Configuration property "slack_username" is not defined

[pierluigilenoci]

I checked the log of Kube-slack and I noticed this error in both K8s clusters that I run in Azure.

Cluster 1

 (node:1) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 268)
(node:1) UnhandledPromiseRejectionWarning: Error: Configuration property "slack_username" is not defined
    at Config.get (/app/node_modules/config/lib/config.js:203:11)
    at SlackNotifier.notify (/app/notify/slack.js:25:48)
    at PodLongNotReady.callback (/app/index.js:27:26)
    at PodLongNotReady.emit (events.js:189:13)
    at PodLongNotReady.check (/app/monitors/longnotready.js:65:18)
    at process._tickCallback (internal/process/next_tick.js:68:7)
(node:1) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 269)
(node:1) UnhandledPromiseRejectionWarning: Error: Configuration property "slack_username" is not defined
    at Config.get (/app/node_modules/config/lib/config.js:203:11)
    at SlackNotifier.notify (/app/notify/slack.js:25:48)
    at PodLongNotReady.callback (/app/index.js:27:26)
    at PodLongNotReady.emit (events.js:189:13)
    at PodLongNotReady.check (/app/monitors/longnotready.js:65:18)
    at process._tickCallback (internal/process/next_tick.js:68:7) 

Cluster 2

 (node:1) UnhandledPromiseRejectionWarning: Error: Configuration property "slack_username" is not defined
    at Config.get (/app/node_modules/config/lib/config.js:203:11)
    at SlackNotifier.notify (/app/notify/slack.js:25:48)
    at PodLongNotReady.callback (/app/index.js:27:26)
    at PodLongNotReady.emit (events.js:189:13)
    at PodLongNotReady.check (/app/monitors/longnotready.js:65:18)
    at process._tickCallback (internal/process/next_tick.js:68:7)
(node:1) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:1) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code. 

My configuration:
K8s 1.12.7 deployed with Kubespray
Kube-Slack v4.2.0 deployed with helm

The pods are not restarted and work fine but this is still an issue.

[pierluigilenoci]

@whs could you please take a look?

[hugolhafner]

@pierluigilenoci helm install stable/kube-slack --set envVars.SLACK_URL="URL" --set envVars.SLACK_USERNAME="USERNAME" --set envVars.SLACK_CHANNEL="CHANNEL" --name kube-slack

The SLACK_USERNAME and SLACK_CHANNEL seem to also be required