script: Add json and yaml commands

go.mod

@@ -5,6 +5,7 @@ go 1.23.0
 require (
 	github.com/cilium/stream v0.0.0-20240209152734-a0792b51812d
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc
+	github.com/jmespath/go-jmespath v0.4.0
 	github.com/mitchellh/mapstructure v1.5.0
 	github.com/spf13/cast v1.6.0
 	github.com/spf13/cobra v1.8.0
@@ -13,8 +14,11 @@ require (
 	github.com/stretchr/testify v1.8.4
 	go.uber.org/dig v1.17.1
 	go.uber.org/goleak v1.3.0
+	golang.org/x/exp v0.0.0-20231206192017-f3f8817b8deb
+	golang.org/x/sys v0.15.0
 	golang.org/x/term v0.15.0
 	golang.org/x/tools v0.16.0
+	sigs.k8s.io/yaml v1.6.0
 )
 
 require (
@@ -32,8 +36,7 @@ require (
 	github.com/spf13/afero v1.11.0 // indirect
 	github.com/subosito/gotenv v1.6.0 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
-	golang.org/x/exp v0.0.0-20231206192017-f3f8817b8deb // indirect
-	golang.org/x/sys v0.15.0 // indirect
+	go.yaml.in/yaml/v2 v2.4.2 // indirect
 	golang.org/x/text v0.14.0 // indirect
 	golang.org/x/time v0.5.0 // indirect
 	gopkg.in/ini.v1 v1.67.0 // indirect

go.sum

@@ -15,6 +15,10 @@ github.com/hashicorp/hcl v1.0.0 h1:0Anlzjpi4vEasTeNFn2mLJgTSwt0+6sfsiTG8qcWGx4=
 github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
+github.com/jmespath/go-jmespath v0.4.0 h1:BEgLn5cpjn8UN1mAw4NjwDrS35OdebyEtFe+9YPoQUg=
+github.com/jmespath/go-jmespath v0.4.0/go.mod h1:T8mJZnbsbmF+m6zOOFylbeCJqk5+pHWvzYPziyZiYoo=
+github.com/jmespath/go-jmespath/internal/testify v1.5.1 h1:shLQSRRSCCPj3f2gpwzGwWFoC7ycTf1rcQZHOlsJ6N8=
+github.com/jmespath/go-jmespath/internal/testify v1.5.1/go.mod h1:L3OGu8Wl2/fWfCI6z80xFu9LTZmf1ZRjMHUOPmWr69U=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
@@ -62,6 +66,10 @@ go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
 go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
 go.uber.org/multierr v1.11.0 h1:blXXJkSxSSfBVBlC76pxqeO+LN3aDfLQo+309xJstO0=
 go.uber.org/multierr v1.11.0/go.mod h1:20+QtiLqy0Nd6FdQB9TLXag12DsQkrbs3htMFfDN80Y=
+go.yaml.in/yaml/v2 v2.4.2 h1:DzmwEr2rDGHl7lsFgAHxmNz/1NlQ7xLIrlN2h5d1eGI=
+go.yaml.in/yaml/v2 v2.4.2/go.mod h1:081UH+NErpNdqlCXm3TtEran0rJZGxAYx9hb/ELlsPU=
+go.yaml.in/yaml/v3 v3.0.3 h1:bXOww4E/J3f66rav3pX3m8w6jDE4knZjGOw8b5Y6iNE=
+go.yaml.in/yaml/v3 v3.0.3/go.mod h1:tBHosrYAkRZjRAOREWbDnBXUf08JOwYq++0QNwQiWzI=
 golang.org/x/exp v0.0.0-20231206192017-f3f8817b8deb h1:c0vyKkb6yr3KR7jEfJaOSv4lG7xPkbN6r52aJz1d8a8=
 golang.org/x/exp v0.0.0-20231206192017-f3f8817b8deb/go.mod h1:iRJReGqOEeBhDZGkGbynYwcHlctCvnjTYIamk7uXpHI=
 golang.org/x/sys v0.15.0 h1:h48lPFYpsTvQJZF4EKyI4aLHaev3CxivZmv7yZig9pc=
@@ -79,6 +87,10 @@ gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogR
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/ini.v1 v1.67.0 h1:Dgnx+6+nfE+IfzjUEISNeydPJh9AXNNsWbGP9KzCsOA=
 gopkg.in/ini.v1 v1.67.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
+gopkg.in/yaml.v2 v2.2.8 h1:obN1ZagJSUGI0Ek/LBmuj4SNLPfIny3KsKFopxRdj10=
+gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+sigs.k8s.io/yaml v1.6.0 h1:G8fkbMSAFqgEFgh4b1wmtzDnioxFCUgTZhlbj5P9QYs=
+sigs.k8s.io/yaml v1.6.0/go.mod h1:796bPqUfzR/0jLAl6XjHl3Ck7MiyVv8dbTdyT3/pMf4=

script/cmds.go

@@ -5,6 +5,7 @@
 package script
 
 import (
+	"encoding/json"
 	"errors"
 	"fmt"
 	"io/fs"
@@ -21,9 +22,12 @@ import (
 	"sync"
 	"time"
 
