autoloading of files

command/deploy.go

@@ -6,6 +6,7 @@ import (
 
 	nomad "github.com/hashicorp/nomad/api"
 
+	"github.com/jrasell/levant/helper"
 	"github.com/jrasell/levant/levant"
 	"github.com/jrasell/levant/logging"
 )
@@ -20,10 +21,15 @@ type DeployCommand struct {
 // Help provides the help information for the deploy command.
 func (c *DeployCommand) Help() string {
 	helpText := `
-Usage: levant deploy [options] TEMPLATE
+Usage: levant deploy [options] [TEMPLATE]
 
   Deploy a Nomad job based on input templates and variable files.
 
+Arguments:
+
+  TEMPLATE  nomad job template
+    If no argument is given we look for a single *.nomad file
+
 General Options:
 
   -address=<http_address>
@@ -40,7 +46,7 @@ General Options:
 
   -var-file=<file>
     Used in conjunction with the -job-file will deploy a templated job to your
-    Nomad cluster.
+    Nomad cluster. [default: levant.(yaml|yml|tf)]
 
   -force-count
     Use the taskgroup count from the Nomad jobfile instead of the count that
@@ -57,7 +63,7 @@ func (c *DeployCommand) Synopsis() string {
 // Run triggers a run of the Levant template and deploy functions.
 func (c *DeployCommand) Run(args []string) int {
 
-	var variables, addr, log string
+	var variables, addr, log, templateFile string
 	var err error
 	var job *nomad.Job
 	var canary int
@@ -78,14 +84,22 @@ func (c *DeployCommand) Run(args []string) int {
 
 	args = flags.Args()
 
-	if len(args) != 1 {
+	logging.SetLevel(log)
+
+	if len(args) == 1 {
+		templateFile = args[0]
+	} else if len(args) == 0 {
+		if templateFile = helper.GetDefaultTmplFile(); templateFile == "" {
+			c.UI.Error(c.Help())
+			c.UI.Error("\nERROR: Template arg missing and no default template found")
+			return 1
+		}
+	} else {
 		c.UI.Error(c.Help())
 		return 1
 	}
 
-	logging.SetLevel(log)
-
-	job, err = levant.RenderJob(args[0], variables, &c.Meta.flagVars)
+	job, err = levant.RenderJob(templateFile, variables, &c.Meta.flagVars)
 	if err != nil {
 		c.UI.Error(fmt.Sprintf("[ERROR] levant/command: %v", err))
 		return 1

command/render.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"strings"
 
+	"github.com/jrasell/levant/helper"
 	"github.com/jrasell/levant/levant"
 )
 
@@ -19,10 +20,15 @@ type RenderCommand struct {
 // Help provides the help information for the template command.
 func (c *RenderCommand) Help() string {
 	helpText := `
-Usage: levant render [options] TEMPLATE
+Usage: levant render [options] [TEMPLATE]
 
   Render a Nomad job template, useful for debugging.
 
+Arguments:
+
+  TEMPLATE  nomad job template
+    If no argument is given we look for a single *.nomad file
+
 General Options:
 
   -out=<file>
@@ -31,7 +37,7 @@ General Options:
     rendered to stdout if this is not set.
 
   -var-file=<file>
-    The variables file to render the template with.
+    The variables file to render the template with. [default: levant.(yaml|yml|tf)]
 `
 	return strings.TrimSpace(helpText)
 }
@@ -44,7 +50,7 @@ func (c *RenderCommand) Synopsis() string {
 // Run triggers a run of the Levant template functions.
 func (c *RenderCommand) Run(args []string) int {
 
-	var variables, outPath string
+	var variables, outPath, templateFile string
 	var err error
 	var tpl *bytes.Buffer
 
@@ -60,12 +66,20 @@ func (c *RenderCommand) Run(args []string) int {
 
 	args = flags.Args()
 
-	if len(args) != 1 {
+	if len(args) == 1 {
+		templateFile = args[0]
+	} else if len(args) == 0 {
+		if templateFile = helper.GetDefaultTmplFile(); templateFile == "" {
+			c.UI.Error(c.Help())
+			c.UI.Error("\nERROR: Template arg missing and no default template found")
+			return 1
+		}
+	} else {
 		c.UI.Error(c.Help())
 		return 1
 	}
 
-	tpl, err = levant.RenderTemplate(args[0], variables, &c.Meta.flagVars)
+	tpl, err = levant.RenderTemplate(templateFile, variables, &c.Meta.flagVars)
 	if err != nil {
 		c.UI.Error(fmt.Sprintf("[ERROR] levant/command: %v", err))
 		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"
 )
@@ -38,11 +38,17 @@ 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 == "" {
+		logging.Debug("levant/templater: no variable file passed, trying defaults")
+		if variableFile = helper.GetDefaultVarFile(); variableFile != "" {
+			logging.Debug("levant/templater: found default variable file, using %s", variableFile)
+		}
+	}
 
 	// Process the variable file extension and log DEBUG so the template can be
 	// correctly rendered.
-	ext := path.Ext(variableFile)
-	if variableFile != "" {
+	var ext string
+	if ext = path.Ext(variableFile); ext != "" {
 		logging.Debug("levant/templater: variable file extension %s detected", ext)
 	}
 
@@ -58,16 +64,15 @@ 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:
 		tpl, err = renderTFTemplte(string(src), variableFile, flagVars)
 
 	case yamlVarExtension, ymlVarExtension:
-		// Run the render using a YAML varaible file.
+		// Run the render using a YAML variable file.
 		tpl, err = renderYAMLVarsTemplate(string(src), variableFile, flagVars)
 
 	case "":
-		// No varibles file passed; render using any passed CLI variables.
+		// No variables file passed; render using any passed CLI variables.
 		logging.Debug("levant/templater: variable file not passed")
 		tpl, err = readJobFile(string(src), flagVars)