joco@joco:~/Downloads$ git clone https://github.com/prometheus/prometheus.git
Cloning into 'prometheus'...
remote: Counting objects: 33927, done.
remote: Compressing objects: 100% (41/41), done.
remote: Total 33927 (delta 18), reused 30 (delta 13), pack-reused 33873
Receiving objects: 100% (33927/33927), 31.58 MiB | 2.79 MiB/s, done.
Resolving deltas: 100% (18745/18745), done.
joco@joco:~/Downloads$ grep -r -e "- alert:" prometheus
prometheus/pkg/rulefmt/testdata/bad_annotation.bad.yaml:    - alert: hola
prometheus/pkg/rulefmt/testdata/test.yaml:  - alert: HighErrors
prometheus/pkg/rulefmt/testdata/test.yaml:  - alert: HighErrors
prometheus/pkg/rulefmt/testdata/test.yaml:  - alert: HighErrors
prometheus/pkg/rulefmt/testdata/test.yaml:  - alert: HighErrors
prometheus/config/testdata/first.rules:  - alert: InstanceDown
prometheus/docs/configuration/alerting_rules.md:  - alert: HighErrorRate
prometheus/docs/configuration/alerting_rules.md:  - alert: InstanceDown
prometheus/docs/configuration/alerting_rules.md:  - alert: APIHighRequestLatency
prometheus/docs/migration.md:  - alert: FrontendRequestLatency