datasource: Move datasources into their own packages.

datasource/proc_cmdline/proc_cmdline.go

@@ -0,0 +1,95 @@
+package proc_cmdline
+
+import (
+	"errors"
+	"io/ioutil"
+	"log"
+	"strings"
+
+	"github.com/coreos/coreos-cloudinit/pkg"
+)
+
+const (
+	ProcCmdlineLocation        = "/proc/cmdline"
+	ProcCmdlineCloudConfigFlag = "cloud-config-url"
+)
+
+type procCmdline struct {
+	Location string
+}
+
+func NewDatasource() *procCmdline {
+	return &procCmdline{Location: ProcCmdlineLocation}
+}
+
+func (c *procCmdline) IsAvailable() bool {
+	contents, err := ioutil.ReadFile(c.Location)
+	if err != nil {
+		return false
+	}
+
+	cmdline := strings.TrimSpace(string(contents))
+	_, err = findCloudConfigURL(cmdline)
+	return (err == nil)
+}
+
+func (c *procCmdline) AvailabilityChanges() bool {
+	return false
+}
+
+func (c *procCmdline) ConfigRoot() string {
+	return ""
+}
+
+func (c *procCmdline) FetchMetadata() ([]byte, error) {
+	return []byte{}, nil
+}
+
+func (c *procCmdline) FetchUserdata() ([]byte, error) {
+	contents, err := ioutil.ReadFile(c.Location)
+	if err != nil {
+		return nil, err
+	}
+
+	cmdline := strings.TrimSpace(string(contents))
+	url, err := findCloudConfigURL(cmdline)
+	if err != nil {
+		return nil, err
+	}
+
+	client := pkg.NewHttpClient()
+	cfg, err := client.GetRetry(url)
+	if err != nil {
+		return nil, err
+	}
+
+	return cfg, nil
+}
+
+func (c *procCmdline) Type() string {
+	return "proc-cmdline"
+}
+
+func findCloudConfigURL(input string) (url string, err error) {
+	err = errors.New("cloud-config-url not found")
+	for _, token := range strings.Split(input, " ") {
+		parts := strings.SplitN(token, "=", 2)
+
+		key := parts[0]
+		key = strings.Replace(key, "_", "-", -1)
+
+		if key != "cloud-config-url" {
+			continue
+		}
+
+		if len(parts) != 2 {
+			log.Printf("Found cloud-config-url in /proc/cmdline with no value, ignoring.")
+			continue
+		}
+
+		url = parts[1]
+		err = nil
+	}
+
+	return
+}

datasource/proc_cmdline/proc_cmdline_test.go

@@ -0,0 +1,88 @@
+package proc_cmdline
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+)
+
+func TestParseCmdlineCloudConfigFound(t *testing.T) {
+	tests := []struct {
+		input  string
+		expect string
+	}{
+		{
+			"cloud-config-url=example.com",
+			"example.com",
+		},
+		{
+			"cloud_config_url=example.com",
+			"example.com",
+		},
+		{
+			"cloud-config-url cloud-config-url=example.com",
+			"example.com",
+		},
+		{
+			"cloud-config-url= cloud-config-url=example.com",
+			"example.com",
+		},
+		{
+			"cloud-config-url=one.example.com cloud-config-url=two.example.com",
+			"two.example.com",
+		},
+		{
+			"foo=bar cloud-config-url=example.com ping=pong",
+			"example.com",
+		},
+	}
+
+	for i, tt := range tests {
+		output, err := findCloudConfigURL(tt.input)
+		if output != tt.expect {
+			t.Errorf("Test case %d failed: %s != %s", i, output, tt.expect)
+		}
+		if err != nil {
+			t.Errorf("Test case %d produced error: %v", i, err)
+		}
+	}
+}
+
+func TestProcCmdlineAndFetchConfig(t *testing.T) {
+
+	var (
+		ProcCmdlineTmpl    = "foo=bar cloud-config-url=%s/config\n"
+		CloudConfigContent = "#cloud-config\n"
+	)
+
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method == "GET" && r.RequestURI == "/config" {
+			fmt.Fprint(w, CloudConfigContent)
+		}
+	}))
+	defer ts.Close()
+
+	file, err := ioutil.TempFile(os.TempDir(), "test_proc_cmdline")
+	defer os.Remove(file.Name())
+	if err != nil {
+		t.Errorf("Test produced error: %v", err)
+	}
+	_, err = file.Write([]byte(fmt.Sprintf(ProcCmdlineTmpl, ts.URL)))
+	if err != nil {
+		t.Errorf("Test produced error: %v", err)
+	}
+
+	p := NewDatasource()
+	p.Location = file.Name()
+	cfg, err := p.FetchUserdata()
+	if err != nil {
+		t.Errorf("Test produced error: %v", err)
+	}
+
+	if string(cfg) != CloudConfigContent {
+		t.Errorf("Test failed, response body: %s != %s", cfg, CloudConfigContent)
+	}
+}