/
templating.go
83 lines (76 loc) · 2.57 KB
/
templating.go
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package model
import (
"bytes"
"fmt"
"github.com/echocat/kubor/template/functions"
"io"
"path/filepath"
"strings"
)
type Templating struct {
TemplateFilePattern []string `yaml:"templateFilePattern" json:"templateFilePattern"`
}
func NewTemplating() Templating {
return Templating{
TemplateFilePattern: []string{
"?{{ .Root }}/kubernetes/templates/*.yml",
"?{{ .Root }}/kubernetes/templates/*.yaml",
},
}
}
func (instance Templating) TemplateFiles(data interface{}) ([]string, error) {
return instance.renderFiles(instance.TemplateFilePattern, "template", data)
}
func (instance Templating) RenderedTemplatesProvider(data interface{}) (ContentProvider, error) {
if files, err := instance.TemplateFiles(data); err != nil {
return nil, err
} else {
i := 0
return func() (string, []byte, error) {
if i >= len(files) {
return "", nil, io.EOF
}
buf := new(bytes.Buffer)
file := files[i]
i++
if err := instance.RenderTemplateFile(file, data, buf); err != nil {
return file, nil, err
}
return file, buf.Bytes(), nil
}, nil
}
}
func (instance Templating) RenderTemplateFile(file string, data interface{}, writer io.Writer) error {
if tmpl, err := functions.DefaultTemplateFactory().NewFromFile(file); err != nil {
return fmt.Errorf("cannot parse template file '%s': %w", file, err)
} else if err := tmpl.Execute(data, writer); err != nil {
return fmt.Errorf("cannot render template file '%s': %w", file, err)
} else {
return nil
}
}
func (instance Templating) renderFiles(patterns []string, name string, data interface{}) ([]string, error) {
var result []string
for _, pattern := range patterns {
atLeastOneMatchExpected := true
if strings.HasPrefix(pattern, "?") {
pattern = pattern[1:]
atLeastOneMatchExpected = false
}
if tmpl, err := functions.DefaultTemplateFactory().New(pattern, pattern); err != nil {
return nil, fmt.Errorf("cannot handle %s pattern '%s': %w", name, pattern, err)
} else if rendered, err := tmpl.ExecuteToString(data); err != nil {
return nil, fmt.Errorf("cannot handle %s pattern: %w", name, err)
} else if rendered == "" {
// Ignore ... could happen if we use {{ if }} clauses
} else if matches, err := filepath.Glob(rendered); err != nil {
return nil, fmt.Errorf("cannot handle %s pattern '%s' => '%s': %w", name, pattern, rendered, err)
} else {
if len(matches) <= 0 && atLeastOneMatchExpected {
return nil, fmt.Errorf("there does not at least one %s file exist that matches '%s' => '%s'", name, pattern, rendered)
}
result = append(result, matches...)
}
}
return result, nil
}