homelab-nomad/core/metrics/grafana.nomad

job "grafana" {
  datacenters = ["dc1"]

  group "grafana" {
    count = 1

    network {
      mode = "bridge"

      port "web" {
        host_network = "wesher"
        to = 3000
      }
    }

    ephemeral_disk {
      migrate = true
      sticky = true
    }

    service {
      name = "grafana"
      provider = "nomad"
      port = "web"

      tags = [
        "traefik.enable=true",
        "traefik.http.routers.grafana.entryPoints=websecure",
        "traefik.http.routers.grafana.middlewares=authelia@nomad",
      ]
    }

    task "stunnel" {
      driver = "docker"

      lifecycle {
        hook = "prestart"
        sidecar = true
      }

      config {
        image = "alpine:3.17"
        args = ["/bin/sh", "$${NOMAD_TASK_DIR}/start.sh"]
      }

      resources {
        cpu = 100
        memory = 100
      }

      template {
        data = <<EOF
set -e
apk add stunnel
exec stunnel {{ env "NOMAD_TASK_DIR" }}/stunnel.conf
        EOF
        destination = "$${NOMAD_TASK_DIR}/start.sh"
      }

      template {
        data = <<EOF
syslog = no
foreground = yes
delay = yes

[mysql_client]
client = yes
accept = 127.0.0.1:3306
{{ range nomadService 1 (env "NOMAD_ALLOC_ID") "mysql-tls" -}}
connect = {{ .Address }}:{{ .Port }}
{{- end }}
PSKsecrets = {{ env "NOMAD_SECRETS_DIR" }}/mysql_stunnel_psk.txt
        EOF
        destination = "$${NOMAD_TASK_DIR}/stunnel.conf"
      }

      # TODO: Get psk for backup jobs despite multiple job declarations
      # Probably should use variable ACLs to grant each node job to this path
      template {
        data = <<EOF
{{- with nomadVar "nomad/jobs/grafana/grafana/stunnel" }}{{ .mysql_stunnel_psk }}{{ end -}}
EOF
        destination = "$${NOMAD_SECRETS_DIR}/mysql_stunnel_psk.txt"
      }
    }

    task "grafana-bootstrap" {
      driver = "docker"

      lifecycle {
        hook = "prestart"
        sidecar = false
      }

      config {
        image = "mariadb:10"
        args = [
          "/usr/bin/timeout",
          "2m",
          "/bin/bash",
          "-c",
          "until /usr/bin/mysql --defaults-extra-file=$${NOMAD_SECRETS_DIR}/my.cnf < $${NOMAD_SECRETS_DIR}/bootstrap.sql; do sleep 10; done",
        ]
      }

      template {
        data = <<EOF
[client]
host=127.0.0.1
port=3306
user=root
{{ with nomadVar "nomad/jobs" -}}
password={{ .mysql_root_password }}
{{ end -}}
        EOF
        destination = "$${NOMAD_SECRETS_DIR}/my.cnf"
      }

      template {
        data = <<EOF
{{ with nomadVar "nomad/jobs/grafana" -}}
{{ if .db_name -}}
CREATE DATABASE IF NOT EXISTS `{{ .db_name }}`;
CREATE USER IF NOT EXISTS '{{ .db_user }}'@'%' IDENTIFIED BY '{{ .db_pass }}';
GRANT ALL ON `{{ .db_name }}`.* to '{{ .db_user }}'@'%';
-- Create Read Only user
CREATE USER IF NOT EXISTS '{{ .db_user_ro }}'@'%' IDENTIFIED BY '{{ .db_pass_ro }}';
{{ else -}}
SELECT 'NOOP';
{{ end -}}
{{ end -}}
        EOF
        destination = "$${NOMAD_SECRETS_DIR}/bootstrap.sql"
      }

      resources {
        cpu = 50
        memory = 50
      }
    }

    task "grafana" {
      driver = "docker"

      config {
        image = "grafana/grafana:9.4.2"
        ports = ["web"]
      }

      env = {
        "GF_INSTALL_PLUGINS" = "grafana-clock-panel,grafana-piechart-panel,grafana-polystat-panel,natel-discrete-panel",
        "GF_PATHS_CONFIG" = "$${NOMAD_ALLOC_DIR}/config/grafana.ini"
        "GF_PATHS_PROVISIONING" = "$${NOMAD_ALLOC_DIR}/config/provisioning"
      }

