From 846a90683409bfa3a4cf3f9dcc97ff9ccf2b687e Mon Sep 17 00:00:00 2001
From: Brad Rydzewski <brad.rydzewski@gmail.com>
Date: Thu, 12 Jan 2017 09:42:43 +0400
Subject: [PATCH] initial support yaml transform extensions

---
 agent/agent.go             |  4 +++
 drone/agent/agent.go       |  6 ++++
 drone/agent/exec.go        |  2 ++
 yaml/transform/rpc.go      | 43 +++++++++++++++++++++++++
 yaml/transform/rpc_test.go | 64 ++++++++++++++++++++++++++++++++++++++
 5 files changed, 119 insertions(+)
 create mode 100644 yaml/transform/rpc.go
 create mode 100644 yaml/transform/rpc_test.go

diff --git a/agent/agent.go b/agent/agent.go
index 4f1e5fc97..c39aa2573 100644
--- a/agent/agent.go
+++ b/agent/agent.go
@@ -28,6 +28,7 @@ type Agent struct {
 	Timeout   time.Duration
 	Platform  string
 	Namespace string
+	Extension string
 	Disable   []string
 	Escalate  []string
 	Netrc     []string
@@ -169,6 +170,9 @@ func (a *Agent) prep(w *model.Work) (*yaml.Config, error) {
 	}
 
 	transform.Pod(conf, a.Platform)
+	if err := transform.RemoteTransform(conf, a.Extension); err != nil {
+		return nil, err
+	}
 
 	return conf, nil
 }
diff --git a/drone/agent/agent.go b/drone/agent/agent.go
index 30f8acaef..a41c87ff7 100644
--- a/drone/agent/agent.go
+++ b/drone/agent/agent.go
@@ -133,6 +133,11 @@ var AgentCmd = cli.Command{
 			Name:   "pull",
 			Usage:  "always pull latest plugin images",
 		},
+		cli.StringFlag{
+			EnvVar: "DRONE_YAML_EXTENSION",
+			Name:   "extension",
+			Usage:  "custom plugin extension endpoint",
+		},
 	},
 }
 
@@ -192,6 +197,7 @@ func start(c *cli.Context) {
 				privileged: c.StringSlice("privileged"),
 				pull:       c.BoolT("pull"),
 				logs:       int64(c.Int("max-log-size")) * 1000000,
+				extension:  c.String("extension"),
 			},
 		}
 
diff --git a/drone/agent/exec.go b/drone/agent/exec.go
index 7ad0b458c..895e6522c 100644
--- a/drone/agent/exec.go
+++ b/drone/agent/exec.go
@@ -19,6 +19,7 @@ type config struct {
 	pull       bool
 	logs       int64
 	timeout    time.Duration
+	extension  string
 }
 
 type pipeline struct {
@@ -47,6 +48,7 @@ func (r *pipeline) run(w *model.Work) {
 		Platform:  r.config.platform,
 		Namespace: r.config.namespace,
 		Escalate:  r.config.privileged,
+		Extension: r.config.extension,
 		Pull:      r.config.pull,
 	}
 
diff --git a/yaml/transform/rpc.go b/yaml/transform/rpc.go
new file mode 100644
index 000000000..852cac138
--- /dev/null
+++ b/yaml/transform/rpc.go
@@ -0,0 +1,43 @@
+package transform
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+
+	"github.com/drone/drone/yaml"
+)
+
+// RemoteTransform makes remote transform requests.
+func RemoteTransform(c *yaml.Config, url string) error {
+	if url == "" {
+		return nil
+	}
+
+	var buf bytes.Buffer
+
+	// encode yaml in json format
+	if err := json.NewEncoder(&buf).Encode(c); err != nil {
+		return err
+	}
+	resp, err := http.Post(url, "application/json", &buf)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	// decode the updated yaml from the body
+	if resp.StatusCode == 200 {
+		err = json.NewDecoder(resp.Body).Decode(c)
+		return err
+	}
+
+	// handle error response
+	out, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return err
+	}
+	return fmt.Errorf(string(out))
+}
diff --git a/yaml/transform/rpc_test.go b/yaml/transform/rpc_test.go
new file mode 100644
index 000000000..12e0ce8ad
--- /dev/null
+++ b/yaml/transform/rpc_test.go
@@ -0,0 +1,64 @@
+package transform
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/drone/drone/yaml"
+	"github.com/franela/goblin"
+)
+
+func handleNetrcRemoval(w http.ResponseWriter, r *http.Request) {
+	c := new(yaml.Config)
+	err := json.NewDecoder(r.Body).Decode(c)
+	if err != nil {
+		w.WriteHeader(http.StatusBadRequest)
+		w.Write([]byte(err.Error()))
+		return
+	}
+	for _, container := range c.Pipeline {
+		if strings.HasPrefix(container.Image, "plugins/git") {
+			continue
+		}
+		container.Environment["DRONE_NETRC_USERNAME"] = ""
+		container.Environment["DRONE_NETRC_PASSWORD"] = ""
+		container.Environment["DRONE_NETRC_MACHINE"] = ""
+	}
+	json.NewEncoder(w).Encode(c)
+}
+
+func Test_rpc_transform(t *testing.T) {
+	g := goblin.Goblin(t)
+	g.Describe("rpc transform", func() {
+
+		g.It("should mutate the yaml", func() {
+			c := newConfig(&yaml.Container{
+				Image: "golang",
+				Environment: map[string]string{
+					"DRONE_NETRC_USERNAME": "foo",
+					"DRONE_NETRC_PASSWORD": "bar",
+					"DRONE_BRANCH":         "master",
+				},
+				Commands: []string{
+					"go build",
+					"go test",
+				},
+			})
+
+			server := httptest.NewServer(http.HandlerFunc(handleNetrcRemoval))
+			defer server.Close()
+
+			err := RemoteTransform(c, server.URL)
+			g.Assert(err == nil).IsTrue()
+			g.Assert(c.Pipeline[0].Image).Equal("golang")
+			g.Assert(c.Pipeline[0].Environment["DRONE_BRANCH"]).Equal("master")
+			g.Assert(c.Pipeline[0].Environment["DRONE_NETRC_USERNAME"]).Equal("")
+			g.Assert(c.Pipeline[0].Environment["DRONE_NETRC_PASSWORD"]).Equal("")
+			g.Assert(c.Pipeline[0].Commands[0]).Equal("go build")
+			g.Assert(c.Pipeline[0].Commands[1]).Equal("go test")
+		})
+	})
+}