Merged envsubst into env operators

pkg/yqlib/doc/operators/env-variable-operators.md

@@ -1,6 +1,21 @@
 # Env Variable Operators
 
-This operator is used to handle environment variables usage in path expressions. While environment variables can, of course, be passed in via your CLI with string interpolation, this often comes with complex quote escaping and can be tricky to write and read. Note that there are two forms, `env` which will parse the environment variable as a yaml (be it a map, array, string, number of boolean) and `strenv` which will always parse the argument as a string.
+These operators are used to handle environment variables usage in expressions and documents. While environment variables can, of course, be passed in via your CLI with string interpolation, this often comes with complex quote escaping and can be tricky to write and read. 
+
+There are three operators:
+-  `env` which takes a single environment variable name and parse the variable as a yaml node (be it a map, array, string, number of boolean) 
+- `strenv` which also takes a single environment variable name, and always parses the variable as a string.
+- `envsubst` which you pipe strings into and it interpolates environment variables in strings using [envsubst](https://github.com/a8m/envsubst). 
+
+
+## Tip
+To replace environment variables across all values in a document, `envsubst` can be used with the recursive descent operator
+as follows:
+
+```bash
+yq eval '(.. | select(tag == "!!str")) |= envsubst' file.yaml
+```
+
 
 ## Read string environment variable
 Running
@@ -77,3 +92,47 @@ will output
 meow
 ```
 
+## Replace strings with envsubst
+Running
+```bash
+myenv="cat" yq eval --null-input '"the ${myenv} meows" | envsubst'
+```
+will output
+```yaml
+the cat meows
+```
+
+## Replace strings with envsubst, missing variables
+Running
+```bash
+myenv="cat" yq eval --null-input '"the ${myenvnonexisting} meows" | envsubst'
+```
+will output
+```yaml
+the  meows
+```
+
+## Replace strings with envsubst, missing variables with defaults
+Running
+```bash
+myenv="cat" yq eval --null-input '"the ${myenvnonexisting-dog} meows" | envsubst'
+```
+will output
+```yaml
+the dog meows
+```
+
+## Replace string environment variable in document
+Given a sample.yml file of:
+```yaml
+v: ${myenv}
+```
+then
+```bash
+myenv="cat meow" yq eval '.v |= envsubst' sample.yml
+```
+will output
+```yaml
+v: cat meow
+```
+

pkg/yqlib/doc/operators/envsubst.md

@@ -1,55 +0,0 @@
-# Envsubst
-
-This operator is used to replace environment variables in strings using [envsubst](https://github.com/a8m/envsubst).
-
-To replace environment variables across all values in a document, this can be used with the recursive descent operator
-as follows:
-
-```bash
-yq eval '(.. | select(tag == "!!str)) |= envsubst' file.yaml
-```
-
-## Replace strings with envsubst
-Running
-```bash
-myenv="cat" yq eval --null-input '"the ${myenv} meows" | envsubst'
-```
-will output
-```yaml
-the cat meows
-```
-
-## Replace strings with envsubst, missing variables
-Running
-```bash
-myenv="cat" yq eval --null-input '"the ${myenvnonexisting} meows" | envsubst'
-```
-will output
-```yaml
-the  meows
-```
-
-## Replace strings with envsubst, missing variables with defaults
-Running
-```bash
-myenv="cat" yq eval --null-input '"the ${myenvnonexisting-dog} meows" | envsubst'
-```
-will output
-```yaml
-the dog meows
-```
-
-## Replace string environment variable in document
-Given a sample.yml file of:
-```yaml
-v: ${myenv}
-```
-then
-```bash
-myenv="cat meow" yq eval '.v |= envsubst' sample.yml
-```
-will output
-```yaml
-v: cat meow
-```
-

pkg/yqlib/doc/operators/headers/env-variable-operators.md

@@ -1,3 +1,18 @@
 # Env Variable Operators
 
-This operator is used to handle environment variables usage in path expressions. While environment variables can, of course, be passed in via your CLI with string interpolation, this often comes with complex quote escaping and can be tricky to write and read. Note that there are two forms, `env` which will parse the environment variable as a yaml (be it a map, array, string, number of boolean) and `strenv` which will always parse the argument as a string.
+These operators are used to handle environment variables usage in expressions and documents. While environment variables can, of course, be passed in via your CLI with string interpolation, this often comes with complex quote escaping and can be tricky to write and read. 
+
+There are three operators:
+-  `env` which takes a single environment variable name and parse the variable as a yaml node (be it a map, array, string, number of boolean) 
+- `strenv` which also takes a single environment variable name, and always parses the variable as a string.
+- `envsubst` which you pipe strings into and it interpolates environment variables in strings using [envsubst](https://github.com/a8m/envsubst). 
+
+
+## Tip
+To replace environment variables across all values in a document, `envsubst` can be used with the recursive descent operator
+as follows:
+
+```bash
+yq eval '(.. | select(tag == "!!str")) |= envsubst' file.yaml
+```
+

pkg/yqlib/doc/operators/headers/envsubst.md

@@ -1,10 +0,0 @@
-# Envsubst
-
