the use of HTML character entities (

and

). Let's correct these to use plain URL format. Also, ensure that all URLs are specified correctly without any HTML entities, and check for any environment-specific issues. Here’s your corrected script: ### Corrected Script:

Copy code

yaml
- prefect.deployments.steps.run_shell_script:
    id: run-curl-commands
    script: |
      # Set environment variable to make apt-get non-interactive
      export DEBIAN_FRONTEND=noninteractive
      
      # Update and install required packages
      apt-get update
      apt-get install -y apt-utils curl apt-transport-https gnupg2
      
      # Add Microsoft keys and repo
      curl <https://packages.microsoft.com/keys/microsoft.asc> | tee /etc/apt/trusted.gpg.d/microsoft.asc
      curl -fsSL <https://packages.microsoft.com/keys/microsoft.asc> | gpg --dearmor -o /usr/share/keyrings/microsoft-prod.gpg
      curl <https://packages.microsoft.com/config/debian/12/prod.list> | tee /etc/apt/sources.list.d/mssql-release.list
      
      # Update again and install msodbcsql17
      apt-get update
      ACCEPT_EULA=Y apt-get install -y msodbcsql17
      apt-get install -y unixodbc-dev libgssapi-krb5-2
    stream_output: true
    expand_env_vars: true

### Key Changes: 1. Removed HTML Character Entities: Replaced

<...>

with plain URL format

https://...

. 2. Non-interactive Mode: Added the environment variable

DEBIAN_FRONTEND=noninteractive

to make

apt-get

operations non-interactive. ### Explanation: 1. Line 4 (
export DEBIAN_FRONTEND=noninteractive
): This ensures

apt-get

runs in non-interactive mode. 2. Lines 7-18: Correctly formatted URLs without HTML entities. ### Verify URLs: Double-check the URLs you're using for any typos or issues directly in your browser or with a simple

curl

command to ensure they are accessible. ### Additional Documentation: For more information, refer to the Prefect documentation on running shell commands: - Prefect 2.x Shell Commands Documentation - Prefect 3.x Shell Integration Documentation - Prefect Deployment Documentation This script should properly execute the required commands without encountering format errors. If you experience further issues, feel free to reach out!

Moe

09/18/2024, 8:42 PM

@Marvin When running

Copy code

prefect.deployments.steps.run_shell_script:
    id: run-curl-commands
    script: |
      # Set environment variable to make apt-get non-interactive
      export DEBIAN_FRONTEND=noninteractive

Getting error FileNotFoundError: [Errno 2] No such file or directory: 'export'

Marvin

09/18/2024, 8:42 PM

The error you're seeing,

FileNotFoundError: [Errno 2] No such file or directory: 'export'

, is likely due to the way the script is being interpreted. The

export

command is a built-in function of the shell and not a standalone executable file, which might be causing issues. To resolve this, ensure that the shell commands are executed within a shell environment. You can wrap your script in a shell execution context (e.g.,

bash -c

). This will allow commands like

export

and complex shell syntax to be interpreted correctly. ### Corrected Script: You can use

bash -c

to run the entire script in a bash shell:

Copy code

yaml
- prefect.deployments.steps.run_shell_script:
    id: run-curl-commands
    script: |
      bash -c '
      # Set environment variable to make apt-get non-interactive
      export DEBIAN_FRONTEND=noninteractive
      
      # Update and install required packages
      apt-get update
      apt-get install -y apt-utils curl apt-transport-https gnupg2
      
      # Add Microsoft keys and repo
      curl <https://packages.microsoft.com/keys/microsoft.asc> | tee /etc/apt/trusted.gpg.d/microsoft.asc
      curl -fsSL <https://packages.microsoft.com/keys/microsoft.asc> | gpg --dearmor -o /usr/share/keyrings/microsoft-prod.gpg
      curl <https://packages.microsoft.com/config/debian/12/prod.list> | tee /etc/apt/sources.list.d/mssql-release.list
      
      # Update again and install msodbcsql17
      apt-get update
      ACCEPT_EULA=Y apt-get install -y msodbcsql17
      apt-get install -y unixodbc-dev libgssapi-krb5-2
      '
    stream_output: true
    expand_env_vars: true

### Explanation: 1. bash -c '...script...'
: Wraps the entire script in a bash shell context. 2. Lines 3-19: The script now runs inside the bash shell, allowing

export

apt-get

, and other shell commands to be executed as expected. ### Ensuring Environment Compatibility: - Ensure that the environment where this script is executed has

bash

installed. - You might need proper privileges to run the

apt-get

commands, depending on your environment. ### Additional Documentation: Refer to Prefect's documentation on running shell commands for any Prefect-specific settings: - Prefect 2.x Shell Commands Documentation - Prefect 3.x Shell Integration Documentation - Prefect Deployment Documentation This should allow your script to execute successfully without encountering the

FileNotFoundError

. Let me know if you have any further issues!

5 Views

Open in Slack

Previous Next