.js

var Promise = require('bluebird'),
    request = Promise.promisifyAll(require('request')),
    extend = require('extend');

// this would be more appropriately imported from some config file
var defaultOptions = {
    /* whatever request options you are using go here */
    url: 'http://jira-url/'
};

// this function ONLY accumulates the list of issues via request batching
function getIssues(batchSize, requestDelay, _options) {
    var options = extend(true, defaultOptions, {
        body: {
            startAt: 0,
            maxResults: batchSize
        }
    }, _options); // _options can be used to override anything you want
    
    // If I knew up front how many requests I'd be making, I could use Promise.reduce
    // but I don't, so I'm using a recursively calling-itself promise instead
    var issues = [ ]; // this scope variable is specific to this batch of requests
    return (function next() {
        return request(options)
        .spread(function (r, body) {
            if (r.statusCode !== 200) {
                // this is a breaking error, we don't want or need to continue our loop
                throw new Error("Failed POST: " + r.statusCode + " " + r.statusMessage);
            }
            
            // add this batch to the array we're working with
            issues = isssues.concat(body.issues);
            
            // see if we need to get another batch
            if (issues.length < body.total) {
                // get the next batch
                // numToRequest should be passed into getIssues most likely
                options.body.startAt += batchSize;
                return Promise.delay(requestDelay).then(next);
            }
            
            // return the accumulated result -- this ends the recursive promise loop thing
            return issues;
        });
    })(); // this empty array initializes 'issues' in the 'next' function
}

// this function ONLY transforms the http issues response into whatever
// format you are trying to put in your database
function listify(issue) {
    return {
        /* whatever transformation you're doing here */
    };
}

// this function ONLY inserts the data
function putIssuesInDatabase(issues) {
    return knex.insert(issues).into('table');
}

// this function composes all the pieces above to present your final api
function doYourStuff(_opts) {
    var opts = extend({
        numToRequest: 50, // default value
        timeToWaitAfterRequest: 1000 // default value
    }, _opts); // overrides values if specified
    
    return getIssues(opts.numToRequest, opts.timeToWaitAfterRequest)
    .map(listifyIssues) // .map is specific to bluebird
    .then(putIssuesInDatabase);
}

// any errors in the above functions will get propagated to here, at the top
// level where we're actually calling the stuff. 
doYourStuff().then(function (result) {
    // result is the return from knex
}).catch(function (err) {
    console.error(err);
    // there was some problem
});