Can not send email through alertmanager

Question

docker-compose.yml: Service is up and running.

version: '3'
services:
  prometheus:
    image: prom/prometheus:latest
    container_name: prometheus
    ports:
      - 9090:9090
    volumes:
      - ./prometheus/conf:/etc/prometheus
#      - ./prometheus.yml:/etc/prometheus/prometheus.yml:ro
      - ./alertmanager/alert_rules.yml:/alertmanager/alert.rules.yml
    command:
      - '--config.file=/etc/prometheus/prometheus.yml'
      - '--storage.tsdb.path=/prometheus'

  alertmanager:
    image: prom/alertmanager:latest
    container_name: alertmanager
    ports:
      - 9093:9093
    volumes:
      - ./alertmanager/:/etc/alertmanager/
    command:
      - '--config.file=/etc/alertmanager/alertmanager.yml'
      - '--storage.path=/alertmanager'

prometheus.yml: Prometheus config file with targets and alerts target sets. The alertmanager target url is working fine.

global:
  scrape_interval: 15s
  scrape_timeout: 10s
  evaluation_interval: 15s
alerting:
  alertmanagers:
  - static_configs:
    - targets:
      - 10.10.5.14:9093
    scheme: http
    timeout: 10s
    api_version: v1
rule_files:
  - "/alertmanager/alert.rules:/alertmanager/alert.rules"
scrape_configs:
  - job_name: 'blackbox'
    metrics_path: /probe
    params:
      module: [http_2xx]
    static_configs:
      - targets:
        - "google.com"
    relabel_configs:
      - source_labels: [__address__]
        target_label: __param_target
      - source_labels: [__param_target]
        target_label: instance
      - target_label: __address__
        replacement: localhost:9115

alert.rules: Standard alert rule.

groups:
- name: example
  rules:

  # Alert for any instance that is unreachable for >1 minutes.
  - alert: InstanceDown
    expr: up == 0
    for: 1m

alertmanager.yml: Code to send alerts via gmail smtp.

route:
  group_by: [Alertname]
  # Send all notifications to me.
  receiver: email-me

receivers:
- name: email-me
  email_configs:
  - to: anyemail.com
    from: senderlogin@gmail.com
    smarthost: smtp.gmail.com:587
    auth_username: "senderlogin@gmail.com"
    auth_identity: "senderlogin@gmail.com"
    auth_password: "password"

Problem: All containers are working but there are no rule in prometheus rules. And the letters do not come accordingly either. I can’t understand what I missed. Any hints are welcome. Thanks. enter image description here enter image description here

Answer 1

Alertmanager is not on localhost from the view of the prometheus container, the networking is namespaced in containers so you need to contact alertmanager using DNS discovery to find the current container IP. With compose, DNS is automatically configured for the service name, in this case alertmanager:

alerting:
  alertmanagers:
  - static_configs:
    - targets:
      - alertmanager:9093