conductor.js - openwhisk-composer - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
  * (the "License"); you may not use this file except in compliance with
  * the License.  You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 /* eslint no-eval: 0 */

 'use strict'

 const fs = require('fs')
 const { minify } = require('terser')
 const openwhisk = require('openwhisk')
 const os = require('os')
 const path = require('path')

 // read conductor version number
 const version = require('./package.json').version

 // synthesize conductor action code from composition
 function synthesize ({ name, composition, ast, version: composer, annotations = [] }) {
   const code = `// generated by composer v${composer} and conductor v${version}\n\nconst composition = ${JSON.stringify(composition, null, 4)}\n\n// do not edit below this point\n\n` +
     minify(`const main=(${main})(composition)`, { output: { max_line_len: 127 } }).code
   annotations = annotations.concat([{ key: 'conductor', value: ast }, { key: 'composerVersion', value: composer }, { key: 'conductorVersion', value: version }])
   return { name, action: { exec: { kind: 'nodejs:default', code }, annotations } }
 }

 // return enhanced openwhisk client capable of deploying compositions
 module.exports = function (options) {
   // try to extract apihost and key first from whisk property file file and then from process.env
   let apihost
   let apikey

   try {
     const wskpropsPath = process.env.WSK_CONFIG_FILE || path.join(os.homedir(), '.wskprops')
     const lines = fs.readFileSync(wskpropsPath, { encoding: 'utf8' }).split('\n')

     for (let line of lines) {
       let parts = line.trim().split('=')
       if (parts.length === 2) {
         if (parts[0] === 'APIHOST') {
           apihost = parts[1]
         } else if (parts[0] === 'AUTH') {
           apikey = parts[1]
         }
       }
     }
   } catch (error) { }

   if (process.env.__OW_API_HOST) apihost = process.env.__OW_API_HOST
   if (process.env.__OW_API_KEY) apikey = process.env.__OW_API_KEY

   const wsk = openwhisk(Object.assign({ apihost, api_key: apikey }, options))
   wsk.compositions = new Compositions(wsk)
   return wsk
 }

 // management class for compositions
 class Compositions {
   constructor (wsk) {
     this.actions = wsk.actions
   }

   deploy (composition, overwrite) {
     const actions = (composition.actions || []).concat(synthesize(composition))
     return actions.reduce((promise, action) => promise.then(() => overwrite && this.actions.delete(action).catch(() => { }))
       .then(() => this.actions.create(action)), Promise.resolve())
       .then(() => actions)
   }
 }

 // runtime code
 function main (composition) {
   const openwhisk = require('openwhisk')
   let wsk

   const isObject = obj => typeof obj === 'object' && obj !== null && !Array.isArray(obj)

   // compile ast to fsm
   const compiler = {
     sequence (parent, node) {
       return [{ parent, type: 'pass' }, ...compile(parent, ...node.components)]
     },

     action (parent, node) {
       return [{ parent, type: 'action', name: node.name }]
     },

     async (parent, node) {
       const body = [...compile(parent, ...node.components)]
       return [{ parent, type: 'async', return: body.length + 2 }, ...body, { parent, type: 'stop' }, { parent, type: 'pass' }]
     },

     function (parent, node) {
       return [{ parent, type: 'function', exec: node.function.exec }]
     },

     finally (parent, node) {
       const finalizer = compile(parent, node.finalizer)
       const fsm = [{ parent, type: 'try' }, ...compile(parent, node.body), { parent, type: 'exit' }, ...finalizer]
       fsm[0].catch = fsm.length - finalizer.length
       return fsm
     },

     let (parent, node) {
       return [{ parent, type: 'let', let: node.declarations }, ...compile(parent, ...node.components), { parent, type: 'exit' }]
     },

     mask (parent, node) {
       return [{ parent, type: 'let', let: null }, ...compile(parent, ...node.components), { parent, type: 'exit' }]
     },

     try (parent, node) {
       const handler = [...compile(parent, node.handler), { parent, type: 'pass' }]
       const fsm = [{ parent, type: 'try' }, ...compile(parent, node.body), { parent, type: 'exit' }, ...handler]
       fsm[0].catch = fsm.length - handler.length
       fsm[fsm.length - handler.length - 1].next = handler.length
       return fsm
     },

     if_nosave (parent, node) {
       const consequent = compile(parent, node.consequent)
       const alternate = [...compile(parent, node.alternate), { parent, type: 'pass' }]
       const fsm = [{ parent, type: 'pass' }, ...compile(parent, node.test), { parent, type: 'choice', then: 1, else: consequent.length + 1 }, ...consequent, ...alternate]
       fsm[fsm.length - alternate.length - 1].next = alternate.length
       return fsm
     },

