Allow sessions without credentials

[kr4ster]

Greetings! We are using IAM to manage connections to AWS resources. I've made a small change to this project which allows connections without credentials, but am not sure what the preferred method of submitting changes. Here's the patch:

diff --git a/config.go b/config.go
index 4b85d0d..968368f 100644
--- a/config.go
+++ b/config.go
@@ -110,11 +110,15 @@ func (r retryer) MaxRetries() int {
 
 // newSession creates a new aws session
 func newSession(c Config) (*session.Session, error) {
-	//sets credentials
-	creds := credentials.NewStaticCredentials(c.Key, c.Secret, "")
-	_, err := creds.Get()
-	if err != nil {
-		return nil, ErrInvalidCreds.Context(err)
+	var creds *credentials.Credentials
+
+	// If Key/Secret are supplied, create static credentials
+	if c.Key != "" && c.Secret != "" {
+		creds = credentials.NewStaticCredentials(c.Key, c.Secret, "")
+		_, err := creds.Get()
+		if err != nil {
+			return nil, ErrInvalidCreds.Context(err)
+		}
 	}
 
 	r := &retryer{retryCount: c.RetryCount}

If you would like me to submit a PR, please let me know!

Thanks,
Bobby

[qhenkart]

@kr4ster this is a great improvement. I am pleased to hear you are enjoying the package and made it useful to you. Please make a PR and I will be happy to review and merge It

[jdoklovic]

Instead of the above diff, I submitted a PR that solves the same problem by allowing callers to set a "SessionProvider" function in the config.

This way the caller can implement complex session setup if needed.

If a SessionProvider is not set, it will use newSession as the default.

See PR #8

[qhenkart]

resolved #8

Thanks everyone