template func: added "log"

This new func runs logrus.Debug to output from test to stdout of the tool

README.md

@@ -2017,6 +2017,10 @@ Example:
 
 **semver_compare** compares to semantic version strings. This calls https://pkg.go.dev/golang.org/x/mod/semver#Compare, so check there for additional documentation. If the version is `""` the version `v0.0.0` is assumed. Before comparing, the function checks if the strings are valid. In case they are not, an error is returned.
 
+## `log` [msg] [args...]
+
+Write **msg** to log output. Args can be given. This uses logrus.Debugf to output.
+
 # HTTP Server
 
 The apitest tool includes an HTTP Server. It can be used to serve files from the local disk temporarily. The HTTP Server can run in test mode. In this mode, the apitest tool does not run any tests, but starts the HTTP Server in the foreground, until CTRL-C in pressed.

pkg/lib/template/template_loader.go

@@ -17,6 +17,7 @@ import (
 	"github.com/Masterminds/sprig/v3"
 	"github.com/pkg/errors"
 	"github.com/programmfabrik/apitest/pkg/lib/datastore"
+	"github.com/sirupsen/logrus"
 	"golang.org/x/mod/semver"
 
 	"github.com/programmfabrik/apitest/pkg/lib/util"
@@ -404,6 +405,10 @@ func (loader *Loader) Render(
 			}
 			return semver.Compare(v, w), nil
 		},
+		"log": func(msg string, args ...any) string {
+			logrus.Debugf(msg, args...)
+			return ""
+		},
 	}
 	tmpl, err := template.
 		New("tmpl").