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Code source

In several runtime objects, it is possible to execute a program (e.g. a function, a query or a workflow) written in a source. This source can be a single code file, a plain text string or a base64 encoded string, a zip archive or a git repository. Beside the source, you need also to define a handler, which is the entrypoint of the code.

Code source definition

In the SDK, there are three different types of source code:

  • code which is a plain string source.
  • base64 which is a base64 encoded string source.
  • code_src which is a code source URI.

Plain text source

You can define a plain text source using the code parameter.

Here follow an example of a plain text source with the Python runtime:

my_code = """
from digitalhub_runtime_python import handler

@handler(outputs=["filtered"])
def myfunction(di: Dataitem, col1: str):
    df = di.as_df()
    df = df[["col1"]]
    return df
"""

func = dh.new_function(project="my-project",
                       name="python-function",
                       kind="python",
                       python_version="PYTHON3_9",
                       code=my_code,
                       handler="myfunction")

In this case the function will execute the code in the my_code variable.

Base64 encoded source

You can define a base64 encoded source using the base64 parameter.

Here follow an example of a base64 encoded source with the Python runtime:

# Same function as above encoded in base64
base64_code = "ZnJvbSBkaWdpdGFsaHViX3J1bnRpbWVfcHl0aG9uIGltcG9ydCBoYW5kbGVyCgpAaGFuZGxlcihvdXRwdXRzPVsiZmlsdGVyZWQiXSkKZGVmIG15ZnVuY3Rpb24oZGk6IERhdGFpdGVtLCBjb2wxOiBzdHIpOgogICAgZGYgPSBkaS5hc19kZigpCiAgICBkZiA9IGRmW1siY29sMSJdXQogICAgcmV0dXJuIGRm"

func = dh.new_function(project="my-project",
                       name="python-function",
                       kind="python",
                       python_version="PYTHON3_9",
                       base64=base64_code,
                       handler="myfunction")

In this case the function will execute the code in the base64_code variable.

Code source URI

You can define a code source URI using the code_src parameter. We support the following types of URIs:

Local file path

The local file path can be specified with the path/to/file.ext format.

my_code = "src/my-func.py"

func = dh.new_function(project="my-project",
                       name="python-function",
                       kind="python",
                       python_version="PYTHON3_9",
                       code_src=my_code,
                       handler="myfunction")

In this case the function will import the code in the src/my-func.py file, encodes it in base64 and then executes it. If the file is not found, the function will raise an exception.

Remote git repository

The remote git repository can be specified with the git+https://repo-host.com/some-user/some-repo format. The anteposition git+ is required, the rest of the URL is the repository URL.

my_repo = "git+https://repo-host/some-user/some-repo"

func = dh.new_function(project="my-project",
                       name="python-function",
                       kind="python",
                       python_version="PYTHON3_9",
                       code_src=my_repo,
                       handler="path:function")

When a git repository is specified, the function try to clone the repository and execute the code in the specified in the handler entrypoint (See below). If the repository does not exist, the function will raise an exception.

Credentials

You may need credentials to access the repository. The credentials can be specified in three environment variables: GIT_TOKEN, GIT_USERand GIT_PASSWORD.

Note

You must set the env variable before defining the function. Token auth is recommended and takes precedence over basic auth. Please also verify that the repo provider supports basic auth.

Token

The token is a plain string. It will be passed in the URL according to the git provider.

Example:

# GitHub token
os.environ["GIT_TOKEN"] = "github_pat_..."

# GitLab token
os.environ["GIT_TOKEN"] = "glpat..."

# function definition
User and password

User and password are plain strings.

os.environ["GIT_USER"] = "some-user"
os.environ["GIT_PASSWORD"] = "some-password"

# function definition

Remote zip s3 archive

The remote zip s3 archive can be specified with the zip+s3://some-bucket/some-key.zip format. The anteposition zip+ is required, the rest of the URL is an S3 URL in the form s3://some-bucket/some-key.zip. The code source is archived in a zip file, which is unpacked at runtime.

my_archive = "zip+s3://some-bucket/some-key.zip"

func = dh.new_function(project="my-project",
                       name="python-function",
                       kind="python",
                       python_version="PYTHON3_9",
                       code_src=my_archive,
                       handler="path:function")

Handler

The handler parameter is the entrypoint of the code. There are some rules to follow when defining it.

If the source code is:

Then the entrypoint should be the function name.

my_code = """
def myfunction():
    ...
"""

func = dh.new_function(...,
                       code=my_code,
                       handler="myfunction")

If the source code is:

Then the entrypoint should be the path to the file where the code is stored (expressed with . separator) and the name of the function separated by a :.

my_code = "git+https://repo-host/some-user/some-repo"

func = dh.new_function(...,
                       code_src=my_code,
                       handler="src.subdir.etc:myfunction")