Retry SSH resolution 5 times

docs/man/git-lfs-config.5.ronn

@@ -51,6 +51,11 @@ be scoped inside the configuration for a remote.
   Sets the maximum time, in seconds, for the HTTP client to maintain keepalive
   connections. Default: 30 minutes.
 
+* `lfs.ssh.retries`
+
+  Specifies the number of times Git LFS will attempt to obtain authorization via
+  SSH before aborting. Default: 5.
+
 * `core.askpass`, GIT_ASKPASS
 
   Given as a program and its arguments, this is invoked when authentication is

lfsapi/client.go

@@ -40,15 +40,8 @@ func (c *Client) NewRequest(method string, e Endpoint, suffix string, body inter
 		fmt.Fprintf(os.Stderr, "\n%s\n", hintFileUrl)
 	}
 
-	sshRes, err := c.SSH.Resolve(e, method)
+	sshRes, err := c.sshResolveWithRetries(e, method)
 	if err != nil {
-		tracerx.Printf("ssh: %s failed, error: %s, message: %s",
-			e.SshUserAndHost, err.Error(), sshRes.Message,
-		)
-
-		if len(sshRes.Message) > 0 {
-			return nil, errors.Wrap(err, sshRes.Message)
-		}
 		return nil, err
 	}
 
@@ -118,6 +111,30 @@ func (c *Client) Close() error {
 	return c.httpLogger.Close()
 }
 
+func (c *Client) sshResolveWithRetries(e Endpoint, method string) (*sshAuthResponse, error) {
+	var sshRes sshAuthResponse
+	var err error
+
+	requests := tools.MaxInt(0, c.sshTries) + 1
+	for i := 0; i < requests; i++ {
+		sshRes, err = c.SSH.Resolve(e, method)
+		if err == nil {
+			return &sshRes, nil
+		}
+
+		tracerx.Printf(
+			"ssh: %s failed, error: %s, message: %s (try: %d/%d)",
+			e.SshUserAndHost, err.Error(), sshRes.Message, i,
+			requests,
+		)
+	}
+
+	if len(sshRes.Message) > 0 {
+		return nil, errors.Wrap(err, sshRes.Message)
+	}
+	return nil, err
+}
+
 func (c *Client) extraHeadersFor(req *http.Request) http.Header {
 	extraHeaders := c.extraHeaders(req.URL)
 	if len(extraHeaders) == 0 {

lfsapi/lfsapi.go

@@ -51,6 +51,8 @@ type Client struct {
 	gitEnv            config.Environment
 	osEnv             config.Environment
 	uc                *config.URLConfig
+
+	sshTries int
 }
 
 type Context interface {
@@ -91,9 +93,10 @@ func NewClient(ctx Context) (*Client, error) {
 		commandCredHelper: &commandCredentialHelper{
 			SkipPrompt: osEnv.Bool("GIT_TERMINAL_PROMPT", false),
 		},
-		gitEnv: gitEnv,
-		osEnv:  osEnv,
-		uc:     config.NewURLConfig(gitEnv),
+		gitEnv:   gitEnv,
+		osEnv:    osEnv,
+		uc:       config.NewURLConfig(gitEnv),
+		sshTries: gitEnv.Int("lfs.ssh.retries", 5),
 	}
 
 	askpass, ok := osEnv.Get("GIT_ASKPASS")