Files
docker-cli/components/engine/cli/compose/interpolation/interpolation.go
Vincent Demeester 229e8f9746 Make sure we error out instead of panic during interpolation
Use type assertion to error out if the type isn't the right one
instead of panic as before this change.

Signed-off-by: Vincent Demeester <vincent@sbr.pm>
Upstream-commit: c165a8bfa1419724eb504f3cb7fdf3ca1b97483b
Component: engine
2017-03-23 16:09:57 +01:00

93 lines
2.0 KiB
Go

package interpolation
import (
"github.com/docker/docker/cli/compose/template"
"github.com/pkg/errors"
)
// Interpolate replaces variables in a string with the values from a mapping
func Interpolate(config map[string]interface{}, section string, mapping template.Mapping) (map[string]interface{}, error) {
out := map[string]interface{}{}
for name, item := range config {
if item == nil {
out[name] = nil
continue
}
mapItem, ok := item.(map[string]interface{})
if !ok {
return nil, errors.Errorf("Invalid type for %s : %T instead of %T", name, item, out)
}
interpolatedItem, err := interpolateSectionItem(name, mapItem, section, mapping)
if err != nil {
return nil, err
}
out[name] = interpolatedItem
}
return out, nil
}
func interpolateSectionItem(
name string,
item map[string]interface{},
section string,
mapping template.Mapping,
) (map[string]interface{}, error) {
out := map[string]interface{}{}
for key, value := range item {
interpolatedValue, err := recursiveInterpolate(value, mapping)
if err != nil {
return nil, errors.Errorf(
"Invalid interpolation format for %#v option in %s %#v: %#v. You may need to escape any $ with another $.",
key, section, name, err.Template,
)
}
out[key] = interpolatedValue
}
return out, nil
}
func recursiveInterpolate(
value interface{},
mapping template.Mapping,
) (interface{}, *template.InvalidTemplateError) {
switch value := value.(type) {
case string:
return template.Substitute(value, mapping)
case map[string]interface{}:
out := map[string]interface{}{}
for key, elem := range value {
interpolatedElem, err := recursiveInterpolate(elem, mapping)
if err != nil {
return nil, err
}
out[key] = interpolatedElem
}
return out, nil
case []interface{}:
out := make([]interface{}, len(value))
for i, elem := range value {
interpolatedElem, err := recursiveInterpolate(elem, mapping)
if err != nil {
return nil, err
}
out[i] = interpolatedElem
}
return out, nil
default:
return value, nil
}
}