Add an xmlvalidate command

go.mod

@@ -45,6 +45,7 @@ require (
 	github.com/robfig/cron v1.2.0 // indirect
 	github.com/rogpeppe/go-internal v1.12.0 // indirect
 	github.com/sirupsen/logrus v1.9.3 // indirect
+	github.com/spf13/pflag v1.0.5
 	github.com/stretchr/objx v0.5.2 // indirect
 	github.com/stretchr/testify v1.9.0 // indirect
 	github.com/therootcompany/xz v1.0.1 // indirect

go.sum

@@ -237,6 +237,8 @@ github.com/rwcarlsen/goexif v0.0.0-20190401172101-9e8deecbddbd/go.mod h1:hPqNNc0
 github.com/sirupsen/logrus v1.4.2/go.mod h1:tLMulIdttU9McNUspp0xgXVQah82FyeX6MwdIuYE2rE=
 github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
 github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
+github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
+github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=

xmlvalidate/README.md

@@ -5,7 +5,7 @@ Validates an XML file against an XSD schema using `xmlint`.
 ## Requirements
 
 This activity requires the `xmllint` command be installed on the system where
-the activity worker is running. This can be installed, in Ubuntu, by entering
+the activity worker is running. This can be installed in Ubuntu by entering
 the following command:
 
 ```bash
@@ -52,16 +52,35 @@ ctx = workflow.WithActivityOptions(ctx, workflow.ActivityOptions{
     RetryPolicy: &temporal.RetryPolicy{MaximumAttempts: 1},
 })
 
-var re xmlvalidate.Result
+var result xmlvalidate.Result
 err := workflow.ExecuteActivity(
     ctx,
     xmlvalidate.Name,
     &xmlvalidate.Params{
-        XMLFilePath: "/path/to/file.xml",
-        XSDFilePath: "/path/to/file.xsd",
+        XMLPath: "/path/to/file.xml",
+        XSDPath: "/path/to/file.xsd",
     },
-).Get(ctx, &re)
+).Get(ctx, &result)
 ```
 
-`err` may contain any non validation error. `re.Failures` contains the
-`xmllint` validation output as `[]bytes`.
+`err` may contain any non validation error. `result.Failures` encodes the
+`xmllint` validation stderr output as `[]string`.
+
+## Command
+
+XMLValidate includes a command-line entry point that can be executed with
+`go run`, e.g.:
+
+```bash
+go run ./xmlvalidate/cmd --xsd xmvalidate/testdata/person.xsd \
+xmlvalidate/testdata/person_invalid.xml
+```
+
+If validation is successful `xmlvalidate` will write "OK" to stdout and exit
+with status code: 0.
+
+If a validation error is encountered, `xmlvalidate` will write the validation
+error to stdout, and will exit with status code: 0.
+
+If a non-validation error is encountered, `xmlvalidate` will write the error
+message to stderr, and exit with status code: 1.

xmlvalidate/cmd/main.go

@@ -0,0 +1,95 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/signal"
+
+	"github.com/spf13/pflag"
+
+	"github.com/artefactual-sdps/temporal-activities/xmlvalidate"
+)
+
+func seeHelp() string {
+	return "See 'xmlvalidate --help' for usage."
+}
+
+func usage() string {
+	return `
+USAGE: xmlvalidate [options] XMLFILE
+
+XMLFILE  Path of the XML file to be validated
+
+OPTIONS:
+  --xsd PATH  Path of an XSD file to validate against
+  --help      Display this help and exit
+
+`
+}
+
+// To test: `go run ./cmd --xsd testdata/person.xsd testdata/person_valid.xml`
+func main() {
+	// Setup signal handlers.
+	ctx, cancel := context.WithCancel(context.Background())
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, os.Interrupt)
+	go func() { <-c; cancel() }()
+
+	// Execute program.
+	out, err := Run(ctx, os.Args)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+
+	fmt.Fprintln(os.Stdout, out)
+}
+
+func Run(ctx context.Context, args []string) (string, error) {
+	var (
+		help bool
+		xsd  string
+	)
+
+	p := pflag.NewFlagSet(args[0], pflag.ExitOnError)
+	p.BoolVarP(&help, "help", "h", false, "display help and exit")
+	p.StringVar(&xsd, "xsd", "", "XSD file `path`")
+
+	var out string
+	p.Usage = func() {
+		out = usage()
+	}
+
+	if err := p.Parse(args[1:]); err != nil {
+		if err == pflag.ErrHelp {
+			return out, nil
+		}
+		return "", err
+	}
+	args = p.Args()
+
+	if help {
+		return usage(), nil
+	}
+
+	if len(args) == 0 {
+		return "", fmt.Errorf("missing XMLFILE\n%s", seeHelp())
+	}
+
+	if xsd == "" {
+		return "", fmt.Errorf("an --xsd file must be specified\n%s", seeHelp())
+	}
+
+	v := xmlvalidate.NewXMLLintValidator()
+	out, err := v.Validate(ctx, args[0], xsd)
+	if err != nil {
+		return "", err
+	}
+
+	if out == "" {
+		out = "OK"
+	}
+
+	return out, nil
+}