lambee/actions/fn-list/listFunctions.js

A tool to help developer work with AWS Lambda.

const AWS = require('aws-sdk')
const cache = require('../../lib/cache')

/**
 * Returns all AWS Lambda function configuration objects.
 * 
 * @param boolean useCache Will cache results to make things quicker.
 * @param string awsProfile The profile to use for authentication with AWS.
 * @param string awsRegion The AWS region to connect to.
 * @param boolean verbose Prints the full object returned by AWS SDK instead of just the function name.
 * @param boolean debug Print debug logs to console.
 */
module.exports = async function list(useCache, awsProfile, awsRegion, verbose, debug) {

    debug && console.debug('list()')

    const cacheKey = `fn-list-${awsProfile}-${awsRegion}-${verbose}`

    if (useCache && cache.get(cacheKey)) return cache.get(cacheKey)

    const fullResult = []
    let nextMarker

    while (nextMarker !== 'done') {
        const data = await listFunctions(nextMarker, awsProfile, awsRegion, debug)
        if (data.Functions) fullResult.push(...data.Functions)
        nextMarker = data.NextMarker ? data.NextMarker : 'done'
    }

    const result = verbose ? 
        JSON.stringify(fullResult, null, 4) : 
        fullResult.map(it => it.FunctionName).sort().join('\n')

    cache.put(cacheKey, result)

    return result

}

/**
 * Runs the AWS SDK listFunctions function and returns it as a promise.
 * 
 * @param nextMarker Support for paging through a large result set.
 * @param verbose Turns on debug logging.
 */
function listFunctions(nextMarker, awsProfile, awsRegion, debug) {
    return new Promise((resolve, reject) => {
        
        debug && console.debug(`listFunctions(${nextMarker})`)
                
        const lambda = new AWS.Lambda({
            apiVersion: '2015-03-31',
            region: awsRegion,
            credentials: awsProfile ? new AWS.SharedIniFileCredentials({profile: awsProfile}) : undefined
        })
        debug && console.debug('AWS Config', lambda.config)
    
        const options = { 
            MaxItems: 50,
            Marker: nextMarker
        }

        lambda.listFunctions(options, (err, data) => {
            if (err) {
                reject(err)
            } else {
                resolve(data)
            }
        })

    })
}