openfaas-json-wrapper

Simple skeleton openfaas wrapper in python for json input/output

1. Modify entrypoint.py as needed or uncomment one of the samples included in the script itself.
2. Test the modified script with your custom input or with mock json from https://jsonplaceholder.typicode.com/
3. Build the docker image
4. Deploy it in OpenFaas

1) Modify entrypoint

Uncomment the """ blocks to enable one sample function at time

2) Testing

Usage example - extract only some fields:

$ cat mock.users.json | ./entrypoint.py
[
    {
        "username": "Bret",
        "name": "Leanne Graham"
    },
    {
        "username": "Antonette",
        "name": "Ervin Howell"
    },
[cut]

Usage example - DNS query and response:

$ cat mock.dnsquery.json
{
    "query": "facciocose.eu",
    "recordtype": "A"
}

$ cat mock.dnsquery.json | ./entrypoint.py 
{
    "status": "OK",
    "response_set": [
        {
            "response": "62.149.128.166"
        },
        {
            "response": "62.149.128.160"
        }
    ]
}

Usage example - Word and characters count

$ cat mock.text.json | ./entrypoint.py 
{
    "chars": "446",
    "rows": "1",
    "words": "69"
}

3) Build the image

Add any needed dependancy in the Dockerfile, for instance to add a python library in the image uncomment:

COPY requirements.txt .
RUN pip install -r requirements.txt

Of course, you need to modify requirements.txt as well

Build and tag it accordingly:

docker build . -t sample-json-wordcount
Sending build context to Docker daemon  118.8kB
Step 1/10 : FROM python:3.4-alpine
3.4-alpine: Pulling from library/python
[cut]

You can run it on a non-standard port:

$ docker run -p 6969:8080 sample-json-wordcount
2018/05/25 20:09:09 Writing lock-file to: /tmp/.lock

then double-check it with cURL:

$ curl -H "Content-Type: application/json" localhost:6969 -d "`cat mock.dnsquery.json`" 
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   600  100   545  100    55   2411    243 --:--:-- --:--:-- --:--:--  2411
{
    "response_set": [
        {
            "response": "62.149.128.163"
        },
        {
            "response": "62.149.128.157"
        },
[cut]

4) Deploy

Now you're ready to deploy the container as function, use openfaas-cli or the web UI