Command functions are invoked using a Command Function Invoker that is provided by riff when building the function.
The command function invoker provides a host for functions implemented as a single executable command (be it a shell script or a binary). It accepts HTTP requests and invokes the command for each request.
Communication with the function is done via
Functions can log by writing to
For each invocation, functions are expected to read stdin until the end of the stream (EOF) and provide a result on stdout.
Correct function execution is assumed if the exit code is zero. Any other value indicates an error.
Authoring a function
This example uses the sample command-wordcount function from projectriff-samples on GitHub. It consists of a single executable file named wordcount.sh with the following content:
' ' | tr -s ' ' '\n' | tr [:upper:] [:lower:] | sort | uniq -c | sort -ntr [:punct:]
Then set the execute bit to make the function executable.
chmod +x wordcount.sh
NOTE: If creating a command function on Windows then the the execute bit cannot be set on the local file. Before committing the function file to a Git repository it must have the execute bit set using the following Git command:
git update-index --chmod=+x wordcount.sh.
Creating a function
Function can either be built from local source or from source committed to a Git repository.
build from local source
--local-pathbuilds option is disabled on Windows.
For local build use:
riff function create wordcount --artifact wordcount.sh --local-path .
build from git repository
When building from a Git repo use something like the example below and replace the
--git-repo value with the new repository URL.
For building from a Git repository use:
riff function create wordcount --artifact wordcount.sh --git-repo https://github.com/projectriff-samples/command-wordcount
Deploying a function
Please see the runtime documentation for how to deploy and invoke the function.
When done with the function, delete the function resource to stop creating new builds.
NOTE: Images built by the function continue to exist in the container registry and may continue to be consumed by a runtime.
riff function delete wordcount
Deleted function "wordcount"