add(func): Add exist built-in function

babarot · Jan 31, 2019 · f3380d0 · f3380d0
1 parent 59a4e0d
commit f3380d0
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Showing 4 changed files with 57 additions and 8 deletions.
diff --git a/_examples/manifests/.policy/rules.hcl b/_examples/manifests/.policy/rules.hcl
@@ -36,3 +36,22 @@ rule "yaml_separator" {
     message = "YAML separator \"---\" should be removed"
   }
 }
+
+rule "pdb_defined" {
+  description = "Check the PDB resouces are defined"
+
+  precondition {
+    cases = [
+      "${kind("Deployment")}",
+    ]
+  }
+
+  conditions = [
+    "${length(glob(format("%s/PodDisruptionBudget/*", dirname(dirname(filename))))) > 0}",
+  ]
+
+  report {
+    level   = "ERROR"
+    message = "PDB for this Deployment not found"
+  }
+}
diff --git a/docs/syntax/interpolation.md b/docs/syntax/interpolation.md
@@ -256,6 +256,22 @@ Usage:
 # => "\x1b[31m\x1b[40mhello!\x1b[0m"
 ```
 
+### `exist(path)`
+
+Returns true if path exists
+
+Types:
+
+- input args: `string`
+- return values: `boolean`
+
+Usage:
+
+```hcl
+"${exist("/path/to/whatever")}"
+# => true (if exists)
+```
+
 ### `jsonpath(query, default...)`
 
 WIP

diff --git a/lint/internal/policy/context.go b/lint/internal/policy/context.go
@@ -17,17 +17,12 @@ import (
 
 // BuildContext is
 func (p Policy) BuildContext(body hcl.Body, filename string, filedata []byte) (*hcl.EvalContext, hcl.Diagnostics) {
-	// var files []cty.Value
-	// for file := range p.Files {
-	// 	files = append(files, cty.StringVal(file))
-	// }
 	ctx := &hcl.EvalContext{
 		Variables: map[string]cty.Value{
 			"filename": cty.StringVal(filename), // alias of path.filename
 			"path": cty.ObjectVal(map[string]cty.Value{
 				"file": cty.StringVal(filename),
 				"dir":  cty.StringVal(filepath.Base(filename)),
-				// "policies": cty.ListVal(files),
 			}),
 		},
 		Functions: map[string]function.Function{
@@ -37,6 +32,7 @@ func (p Policy) BuildContext(body hcl.Body, filename string, filedata []byte) (*
 			"glob":        funcs.GlobFunc,
 			"pathshorten": funcs.PathShortenFunc,
 			"ext":         funcs.ExtFunc,
+			"exist":       funcs.ExistFunc,
 			// basic
 			"match": funcs.MatchFunc,
 			"color": funcs.ColorFunc,

diff --git a/lint/internal/policy/funcs/filepath.go b/lint/internal/policy/funcs/filepath.go
@@ -1,14 +1,15 @@
 package funcs
 
 import (
+	"os"
 	"path/filepath"
 
 	pathshorten "github.com/b4b4r07/go-pathshorten"
 	"github.com/zclconf/go-cty/cty"
 	"github.com/zclconf/go-cty/cty/function"
 )
 
-// GlobFunc is
+// GlobFunc returns a list of files matching a given pattern
 var GlobFunc = function.New(&function.Spec{
 	Params: []function.Parameter{
 		{
@@ -37,7 +38,7 @@ var GlobFunc = function.New(&function.Spec{
 	},
 })
 
-// PathShortenFunc is
+// PathShortenFunc returns the shorten path of given path
 var PathShortenFunc = function.New(&function.Spec{
 	Params: []function.Parameter{
 		{
@@ -52,7 +53,7 @@ var PathShortenFunc = function.New(&function.Spec{
 	},
 })
 
-// ExtFunc is
+// ExtFunc returns an extension of given file
 var ExtFunc = function.New(&function.Spec{
 	Params: []function.Parameter{
 		{
@@ -65,3 +66,20 @@ var ExtFunc = function.New(&function.Spec{
 		return cty.StringVal(filepath.Ext(args[0].AsString())), nil
 	},
 })
+
+// ExistFunc returns true if given path exists
+var ExistFunc = function.New(&function.Spec{
+	Params: []function.Parameter{
+		{
+			Name: "path",
+			Type: cty.String,
+		},
+	},
+	Type: function.StaticReturnType(cty.Bool),
+	Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
+		path := args[0].AsString()
+		_, err = os.Stat(path)
+		exist := !os.IsNotExist(err)
+		return cty.BoolVal(exist), nil
+	},
+})