feat(sensor): email trigger

api/jsonschema/schema.json

@@ -3460,8 +3460,11 @@
           "type": "string"
         },
         "to": {
-          "description": "To refers to the email address to which email is send.",
-          "type": "string"
+          "description": "To refers to the email addresses to which the emails are send.",
+          "items": {
+            "type": "string"
+          },
+          "type": "array"
         },
         "username": {
           "description": "Username refers to the username used to connect to the smtp server.",

controllers/sensor/validate.go

@@ -375,12 +375,6 @@ func validateEmailTrigger(trigger *v1alpha1.EmailTrigger) error {
 	if trigger == nil {
 		return fmt.Errorf("trigger can't be nil")
 	}
-	if trigger.SMTPPassword == nil {
-		return fmt.Errorf("smtp password can't be empty")
-	}
-	if trigger.Username == "" {
-		return fmt.Errorf("username can't be empty")
-	}
 	if trigger.Host == "" {
 		return fmt.Errorf("host can't be empty")
 	}

docs/sensors/triggers/email-trigger.md

@@ -0,0 +1,104 @@
+# Email Trigger
+
+The Email trigger is used to send a custom email to a desired set of email addresses using an SMTP server. The intended use is for notifications for a build pipeline, but can be used for any notification scenario.
+
+## Prerequisite
+
+1. Deploy the eventbus in the namespace.
+
+2. Have an SMTP server setup.
+
+3. Create a kubernetes secret with the SMTP password in your cluster.
+
+        kubectl create secret generic smtp-secret --from-literal=password=$SMTP_PASSWORD
+
+      **Note**: If your SMTP server doesnot require authentication this step can be skipped.
+
+4. Create a webhook event-source.
+
+        kubectl -n argo-events apply -f https://raw.githubusercontent.com/argoproj/argo-events/stable/examples/event-sources/webhook.yaml
+
+5. Set up port-forwarding to expose the http server. We will
+   use port-forwarding here.
+
+        kubectl port-forward -n argo-events <event-source-pod-name> 12000:12000
+
+## Email Trigger
+
+Lets say we want to send an email to a dynamic recepient using a custom email body template.
+
+The custom email body template we are going to use is the following:
+```
+Hi <name>,
+  Hello There
+
+Thanks,
+Obi
+``` 
+where the name has to be substituted with the receiver name from the event.
+
+1. Create a sensor with Email trigger.
+
+        kubectl -n argo-events apply -f https://raw.githubusercontent.com/argoproj/argo-events/stable/examples/sensors/email-trigger.yaml
+
+      **Note**: Please update ```email.port```, ```email.host``` and ```email.username``` to that of your SMTP server.
+        If your SMTP server doesnot require authentication, the ```email.username``` and ```email.smtpPassword``` should be ommitted.
+
+2. Send a http request to the event-source-pod to fire the Email trigger.
+
+        curl -d '{"name":"Luke", "to":"[email protected]"}' -H "Content-Type: application/json" -X POST http://localhost:12000/example
+
+      **Note**: You can modify the value for key ```"to"``` to send the email to your address.
+
+2. Alternatively you can skip providing the ```"to"``` in the payload to send an email to static email address provided in the trigger.
+
+        curl -d '{"name":"Luke"}' -H "Content-Type: application/json" -X POST http://localhost:12000/example
+
+      **Note**: You have to remove the parameterization for ```email.to.0``` and add ```email.to``` like so:
+        ```yaml
+        email:
+          ...
+          to:
+            - [email protected]
+            - [email protected]
+          ...
+        ```
+
+## Parameterization
+
+We can parameterize the to, from, subject and body of the email trigger for dynamic capabilities.
+
+The email trigger parameters have the following structure,
+
+    - parameters:
+        - src:
+            dependencyName: test-dep
+            dataKey: body.to
+          dest: email.to.0
+        - src:
+            dependencyName: test-dep
+            dataKey: body.to
+          dest: email.to.-1
+        - src:
+            dependencyName: test-dep
+            dataKey: body.from
+          dest: email.from
+        - src:
+            dependencyName: test-dep
+            dataKey: body.subject
+          dest: email.subject
+        - src:
+            dependencyName: test-dep
+            dataKey: body.emailBody
+          dest: email.body
+
+
+- ```email.to.index``` can be used to overwite an email address already specified in the trigger at the provided index. (where index is an integer)
+- ```email.to.-1``` can be used to append a new email address to the addresses to which an email will be sent.
+- ```email.from``` can be used to specify the from address of the email sent.
+- ```email.body``` can be used to specify the body of the email which will be sent.
+- ```email.subject``` can be used to specify the subject of the email which will be sent.
+
+To understand more on parameterization, take a look at [this tutorial](https://argoproj.github.io/argo-events/tutorials/02-parameterization/).
+
+The complete specification of Email trigger is available [here](https://github.com/argoproj/argo-events/blob/master/api/sensor.md#emailtrigger).

examples/sensors/email-trigger.yaml

@@ -12,10 +12,10 @@ spec:
         - src:
             dependencyName: test-dep
             dataKey: body.to
-          dest: email.to
+          dest: email.to.-1
         - src:
             dependencyName: test-dep
-            DataTemplate: "Hi {{.Input.body.name}},\n\n\tHello There.\n\nThanks,\nObi"
+            dataTemplate: "Hi {{.Input.body.name}},\n\n\tHello There.\n\nThanks,\nObi"
           dest: email.body
       template:
         name: email-trigger
@@ -24,6 +24,9 @@ spec:
           smtpPassword:
             key: password
             name: smtp-secret
+          # to:
+          #   - [email protected]
+          #   - [email protected]
           host: smtp.example.net
           port: 587
           from: [email protected]