Initial checkin from CRI-O repo

Signed-off-by: Matthew Heon <matthew.heon@gmail.com>

2 files changed, 221 insertions, 0 deletions

diff --git a/cmd/kpod/formats/formats.go b/cmd/kpod/formats/formats.go
new file mode 100644
index 000000000..6e5dd2425
--- /dev/null
+++ b/cmd/kpod/formats/formats.go
@@ -0,0 +1,143 @@
+package formats
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"strings"
+	"text/tabwriter"
+	"text/template"
+
+	"bytes"
+	"github.com/ghodss/yaml"
+	"github.com/pkg/errors"
+)
+
+const (
+	// JSONString const to save on duplicate variable names
+	JSONString = "json"
+	// IDString const to save on duplicates for Go templates
+	IDString = "{{.ID}}"
+)
+
+// Writer interface for outputs
+type Writer interface {
+	Out() error
+}
+
+// JSONStructArray for JSON output
+type JSONStructArray struct {
+	Output []interface{}
+}
+
+// StdoutTemplateArray for Go template output
+type StdoutTemplateArray struct {
+	Output   []interface{}
+	Template string
+	Fields   map[string]string
+}
+
+// JSONStruct for JSON output
+type JSONStruct struct {
+	Output interface{}
+}
+
+// StdoutTemplate for Go template output
+type StdoutTemplate struct {
+	Output   interface{}
+	Template string
+	Fields   map[string]string
+}
+
+// YAMLStruct for YAML output
+type YAMLStruct struct {
+	Output interface{}
+}
+
+// Out method for JSON Arrays
+func (j JSONStructArray) Out() error {
+	data, err := json.MarshalIndent(j.Output, "", "    ")
+	if err != nil {
+		return err
+	}
+
+	// JSON returns a byte array with a literal null [110 117 108 108] in it
+	// if it is passed empty data.  We used bytes.Compare to see if that is
+	// the case.
+	if diff := bytes.Compare(data, []byte("null")); diff == 0 {
+		data = []byte("[]")
+	}
+
+	// If the we did get NULL back, we should spit out {} which is
+	// at least valid JSON for the consumer.
+	fmt.Printf("%s\n", data)
+	return nil
+}
+
+// Out method for Go templates
+func (t StdoutTemplateArray) Out() error {
+	w := tabwriter.NewWriter(os.Stdout, 0, 0, 3, ' ', 0)
+	if strings.HasPrefix(t.Template, "table") {
+		// replace any spaces with tabs in template so that tabwriter can align it
+		t.Template = strings.Replace(strings.TrimSpace(t.Template[5:]), " ", "\t", -1)
+		headerTmpl, err := template.New("header").Funcs(headerFunctions).Parse(t.Template)
+		if err != nil {
+			return errors.Wrapf(err, "Template parsing error")
+		}
+		err = headerTmpl.Execute(w, t.Fields)
+		if err != nil {
+			return err
+		}
+		fmt.Fprintln(w, "")
+	}
+	t.Template = strings.Replace(t.Template, " ", "\t", -1)
+	tmpl, err := template.New("image").Funcs(basicFunctions).Parse(t.Template)
+	if err != nil {
+		return errors.Wrapf(err, "Template parsing error")
+	}
+	for _, img := range t.Output {
+		basicTmpl := tmpl.Funcs(basicFunctions)
+		err = basicTmpl.Execute(w, img)
+		if err != nil {
+			return err
+		}
+		fmt.Fprintln(w, "")
+	}
+	return w.Flush()
+}
+
+// Out method for JSON struct
+func (j JSONStruct) Out() error {
+	data, err := json.MarshalIndent(j.Output, "", "    ")
+	if err != nil {
+		return err
+	}
+	fmt.Printf("%s\n", data)
+	return nil
+}
+
+//Out method for Go templates
+func (t StdoutTemplate) Out() error {
+	tmpl, err := template.New("image").Parse(t.Template)
+	if err != nil {
+		return errors.Wrapf(err, "template parsing error")
+	}
+	err = tmpl.Execute(os.Stdout, t.Output)
+	if err != nil {
+		return err
+	}
+	fmt.Println()
+	return nil
+}
+
+// Out method for YAML
+func (y YAMLStruct) Out() error {
+	var buf []byte
+	var err error
+	buf, err = yaml.Marshal(y.Output)
+	if err != nil {
+		return err
+	}
+	fmt.Println(string(buf))
+	return nil
+}
diff --git a/cmd/kpod/formats/templates.go b/cmd/kpod/formats/templates.go
new file mode 100644
index 000000000..c2582552a
--- /dev/null
+++ b/cmd/kpod/formats/templates.go
@@ -0,0 +1,78 @@
+package formats
+
+import (
+	"bytes"
+	"encoding/json"
+	"strings"
+	"text/template"
+)
+
+// basicFunctions are the set of initial
+// functions provided to every template.
+var basicFunctions = template.FuncMap{
+	"json": func(v interface{}) string {
+		buf := &bytes.Buffer{}
+		enc := json.NewEncoder(buf)
+		enc.SetEscapeHTML(false)
+		_ = enc.Encode(v)
+		// Remove the trailing new line added by the encoder
+		return strings.TrimSpace(buf.String())
+	},
+	"split":    strings.Split,
+	"join":     strings.Join,
+	"title":    strings.Title,
+	"lower":    strings.ToLower,
+	"upper":    strings.ToUpper,
+	"pad":      padWithSpace,
+	"truncate": truncateWithLength,
+}
+
+// HeaderFunctions are used to created headers of a table.
+// This is a replacement of basicFunctions for header generation
+// because we want the header to remain intact.
+// Some functions like `split` are irrelevant so not added.
+var headerFunctions = template.FuncMap{
+	"json": func(v string) string {
+		return v
+	},
+	"title": func(v string) string {
+		return v
+	},
+	"lower": func(v string) string {
+		return v
+	},
+	"upper": func(v string) string {
+		return v
+	},
+	"truncate": func(v string, l int) string {
+		return v
+	},
+}
+
+// Parse creates a new anonymous template with the basic functions
+// and parses the given format.
+func Parse(format string) (*template.Template, error) {
+	return NewParse("", format)
+}
+
+// NewParse creates a new tagged template with the basic functions
+// and parses the given format.
+func NewParse(tag, format string) (*template.Template, error) {
+	return template.New(tag).Funcs(basicFunctions).Parse(format)
+}
+
+// padWithSpace adds whitespace to the input if the input is non-empty
+func padWithSpace(source string, prefix, suffix int) string {
+	if source == "" {
+		return source
+	}
+	return strings.Repeat(" ", prefix) + source + strings.Repeat(" ", suffix)
+}
+
+// truncateWithLength truncates the source string up to the length provided by the input
+func truncateWithLength(source string, length int) string {
+	if len(source) < length {
+		return source
+	}
+	return source[:length]
+}