     while_nosave (parent, node) {
       const body = compile(parent, node.body)
       const fsm = [{ parent, type: 'pass' }, ...compile(parent, node.test), { parent, type: 'choice', then: 1, else: body.length + 1 }, ...body, { parent, type: 'pass' }]
       fsm[fsm.length - 2].next = 2 - fsm.length
       return fsm
     },

     dowhile_nosave (parent, node) {
       const fsm = [{ parent, type: 'pass' }, ...compile(parent, node.body), ...compile(parent, node.test), { parent, type: 'choice', else: 1 }, { parent, type: 'pass' }]
       fsm[fsm.length - 2].then = 2 - fsm.length
       return fsm
     }
   }

   function compile (parent, node) {
     if (arguments.length === 1) return [{ parent, type: 'empty' }]
     if (arguments.length === 2) return Object.assign(compiler[node.type](node.path || parent, node), { path: node.path })
     return Array.prototype.slice.call(arguments, 1).reduce((fsm, node) => { fsm.push(...compile(parent, node)); return fsm }, [])
   }

   const fsm = compile('', composition)

   const conductor = {
     choice ({ p, node, index }) {
       p.s.state = index + (p.params.value ? node.then : node.else)
     },

     try ({ p, node, index }) {
       p.s.stack.unshift({ catch: index + node.catch })
     },

     let ({ p, node, index }) {
       p.s.stack.unshift({ let: JSON.parse(JSON.stringify(node.let)) })
     },

     exit ({ p, node, index }) {
       if (p.s.stack.length === 0) return internalError(`pop from an empty stack`)
       p.s.stack.shift()
     },

     action ({ p, node, index }) {
       return { method: 'action', action: node.name, params: p.params, state: { $resume: p.s } }
     },

     function ({ p, node, index }) {
       return Promise.resolve().then(() => run(node.exec.code, p))
         .catch(error => {
           console.error(error)
           return { error: `Function combinator threw an exception at AST node root${node.parent} (see log for details)` }
         })
         .then(result => {
           if (typeof result === 'function') result = { error: `Function combinator evaluated to a function type at AST node root${node.parent}` }
           // if a function has only side effects and no return value, return params
           p.params = JSON.parse(JSON.stringify(result === undefined ? p.params : result))
           inspect(p)
           return step(p)
         })
     },

     empty ({ p, node, index }) {
       inspect(p)
     },

     pass ({ p, node, index }) {
     },

     async ({ p, node, index, inspect, step }) {
       p.params.$resume = { state: p.s.state, stack: [{ marker: true }].concat(p.s.stack) }
       p.s.state = index + node.return
       if (!wsk) wsk = openwhisk({ ignore_certs: true })
       return wsk.actions.invoke({ name: process.env.__OW_ACTION_NAME, params: p.params })
         .then(response => ({ method: 'async', activationId: response.activationId, sessionId: p.s.session }), error => {
           console.error(error) // invoke failed
           return { error: `Async combinator failed to invoke composition at AST node root${node.parent} (see log for details)` }
         })
         .then(result => {
           p.params = result
           inspect(p)
           return step(p)
         })
     },

     stop ({ p, node, index, inspect, step }) {
       p.s.state = -1
     }
   }

   function finish (p) {
     return p.params.error ? p.params : { params: p.params }
   }

   const internalError = error => Promise.reject(error) // terminate composition execution and record error

   // wrap params if not a dictionary, branch to error handler if error
   function inspect (p) {
     if (!isObject(p.params)) p.params = { value: p.params }
     if (p.params.error !== undefined) {
       p.params = { error: p.params.error } // discard all fields but the error field
       p.s.state = -1 // abort unless there is a handler in the stack
       while (p.s.stack.length > 0 && !p.s.stack[0].marker) {
         if ((p.s.state = p.s.stack.shift().catch || -1) >= 0) break
       }
     }
   }

   // run function f on current stack
   function run (f, p) {
     // handle let/mask pairs
     const view = []
     let n = 0
     for (let frame of p.s.stack) {
       if (frame.let === null) {
         n++
       } else if (frame.let !== undefined) {
         if (n === 0) {
           view.push(frame)
         } else {
           n--
         }
       }
     }

     // update value of topmost matching symbol on stack if any
     function set (symbol, value) {
       const element = view.find(element => element.let !== undefined && element.let[symbol] !== undefined)
       if (element !== undefined) element.let[symbol] = JSON.parse(JSON.stringify(value))
     }