-This operator is used to replace environment variables in strings using [envsubst](https://github.com/a8m/envsubst).
-
-To replace environment variables across all values in a document, this can be used with the recursive descent operator
-as follows:
-
-```bash
-yq eval '(.. | select(tag == "!!str")) |= envsubst' file.yaml
-```

pkg/yqlib/operator_env.go

@@ -1,10 +1,12 @@
 package yqlib
 
 import (
+	"container/list"
 	"fmt"
 	"os"
 	"strings"
 
+	envsubst "github.com/a8m/envsubst"
 	yaml "gopkg.in/yaml.v3"
 )
 
@@ -47,3 +49,26 @@ func envOperator(d *dataTreeNavigator, context Context, expressionNode *Expressi
 
 	return context.SingleChildContext(target), nil
 }
+
+func envsubstOperator(d *dataTreeNavigator, context Context, expressionNode *ExpressionNode) (Context, error) {
+	var results = list.New()
+
+	for el := context.MatchingNodes.Front(); el != nil; el = el.Next() {
+		candidate := el.Value.(*CandidateNode)
+		node := unwrapDoc(candidate.Node)
+		if node.Tag != "!!str" {
+			log.Warning("EnvSubstOperator, env name:", node.Tag, node.Value)
+			return Context{}, fmt.Errorf("cannot substitute with %v, can only substitute strings. Hint: Most often you'll want to use '|=' over '=' for this operation", node.Tag)
+		}
+
+		value, err := envsubst.String(node.Value)
+		if err != nil {
+			return Context{}, err
+		}
+		targetNode := &yaml.Node{Kind: yaml.ScalarNode, Value: value, Tag: "!!str"}
+		result := candidate.CreateReplacement(targetNode)
+		results.PushBack(result)
+	}
+
+	return context.ChildContext(results), nil
+}

pkg/yqlib/operator_env_test.go

@@ -62,6 +62,39 @@ var envOperatorScenarios = []expressionScenario{
 			"D0, P[cat], (!!str)::meow\n",
 		},
 	},
+	{
+		description:         "Replace strings with envsubst",
+		environmentVariable: "cat",
+		expression:          `"the ${myenv} meows" | envsubst`,
+		expected: []string{
+			"D0, P[], (!!str)::the cat meows\n",
+		},
+	},
+	{
+		description:         "Replace strings with envsubst, missing variables",
+		environmentVariable: "cat",
+		expression:          `"the ${myenvnonexisting} meows" | envsubst`,
+		expected: []string{
+			"D0, P[], (!!str)::the  meows\n",
+		},
+	},
+	{
+		description:         "Replace strings with envsubst, missing variables with defaults",
+		environmentVariable: "cat",
+		expression:          `"the ${myenvnonexisting-dog} meows" | envsubst`,
+		expected: []string{
+			"D0, P[], (!!str)::the dog meows\n",
+		},
+	},
+	{
+		description:         "Replace string environment variable in document",
+		environmentVariable: "cat meow",
+		document:            "{v: \"${myenv}\"}",
+		expression:          `.v |= envsubst`,
+		expected: []string{
+			"D0, P[], (doc)::{v: \"cat meow\"}\n",
+		},
+	},
 }
 
 func TestEnvOperatorScenarios(t *testing.T) {

pkg/yqlib/operator_envsubst.go

@@ -1,32 +0,0 @@
-package yqlib
-
-import (
-	"container/list"
-	"fmt"
-
-	envsubst "github.com/a8m/envsubst"
-	yaml "gopkg.in/yaml.v3"
-)
-
-func envsubstOperator(d *dataTreeNavigator, context Context, expressionNode *ExpressionNode) (Context, error) {
-	var results = list.New()
-
-	for el := context.MatchingNodes.Front(); el != nil; el = el.Next() {
-		candidate := el.Value.(*CandidateNode)
-		node := unwrapDoc(candidate.Node)
-		if node.Tag != "!!str" {
-			log.Warning("EnvSubstOperator, env name:", node.Tag, node.Value)
-			return Context{}, fmt.Errorf("cannot substitute with %v, can only substitute strings. Hint: Most often you'll want to use '|=' over '=' for this operation", node.Tag)
-		}
-
-		value, err := envsubst.String(node.Value)
-		if err != nil {
-			return Context{}, err
-		}
-		targetNode := &yaml.Node{Kind: yaml.ScalarNode, Value: value, Tag: "!!str"}
-		result := candidate.CreateReplacement(targetNode)
-		results.PushBack(result)
-	}
-
-	return context.ChildContext(results), nil
-}

pkg/yqlib/operator_envsubst_test.go

@@ -1,48 +0,0 @@
-package yqlib
-
-import (
-	"testing"
-)
-
-var envsubstOperatorScenarios = []expressionScenario{
-	{
-		description:         "Replace strings with envsubst",
-		environmentVariable: "cat",
-		expression:          `"the ${myenv} meows" | envsubst`,
-		expected: []string{
-			"D0, P[], (!!str)::the cat meows\n",
-		},
-	},
-	{
-		description:         "Replace strings with envsubst, missing variables",
-		environmentVariable: "cat",
-		expression:          `"the ${myenvnonexisting} meows" | envsubst`,
-		expected: []string{
-			"D0, P[], (!!str)::the  meows\n",
-		},
-	},
-	{
-		description:         "Replace strings with envsubst, missing variables with defaults",
-		environmentVariable: "cat",
-		expression:          `"the ${myenvnonexisting-dog} meows" | envsubst`,
-		expected: []string{
-			"D0, P[], (!!str)::the dog meows\n",
-		},
-	},
-	{
-		description:         "Replace string environment variable in document",
-		environmentVariable: "cat meow",
-		document:            "{v: \"${myenv}\"}",
-		expression:          `.v |= envsubst`,
-		expected: []string{
-			"D0, P[], (doc)::{v: \"cat meow\"}\n",
-		},
-	},
-}
-
-func TestEnvSubstOperatorScenarios(t *testing.T) {
-	for _, tt := range envsubstOperatorScenarios {
-		testScenario(t, &tt)
-	}
-	documentOperatorScenarios(t, "envsubst", envsubstOperatorScenarios)
-}