From f217b40f9a884e07b4be2461fe181df1def74117 Mon Sep 17 00:00:00 2001
From: Brad Rydzewski <brad.rydzewski@gmail.com>
Date: Wed, 11 May 2016 18:43:24 -0700
Subject: [PATCH] CLI commands for listing agents, queue items

---
 client/client.go      |  5 +++-
 client/client_impl.go | 13 +++++++++
 drone/agent_list.go   | 64 +++++++++++++++++++++++++++++++++++++++++++
 drone/build_queue.go  |  6 ++++
 drone/main.go         |  1 +
 5 files changed, 88 insertions(+), 1 deletion(-)
 create mode 100644 drone/agent_list.go

diff --git a/client/client.go b/client/client.go
index 51a48768..37b6e99e 100644
--- a/client/client.go
+++ b/client/client.go
@@ -86,8 +86,11 @@ type Client interface {
 	// target environment.
 	Deploy(string, string, int, string) (*model.Build, error)
 
+	// AgentList returns a list of build agents.
+	AgentList() ([]*model.Agent, error)
+
 	//
-	// queue functions
+	// below items for Queue (internal use only)
 	//
 
 	// Pull pulls work from the server queue.
diff --git a/client/client_impl.go b/client/client_impl.go
index ea83fd3a..96d6814e 100644
--- a/client/client_impl.go
+++ b/client/client_impl.go
@@ -43,6 +43,7 @@ const (
 	pathUsers      = "%s/api/users"
 	pathUser       = "%s/api/users/%s"
 	pathBuildQueue = "%s/api/builds"
+	pathAgent      = "%s/api/agents"
 )
 
 type client struct {
@@ -265,6 +266,18 @@ func (c *client) Sign(owner, name string, in []byte) ([]byte, error) {
 	return ioutil.ReadAll(rc)
 }
 
+// AgentList returns a list of build agents.
+func (c *client) AgentList() ([]*model.Agent, error) {
+	var out []*model.Agent
+	uri := fmt.Sprintf(pathAgent, c.base)
+	err := c.get(uri, &out)
+	return out, err
+}
+
+//
+// below items for Queue (internal use only)
+//
+
 // Pull pulls work from the server queue.
 func (c *client) Pull(os, arch string) (*queue.Work, error) {
 	out := new(queue.Work)
diff --git a/drone/agent_list.go b/drone/agent_list.go
new file mode 100644
index 00000000..4bb435b4
--- /dev/null
+++ b/drone/agent_list.go
@@ -0,0 +1,64 @@
+package main
+
+import (
+	"html/template"
+	"log"
+	"os"
+	"time"
+
+	"github.com/codegangsta/cli"
+)
+
+var agentsCmd = cli.Command{
+	Name:  "agents",
+	Usage: "manage agents",
+	Action: func(c *cli.Context) {
+		if err := agentList(c); err != nil {
+			log.Fatalln(err)
+		}
+	},
+	Flags: []cli.Flag{
+		cli.StringFlag{
+			Name:  "format",
+			Usage: "format output",
+			Value: tmplAgentList,
+		},
+	},
+}
+
+func agentList(c *cli.Context) error {
+	client, err := newClient(c)
+	if err != nil {
+		return err
+	}
+
+	agents, err := client.AgentList()
+	if err != nil {
+		return err
+	}
+
+	tmpl, err := template.New("_").Funcs(funcMap).Parse(c.String("format") + "\n")
+	if err != nil {
+		return err
+	}
+
+	for _, agent := range agents {
+		tmpl.Execute(os.Stdout, agent)
+	}
+	return nil
+}
+
+// template for build list information
+var tmplAgentList = "\x1b[33m{{ .Address }} \x1b[0m" + `
+Platform: {{ .Platform }}
+Capacity: {{ .Capacity }} concurrent build(s)
+Pinged: {{ since .Updated }} ago
+Uptime: {{ since .Created }}
+`
+
+var funcMap = template.FuncMap{
+	"since": func(t int64) string {
+		d := time.Now().Sub(time.Unix(t, 0))
+		return d.String()
+	},
+}
diff --git a/drone/build_queue.go b/drone/build_queue.go
index e67f8029..c9450ab8 100644
--- a/drone/build_queue.go
+++ b/drone/build_queue.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"log"
 	"os"
 	"text/template"
@@ -37,6 +38,11 @@ func buildQueue(c *cli.Context) error {
 		return err
 	}
 
+	if len(builds) == 0 {
+		fmt.Println("there are no pending or running builds")
+		return nil
+	}
+
 	tmpl, err := template.New("_").Parse(c.String("format") + "\n")
 	if err != nil {
 		return err
diff --git a/drone/main.go b/drone/main.go
index d1847086..f50e7188 100644
--- a/drone/main.go
+++ b/drone/main.go
@@ -32,6 +32,7 @@ func main() {
 	}
 	app.Commands = []cli.Command{
 		agent.AgentCmd,
+		agentsCmd,
 		buildCmd,
 		deployCmd,
 		execCmd,