NEW FEATURE: diff2: A better "diff" mechanism (#1852)

pkg/diff2/unmanaged.go

@@ -0,0 +1,129 @@
+package diff2
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/gobwas/glob"
+
+	"github.com/StackExchange/dnscontrol/v3/models"
+	"github.com/StackExchange/dnscontrol/v3/pkg/printer"
+)
+
+func handsoff(
+	existing, desired models.Records,
+	unmanaged []*models.UnmanagedConfig,
+	beSafe bool,
+) (models.Records, error) {
+
+	// What foreign items should we ignore?
+	foreign, err := manyQueries(existing, unmanaged)
+	if err != nil {
+		return nil, err
+	}
+	if len(foreign) != 0 {
+		printer.Printf("INFO: Foreign records being ignored: (%d)\n", len(foreign))
+		for i, r := range foreign {
+			printer.Printf("- % 4d: %s %s %s\n", i, r.GetLabelFQDN(), r.Type, r.GetTargetRFC1035Quoted())
+		}
+	}
+
+	// What desired items might conflict?
+	conflicts, err := manyQueries(desired, unmanaged)
+	if err != nil {
+		return nil, err
+	}
+	if len(conflicts) != 0 {
+		level := "WARN"
+		if beSafe {
+			level = "ERROR"
+		}
+		printer.Printf("%s: dnsconfig.js records that overlap MANAGED: (%d)\n", level, len(conflicts))
+		for i, r := range conflicts {
+			printer.Printf("- % 4d: %s %s %s\n", i, r.GetLabelFQDN(), r.Type, r.GetTargetRFC1035Quoted())
+		}
+		if beSafe {
+			return nil, fmt.Errorf("ERROR: Unsafe to continue. Add DISABLE_UNMANAGED_SAFETY_CHECK to D() to override")
+		}
+	}
+
+	// Add the foreign items to the desired list.
+	// (Rather than literally ignoring them, we just add them to the desired list
+	// and all the diffing algorithms become more simple.)
+	desired = append(desired, foreign...)
+
+	return desired, nil
+}
+
+func manyQueries(rcs models.Records, queries []*models.UnmanagedConfig) (result models.Records, err error) {
+
+	for _, q := range queries {
+
+		lab := q.Label
+		if lab == "" {
+			lab = "*"
+		}
+		glabel, err := glob.Compile(lab)
+		if err != nil {
+			return nil, err
+		}
+
+		targ := q.Target
+		if targ == "" {
+			targ = "*"
+		}
+		gtarget, err := glob.Compile(targ)
+		if err != nil {
+			return nil, err
+		}
+
+		hasRType := compileTypeGlob(q.RType)
+
+		for _, rc := range rcs {
+			if match(rc, glabel, gtarget, hasRType) {
+				result = append(result, rc)
+			}
+		}
+	}
+	return result, nil
+}
+
+func compileTypeGlob(g string) map[string]bool {
+	m := map[string]bool{}
+	for _, j := range strings.Split(g, ",") {
+		m[strings.TrimSpace(j)] = true
+	}
+	return m
+}
+
+func match(rc *models.RecordConfig, glabel, gtarget glob.Glob, hasRType map[string]bool) bool {
+	printer.Printf("DEBUG: match(%v, %v, %v, %v)\n", rc.NameFQDN, glabel, gtarget, hasRType)
+
+	// _ = glabel.Match(rc.NameFQDN)
+	// _ = matchType(rc.Type, hasRType)
+	// x := rc.GetTargetField()
+	// _ = gtarget.Match(x)
+
+	if !glabel.Match(rc.NameFQDN) {
+		printer.Printf("DEBUG: REJECTED LABEL: %s:%v\n", rc.NameFQDN, glabel)
+		return false
+	} else if !matchType(rc.Type, hasRType) {
+		printer.Printf("DEBUG: REJECTED TYPE: %s:%v\n", rc.Type, hasRType)
+		return false
+	} else if gtarget == nil {
+		return true
+	} else if !gtarget.Match(rc.GetTargetField()) {
+		printer.Printf("DEBUG: REJECTED TARGET: %v:%v\n", rc.GetTargetField(), gtarget)
+		return false
+	}
+	return true
+}
+
+func matchType(s string, hasRType map[string]bool) bool {
+	printer.Printf("DEBUG: matchType map=%v\n", hasRType)
+	if len(hasRType) == 0 {
+		return true
+	}
+	_, ok := hasRType[s]
+	return ok
+}