Add Pagerduty trigger example in go

docs/site/examples.md

@@ -21,7 +21,7 @@ examples:
        url: "/tree/master/examples/python/tagging"
      - language: powercli
        url: "/tree/master/examples/powercli/tagging"
-     - language: golang
+     - language: go
        url: "/tree/master/examples/go/tagging"
 
   - title: Send VM Configuration Changes to Slack
@@ -91,6 +91,8 @@ examples:
     links: 
     - language: python
       url: "/tree/master/examples/python/trigger-pagerduty-incident"
+    - language: go
+      url: "/tree/master/examples/go/pagerduty-trigger"
 
   - title: POST to any REST API
     usecases: 

examples/go/pagerduty-trigger/.gitignore

@@ -0,0 +1,2 @@
+template
+build

examples/go/pagerduty-trigger/README.md

@@ -0,0 +1,128 @@
+# Installing and using PagerDuty Trigger Function in Go
+
+## Function Purpose
+
+A benefit of using VEBA is being able to integrate vSphere events with external
+applications. This can be done by writing a handler function that makes an HTTP
+request to an API. This function is an example written in Go that responds to a
+`VmReconfiguredEvent`, sends information regarding the event to PagerDuty.
+
+## Clone the VEBA repo
+
+The VEBA repository contains many function examples, including go-pagerduty-trigger.
+Clone it to get a local copy.
+
+```bash
+git clone https://github.com/vmware-samples/vcenter-event-broker-appliance
+cd vcenter-event-broker-appliance/examples/go/pagerduty-trigger
+git checkout master
+```
+
+## PagerDuty
+
+For go-pagerduty-trigger function to work, you'll need a PagerDuty account and
+setup, which will not be covered here. PK goes over the setup in (a Medium blog)[https://medium.com/@pkblah/integrating-vcenter-with-pagerduty-241d3813871c].
+
+## Customize the function
+
+For security reasons, do not expose sensitive data. We will create a Kubernetes [secret](https://kubernetes.io/docs/concepts/configuration/secret/)
+which will hold the PagerDuty routing key and trigger. This secret will be mounted
+(by the appliance) into the function during runtime. The secret will need to be
+created via `faas-cli`.
+
+First, change the configuration file [pdconfig.toml](pdconfig.toml) holding your secret vCenter
+information located in this folder:
+
+```toml
+# pdconfig.toml contents
+# Replace with your own values.
+[pagerduty]
+routingKey = "<replace with your routing key>"
+eventAction = "trigger"
+```
+
+Store the pdconfig.toml configuration file as secret in the appliance using the
+following:
+
+```bash
+# Set up faas-cli for first use.
+export OPENFAAS_URL=https://VEBA_FQDN_OR_IP
+
+# Log into the OpenFaaS client. The username and password were set during the vCenter
+# Event Broker Appliance deployment process. The username can be excluded in the
+# command if the default, admin, was used.
+faas-cli login -p VEBA_OPENFAAS_PASSWORD --tls-no-verify
+
+# Create the secret
+faas-cli secret create pdconfig --from-file=pdconfig.toml --tls-no-verify
+
+# Update the secret if needed
+faas-cli secret update pdconfig --from-file=pdconfig.toml --tls-no-verify
+```
+
+> **Note:** Delete the local `pdconfig.toml` after you're done with this exercise
+to not expose this sensitive information.
+
+Lastly, define the vCenter event which will trigger this function. Such function-
+specific settings are performed in the `stack.yml` file. Open and edit the `stack.yml`
+provided in the examples/go/pagerduty-trigger directory. Change `gateway` and `topic`
+as per your environment/needs.
+
+> **Note:** A key-value annotation under `topic` defines which VM event should
+trigger the function. A list of VM events from vCenter can be found [here](https://code.vmware.com/doc/preview?id=4206#/doc/vim.event.VmEvent.html).
+A single topic can be written as `topic: VmPoweredOnEvent`. Multiple topics can
+be specified using a `","` delimiter syntax, e.g. "`topic: "VmPoweredOnEvent,VmPoweredOffEvent"`".
+
+```yaml
+version: 1.0
+provider:
+  name: openfaas
+  gateway: https://veba.yourdomain.com # Replace with your VEBA environment.
+functions:
+  go-pagerduty-trigger-fn:
+    lang: golang-http
+    handler: ./handler
+    image: vmware/veba-go-pagerduty-trigger:latest
+    secrets:
+      - pdconfig # Ensure this name matches the secret you created.
+    annotations:
+      topic: VmReconfiguredEvent
+```
+
+> **Note:** If you are running a vSphere DRS-enabled cluster the topic annotation
+above should be `DrsVmPoweredOnEvent`. Otherwise, the function would never be triggered.
+
+## Deploy the function
+
+After you've performed the steps and modifications above, you can deploy the function:
+
+```bash
+faas template store pull golang-http # only required during the first deployment
+faas-cli deploy -f stack.yml --tls-no-verify
+Deployed. 202 Accepted.
+```
+
+## Trigger the function
+
+1. Reconfigure the VM (e.g. change numCPU, memoryMB, cpuHotAddEnabled, etc.)
+1. Log into PagerDuty to see the reaction to the trigger event.
+
+> **Note:** If the function doesn't trigger a PagerDuty notification, then verify
+that you correctly followed each step above. Ensure the IPs/FQDNs and credentials
+are correct and see the [troubleshooting](#troubleshooting) section below.
+
+## Troubleshooting
+
+If you reconfigured your VM but don't see a PagerDuty notification, verify:
+
+- PagerDuty routing key
+- Whether the components can talk to each other (VMware Event Router to vCenter
+and OpenFaaS, function to vCenter)
+- Check the logs:
+
+```bash
+faas-cli logs go-pagerduty-trigger-fn --follow --tls-no-verify
+
+# Successful log message will look something similar to
+POST / - 200 OK - ContentLength: 95
+```

