Convert SDK to the new options API (#238)

api/authmethods/authenticate.go

@@ -0,0 +1,48 @@
+package authmethods
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/hashicorp/watchtower/api"
+	"github.com/hashicorp/watchtower/api/authtokens"
+)
+
+// TODO: This will need to be changed when we add Auth Method API to watchtower.  We'll also need a better
+// way to handle different auth method types.
+func (c *authmethodClient) Authenticate(ctx context.Context, authMethodId, name, password string, opt ...Option) (*authtokens.AuthToken, *api.Error, error) {
+	if c.client == nil {
+		return nil, nil, fmt.Errorf("nil client in Authenticate request")
+	}
+
+	_, apiOpts := getOpts(opt...)
+
+	reqBody := map[string]interface{}{
+		"credentials": map[string]string{
+			"name":     name,
+			"password": password,
+		},
+	}
+
+	req, err := c.client.NewRequest(ctx, "POST", fmt.Sprintf("auth-methods/%s:authenticate", authMethodId), reqBody, apiOpts...)
+	if err != nil {
+		return nil, nil, fmt.Errorf("error creating Authenticate request: %w", err)
+	}
+
+	resp, err := c.client.Do(req)
+	if err != nil {
+		return nil, nil, fmt.Errorf("error performing client request during Authenticate call: %w", err)
+	}
+
+	target := new(authtokens.AuthToken)
+	apiErr, err := resp.Decode(target)
+	if err != nil {
+		return nil, nil, fmt.Errorf("error decoding Authenticate response: %w", err)
+	}
+
+	if target.Token != "" {
+		c.client.SetToken(target.Token)
+	}
+
+	return target, apiErr, nil
+}