feat(alerting): Add group-specific webhook URL for teams

[appleboy]

Add group-specific webhook URL for teams alert

Provides support for paging multiple teams based on the group selector while keeping backward compatibility to the old Teams configuration manifest

integration per team can be specified in the overrides sections in an array form.

alerting:
  teams:
    webhook-url: "https://********.webhook.office.com/webhookb2/************"
    # You can also add group-specific to keys, which will 
    # override the to key above for the specified groups
    overrides:
      - group: "core"
        webhook-url: "https://********.webhook.office.com/webhookb3/************"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: teams
        enabled: true
        description: "healthcheck failed"
        send-on-resolved: true

  - name: back-end
    group: core
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[CERTIFICATE_EXPIRATION] > 48h"
    alerts:
      - type: teams
        enabled: true
        description: "healthcheck failed"
        send-on-resolved: true

ref: #96

Signed-off-by: Bo-Yi Wu [email protected]

[appleboy]

@TwiN I also reset the table format in README.md.

[codecov-commenter]

Codecov Report

Merging #266 (c7e7bb9) into master (0bf2271) will increase coverage by 0.06%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #266      +/-   ##
==========================================
+ Coverage   83.57%   83.64%   +0.06%     
==========================================
  Files          53       53              
  Lines        3434     3448      +14     
==========================================
+ Hits         2870     2884      +14     
  Misses        439      439              
  Partials      125      125              

Impacted Files	Coverage Δ
alerting/provider/teams/teams.go	91.78% <100.00%> (+1.95%)	⬆️

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[appleboy]

@TwiN Any feebacks?

[TwiN]

@appleboy Sorry for the delay; I've been very busy during the past few weeks and have had little time to spare.
I'll review it in a few minutes!

[TwiN]

Awesome work! Thank you for the contribution @appleboy!

[appleboy]

@TwiN Thanks. I will prepare the slides to promote this project.