examples/go/pagerduty-trigger/handler/go.mod

@@ -0,0 +1,9 @@
+module github.com/codegold79/vcenter-event-broker-appliance/examples/go/pagerduty-trigger/handler
+
+go 1.14
+
+require (
+	github.com/openfaas/templates-sdk v0.0.0-20200723110415-a699ec277c12
+	github.com/pelletier/go-toml v1.8.0
+	github.com/vmware/govmomi v0.23.1
+)

examples/go/pagerduty-trigger/handler/go.sum

@@ -0,0 +1,20 @@
+github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
+github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-xdr v0.0.0-20161123171359-e6a2ba005892/go.mod h1:CTDl0pzVzE5DEzZhPfvhY/9sPFMQIxaJ9VAMs9AagrE=
+github.com/google/uuid v0.0.0-20170306145142-6a5e28554805/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/openfaas/templates-sdk v0.0.0-20200723110415-a699ec277c12 h1:P5IjrDQug3GRIfNC9/S7+UvXAbNdenhnHtjz4Qs8Kd8=
+github.com/openfaas/templates-sdk v0.0.0-20200723110415-a699ec277c12/go.mod h1:JWcVHdzlHcR7nLuaDL88Mz68wOqDvOn0CLO6t27OMhk=
+github.com/pelletier/go-toml v1.8.0 h1:Keo9qb7iRJs2voHvunFtuuYFsbWeOBh8/P9v/kVMFtw=
+github.com/pelletier/go-toml v1.8.0/go.mod h1:D6yutnOGMveHEPV7VQOuvI/gXY61bv+9bAOTRnLElKs=
+github.com/vmware/govmomi v0.23.1 h1:vU09hxnNR/I7e+4zCJvW+5vHu5dO64Aoe2Lw7Yi/KRg=
+github.com/vmware/govmomi v0.23.1/go.mod h1:Y+Wq4lst78L85Ge/F8+ORXIWiKYqaro1vhAulACy9Lc=
+github.com/vmware/vmw-guestinfo v0.0.0-20170707015358-25eff159a728/go.mod h1:x9oS4Wk2s2u4tS29nEaDLdzvuHdB19CvSGJjPgkZJNk=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.3.0 h1:clyUAQHOM3G0M3f5vQj7LuJrETvjVot3Z5el9nffUtU=
+gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