     // collapse stack for invocation
     const env = view.reduceRight((acc, cur) => cur.let ? Object.assign(acc, cur.let) : acc, {})
     let main = '(function(){try{const require=arguments[2];'
     for (const name in env) main += `var ${name}=arguments[1]['${name}'];`
     main += `return eval((function(){return(${f})})())(arguments[0])}finally{`
     for (const name in env) main += `arguments[1]['${name}']=${name};`
     main += '}})'
     try {
       return (1, eval)(main)(p.params, env, require)
     } finally {
       for (const name in env) set(name, env[name])
     }
   }

   function step (p) {
     // final state, return composition result
     if (p.s.state < 0 || p.s.state >= fsm.length) {
       console.log(`Entering final state`)
       console.log(JSON.stringify(p.params))
       return
     }

     // process one state
     const node = fsm[p.s.state] // json definition for index state
     if (node.path !== undefined) console.log(`Entering composition${node.path}`)
     const index = p.s.state // current state
     p.s.state = p.s.state + (node.next || 1) // default next state
     if (typeof conductor[node.type] !== 'function') return internalError(`unexpected "${node.type}" combinator`)
     return conductor[node.type]({ p, index, node, inspect, step }) || step(p)
   }

   // do invocation
   return (params) => {
     // extract parameters
     const $resume = params.$resume || {}
     delete params.$resume
     $resume.session = $resume.session || process.env.__OW_ACTIVATION_ID

     // current state
     const p = { s: Object.assign({ state: 0, stack: [], resuming: true }, $resume), params }

     // step and catch all errors
     return Promise.resolve().then(() => {
       if (typeof p.s.state !== 'number') return internalError('state parameter is not a number')
       if (!Array.isArray(p.s.stack)) return internalError('stack parameter is not an array')

       if ($resume.resuming) inspect(p) // handle error objects when resuming

       return step(p)
     }).catch(error => {
       const message = (typeof error.error === 'string' && error.error) || error.message || (typeof error === 'string' && error)
       p.params = { error: message ? `Internal error: ${message}` : 'Internal error' }
     }).then(params => params || finish(p)) // params is defined iff execution will be resumed
   }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You under the Apache License, Version 2.0
	* (the "License"); you may not use this file except in compliance with
	* the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	/* eslint no-eval: 0 */

	'use strict'

	const fs = require('fs')
	const { minify } = require('terser')
	const openwhisk = require('openwhisk')
	const os = require('os')
	const path = require('path')

	// read conductor version number
	const version = require('./package.json').version

	// synthesize conductor action code from composition
	function synthesize ({ name, composition, ast, version: composer, annotations = [] }) {
	const code = `// generated by composer v${composer} and conductor v${version}\n\nconst composition = ${JSON.stringify(composition, null, 4)}\n\n// do not edit below this point\n\n` +
	minify(`const main=(${main})(composition)`, { output: { max_line_len: 127 } }).code
	annotations = annotations.concat([{ key: 'conductor', value: ast }, { key: 'composerVersion', value: composer }, { key: 'conductorVersion', value: version }])
	return { name, action: { exec: { kind: 'nodejs:default', code }, annotations } }
	}

	// return enhanced openwhisk client capable of deploying compositions
	module.exports = function (options) {
	// try to extract apihost and key first from whisk property file file and then from process.env
	let apihost
	let apikey

	try {
	const wskpropsPath = process.env.WSK_CONFIG_FILE \|\| path.join(os.homedir(), '.wskprops')
	const lines = fs.readFileSync(wskpropsPath, { encoding: 'utf8' }).split('\n')

	for (let line of lines) {
	let parts = line.trim().split('=')
	if (parts.length === 2) {
	if (parts[0] === 'APIHOST') {
	apihost = parts[1]
	} else if (parts[0] === 'AUTH') {
	apikey = parts[1]
	}
	}
	}
	} catch (error) { }

	if (process.env.__OW_API_HOST) apihost = process.env.__OW_API_HOST
	if (process.env.__OW_API_KEY) apikey = process.env.__OW_API_KEY

	const wsk = openwhisk(Object.assign({ apihost, api_key: apikey }, options))
	wsk.compositions = new Compositions(wsk)
	return wsk
	}

	// management class for compositions
	class Compositions {
	constructor (wsk) {
	this.actions = wsk.actions
	}

	deploy (composition, overwrite) {
	const actions = (composition.actions \|\| []).concat(synthesize(composition))
	return actions.reduce((promise, action) => promise.then(() => overwrite && this.actions.delete(action).catch(() => { }))
	.then(() => this.actions.create(action)), Promise.resolve())
	.then(() => actions)
	}
	}

