Feat/new envsubst

go.mod

@@ -3,7 +3,7 @@ module github.com/logandavies181/kustomize-krm-envsubst
 go 1.19
 
 require (
-	github.com/drone/envsubst v1.0.3
+	github.com/logandavies181/envsubst v0.1.0
 	sigs.k8s.io/kustomize/kyaml v0.13.10
 )
 

go.sum

@@ -14,8 +14,6 @@ github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSs
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/docopt/docopt-go v0.0.0-20180111231733-ee0de3bc6815/go.mod h1:WwZ+bS3ebgob9U8Nd0kOddGdZWjyMGR8Wziv+TBNwSE=
-github.com/drone/envsubst v1.0.3 h1:PCIBwNDYjs50AsLZPYdfhSATKaRg/FJmDc2D6+C2x8g=
-github.com/drone/envsubst v1.0.3/go.mod h1:N2jZmlMufstn1KEqvbHjw40h1KyTmnVzHcSc9bFiJ2g=
 github.com/emicklei/go-restful v0.0.0-20170410110728-ff4f55a20633/go.mod h1:otzb+WCGbkyDHkqmQmT5YD2WR4BBwUdeQoFo8l/7tVs=
 github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/protoc-gen-validate v0.1.0/go.mod h1:iSmxcyjqTsJpI2R4NaDN7+kN2VEUnK/pcBlmesArF7c=
@@ -72,6 +70,8 @@ github.com/kr/pretty v0.2.1 h1:Fmg33tUaq4/8ym9TJN1x7sLJnHVwhP33CNkpYV/7rwI=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/logandavies181/envsubst v0.1.0 h1:r/y5QwzcMw26kchMjzKYtq/DkAkGwuv7qSp47Lmb4OM=
+github.com/logandavies181/envsubst v0.1.0/go.mod h1:5vxEu24ve2msUFvdG9LsDa1dK8HGFcEElF8QJb1r/Vg=
 github.com/mailru/easyjson v0.0.0-20190614124828-94de47d64c63/go.mod h1:C1wdFJiN94OJF2b5HbByQZoLdCWB1Yqtg26g4irojpc=
 github.com/mailru/easyjson v0.0.0-20190626092158-b2ccc519800e/go.mod h1:C1wdFJiN94OJF2b5HbByQZoLdCWB1Yqtg26g4irojpc=
 github.com/mailru/easyjson v0.7.7 h1:UGYAvKxe3sBsEDzO8ZeWOSlIQfWFlxbzLZe7hwFURr0=
@@ -103,7 +103,7 @@ github.com/stretchr/objx v0.4.0 h1:M2gUjqZET1qApGOWNSnZ49BAIMX4F/1plDv3+l31EJ4=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/stretchr/testify v1.8.0 h1:pSgiaMZlXftHpm5L7V1+rVB+AZJydKsMxsQBIJw4PKk=
+github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
 github.com/xlab/treeprint v1.1.0 h1:G/1DjNkPpfZCFt9CSh6b5/nY4VimlbHF3Rh4obvtzDk=
 github.com/xlab/treeprint v1.1.0/go.mod h1:gj5Gd3gPdKtR1ikdDK6fnFLdmIS0X30kTTuNd/WEJu0=
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=

main.go

@@ -4,45 +4,73 @@ import (
 	"fmt"
 	"os"
 
-	"github.com/drone/envsubst"
+	"github.com/logandavies181/envsubst"
+
 	"sigs.k8s.io/kustomize/kyaml/fn/framework"
 	"sigs.k8s.io/kustomize/kyaml/fn/framework/command"
 	"sigs.k8s.io/kustomize/kyaml/kio"
 	"sigs.k8s.io/kustomize/kyaml/yaml"
 )
 
