homelab-nomad/core/syslogng.nomad

job "syslogng" {
  datacenters = ["dc1"]
  type = "service"

  group "promtail" {
    count = 1

    network {
      mode = "bridge"

      port "main" {
        to = 1514
      }

      port "metrics" {
        to = 9080
      }
    }

    service {
      name = "syslogng-promtail"
      provider = "nomad"
      port = "main"
    }

    task "promtail" {
      driver = "docker"

      meta = {
        "diun.sort_tags" = "semver"
        "diun.watch_repo" = true
        "diun.include_tags" = "^[0-9]+\\.[0-9]+\\.[0-9]+$"
      }

      config {
        image = "grafana/promtail:2.9.1"
        ports = ["main", "metrics"]
        args = ["--config.file=/etc/promtail/promtail.yml"]

        mount {
          type = "bind"
          target = "/etc/promtail/promtail.yml"
          source = "local/promtail.yml"
        }
      }

      template {
        data = <<EOF
---
server:
  http_listen_address: 0.0.0.0
  http_listen_port: 9080

clients:
  {{ range nomadService 1 (env "NOMAD_ALLOC_ID") "loki" -}}
  - url: http://{{ .Address }}:{{ .Port }}/loki/api/v1/push
  {{- end }}

scrape_configs:
  # TCP syslog receiver
  - job_name: syslog
    syslog:
      listen_address: 0.0.0.0:{{ env "NOMAD_PORT_main" }}
      labels:
        job: syslog
    relabel_configs:
      - source_labels: ['__syslog_message_hostname']
        target_label: hostname
EOF
        destination = "local/promtail.yml"
      }

      resources {
        cpu = 50
        memory = 20
      }
    }
  }

  group "syslogng" {
    count = 1

    network {
      mode = "bridge"
      port "main" {
        to = 514
      }
    }

    service {
      name = "syslogng"
      provider = "nomad"
      port = "main"
    }

    task "syslogng" {
      driver = "docker"

      config {
        image = "balabit/syslog-ng:3.37.1"
        ports = ["main"]
        args = ["--no-caps"]

        mount {
          type = "bind"
          target = "/etc/syslog-ng/syslog-ng.conf"
          source = "local/syslog-ng.conf"
        }
      }

      template {
        data = <<EOF
@version: 3.37
@include "scl.conf"

source s_network {
    default-network-drivers(
    );
};

source s_internal {
    internal();
};

destination d_loki {
    {{ range nomadService 1 (env "NOMAD_ALLOC_ID") "syslogng-promtail" -}}
    syslog("{{ .Address }}" transport("tcp") port({{ .Port }}));
    {{- end }}
};

log { source(s_internal); destination(d_loki); };
log { source(s_network); destination(d_loki); };
EOF
        destination = "local/syslog-ng.conf"
      }

      resources {
        cpu = 50
        memory = 10
      }
    }
  }
}