	// runtime code
	function main (composition) {
	const openwhisk = require('openwhisk')
	let wsk

	const isObject = obj => typeof obj === 'object' && obj !== null && !Array.isArray(obj)

	// compile ast to fsm
	const compiler = {
	sequence (parent, node) {
	return [{ parent, type: 'pass' }, ...compile(parent, ...node.components)]
	},

	action (parent, node) {
	return [{ parent, type: 'action', name: node.name }]
	},

	async (parent, node) {
	const body = [...compile(parent, ...node.components)]
	return [{ parent, type: 'async', return: body.length + 2 }, ...body, { parent, type: 'stop' }, { parent, type: 'pass' }]
	},

	function (parent, node) {
	return [{ parent, type: 'function', exec: node.function.exec }]
	},

	finally (parent, node) {
	const finalizer = compile(parent, node.finalizer)
	const fsm = [{ parent, type: 'try' }, ...compile(parent, node.body), { parent, type: 'exit' }, ...finalizer]
	fsm[0].catch = fsm.length - finalizer.length
	return fsm
	},

	let (parent, node) {
	return [{ parent, type: 'let', let: node.declarations }, ...compile(parent, ...node.components), { parent, type: 'exit' }]
	},

	mask (parent, node) {
	return [{ parent, type: 'let', let: null }, ...compile(parent, ...node.components), { parent, type: 'exit' }]
	},

	try (parent, node) {
	const handler = [...compile(parent, node.handler), { parent, type: 'pass' }]
	const fsm = [{ parent, type: 'try' }, ...compile(parent, node.body), { parent, type: 'exit' }, ...handler]
	fsm[0].catch = fsm.length - handler.length
	fsm[fsm.length - handler.length - 1].next = handler.length
	return fsm
	},

	if_nosave (parent, node) {
	const consequent = compile(parent, node.consequent)
	const alternate = [...compile(parent, node.alternate), { parent, type: 'pass' }]
	const fsm = [{ parent, type: 'pass' }, ...compile(parent, node.test), { parent, type: 'choice', then: 1, else: consequent.length + 1 }, ...consequent, ...alternate]
	fsm[fsm.length - alternate.length - 1].next = alternate.length
	return fsm
	},

	while_nosave (parent, node) {
	const body = compile(parent, node.body)
	const fsm = [{ parent, type: 'pass' }, ...compile(parent, node.test), { parent, type: 'choice', then: 1, else: body.length + 1 }, ...body, { parent, type: 'pass' }]
	fsm[fsm.length - 2].next = 2 - fsm.length
	return fsm
	},

	dowhile_nosave (parent, node) {
	const fsm = [{ parent, type: 'pass' }, ...compile(parent, node.body), ...compile(parent, node.test), { parent, type: 'choice', else: 1 }, { parent, type: 'pass' }]
	fsm[fsm.length - 2].then = 2 - fsm.length
	return fsm
	}
	}

	function compile (parent, node) {
	if (arguments.length === 1) return [{ parent, type: 'empty' }]
	if (arguments.length === 2) return Object.assign(compiler[node.type](node.path \|\| parent, node), { path: node.path })
	return Array.prototype.slice.call(arguments, 1).reduce((fsm, node) => { fsm.push(...compile(parent, node)); return fsm }, [])
	}

	const fsm = compile('', composition)

	const conductor = {
	choice ({ p, node, index }) {
	p.s.state = index + (p.params.value ? node.then : node.else)
	},

	try ({ p, node, index }) {
	p.s.stack.unshift({ catch: index + node.catch })
	},

	let ({ p, node, index }) {
	p.s.stack.unshift({ let: JSON.parse(JSON.stringify(node.let)) })
	},

	exit ({ p, node, index }) {
	if (p.s.stack.length === 0) return internalError(`pop from an empty stack`)
	p.s.stack.shift()
	},

	action ({ p, node, index }) {
	return { method: 'action', action: node.name, params: p.params, state: { $resume: p.s } }
	},

	function ({ p, node, index }) {
	return Promise.resolve().then(() => run(node.exec.code, p))
	.catch(error => {
	console.error(error)
	return { error: `Function combinator threw an exception at AST node root${node.parent} (see log for details)` }
	})
	.then(result => {
	if (typeof result === 'function') result = { error: `Function combinator evaluated to a function type at AST node root${node.parent}` }
	// if a function has only side effects and no return value, return params
	p.params = JSON.parse(JSON.stringify(result === undefined ? p.params : result))
	inspect(p)
	return step(p)
	})
	},

