x509: certificate signed by unknown authority error while sending notification to Teams

[SachinKut]

Hi,
We are expecting the notification controller to send notification to Teams. But we are getting the following error:

{
"level": "error",
"ts": "2021-09-18T13:52:06.784Z",
"logger": "event-server",
"msg": "failed to send notification",
"reconciler kind": "Kustomization",
"name": "xxxx-service-dev",
"namespace": "flux-system",
"error": "postMessage failed: failed to execute request: POST https://xxxxx.webhook.office.com/webhookb2/12345-12345-xxxxx/IncomingWebhook/xxxxx/xxxx-xxxx giving up after 1 attempt(s): Post "https://xxxxx.webhook.office.com/webhookb2/12345-12345-xxxxx/IncomingWebhook/xxxxx/xxxx-xxxx\": x509: certificate signed by unknown authority"
}
{
"level": "info",
"ts": "2021-09-18T13:52:07.840Z",
"logger": "event-server",
"msg": "Dispatching event: kustomize create failed: failed to decode Kubernetes YAML from /tmp/xxxxx/Charts/Chart.yaml: error unmarshaling JSON: while decoding JSON: Object 'Kind' is missing in '{"apiVersion":"v2","appVersion":"0.0.36","description":"A Helm chart for Kubernetes","name":"xxxx-service","type":"application","version":"0.1.32"}'",
"reconciler kind": "Kustomization",
"name": "xxxx-service-dev",
"namespace": "flux-system"
}

We added a configmap with the root CA and the intermediate of https://xxxxx.webhook.office.com and mounted it at /etc/ssl/certs. But continue to get the same error.
Are we mounting the certs at the right location?
Is this similar to issue #203 ? @phillebaba @stefanprodan

Appreciate all the help to resolve this issue.

Thanks
Sachin

[SachinKut]

Thank you @phillebaba for creating the PR to fix this issue. I saw that a test is failing.
Could this be because of the line 42 in the file internal/notifier/teams_test.go is missing the new parameter of type x509.CertPool, that you just added?

[phillebaba]

Sorry forgot to check back on the PR, will fix it 😅