Add png graph handler

server/dnsanswers.go

@@ -24,9 +24,7 @@ const pointSymbol = "‱"
 
 func (srv *Server) dnsAnswers(c echo.Context) error {
 	log := logger.Setup()
-	ctx := c.Request().Context()
-
-	ctx, span := tracing.Tracer().Start(ctx, "dnsanswers")
+	ctx, span := tracing.Tracer().Start(c.Request().Context(), "dnsanswers")
 	defer span.End()
 
 	// for errors and 404s, a shorter cache time

server/graph_image.go

@@ -0,0 +1,161 @@
+package server
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/http/httptrace"
+	"net/url"
+	"os"
+	"strconv"
+	"time"
+
+	"github.com/hashicorp/go-retryablehttp"
+	"github.com/labstack/echo/v4"
+	"go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace"
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/trace"
+
+	"go.ntppool.org/common/logger"
+	"go.ntppool.org/common/tracing"
+
+	"go.ntppool.org/data-api/ntpdb"
+)
+
+func (srv *Server) graphImage(c echo.Context) error {
+	log := logger.Setup()
+	ctx, span := tracing.Tracer().Start(c.Request().Context(), "graphImage")
+	defer span.End()
+
+	// cache errors briefly
+	c.Response().Header().Set("Cache-Control", "public,max-age=240")
+
+	serverID := c.Param("server")
+	imageType := c.Param("type")
+	log = log.With("serverID", serverID).With("type", imageType)
+	log.Info("graph parameters")
+
+	if imageType != "offset.png" {
+		return c.String(http.StatusNotFound, "invalid image name")
+	}
+
+	if len(c.QueryString()) > 0 {
+		// people breaking the varnish cache by adding query parameters
+		redirectURL := c.Request().URL
+		redirectURL.RawQuery = ""
+		log.InfoContext(ctx, "redirecting", "url", redirectURL.String())
+		return c.Redirect(308, redirectURL.String())
+	}
+
+	q := ntpdb.NewWrappedQuerier(ntpdb.New(srv.db))
+
+	var serverData ntpdb.Server
+	var dberr error
+	if id, err := strconv.Atoi(serverID); id > 0 && err == nil {
+		serverData, dberr = q.GetServerByID(ctx, uint32(id))
+	} else {
+		serverData, dberr = q.GetServerByIP(ctx, serverID)
+	}
+	if dberr != nil {
+		if !errors.Is(dberr, sql.ErrNoRows) {
+			log.Error("could not query server id", "err", dberr)
+			return c.String(http.StatusInternalServerError, "server error")
+		}
+		return c.String(http.StatusNotFound, "not found")
+	}
+
+	if serverData.ID == 0 || (serverData.DeletionOn.Valid && serverData.DeletionOn.Time.Before(time.Now())) {
+		return c.String(http.StatusNotFound, "not found")
+	}
+
+	if serverData.Ip != serverID {
+		return c.Redirect(308, fmt.Sprintf("/graph/%s/offset.png", serverData.Ip))
+	}
+
+	contentType, data, err := srv.fetchGraph(ctx, serverData.Ip)
+	if err != nil {
+		span.RecordError(err)
+		return c.String(http.StatusInternalServerError, "server error")
+
+	}
+	if len(data) == 0 {
+		span.RecordError(fmt.Errorf("no data"))
+		return c.String(http.StatusInternalServerError, "server error")
+	}
+
+	ttl := 1800
+	c.Response().Header().Set("Cache-Control",
+		fmt.Sprintf("public,max-age=%d,s-maxage=%.0f",
+			ttl, float64(ttl)*0.75,
+		),
+	)
+
+	return c.Blob(http.StatusOK, contentType, data)
+}
+
+func (srv *Server) fetchGraph(ctx context.Context, serverIP string) (string, []byte, error) {
+	log := logger.Setup()
+	ctx, span := tracing.Tracer().Start(ctx, "fetchGraph")
+	defer span.End()
+
+	// q := url.Values{}
+	// q.Set("graph_only", "1")
+	// pagePath := srv.config.WebURL("/scores/" + serverIP, q)
+
+	serviceHost := os.Getenv("screensnap_service")
+	if len(serviceHost) == 0 {
+		serviceHost = "screensnap"
+	}
+
+	reqURL := url.URL{
+		Scheme: "http",
+		Host:   serviceHost,
+		Path:   fmt.Sprintf("/image/offset/%s", serverIP),
+	}
+
+	client := retryablehttp.NewClient()
+	client.Logger = log
+	client.HTTPClient.Transport = otelhttp.NewTransport(
+		client.HTTPClient.Transport,
+		otelhttp.WithClientTrace(func(ctx context.Context) *httptrace.ClientTrace {
+			return otelhttptrace.NewClientTrace(ctx)
+		}),
+	)
+
+	req, err := retryablehttp.NewRequestWithContext(ctx, "GET", reqURL.String(), nil)
+	if err != nil {
+		return "", nil, err
+	}
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return "", nil, err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != 200 {
+		span.AddEvent("unexpected status code", trace.WithAttributes(attribute.Int64("http.status", int64(resp.StatusCode))))
+		return "text/plain", nil, fmt.Errorf("upstream error %d", resp.StatusCode)
+	}
+
+	b, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", nil, err
+	}
+
+	return resp.Header.Get("Content-Type"), b, nil
+}
+
+// # my $data = JSON::encode_json(
+// #     {   url              => $url->as_string(),
+// #         timeout          => 10,
+// #         viewport         => "501x233",
+// #         height           => 233,
+// #         resource_timeout => 5,
+// #         wait             => 0.5,
+// #         scale_method     => "vector",
+// #     }
+// # );

server/server.go

@@ -25,13 +25,16 @@ import (
 	"go.ntppool.org/common/version"
 	"go.ntppool.org/common/xff/fastlyxff"
 
+	"go.ntppool.org/api/config"
+
 	chdb "go.ntppool.org/data-api/chdb"
 	"go.ntppool.org/data-api/ntpdb"
 )
 
 type Server struct {
-	db *sql.DB
-	ch *chdb.ClickHouse
+	db     *sql.DB
+	ch     *chdb.ClickHouse
+	config *config.Config
 
 	ctx context.Context
 
@@ -40,6 +43,8 @@ type Server struct {
 }
 
 func NewServer(ctx context.Context, configFile string) (*Server, error) {
+	log := logger.Setup()
+
 	ch, err := chdb.New(ctx, configFile)
 	if err != nil {
 		return nil, fmt.Errorf("clickhouse open: %w", err)
@@ -49,10 +54,16 @@ func NewServer(ctx context.Context, configFile string) (*Server, error) {
 		return nil, fmt.Errorf("mysql open: %w", err)
 	}
 
+	conf := config.New()
+	if !conf.Valid() {
+		log.Error("invalid ntppool config")
+	}
+
 	srv := &Server{
 		ch:      ch,
 		db:      db,
 		ctx:     ctx,
+		config:  conf,
 		metrics: metricsserver.New(),
 	}
 
@@ -171,6 +182,8 @@ func (srv *Server) Run() error {
 
 	e.GET("/api/usercc", srv.userCountryData)
 	e.GET("/api/server/dns/answers/:server", srv.dnsAnswers)
+	e.GET("/graph/:server/:type", srv.graphImage)
+
 	// e.GET("/api/server/scores/:server/:type", srv.logScores)
 
 	g.Go(func() error {