From 2eacfe65f0b4dcefc65060642aa5db92403f188d Mon Sep 17 00:00:00 2001
From: Sebastian Harl <sh@tokkee.org>
Date: Thu, 14 May 2015 12:42:51 +0200
Subject: [PATCH] Add rudimentary support for dynamic graphs based on a metrics
 query.

A new page now allows to query metrics using the simple query language of the
webUI. All returned metrics will be thrown into a single graph.
---
 server/graph.go       | 55 ++++++++++++++++++++++++++++++++++++++++---
 server/query.go       | 18 +++++++++++++-
 server/server.go      |  3 ++-
 static/style/main.css |  7 ++++++
 templates/graphs.tmpl | 12 ++++++++++
 templates/main.tmpl   |  1 +
 6 files changed, 91 insertions(+), 5 deletions(-)
 create mode 100644 templates/graphs.tmpl

diff --git a/server/graph.go b/server/graph.go
index 7509485..ddc8c4d 100644
--- a/server/graph.go
+++ b/server/graph.go
@@ -35,6 +35,7 @@ import (
 	"time"
 
 	"github.com/gonum/plot/vg"
+	"github.com/sysdb/go/sysdb"
 	"github.com/sysdb/webui/graph"
 )
 
@@ -61,11 +62,20 @@ func (s *Server) graph(w http.ResponseWriter, req request) {
 			return
 		}
 	}
+
 	g := &graph.Graph{
-		Start:   start,
-		End:     end,
-		Metrics: []graph.Metric{{Hostname: req.args[0], Identifier: req.args[1]}},
+		Start: start,
+		End:   end,
+	}
+	if req.args[0] == "q" {
+		if g.Metrics, err = s.queryMetrics(req.args[1]); err != nil {
+			s.badrequest(w, fmt.Errorf("Failed to query metrics: %v", err))
+			return
+		}
+	} else {
+		g.Metrics = []graph.Metric{{Hostname: req.args[0], Identifier: req.args[1]}}
 	}
+
 	p, err := g.Plot(s.c)
 	if err != nil {
 		s.internal(w, err)
@@ -88,4 +98,43 @@ func (s *Server) graph(w http.ResponseWriter, req request) {
 	io.Copy(w, &buf)
 }
 
+func (s *Server) queryMetrics(q string) ([]graph.Metric, error) {
+	raw, err := parseQuery(q)
+	if err != nil {
+		return nil, err
+	}
+	if raw.typ != "" && raw.typ != "metrics" {
+		return nil, fmt.Errorf("Invalid object type %q for graphs", raw.typ)
+	}
+
+	var args string
+	for name, value := range raw.args {
+		if len(args) > 0 {
+			args += " AND"
+		}
+
+		if name == "name" {
+			args += fmt.Sprintf(" name =~ %s", value)
+		} else {
+			args += fmt.Sprintf(" %s = %s", name, value)
+		}
+	}
+
+	res, err := s.c.Query("LOOKUP metrics MATCHING" + args)
+	if err != nil {
+		return nil, err
+	}
+	hosts, ok := res.([]sysdb.Host)
+	if !ok {
+		return nil, fmt.Errorf("LOOKUP did not return a list of hosts but %T", res)
+	}
+	var metrics []graph.Metric
+	for _, h := range hosts {
+		for _, m := range h.Metrics {
+			metrics = append(metrics, graph.Metric{Hostname: h.Name, Identifier: m.Name})
+		}
+	}
+	return metrics, nil
+}
+
 // vim: set tw=78 sw=4 sw=4 noexpandtab :
diff --git a/server/query.go b/server/query.go
index 962e3ef..bde450f 100644
--- a/server/query.go
+++ b/server/query.go
@@ -64,6 +64,9 @@ func lookup(req request, s *Server) (*page, error) {
 		return nil, err
 	}
 
+	if raw.typ == "" {
+		raw.typ = "hosts"
+	}
 	var args string
 	for name, value := range raw.args {
 		if len(args) > 0 {
@@ -126,6 +129,19 @@ func fetch(req request, s *Server) (*page, error) {
 	return tmpl(s.results[req.cmd], res)
 }
 
+func graphs(req request, s *Server) (*page, error) {
+	p := struct {
+		Query, Metrics string
+	}{
+		Query: req.r.PostForm.Get("metrics-query"),
+	}
+
+	if req.r.Method == "POST" {
+		p.Metrics = p.Query
+	}
+	return tmpl(s.results["graphs"], &p)
+}
+
 var datetime = "2006-01-02 15:04:05"
 
 func metric(req request, res interface{}, s *Server) (*page, error) {
@@ -195,7 +211,7 @@ func parseQuery(s string) (*query, error) {
 		return nil, errors.New("Empty query")
 	}
 
-	q := &query{typ: "hosts", args: make(map[string]string)}
+	q := &query{args: make(map[string]string)}
 	for i, tok := range tokens {
 		if fields := strings.SplitN(tok, ":", 2); len(fields) == 2 {
 			// Query: [<type>:] [<sibling-type>.]<attribute>:<value> ...
diff --git a/server/server.go b/server/server.go
index 8d0d72d..1f5ea94 100644
--- a/server/server.go
+++ b/server/server.go
@@ -79,7 +79,7 @@ func New(addr, user string, cfg Config) (*Server, error) {
 	if s.main, err = cfg.parse("main.tmpl"); err != nil {
 		return nil, err
 	}
-	types := []string{"host", "hosts", "service", "services", "metric", "metrics"}
+	types := []string{"graphs", "host", "hosts", "service", "services", "metric", "metrics"}
 	for _, t := range types {
 		s.results[t], err = cfg.parse(t + ".tmpl")
 		if err != nil {
@@ -120,6 +120,7 @@ var content = map[string]func(request, *Server) (*page, error){
 	"": index,
 
 	// Queries
+	"graphs":   graphs,
 	"host":     fetch,
 	"service":  fetch,
 	"metric":   fetch,
diff --git a/static/style/main.css b/static/style/main.css
index 4127602..1bcae86 100644
--- a/static/style/main.css
+++ b/static/style/main.css
@@ -173,6 +173,13 @@ input[type=text].datetime {
 	padding: 0px 3px;
 }
 
+input[type=text].query {
+	width: 25em;
+	height: 25px;
+	border: 1px solid #000;
+	padding: 0px 3px;
+}
+
 button {
 	background-color: #000;
 	color: #fff;
diff --git a/templates/graphs.tmpl b/templates/graphs.tmpl
new file mode 100644
index 0000000..43ec622
--- /dev/null
+++ b/templates/graphs.tmpl
@@ -0,0 +1,12 @@
+<section>
+	<h1>Graphs</h1>
+	<form action="/graphs" method="POST">
+		<input type="text" name="metrics-query" value="{{.Query}}"
+		       class="query" placeholder="Search metrics" required />
+		<button type="submit">GO</button>
+	</form><br />
+{{if .Metrics}}
+	<img src="/graph/q/{{.Metrics}}" border="0" />
+{{end}}
+	<p>&nbsp;</p>
+</section>
diff --git a/templates/main.tmpl b/templates/main.tmpl
index 254a22a..e6049eb 100644
--- a/templates/main.tmpl
+++ b/templates/main.tmpl
@@ -38,6 +38,7 @@
 			<a href="/hosts">Hosts</a>
 			<a href="/services">Services</a>
 			<a href="/metrics">Metrics</a>
+			<a href="/graphs">Graphs</a>
 		</nav></aside>
 
 		<div class="content">
-- 
2.30.2