examples/go/pagerduty-trigger/handler/handler.go

@@ -0,0 +1,193 @@
+package function
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"time"
+
+	handler "github.com/openfaas/templates-sdk/go-http"
+	toml "github.com/pelletier/go-toml"
+)
+
+const (
+	pdApiPath         = "https://events.pagerduty.com/v2/enqueue"
+	pdConfigPath      = "/var/openfaas/secrets/pdconfig"
+	httpClientTimeout = 10 * time.Second
+)
+
+// Handle a function invocation.
+func Handle(req handler.Request) (handler.Response, error) {
+	ctx := context.Background()
+
+	// Load the PagerDuty config file at every function invocation.
+	pdCfg, err := loadConfig(pdConfigPath)
+	if err != nil {
+		return handlerResponseWithError(
+			"load PagerDuty configs: %w",
+			http.StatusBadRequest,
+			err,
+		)
+	}
+
+	// Transfer event information data to PagerDuty payload.
+	pdPld, err := parseEvent(req.Body, pdCfg)
+	if err != nil {
+		return handlerResponseWithError(
+			"parse event data: %w",
+			http.StatusInternalServerError,
+			err,
+		)
+	}
+
+	// Send information to PagerDuty.
+	pdRes, err := pdSendRequest(ctx, pdApiPath, pdPld)
+	if err != nil {
+		return handlerResponseWithError(
+			"connect to PagerDuty API: %w",
+			http.StatusInternalServerError,
+			err,
+		)
+	}
+
+	// Display PagerDuty response.
+	return handler.Response{
+		Body:       pdRes,
+		StatusCode: http.StatusOK,
+	}, nil
+}
+
+func handlerResponseWithError(msg string, code int, err error) (handler.Response, error) {
+	wrapErr := fmt.Errorf(msg, err)
+	log.Println(wrapErr.Error())
+
+	return handler.Response{
+		Body:       []byte(wrapErr.Error()),
+		StatusCode: code,
+	}, wrapErr
+}
+
+func loadConfig(path string) (pdConfig, error) {
+	var pdc pdConfig
+
+	secret, err := toml.LoadFile(path)
+	if err != nil {
+		return pdConfig{}, fmt.Errorf("read pdconfig.toml: %w", err)
+	}
+
+	if err := secret.Unmarshal(&pdc); err != nil {
+		return pdConfig{}, fmt.Errorf("unmarshal pdconfig.toml: %w", err)
+	}
+
+	if err := validatePdConf(pdc); err != nil {
+		return pdConfig{}, err
+	}
+
+	return pdc, nil
+}
+
+func validatePdConf(pdc pdConfig) error {
+	if pdc.PagerDuty.RoutingKey == "" {
+		return errors.New("PagerDuty routing key cannot be empty in pdconfig.toml")
+	}
+
+	if pdc.PagerDuty.EventAction == "" {
+		return errors.New("PagerDuty event action cannot be empty in pdconfig.toml")
+	}
+
+	return nil
+}
+
+// parseEvent saves info from the triggering event into a PagerDuty data object.
+func parseEvent(req []byte, pdc pdConfig) (pdPayload, error) {
+	var ce cloudEvent
+	var pd pdPayload
+
+	if err := json.Unmarshal(req, &ce); err != nil {
+		return pd, err
+	}
+
+	if err := validateEvent(ce); err != nil {
+		return pd, err
+	}
+
+	pd.RoutingKey = pdc.PagerDuty.RoutingKey
+	pd.EventAction = pdc.PagerDuty.EventAction
+	pd.Client = "VMware Event Broker Appliance"
+	pd.ClientURL = ce.Source
+	pd.Payload.Summary = ce.Data.FullFormattedMessage
+	pd.Payload.Timestamp = ce.Data.CreatedTime
+	pd.Payload.Source = ce.Source
+	pd.Payload.Severity = "info"
+	pd.Payload.Component = ce.Data.Vm.Name
+	pd.Payload.Group = ce.Data.Host.Name
+	pd.Payload.Class = ce.Subject
+	pd.Payload.CustomDetails.User = ce.Data.UserName
+	pd.Payload.CustomDetails.Datacenter = ce.Data.Datacenter
+	pd.Payload.CustomDetails.ComputeResource = ce.Data.ComputeResource
+	pd.Payload.CustomDetails.Host = ce.Data.Host
+	pd.Payload.CustomDetails.VM = ce.Data.Vm
+
+	return pd, nil
+}
+
+func validateEvent(event cloudEvent) error {
+	var msg string
+
+	switch true {
+	case event.Source == "":
+		msg = "does not contain Source"
+	case event.Subject == "":
+		msg = "does not contain Subject"
+	case event.Data.FullFormattedMessage == "":
+		msg = "does not contain Data.FullFormattedMessage"
+	case (event.Data.CreatedTime == time.Time{}):
+		msg = "does not contain Data.CreatedTime"
+	case event.Data.Vm.Name == "":
+		msg = "does not contain Data.Vm.Name"
+	case event.Data.Host.Name == "":
+		msg = "does not contain Data.Vm.Name"
+	}
+
+	if msg != "" {
+		return errors.New("invalid event: " + msg)
+	}
+
+	return nil
+}
+
+func pdSendRequest(ctx context.Context, path string, pdp pdPayload) ([]byte, error) {
+	clt := &http.Client{
+		Timeout: httpClientTimeout,
+	}
+
+	reqBody, err := json.Marshal(pdp)
+	if err != nil {
+		return []byte{}, err
+	}
+
+	res, err := clt.Post(path, "application/json", bytes.NewBuffer(reqBody))
+	if res != nil {
+		defer res.Body.Close()
+	}
+
+	if err != nil {
+		return []byte{}, fmt.Errorf("execute http request %w", err)
+	}
+
+	body, err := ioutil.ReadAll(res.Body)
+	if err != nil {
+		return []byte{}, fmt.Errorf("read http response body: %w", err)
+	}
+
+	if res.StatusCode < 200 || res.StatusCode >= 400 {
+		return []byte{}, fmt.Errorf("http response: %d, %+v", res.StatusCode, string(body))
+	}
+
+	return body, nil
+}