Denoflow

Table of Contents

• About
• Getting Started
• Usage
• Contributing

About

Denoflow is a serverless, automated workflow based yaml workflow file, you can use any Deno module or Typescript/Javascript code to run your workflow.

It’s still a very earlier phase, use with care!

The Ideal result is having some app schemas, using rjsf to render a web gui, gui can help us to generate yaml configs.

The Ideal runtime is using cloud serverless platform, or CI platform, like Github Actions, Gitlab CI, self-hosted with Deno, or any Docker runtime.

Deno Deploy is not supported yet, because it doesn’t support Code generation from strings, Error Detail: Code generation from strings disallowed for this context See Github Actions Example: test.yml

Now we can only write yaml by ourself, and actually, it’s not that hard.

Join our Discord chat channel to discuss about Denoflow!

Stable deno land version see Denoflow

Getting Started

Fetch from Hacker News API to webhook example:

mkdir workflows

touch workflows/fetch.yml

sources:
  - use: fetch
    args:
      - https://test.owenyoung.com/slim.json
    run: return ctx.result.json()
    itemsPath: hits
    key: objectID
    limit: 1
steps: 
  - use: fetch
    args:
      - https://enyvb91j5zjv9.x.pipedream.net/
      - method: POST
        headers:
          Content-Type: application/json
        body: ${{JSON.stringify(ctx.item)}}

Open: https://requestbin.com/r/enyvb91j5zjv9/23eNPamD4DK4YK1rfEB1FAQOKIj , See live webhook request.

deno run --allow-read --allow-net --allow-write --allow-env --allow-run --unstable https://denopkg.com/denoflow/denoflow@main/cli.ts run

It will scan the workflows directory and run all valid .yml files.

RSS Feed to Discord Webhook Message

touch workflows/rss.yml

sources:
  - use: fetch
    args:
      - https://actionsflow.github.io/test-page/hn-rss.xml
    run: |
      const rss = await import("https://deno.land/x/rss/mod.ts");
      const xml = await ctx.result.text();
      const feed = await rss.parseFeed(xml);
      return feed.entries;
steps:
  - use: fetch
    args:
      - ${{ctx.env.DISCORD_WEBHOOK}}
      - method: POST
        headers:
          'Content-Type': 'application/json'
        body: ${{ JSON.stringify({content:ctx.item.title.value}) }}

deno run --allow-read --allow-net --allow-write --allow-run --allow-env --unstable https://denopkg.com/denoflow/denoflow@main/cli.ts run

Life Cycle

1. on?: when to run the workflow, Record<EventType,EventConfig>, can be schedule or http,always, default is always.
2. sources?: where to fetch the data, Source[], can be one or more sources. Every source should return an array of items.
   1. from?: import ts/js script from url or file path
   2. use?: run moduleName from above from , or if from is not provided, run globalFunction like fetch, args will be passed to the function, the return value will be attached to ctx.result and ctx.sources[index].result
   3. run?: run ts/js code, you can handle use result here. Return a result that can be stringified to json. The return value will be attached to ctx.result and ctx.sources[index].result
   4. itemsPath?: the path to the items in the result, like hits in https://test.owenyoung.com/slim.json
   5. key?: the key to identify the item, like objectID in https://test.owenyoung.com/slim.json, if not provided, will use id, denoflow will hash the id, then the same item with id will be skipped.
   6. filter?, string, script code, should handle ctx.item -> return true or false
   7. cmd: string, exec a shell command after all other task, the return value will be attached to ctx.cmdResult and ctx.sources[index].cmdResult
   8. post?: post script code, you can do some check, clean, things here, change ctx.state
3. filter? filter from all sources items, handle ctx.items, expected return a new boolean[],
   1. from?: import ts/js script from url or file path
   2. use?: run moduleName from above from , or if from is not provided, run globalFunction like fetch, args will be passed to the function, the return value will be attached to ctx.result and filter.result
   3. run?: run ts/js code, you can handle use result here.handle ctx.items, expected return a new boolean[], flag which item will be used. e.g. run: return ctx.items.map(item => item.title.value.includes('test'))
   4. cmd?: string, exec a shell command after all other task, the return value will be attached to ctx.cmdResult and filter.cmdResult
   5. post?: post script code, you can do some check, clean, things here, change ctx.state
4. steps? the steps to run, Step[], can be one or more steps.
   1. from?: import script from url or file path
   2. use?: run moduleName from above from , or if from is not provided, run globalFunction like fetch, args will be passed to the function
   3. run?: run ts/js code, you can handle use result here. Return a result that can be stringified to json. the result will be attached to the ctx.steps[index].result
   4. cmd?: exec shell commands, will be run after run, the result will be attached to the ctx.steps[index].cmdResult . post?`: post script code, you can do some check, clean, things here, change ctx.state

Prerequisites

Install Deno first.

Installing

deno install -n denoflow --allow-read --allow-net --allow-write --allow-run --allow-env  https://denopkg.com/denoflow/denoflow@main/cli.ts

Then, you can run it with denoflow run , or denoflow run <files>

Update to latest version

deno cache --reload https://denopkg.com/denoflow/denoflow@main/cli.ts

Usage

denoflow/0.0.0

Usage:
  $ denoflow run [...files]

Options:
  --force     Force run workflow files, if true, will ignore to read/save state (default: false)
  --limit     max items for workflow every runs 
  -h, --help  Display this message 

YAML Syntax

You can use ${{variable}} in any fields to inject variables into your workflow, we inject ctx variable in template and script. For example:

Expressions

steps:
  - if: ${{ctx.items.lengh>10}}
    run: console.log(ctx.item);

All ctx see [Context] in the following doc.

State

You can simply use ctx.state to get or set state, for example:

let currentState = ctx.state || {};

let sent = ctx.state.sent || [];

if(sent.includes(ctx.item.id)){
  sent.push(ctx.item.id);
}

ctx.state = {
  sent
};

// deno flow will save the state for you , next you can read it.
return;

The state will be saved to data folder in json format. You can also use sqlite to store the state. Just set database: sqlite://data.sqlite in your workflow config file.

Syntax

All workflow syntax:

See Interface

Todo

• • Support Sleep Option
• • Support GUI generated workflow
• • Support on options, schedule and http
• • Support clean command
• • denoflow playground