-	"github.com/cilium/hive/script/internal/diff"
+	"github.com/jmespath/go-jmespath"
 	"github.com/spf13/pflag"
 	"golang.org/x/term"
+	"sigs.k8s.io/yaml"
+
+	"github.com/cilium/hive/script/internal/diff"
 )
 
 // DefaultCmds returns a set of broadly useful script commands.
@@ -57,6 +61,8 @@ func DefaultCmds() map[string]Cmd {
 		"symlink": Symlink(),
 		"wait":    Wait(),
 		"break":   Break(),
+		"json":    Json(),
+		"yaml":    Yaml(),
 	}
 }
 
@@ -1575,3 +1581,104 @@ func dirEntryIsExec(entry os.DirEntry) bool {
 	}
 	return info.Mode()&execAny != 0
 }
+
+func Json() Cmd {
+	return jsonOrYaml(false)
+}
+
+func Yaml() Cmd {
+	return jsonOrYaml(true)
+}
+
+func jsonOrYaml(yamlMode bool) Cmd {
+	which := "JSON"
+	if yamlMode {
+		which = "YAML"
+	}
+	return Command(
+		CmdUsage{
+			Summary: "Transform a "+which+" document with a JMESPath expression",
+			Args:    "expression",
+			Detail: []string{
+				"See https://jmespath.org/tutorial.html for tutorial on JMESPath expressions.",
+			},
+			Flags: func(fs *pflag.FlagSet) {
+				fs.StringP("input", "i", "", "File to read from instead of stdout buffer")
+				fs.StringP("output", "o", "", "File to write to instead of stdout buffer")
+				fs.BoolP("quiet", "q", false, "Do not output the transformed document")
+				fs.BoolP("fail", "f", false, "Fail on null (no match)")
+			},
+		},
+		func(s *State, args ...string) (WaitFunc, error) {
+			if len(args) != 1 {
+				return nil, fmt.Errorf("%s: expected expression", ErrUsage)
+			}
+			expr := args[0]
+			return func(s *State) (stdout string, stderr string, err error) {
+				input := []byte(s.Stdout())
+				if inputFile, err := s.Flags.GetString("input"); err != nil {
+					return "", "", err
+				} else if inputFile != "" {
+					b, err := os.ReadFile(s.Path(inputFile))
+					if err != nil {
+						return "", "", err
+					}
+					input = b
+				}
+
+				if yamlMode {
+					input, err = yaml.YAMLToJSON(input)
+					if err != nil {
+						return "", "", err
+					}
+				}
+
+				var data any
+				if err := json.Unmarshal(input, &data); err != nil {
+					return "", "", err
+				}
+				result, err := jmespath.Search(expr, data)
+				if err != nil {
+					return "", "", err
+				}
+
+				if fail, err := s.Flags.GetBool("fail"); err != nil {
+					return "", "", err
+				} else if fail && result == nil {
+					return "", "", errors.New("No match")
+				}
+
+				if quiet, err := s.Flags.GetBool("quiet"); err != nil {
+					return "", "", err
+				} else if quiet {
+					return "", "", nil
+				}
+
+				var out []byte
+				if yamlMode {
+					out, err = yaml.Marshal(result)
+					if err != nil {
+						return "", "", err
+					}
+				} else {
+					out, err = json.Marshal(result)
+					if err != nil {
+						return "", "", err
+					}
+				}
+
+				if outputFile, err := s.Flags.GetString("output"); err != nil {
+					return "", "", err
+				} else if outputFile != "" {
+					err := os.WriteFile(s.Path(outputFile), out, 0644)
+					return "", "", err
+				}
+
+				return string(out), "", nil
+			}, nil
+
+		},
+	)
+}
+
+

script/scripttest/testdata/jmes.txt

@@ -0,0 +1,39 @@
+# Tests for the json/yaml commands for transforming a JSON/YAML document using
+# a JMESPath expression.
+
+# stdout
+echo '{"a": "b"}'
+json a
+stdout "b"
+
+echo 'a: b'
+yaml a
+stdout b
+
+# from input file
+json -i test.json a
+stdout ^{"aa":"foo"}$
+
+json -i test.json a.aa
+stdout "foo"
+
+json -i test.json c[?v>`1`].v
+stdout [2]
+
+yaml -i test.yaml c[?v>`1`].v
+stdout '\- 2'
+
+# fail when no matches
+! json --fail --input test.json 'c[2]'
+! json --fail --input test.json 'd'
+
+-- test.json --
+{"a": {"aa": "foo"}, "b": 10, "c": [{"v": 1}, {"v": 2}]}
+
+-- test.yaml --
+a:
+  aa: foo
+b: 10
+c:
+  - v: 1
+  - v: 2