	empty ({ p, node, index }) {
	inspect(p)
	},

	pass ({ p, node, index }) {
	},

	async ({ p, node, index, inspect, step }) {
	p.params.$resume = { state: p.s.state, stack: [{ marker: true }].concat(p.s.stack) }
	p.s.state = index + node.return
	if (!wsk) wsk = openwhisk({ ignore_certs: true })
	return wsk.actions.invoke({ name: process.env.__OW_ACTION_NAME, params: p.params })
	.then(response => ({ method: 'async', activationId: response.activationId, sessionId: p.s.session }), error => {
	console.error(error) // invoke failed
	return { error: `Async combinator failed to invoke composition at AST node root${node.parent} (see log for details)` }
	})
	.then(result => {
	p.params = result
	inspect(p)
	return step(p)
	})
	},

	stop ({ p, node, index, inspect, step }) {
	p.s.state = -1
	}
	}

	function finish (p) {
	return p.params.error ? p.params : { params: p.params }
	}

	const internalError = error => Promise.reject(error) // terminate composition execution and record error

	// wrap params if not a dictionary, branch to error handler if error
	function inspect (p) {
	if (!isObject(p.params)) p.params = { value: p.params }
	if (p.params.error !== undefined) {
	p.params = { error: p.params.error } // discard all fields but the error field
	p.s.state = -1 // abort unless there is a handler in the stack
	while (p.s.stack.length > 0 && !p.s.stack[0].marker) {
	if ((p.s.state = p.s.stack.shift().catch \|\| -1) >= 0) break
	}
	}
	}

	// run function f on current stack
	function run (f, p) {
	// handle let/mask pairs
	const view = []
	let n = 0
	for (let frame of p.s.stack) {
	if (frame.let === null) {
	n++
	} else if (frame.let !== undefined) {
	if (n === 0) {
	view.push(frame)
	} else {
	n--
	}
	}
	}

	// update value of topmost matching symbol on stack if any
	function set (symbol, value) {
	const element = view.find(element => element.let !== undefined && element.let[symbol] !== undefined)
	if (element !== undefined) element.let[symbol] = JSON.parse(JSON.stringify(value))
	}

	// collapse stack for invocation
	const env = view.reduceRight((acc, cur) => cur.let ? Object.assign(acc, cur.let) : acc, {})
	let main = '(function(){try{const require=arguments[2];'
	for (const name in env) main += `var ${name}=arguments[1]['${name}'];`
	main += `return eval((function(){return(${f})})())(arguments[0])}finally{`
	for (const name in env) main += `arguments[1]['${name}']=${name};`
	main += '}})'
	try {
	return (1, eval)(main)(p.params, env, require)
	} finally {
	for (const name in env) set(name, env[name])
	}
	}

	function step (p) {
	// final state, return composition result
	if (p.s.state < 0 \|\| p.s.state >= fsm.length) {
	console.log(`Entering final state`)
	console.log(JSON.stringify(p.params))
	return
	}

	// process one state
	const node = fsm[p.s.state] // json definition for index state
	if (node.path !== undefined) console.log(`Entering composition${node.path}`)
	const index = p.s.state // current state
	p.s.state = p.s.state + (node.next \|\| 1) // default next state
	if (typeof conductor[node.type] !== 'function') return internalError(`unexpected "${node.type}" combinator`)
	return conductor[node.type]({ p, index, node, inspect, step }) \|\| step(p)
	}

	// do invocation
	return (params) => {
	// extract parameters
	const $resume = params.$resume \|\| {}
	delete params.$resume
	$resume.session = $resume.session \|\| process.env.__OW_ACTIVATION_ID

	// current state
	const p = { s: Object.assign({ state: 0, stack: [], resuming: true }, $resume), params }

	// step and catch all errors
	return Promise.resolve().then(() => {
	if (typeof p.s.state !== 'number') return internalError('state parameter is not a number')
	if (!Array.isArray(p.s.stack)) return internalError('stack parameter is not an array')

	if ($resume.resuming) inspect(p) // handle error objects when resuming

	return step(p)
	}).catch(error => {
	const message = (typeof error.error === 'string' && error.error) \|\| error.message \|\| (typeof error === 'string' && error)
	p.params = { error: message ? `Internal error: ${message}` : 'Internal error' }
	}).then(params => params \|\| finish(p)) // params is defined iff execution will be resumed
	}
	}