round 2 of autoloading

  * If no TEMPLATE is given as positional arg we scan the working
    directory for *.nomad files. If only 1 match is found we use that to
    proceed.
  * If no -var-file is given we check the working directory for files
    (in this order) named:
    - levant.yaml
    - levant.yml
    - levant.tf
    The first match will be used.

command/deploy.go

@@ -2,11 +2,11 @@ package command
 
 import (
 	"fmt"
-	"os"
 	"strings"
 
 	nomad "github.com/hashicorp/nomad/api"
 
+	"github.com/jrasell/levant/helper"
 	"github.com/jrasell/levant/levant"
 	"github.com/jrasell/levant/logging"
 )
@@ -27,7 +27,8 @@ Usage: levant deploy [options] [TEMPLATE]
 
 Arguments:
 
-  TEMPLATE  nomad job template [default: levant.nomad]
+  TEMPLATE  nomad job template
+    If no argument is given we look for a single *.nomad file
 
 General Options:
 
@@ -83,11 +84,12 @@ func (c *DeployCommand) Run(args []string) int {
 
 	args = flags.Args()
 
+	logging.SetLevel(log)
+
 	if len(args) == 1 {
 		templateFile = args[0]
 	} else if len(args) == 0 {
-		templateFile = "levant.nomad"
-		if _, err := os.Stat(templateFile); os.IsNotExist(err) {
+		if templateFile = helper.GetDefaultTmplFile(); templateFile == "" {
 			c.UI.Error(c.Help())
 			return 1
 		}
@@ -96,8 +98,6 @@ func (c *DeployCommand) Run(args []string) int {
 		return 1
 	}
 
-	logging.SetLevel(log)
-
 	job, err = levant.RenderJob(templateFile, variables, &c.Meta.flagVars)
 	if err != nil {
 		c.UI.Error(fmt.Sprintf("[ERROR] levant/command: %v", err))

command/render.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"strings"
 
+	"github.com/jrasell/levant/helper"
 	"github.com/jrasell/levant/levant"
 )
 
@@ -25,7 +26,8 @@ Usage: levant render [options] [TEMPLATE]
 
 Arguments:
 
-  TEMPLATE  nomad job template [default: levant.nomad]
+  TEMPLATE  nomad job template
+    If no argument is given we look for a single *.nomad file
 
 General Options:
 	
@@ -67,8 +69,7 @@ func (c *RenderCommand) Run(args []string) int {
 	if len(args) == 1 {
 		templateFile = args[0]
 	} else if len(args) == 0 {
-		templateFile = "levant.nomad"
-		if _, err := os.Stat(templateFile); os.IsNotExist(err) {
+		if templateFile = helper.GetDefaultTmplFile(); templateFile == "" {
 			c.UI.Error(c.Help())
 			return 1
 		}

helper/files.go

@@ -0,0 +1,40 @@
+package helper
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/jrasell/levant/logging"
+)
+
+// GetDefaultTmplFile checks the current working directory for *.nomad files.
+// If only 1 is found we return the match.
+func GetDefaultTmplFile() (templateFile string) {
+	if matches, _ := filepath.Glob("*.nomad"); matches != nil {
+		if len(matches) == 1 {
+			templateFile = matches[0]
+			logging.Debug("helper/files: using templatefile `%v`", templateFile)
+			return templateFile
+		}
+	}
+	return ""
+}
+
+// GetDefaultVarFile checks the current working directory for levant.(yaml|yml|tf) files.
+// The first match is returned.
+func GetDefaultVarFile() (varFile string) {
+	if _, err := os.Stat("levant.yaml"); !os.IsNotExist(err) {
+		logging.Debug("helper/files: using default var-file `levant.yaml`")
+		return "levant.yaml"
+	}
+	if _, err := os.Stat("levant.yml"); !os.IsNotExist(err) {
+		logging.Debug("helper/files: using default var-file `levant.yml`")
+		return "levant.yml"
+	}
+	if _, err := os.Stat("levant.tf"); !os.IsNotExist(err) {
+		logging.Debug("helper/files: using default var-file `levant.tf`")
+		return "levant.tf"
+	}
+	logging.Debug("helper/files: no default var-file found")
+	return ""
+}

levant/templater.go

@@ -17,7 +17,7 @@ import (
 )
 
 const (
-	terraformVarExtention = ".tf"
+	terraformVarExtension = ".tf"
 	yamlVarExtension      = ".yaml"
 	ymlVarExtension       = ".yml"
 )
@@ -38,6 +38,10 @@ func RenderJob(templateFile, variableFile string, flagVars *map[string]string) (
 // RenderTemplate is the main entry point to render the template based on the
 // passed variables file.
 func RenderTemplate(templateFile, variableFile string, flagVars *map[string]string) (tpl *bytes.Buffer, err error) {
+	if variableFile == "" {
+		variableFile = helper.GetDefaultVarFile()
+	}
+
 	// Process the variable file extension and log DEBUG so the template can be
 	// correctly rendered.
 	ext := path.Ext(variableFile)
@@ -57,8 +61,8 @@ func RenderTemplate(templateFile, variableFile string, flagVars *map[string]stri
 	}
 
 	switch ext {
-	case terraformVarExtention:
-		// Run the render using variables formatted in Terraforms .tf extension.
+	case terraformVarExtension:
+		logging.Debug("levant/templater: detected .tf variable file extension")
 		tpl, err = renderTFTemplte(string(src), variableFile, flagVars)
 
 	case yamlVarExtension, ymlVarExtension: