Merge pull request #3799 from Shopify/dbg-certs

Add /dbg certs command

cmd/dbg/main.go

@@ -28,6 +28,7 @@ import (
 const (
 	backendsPath = "/configuration/backends"
 	generalPath  = "/configuration/general"
+	certsPath    = "/configuration/certs"
 )
 
 func main() {
@@ -70,6 +71,24 @@ func main() {
 	}
 	backendsCmd.AddCommand(backendsGetCmd)
 
+	certCmd := &cobra.Command{
+		Use:   "certs",
+		Short: "Inspect dynamic SSL certificates",
+	}
+
+	certGetCmd := &cobra.Command{
+		Use:   "get [hostname]",
+		Short: "Get the dynamically-loaded certificate information for the given hostname",
+		Args:  cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			certGet(args[0])
+			return nil
+		},
+	}
+	certCmd.AddCommand(certGetCmd)
+
+	rootCmd.AddCommand(certCmd)
+
 	generalCmd := &cobra.Command{
 		Use:   "general",
 		Short: "Output the general dynamic lua state",
@@ -102,7 +121,7 @@ func backendsAll() {
 		return
 	}
 	if statusCode != 200 {
-		fmt.Printf("Nginx returned code %v", statusCode)
+		fmt.Printf("Nginx returned code %v\n", statusCode)
 		return
 	}
 
@@ -123,7 +142,7 @@ func backendsList() {
 		return
 	}
 	if statusCode != 200 {
-		fmt.Printf("Nginx returned code %v", statusCode)
+		fmt.Printf("Nginx returned code %v\n", statusCode)
 		return
 	}
 
@@ -148,7 +167,7 @@ func backendsGet(name string) {
 		return
 	}
 	if statusCode != 200 {
-		fmt.Printf("Nginx returned code %v", statusCode)
+		fmt.Printf("Nginx returned code %v\n", statusCode)
 		return
 	}
 
@@ -171,14 +190,33 @@ func backendsGet(name string) {
 	fmt.Println("A backend of this name was not found.")
 }
 
+func certGet(host string) {
+	statusCode, body, requestErr := nginx.NewGetStatusRequest(certsPath + "?hostname=" + host)
+	if requestErr != nil {
+		fmt.Println(requestErr)
+		return
+	}
+
+	if statusCode == 200 {
+		fmt.Print(string(body))
+		return
+	} else if statusCode != 404 {
+		fmt.Printf("Nginx returned code %v\n", statusCode)
+		fmt.Println(string(body))
+		return
+	}
+
+	fmt.Printf("No cert found for host %v\n", host)
+}
+
 func general() {
 	statusCode, body, requestErr := nginx.NewGetStatusRequest(generalPath)
 	if requestErr != nil {
 		fmt.Println(requestErr)
 		return
 	}
 	if statusCode != 200 {
-		fmt.Printf("Nginx returned code %v", statusCode)
+		fmt.Printf("Nginx returned code %v\n", statusCode)
 		return
 	}
 

internal/nginx/main.go

@@ -23,6 +23,7 @@ import (
 	"io/ioutil"
 	"net/http"
 	"os"
+	"strings"
 	"time"
 
 	"github.com/tv42/httpunix"
@@ -88,15 +89,39 @@ func NewPostStatusRequest(path, contentType string, data interface{}) (int, []by
 	return res.StatusCode, body, nil
 }
 
+// GetServerBlock takes an nginx.conf file and a host and tries to find the server block for that host
+func GetServerBlock(conf string, host string) (string, error) {
+	startMsg := fmt.Sprintf("## start server %v", host)
+	endMsg := fmt.Sprintf("## end server %v", host)
+
+	blockStart := strings.Index(conf, startMsg)
+	if blockStart < 0 {
+		return "", fmt.Errorf("Host %v was not found in the controller's nginx.conf", host)
+	}
+	blockStart = blockStart + len(startMsg)
+
+	blockEnd := strings.Index(conf, endMsg)
+	if blockEnd < 0 {
+		return "", fmt.Errorf("The end of the host server block could not be found, but the beginning was")
+	}
+
+	return conf[blockStart:blockEnd], nil
+}
+
 // ReadNginxConf reads the nginx configuration file into a string
 func ReadNginxConf() (string, error) {
-	confFile, err := os.Open("/etc/nginx/nginx.conf")
+	return ReadFileToString("/etc/nginx/nginx.conf")
+}
+
+// ReadFileToString reads any file into a string
+func ReadFileToString(path string) (string, error) {
+	f, err := os.Open(path)
 	if err != nil {
 		return "", err
 	}
-	defer confFile.Close()
+	defer f.Close()
 
-	contents, err := ioutil.ReadAll(confFile)
+	contents, err := ioutil.ReadAll(f)
 	if err != nil {
 		return "", err
 	}

rootfs/etc/nginx/lua/configuration.lua

@@ -110,6 +110,32 @@ local function handle_general()
   ngx.status = ngx.HTTP_CREATED
 end
 
+local function handle_certs()
+  if ngx.var.request_method ~= "GET" then
+    ngx.status = ngx.HTTP_BAD_REQUEST
+    ngx.print("Only GET requests are allowed!")
+    return
+  end
+
+  local query = ngx.req.get_uri_args()
+  if not query["hostname"] then
+    ngx.status = ngx.HTTP_BAD_REQUEST
+    ngx.print("Hostname must be specified.")
+    return
+  end
+
+  local key = _M.get_pem_cert_key(query["hostname"])
+  if key then
+    ngx.status = ngx.HTTP_OK
+    ngx.print(key)
+    return
+  else
+    ngx.status = ngx.HTTP_NOT_FOUND
+    ngx.print("No key associated with this hostname.")
+    return
+  end
+end
+
 function _M.call()
   if ngx.var.request_method ~= "POST" and ngx.var.request_method ~= "GET" then
     ngx.status = ngx.HTTP_BAD_REQUEST
@@ -127,6 +153,11 @@ function _M.call()
     return
   end
 
+  if ngx.var.uri == "/configuration/certs" then
+    handle_certs()
+    return
+  end
+
   if ngx.var.request_uri ~= "/configuration/backends" then
     ngx.status = ngx.HTTP_NOT_FOUND
     ngx.print("Not found!")