-func walkSequenceNode(in *yaml.RNode) error {
-	_, err := filter(in)
+type Config struct {
+	envMapping envsubst.AdvancedMapping
+
+	AllowEmpty   bool     `yaml:"allowEmpty" json:"allowEmpty"`
+	ExcludedVars []string `yaml:"excludedVars" json:"excludedVars"`
+	IncludedVars []string `yaml:"includedVars" json:"includedVars"`
+}
+
+func isEmpty(str string) bool {
+	switch str {
+	case "", `""`, "''", "\n":
+		return true
+	default:
+		return false
+	}
+}
+
+func contains(list []string, str string) bool {
+	for _, v := range list {
+		if str == v {
+			return true
+		}
+	}
+
+	return false
+}
+
+func (c Config) walkSequenceNode(in *yaml.RNode) error {
+	_, err := c.Filter(in)
 	if err != nil {
 		return err
 	}
 
 	return nil
 }
 
-func walkMapNode(in *yaml.MapNode) error {
-	_, err := filter(in.Value)
+func (c Config) walkMapNode(in *yaml.MapNode) error {
+	_, err := c.Filter(in.Value)
 	if err != nil {
 		return err
 	}
 
 	return nil
 }
 
-func filter(in *yaml.RNode) (*yaml.RNode, error) {
+func (c Config) Filter(in *yaml.RNode) (*yaml.RNode, error) {
 	if in.IsNil() {
 		return nil, nil
 	}
 
 	switch y := in.YNode().Kind; y {
 	case yaml.MappingNode:
-		err := in.VisitFields(walkMapNode)
+		err := in.VisitFields(c.walkMapNode)
 		if err != nil {
 			return nil, fmt.Errorf("Could not visit fields: %v", err)
 		}
 		return in, nil
 	case yaml.SequenceNode:
-		err := in.VisitElements(walkSequenceNode)
+		err := in.VisitElements(c.walkSequenceNode)
 		if err != nil {
 			return nil, fmt.Errorf("Could not visit elements: %v", err)
 		}
@@ -54,17 +82,29 @@ func filter(in *yaml.RNode) (*yaml.RNode, error) {
 			return nil, fmt.Errorf("Could not parse node into string: %v", err)
 		}
 
-		substed, err := envsubst.EvalEnv(str)
+		substed, err := envsubst.EvalAdvanced(str, envsubst.AdvancedMapping(c.envMapping))
 		if err != nil {
-			return nil, fmt.Errorf("Could not envsubt: %v", err)
+			return nil, fmt.Errorf("Could not envsubst: %v", err)
 		}
 
 		if substed == str {
 			return in, nil
 		}
 
+		if isEmpty(substed) {
+			if !c.AllowEmpty {
+				return nil, fmt.Errorf(
+					"Value %s evaluated to empty string. Did you forget to set an environment variable?",
+					str)
+			}
+
+			substed = `""`
+		}
+
 		strNode, err := yaml.Parse(substed)
 		if err != nil {
+			fmt.Fprintln(os.Stderr, substed)
+			fmt.Fprintln(os.Stderr, len(substed))
 			return nil, fmt.Errorf("Could not parse node after envsubsting: %v", err)
 		}
 
@@ -83,16 +123,34 @@ func filter(in *yaml.RNode) (*yaml.RNode, error) {
 }
 
 func main() {
+	config := new(Config)
 	fn := func(items []*yaml.RNode) ([]*yaml.RNode, error) {
+		config.envMapping = func(str string, nodeInfo envsubst.NodeInfo) (string, bool) {
+			if len(config.IncludedVars) == 0 {
+				if contains(config.ExcludedVars, str) {
+					return nodeInfo.Orig(), false
+				}
+
+				return str, true
+			}
+
+			if !contains(config.IncludedVars, str) {
+				return nodeInfo.Orig(), false
+			}
+
+			return str, true
+		}
+
 		for i := range items {
-			err := items[i].PipeE(yaml.FilterFunc(filter))
+			err := items[i].PipeE(config)
 			if err != nil {
-				return nil, fmt.Errorf("kustomize-krm-envsubt: %v", err)
+				return nil, fmt.Errorf("kustomize-krm-envsubst: %v ", // leave a space because kustomize doesn't
+					err)
 			}
 		}
 		return items, nil
 	}
-	p := framework.SimpleProcessor{Config: nil, Filter: kio.FilterFunc(fn)}
+	p := framework.SimpleProcessor{Config: config, Filter: kio.FilterFunc(fn)}
 	cmd := command.Build(p, command.StandaloneDisabled, false)
 	command.AddGenerateDockerfile(cmd)
 	if err := cmd.Execute(); err != nil {

test/transformer.yaml

@@ -5,4 +5,4 @@ metadata:
   annotations:
     config.kubernetes.io/function: |
       exec:
-        path: ./kustomize-krm-envsubst
+        path: ../kustomize-krm-envsubst