dnscontrol/pkg/diff/diff.go
2023-10-22 13:56:13 -04:00

79 lines
2.8 KiB
Go

package diff
import (
"github.com/StackExchange/dnscontrol/v4/models"
"github.com/fatih/color"
)
// Correlation stores a difference between two records.
type Correlation struct {
d *differ
Existing *models.RecordConfig
Desired *models.RecordConfig
}
// Changeset stores many Correlation.
type Changeset []Correlation
// Differ is an interface for computing the difference between two zones.
type Differ interface {
// IncrementalDiff performs a diff on a record-by-record basis, and returns a sets for which records need to be created, deleted, or modified.
IncrementalDiff(existing []*models.RecordConfig) (reportMsgs []string, create, toDelete, modify Changeset, err error)
// ChangedGroups performs a diff more appropriate for providers with a "RecordSet" model, where all records with the same name and type are grouped.
// Individual record changes are often not useful in such scenarios. Instead we return a map of record keys to a list of change descriptions within that group.
ChangedGroups(existing []*models.RecordConfig) (map[models.RecordKey][]string, []string, error)
}
type differ struct {
}
// get normalized content for record. target, ttl, mxprio, and specified metadata
func (d *differ) content(r *models.RecordConfig) string {
return r.ToDiffable()
}
// ChangesetLess returns true if c[i] < c[j].
func ChangesetLess(c Changeset, i, j int) bool {
var a, b string
// Which fields are we comparing?
// Usually only Desired OR Existing content exists (we're either
// adding or deleting records). In those cases, just use whichever
// isn't nil.
// In the case where both Desired AND Existing exist, it doesn't
// matter which we use as long as we are consistent. I flipped a
// coin and picked to use Desired in that case.
if c[i].Desired != nil {
a = c[i].Desired.NameFQDN
} else {
a = c[i].Existing.NameFQDN
}
if c[j].Desired != nil {
b = c[j].Desired.NameFQDN
} else {
b = c[j].Existing.NameFQDN
}
return a < b
// TODO(tlim): This won't correctly sort:
// []string{"example.com", "foo.example.com", "bar.example.com"}
// A simple way to do that correctly is to split on ".", reverse the
// elements, and sort on the result.
}
// CorrectionLess returns true when comparing corrections.
func CorrectionLess(c []*models.Correction, i, j int) bool {
return c[i].Msg < c[j].Msg
}
func (c Correlation) String() string {
if c.Existing == nil {
return color.GreenString("+ CREATE %s %s %s", c.Desired.Type, c.Desired.GetLabelFQDN(), c.d.content(c.Desired))
}
if c.Desired == nil {
return color.RedString("- DELETE %s %s %s", c.Existing.Type, c.Existing.GetLabelFQDN(), c.d.content(c.Existing))
}
return color.YellowString("± MODIFY %s %s: (%s) -> (%s)", c.Existing.Type, c.Existing.GetLabelFQDN(), c.d.content(c.Existing), c.d.content(c.Desired))
}