Add scheduled event

README.md

@@ -160,6 +160,56 @@ You can input an value as json in request body, the value is passed as the input
 ```
 $ curl -XPOST https://xxxxxxxxx.execute-api.us-east-1.amazonaws.com/dev/posts/create -d '{"foo":"bar"}'
 ```
+### Schedule
+The following config will attach a schedule event and causes the stateMachine `crawl` to be called every 2 hours. The configuration allows you to attach multiple schedules to the same stateMachine. You can either use the `rate` or `cron` syntax. Take a look at the [AWS schedule syntax documentation](http://docs.aws.amazon.com/AmazonCloudWatch/latest/events/ScheduledEvents.html) for more details.
+
+```yaml
+stepFunctions:
+  stateMachines:
+    crawl:
+      events:
+        - schedule: rate(2 hours)
+        - schedule: cron(0 12 * * ? *)
+      definition:
+```
+
+## Enabling / Disabling
+
+**Note:** `schedule` events are enabled by default.
+
+This will create and attach a schedule event for the `aggregate` stateMachine which is disabled. If enabled it will call
+the `aggregate` stateMachine every 10 minutes.
+
+```yaml
+stepFunctions:
+  stateMachines:
+    aggregate:
+      events:
+        - schedule:
+            rate: rate(10 minutes)
+            enabled: false
+            input:
+              key1: value1
+              key2: value2
+              stageParams:
+                stage: dev
+        - schedule:
+            rate: cron(0 12 * * ? *)
+            enabled: false
+            inputPath: '$.stageVariables'
+```
+
+## Specify Name and Description
+
+Name and Description can be specified for a schedule event. These are not required properties.
+
+```yaml
+events:
+  - schedule:
+      name: your-scheduled-rate-event-name
+      description: 'your scheduled rate event description'
+      rate: rate(2 hours)
+```
 
 ## Command
 ### deploy

lib/deploy/events/schedule/compileScheduledEvents.js

@@ -0,0 +1,164 @@
+'use strict';
+
+const _ = require('lodash');
+const BbPromise = require('bluebird');
+
+module.exports = {
+  compileScheduledEvents() {
+    _.forEach(this.getAllStateMachines(), (stateMachineName) => {
+      const stateMachineObj = this.getStateMachine(stateMachineName);
+      let scheduleNumberInFunction = 0;
+
+      if (stateMachineObj.events) {
+        _.forEach(stateMachineObj.events, (event) => {
+          if (event.schedule) {
+            scheduleNumberInFunction++;
+            let ScheduleExpression;
+            let State;
+            let Input;
+            let InputPath;
+            let Name;
+            let Description;
+
+            // TODO validate rate syntax
+            if (typeof event.schedule === 'object') {
+              if (!event.schedule.rate) {
+                const errorMessage = [
+                  `Missing "rate" property for schedule event in stateMachine ${stateMachineName}`,
+                  ' The correct syntax is: schedule: rate(10 minutes)',
+                  ' OR an object with "rate" property.',
+                  ' Please check the README for more info.',
+                ].join('');
+                throw new this.serverless.classes
+                  .Error(errorMessage);
+              }
+              ScheduleExpression = event.schedule.rate;
+              State = 'ENABLED';
+              if (event.schedule.enabled === false) {
+                State = 'DISABLED';
+              }
+              Input = event.schedule.input;
+              InputPath = event.schedule.inputPath;
+              Name = event.schedule.name;
+              Description = event.schedule.description;
+
+              if (Input && InputPath) {
+                const errorMessage = [
+                  'You can\'t set both input & inputPath properties at the',
+                  'same time for schedule events.',
+                  'Please check the AWS docs for more info',
+                ].join('');
+                throw new this.serverless.classes
+                  .Error(errorMessage);
+              }
+
+              if (Input && typeof Input === 'object') {
+                Input = JSON.stringify(Input);
+              }
+              if (Input && typeof Input === 'string') {
+                // escape quotes to favor JSON.parse
+                Input = Input.replace(/\"/g, '\\"'); // eslint-disable-line
+              }
+            } else if (typeof event.schedule === 'string') {
+              ScheduleExpression = event.schedule;
+              State = 'ENABLED';
+            } else {
+              const errorMessage = [
+                `Schedule event of stateMachine ${stateMachineName} is not an object nor a string`,
+                ' The correct syntax is: schedule: rate(10 minutes)',
+                ' OR an object with "rate" property.',
+                ' Please check the README for more info.',
+              ].join('');
+              throw new this.serverless.classes
+                .Error(errorMessage);
+            }
+
+            const stateMachineLogicalId = this
+              .getStateMachineLogicalId(stateMachineName, stateMachineObj.name);
+            const scheduleLogicalId = this
+              .getScheduleLogicalId(stateMachineName, scheduleNumberInFunction);
+            const scheduleIamRoleLogicalId = this
+              .getScheduleToStepFunctionsIamRoleLogicalId(stateMachineName);
+            const scheduleId = this.getScheduleId(stateMachineName);
+            const policyName = this.getSchedulePolicyName(stateMachineName);
+
+            const scheduleTemplate = `
+              {
+                "Type": "AWS::Events::Rule",
+                "Properties": {
+                  "ScheduleExpression": "${ScheduleExpression}",
+                  "State": "${State}",
+                  ${Name ? `"Name": "${Name}",` : ''}
+                  ${Description ? `"Description": "${Description}",` : ''}
+                  "Targets": [{
+                    ${Input ? `"Input": "${Input}",` : ''}
+                    ${InputPath ? `"InputPath": "${InputPath}",` : ''}
+                    "Arn": { "Ref": "${stateMachineLogicalId}" },
+                    "Id": "${scheduleId}",
+                    "RoleArn": {
+                      "Fn::GetAtt": [
+                        "${scheduleIamRoleLogicalId}",
+                        "Arn"
+                      ]
+                    }
+                  }]
+                }
+              }
+            `;
+
+            const iamRoleTemplate = `
+            {
+              "Type": "AWS::IAM::Role",
+              "Properties": {
+                "AssumeRolePolicyDocument": {
+                  "Version": "2012-10-17",
+                  "Statement": [
+                    {
+                      "Effect": "Allow",
+                      "Principal": {
+                        "Service": "events.amazonaws.com"
+                      },
+                      "Action": "sts:AssumeRole"
+                    }
+                  ]
+                },
+                "Policies": [
+                  {
+                    "PolicyName": "${policyName}",
+                    "PolicyDocument": {
+                      "Version": "2012-10-17",
+                      "Statement": [
+                        {
+                          "Effect": "Allow",
+                          "Action": [
+                            "states:StartExecution"
+                          ],
+                          "Resource": {
+                            "Ref": "${stateMachineLogicalId}"
+                          }
+                        }
+                      ]
+                    }
+                  }
+                ]
+              }
+            }
+            `;
+
+            const newScheduleObject = {
+              [scheduleLogicalId]: JSON.parse(scheduleTemplate),
+            };
+
+            const newPermissionObject = {
+              [scheduleIamRoleLogicalId]: JSON.parse(iamRoleTemplate),
+            };
+
+            _.merge(this.serverless.service.provider.compiledCloudFormationTemplate.Resources,
+              newScheduleObject, newPermissionObject);
+          }
+        });
+      }
+    });
+    return BbPromise.resolve();
+  },
+};