      template {
        data = <<EOF
{{ with nomadVar "nomad/jobs/grafana" -}}
GF_SECURITY_ADMIN_PASSWORD={{ .admin_pw }}
GF_SMTP_USER={{ .smtp_user }}
GF_SMTP_PASSWORD={{ .smtp_password }}
GF_EXTERNAL_IMAGE_STORAGE_S3_ACCESS_KEY={{ .minio_access_key }}
GF_EXTERNAL_IMAGE_STORAGE_S3_SECRET_KEY={{ .minio_secret_key }}
GRAFANA_ALERT_EMAIL_ADDRESSES={{ .alert_email_addresses }}
{{ if .db_name -}}
# Database storage
GF_DATABASE_TYPE=mysql
GF_DATABASE_HOST=127.0.0.1:3306
GF_DATABASE_NAME={{ .db_name }}
GF_DATABASE_USER={{ .db_user }}
GF_DATABASE_PASSWORD={{ .db_pass }}
{{- end }}
SLACK_BOT_URL={{ .slack_bot_url }}
SLACK_BOT_TOKEN={{ .slack_bot_token }}
SLACK_HOOK_URL={{ .slack_hook_url }}
{{ end -}}
        EOF
        env = true
        destination = "secrets/conf.env"
      }

      resources {
        cpu = 100
        memory = 200
      }
    }

    task "grafana-reprovisioner" {
      driver = "docker"

      lifecycle {
        hook = "prestart"
        sidecar = true
      }

      config {
        image = "alpine"
        args = ["$${NOMAD_TASK_DIR}/startup.sh"]
      }

      resources {
        cpu = 100
        memory = 100
      }

      env = {
        LOG_FILE = "/var/log/grafana_reloader.log"
      }

      template {
        data = <<EOF
#! /bin/sh
apk add curl
touch "$LOG_FILE"
exec tail -f "$LOG_FILE"
        EOF
        perms = "777"
        destination = "$${NOMAD_TASK_DIR}/startup.sh"
      }

      template {
        data = <<EOF
{{ with nomadVar "nomad/jobs/grafana" -}}
GF_SECURITY_ADMIN_PASSWORD={{ .admin_pw }}
{{ end -}}
        EOF
        env = true
        destination = "$${NOMAD_SECRETS_DIR}/conf.env"
      }

      template {
        data = <<EOF
#! /bin/sh
exec > "$LOG_FILE"
exec 2>&1
GRAFANA_URL=http://127.0.0.1:3000
echo "Reload dashboards"
curl -s -S --user admin:$GF_SECURITY_ADMIN_PASSWORD --request POST $GRAFANA_URL/api/admin/provisioning/dashboards/reload
echo "Reload datasources"
curl -s -S --user admin:$GF_SECURITY_ADMIN_PASSWORD --request POST $GRAFANA_URL/api/admin/provisioning/datasources/reload
echo "Reload plugins"
curl -s -S --user admin:$GF_SECURITY_ADMIN_PASSWORD --request POST $GRAFANA_URL/api/admin/provisioning/plugins/reload
echo "Reload notifications"
curl -s -S --user admin:$GF_SECURITY_ADMIN_PASSWORD --request POST $GRAFANA_URL/api/admin/provisioning/notifications/reload
echo "Reload access-control"
curl -s -S --user admin:$GF_SECURITY_ADMIN_PASSWORD --request POST $GRAFANA_URL/api/admin/provisioning/access-control/reload
echo "Reload alerting"
curl -s -S --user admin:$GF_SECURITY_ADMIN_PASSWORD --request POST $GRAFANA_URL/api/admin/provisioning/alerting/reload
        EOF
        change_mode = "noop"
        perms = "777"
        destination = "$${NOMAD_TASK_DIR}/reload_config.sh"
      }

      %{ for config_file in fileset(join("/", [module_path, "grafana"]), "**") ~}
      template {
        data = <<EOF
${file(join("/", [module_path, "grafana", config_file]))}
        EOF
        destination = "$${NOMAD_ALLOC_DIR}/config/${config_file}"
        perms = 777
        # Set owner to grafana uid
        # uid = 472
        # Change template delimeter for dashboard files that use json and have double curly braces and square braces
        %{ if length(regexall("dashboard", config_file)) > 0 ~}
        left_delimiter = "<<<<"
        right_delimiter = ">>>>"
        %{ endif }
        change_mode = "script"
        change_script {
          command = "/local/reload_config.sh"
        }
      }
      %{ endfor }

    }

    task "grafana-image-renderer" {
      driver = "docker"

      config {
        image = "grafana/grafana-image-renderer:3.6.1"
        ports = ["renderer"]
      }

      env = {
        "RENDERING_MODE" = "clustered"
        "RENDERING_CLUSTERING_MODE" = "browser"
        "RENDERING_CLUSTERING_MAX_CONCURRENCY" = 5
        "RENDERING_CLUSTERING_TIMEOUT" = 30
      }
    }
  }
}