diff --git a/templater/templater.go b/templater/templater.go new file mode 100644 index 000000000..f4be1e6fa --- /dev/null +++ b/templater/templater.go @@ -0,0 +1,97 @@ +package templater + +import ( + "fmt" + "io/ioutil" + "strings" + "os" + "path" + "text/template" + "bytes" + + "github.com/tazjin/kontemplate/context" + "github.com/polydawn/meep" +) + +// Error that is caused by non-existent template files being specified +type TemplateNotFoundError struct { + meep.AllTraits + Name string +} + +// Error that is caused during templating, e.g. required value being absent or invalid template format +type TemplatingError struct { + meep.AllTraits +} + +func LoadAndPrepareTemplates(c *context.Context) ([]string, error) { + output := make([]string, 0) + + for _, rs := range c.ResourceSets { + fmt.Fprintf(os.Stderr,"Loading resources for %s\n", rs.Name) + + rp := path.Join(c.BaseDir, rs.Name) + files, err := ioutil.ReadDir(rp) + + if err != nil { + return nil, meep.New( + &TemplateNotFoundError{Name: rs.Name}, + meep.Cause(err), + ) + } + + + for _, file := range files { + if !file.IsDir() && isResourceFile(file) { + p := path.Join(rp, file.Name()) + o, err := templateFile(c, &rs, p) + + if err != nil { + return nil, err + } + + output = append(output, o) + } + } + } + + return output, nil +} + +func templateFile(c *context.Context, rs *context.ResourceSet, filename string) (string, error) { + tpl, err := template.ParseFiles(filename) + + if err != nil { + return "", meep.New( + &TemplateNotFoundError{Name: filename}, + meep.Cause(err), + ) + } + + var b bytes.Buffer + + // Merge global and resourceset-specific values (don't override from global) + for k, v := range c.Global { + if _, ok := rs.Values[k]; !ok { + rs.Values[k] = v + } + } + + err = tpl.Execute(&b, rs.Values) + + if err != nil { + return "", meep.New( + &TemplatingError{}, + meep.Cause(err), + ) + } + + return b.String(), nil +} + +// Checks whether a file is a resource file (i.e. is YAML or JSON) +func isResourceFile(f os.FileInfo) bool { + return strings.HasSuffix(f.Name(), "yaml") || + strings.HasSuffix(f.Name(), "yml") || + strings.HasSuffix(f.Name(), "json") +}