1 files changed, 96 insertions, 0 deletions
diff --git a/app/models/prometheus_metric.rb b/app/models/prometheus_metric.rb
new file mode 100644
index 00000000000..87ea0762856
--- /dev/null
+++ b/app/models/prometheus_metric.rb
@@ -0,0 +1,96 @@
+class PrometheusMetric < ActiveRecord::Base
+  belongs_to :project, validate: true, inverse_of: :prometheus_metrics
+
+  enum group: {
+    # built-in groups
+    nginx_ingress: -1,
+    ha_proxy: -2,
+    aws_elb: -3,
+    nginx: -4,
+    kubernetes: -5,
+
+    # custom/user groups
+    business: 0,
+    response: 1,
+    system: 2
+  }
+
+  validates :title, presence: true
+  validates :query, presence: true
+  validates :group, presence: true
+  validates :y_label, presence: true
+  validates :unit, presence: true
+
+  validate :require_project
+
+  scope :common, -> { where(common: true) }
+
+  GROUP_TITLES = {
+    # built-in groups
+    nginx_ingress: _('Response metrics (NGINX Ingress)'),
+    ha_proxy: _('Response metrics (HA Proxy)'),
+    aws_elb: _('Response metrics (AWS ELB)'),
+    nginx: _('Response metrics (NGINX)'),
+    kubernetes: _('System metrics (Kubernetes)'),
+
+    # custom/user groups
+    business: _('Business metrics (Custom)'),
+    response: _('Response metrics (Custom)'),
+    system: _('System metrics (Custom)')
+  }.freeze
+
+  REQUIRED_METRICS = {
+    nginx_ingress: %w(nginx_upstream_responses_total nginx_upstream_response_msecs_avg),
+    ha_proxy: %w(haproxy_frontend_http_requests_total haproxy_frontend_http_responses_total),
+    aws_elb: %w(aws_elb_request_count_sum aws_elb_latency_average aws_elb_httpcode_backend_5_xx_sum),
+    nginx: %w(nginx_server_requests nginx_server_requestMsec),
+    kubernetes: %w(container_memory_usage_bytes container_cpu_usage_seconds_total)
+  }.freeze
+
+  def group_title
+    GROUP_TITLES[group.to_sym]
+  end
+
+  def required_metrics
+    (REQUIRED_METRICS[group.to_sym] || []).map(&:to_s)
+  end
+
+  def to_query_metric
+    Gitlab::Prometheus::Metric.new(id: id, title: title, required_metrics: required_metrics, weight: 0, y_label: y_label, queries: queries)
+  end
+
+  def queries
+    [
+      {
+        query_range: query,
+        unit: unit,
+        label: legend,
+        series: query_series
+      }
+    ]
+  end
+
+  def query_series
+    case legend
+    when 'Status Code'
+      {
+        label: 'status_code',
+        when: [
+          { value: '2xx', color: 'green' },
+          { value: '4xx', color: 'orange' },
+          { value: '5xx', color: 'red' }
+        ]
+      }
+    end
+  end
+
+  private
+
+  def require_project
+    if project
+      errors.add(:project, "cannot be set if this is common metric") if common?
+    else
+      errors.add(:project, "has to be set when this is project-specific metric") unless common?
+    end
+  end
+end