given an environment variable for the grafana api token and any number of dashboard slug arguments, generate prometheus yaml rules config files from legacy grafana dashboard alerts. makes a lot of assumptions like there only being one condition in each alert (one query reference). requires hand-editing of results rule ".expr" attributes to pass …

make-grafana-cloud-alerting-yaml-rules-from-dashboard-alerts-by-dashboard-slug.sh

if [ -z "${GRAFANA_API_TOKEN}" ]; then
  echo Error: missing environment variable: GRAFANA_API_TOKEN
  exit 1
fi

DASHBOARD_SLUGS="${*}"
if [ -z "${DASHBOARD_SLUGS}" ]; then
  echo Error: missing argument1...n: DASHBOARD_SLUGS
  exit 1
fi

alerts=$( curl -s X GET https://grafana.net/api/alerts/ \
            -H "Authorization: Bearer $GRAFANA_API_TOKEN" )

# for each dashboard in list of dashboard slugs
dashboard_groups=$( jq -n '[]' )
for slug in $DASHBOARD_SLUGS; do
  echo "slug=${slug}"
  namespace="${slug}-rules"
  filename="${namespace}.yml"
  this_uid=$( .gitlab/ci/get-dashboard-uid-from-alerts-by-slug.sh "$alerts" "$slug")
  # echo "this_uid=${this_uid}"
  this_alerts=$( .gitlab/ci/get-alerts-from-all-alerts-by-dashboard-slug.sh "$alerts" "$slug")
  # echo "this_alerts=${this_alerts}"

  this_dashboard=$( .gitlab/ci/get-dashboard-by-uid.sh "$this_uid" )
  this_dashboard_name="$( jq -r '.title' <<< $this_dashboard )"
  # echo "this_dashboard=${this_dashboard}"

  # for each panel from dashboard alerts
  this_panel_ids=$( jq 'map(.panelId)' <<< $this_alerts )
  dashboard_alert_jsons=$( jq -n '[]' )
  # echo "this_panel_ids=${this_panel_ids}"
  for p in $( .gitlab/ci/get-indexes-from-json.sh "$this_panel_ids" ); do
    this_panel_id=$( .gitlab/ci/get-element-from-json-by-index.sh "$this_panel_ids" "$p" )
    echo "this_panel_id=${this_panel_id}"
    this_panel=$( .gitlab/ci/get-panel-from-dashboard-json-by-id.sh "$this_dashboard" "$this_panel_id" )
    # echo "this_panel=${this_panel}"
    this_panel_alert=$( jq '.alert' <<< $this_panel )
    # echo "this_panel_alert=${this_panel_alert}"

    # get the query expression from the alert's conditions.refId
    targets=$( jq '.targets' <<< $this_panel )
    conditions=$( jq '.conditions' <<< $this_panel_alert )
    # echo "targets=${targets}"
    # echo "conditions=${conditions}"
    for m in $( .gitlab/ci/get-indexes-from-json.sh "$conditions" ); do
      this_condition=$( .gitlab/ci/get-element-from-json-by-index.sh "$conditions" "$m" )

      ref_id=$( jq -r '.query.params[0]' <<< $this_condition )
      # echo "ref_id=${ref_id}"
      this_expr=$( .gitlab/ci/get-expr-from-targets-by-ref-id.sh "$targets" "$ref_id" )
      # echo "this_expr=${this_expr}"

      this_condition=$( jq --arg this_expr "$this_expr" '{evaluator: .evaluator, operator: .operator, query: $this_expr}' <<< $this_condition )
      # echo "this_condition=${this_condition}"
    done

    # form a new json object representing one alert rule
    this_alert=$( .gitlab/ci/get-element-from-json-by-index.sh "$this_alerts" "$p" )
    # echo "this_alert=${this_alert}"
    this_alert_json=$( jq \
      --argjson panel_id "$this_panel_id" \
      --arg dashboard "$this_dashboard_name" \
      --argjson query "$this_condition" \
      --arg folder "$( .gitlab/ci/get-folder-by-dashboard-uid.sh "$this_uid" )" \
      --arg panel "$( jq -r '.title' <<< $this_panel )" \
      '{for: .for, alert: .name, labels: .alertRuleTags, expr: $query, annotations: {message: .message, panel: $panel, panel_id: $panel_id, dashboard: $dashboard, folder: $folder}}' \
    <<< $this_panel_alert )

    # echo "this_alert_json=${this_alert_json}"
    dashboard_alert_jsons=$( jq --argjson this_json "[$this_alert_json]" '. += $this_json' <<< $dashboard_alert_jsons )

  done

  # echo "dashboard_alert_jsons=${dashboard_alert_jsons}"
  dashboard_groups=$( jq \
    --arg dashboard "$this_dashboard_name" \
    --argjson this_json_array "$dashboard_alert_jsons" \
    '. += [{name: $dashboard, rules: $this_json_array}]' \
  <<< $dashboard_groups )

  rules_json=$( jq -n \
    --argjson dashboard_groups "$dashboard_groups" \
    --arg namespace "$namespace" \
    '{namespace: $namespace, groups: $dashboard_groups}' \
  )

  yq e -P - <<< $rules_json > "$filename"

done

requires jq and yq. probably only works with bash; that's the only shell i tested with.