Allow to partially uninstall a package graph, make uninstall --full optional

cmd/uninstall.go

@@ -57,6 +57,8 @@ var uninstallCmd = &cobra.Command{
 			attempts := LuetCfg.Viper.GetInt("solver.max_attempts")
 			force := LuetCfg.Viper.GetBool("force")
 			nodeps := LuetCfg.Viper.GetBool("nodeps")
+			full, _ := cmd.Flags().GetBool("full")
+			checkconflicts, _ := cmd.Flags().GetBool("conflictscheck")
 
 			LuetCfg.GetSolverOptions().Type = stype
 			LuetCfg.GetSolverOptions().LearnRate = float32(rate)
@@ -66,10 +68,12 @@ var uninstallCmd = &cobra.Command{
 			Debug("Solver", LuetCfg.GetSolverOptions().CompactString())
 
 			inst := installer.NewLuetInstaller(installer.LuetInstallerOptions{
-				Concurrency:   LuetCfg.GetGeneral().Concurrency,
-				SolverOptions: *LuetCfg.GetSolverOptions(),
-				NoDeps:        nodeps,
-				Force:         force,
+				Concurrency:    LuetCfg.GetGeneral().Concurrency,
+				SolverOptions:  *LuetCfg.GetSolverOptions(),
+				NoDeps:         nodeps,
+				Force:          force,
+				FullUninstall:  full,
+				CheckConflicts: checkconflicts,
 			})
 
 			if LuetCfg.GetSystem().DatabaseEngine == "boltdb" {
@@ -98,8 +102,10 @@ func init() {
 	uninstallCmd.Flags().Float32("solver-rate", 0.7, "Solver learning rate")
 	uninstallCmd.Flags().Float32("solver-discount", 1.0, "Solver discount rate")
 	uninstallCmd.Flags().Int("solver-attempts", 9000, "Solver maximum attempts")
-	uninstallCmd.Flags().Bool("nodeps", false, "Don't consider package dependencies (harmful!)")
+	uninstallCmd.Flags().Bool("nodeps", false, "Don't consider package dependencies (harmful! overrides checkconflicts and full!)")
 	uninstallCmd.Flags().Bool("force", false, "Force uninstall")
+	uninstallCmd.Flags().Bool("full", false, "Attempts to remove as much packages as possible which aren't required (slow)")
+	uninstallCmd.Flags().Bool("conflictscheck", true, "Check if the package marked for deletion is required by other packages")
 
 	RootCmd.AddCommand(uninstallCmd)
 }

pkg/installer/installer.go

@@ -41,6 +41,8 @@ type LuetInstallerOptions struct {
 	OnlyDeps                    bool
 	Force                       bool
 	PreserveSystemEssentialData bool
+	FullUninstall               bool
+	CheckConflicts              bool
 }
 
 type LuetInstaller struct {
@@ -132,10 +134,8 @@ func (l *LuetInstaller) swap(syncedRepos Repositories, toRemove pkg.Packages, to
 	// if the old A results installed in the system. This is due to the fact that
 	// now the solver enforces the constraints and explictly denies two packages
 	// of the same version installed.
-	forced := false
-	if l.Options.Force {
-		forced = true
-	}
+	forced := l.Options.Force
+
 	l.Options.Force = true
 
 	for _, u := range toRemove {
@@ -572,10 +572,13 @@ func (l *LuetInstaller) Uninstall(p pkg.Package, s *System) error {
 	// compute uninstall from all world - remove packages in parallel - run uninstall finalizer (in order) TODO - mark the uninstallation in db
 	// Get installed definition
 
-	checkConflicts := true
-	if l.Options.Force == true {
+	checkConflicts := l.Options.CheckConflicts
+	full := l.Options.FullUninstall
+	if l.Options.Force == true { // IF forced, we want to remove the package and all its requires
 		checkConflicts = false
+		full = false
 	}
+
 	// Create a temporary DB with the installed packages
 	// so the solver is much faster finding the deptree
 	installedtmp := pkg.NewInMemoryDatabase(false)
@@ -589,7 +592,7 @@ func (l *LuetInstaller) Uninstall(p pkg.Package, s *System) error {
 
 	if !l.Options.NoDeps {
 		solv := solver.NewResolver(installedtmp, installedtmp, pkg.NewInMemoryDatabase(false), l.Options.SolverOptions.Resolver())
-		solution, err := solv.Uninstall(p, checkConflicts)
+		solution, err := solv.Uninstall(p, checkConflicts, full)
 		if err != nil && !l.Options.Force {
 			return errors.Wrap(err, "Could not solve the uninstall constraints. Tip: try with --solver-type qlearning or with --force, or by removing packages excluding their dependencies with --nodeps")
 		}

pkg/solver/solver.go

@@ -18,6 +18,8 @@ package solver
 import (
 
 	//. "github.com/mudler/luet/pkg/logger"
+	"fmt"
+
 	"github.com/pkg/errors"
 
 	"github.com/crillab/gophersat/bf"
@@ -28,7 +30,7 @@ import (
 type PackageSolver interface {
 	SetDefinitionDatabase(pkg.PackageDatabase)
 	Install(p pkg.Packages) (PackagesAssertions, error)
-	Uninstall(candidate pkg.Package, checkconflicts bool) (pkg.Packages, error)
+	Uninstall(candidate pkg.Package, checkconflicts, full bool) (pkg.Packages, error)
 	ConflictsWithInstalled(p pkg.Package) (bool, error)
 	ConflictsWith(p pkg.Package, ls pkg.Packages) (bool, error)
 	Conflicts(pack pkg.Package, lsp pkg.Packages) (bool, error)
@@ -175,7 +177,15 @@ func (s *Solver) Conflicts(pack pkg.Package, lsp pkg.Packages) (bool, error) {
 	visited := make(map[string]interface{})
 	revdeps := p.ExpandedRevdeps(temporarySet, visited)
 
-	return len(revdeps) != 0, nil
+	var revdepsErr error
+	for _, r := range revdeps {
+		if revdepsErr == nil {
+			revdepsErr = errors.New("")
+		}
+		revdepsErr = errors.New(fmt.Sprintf("%s\n%s", revdepsErr.Error(), r.HumanReadableString()))
+	}
+
+	return len(revdeps) != 0, revdepsErr
 }
 
 // ConflictsWith return true if a package is part of the requirement set of a list of package
@@ -271,7 +281,7 @@ func (s *Solver) Upgrade(checkconflicts bool) (pkg.Packages, PackagesAssertions,
 	s2.SetResolver(s.Resolver)
 	// Then try to uninstall the versions in the system, and store that tree
 	for _, p := range toUninstall {
-		r, err := s.Uninstall(p, checkconflicts)
+		r, err := s.Uninstall(p, checkconflicts, false)
 		if err != nil {
 			return nil, nil, errors.Wrap(err, "Could not compute upgrade - couldn't uninstall selected candidate "+p.GetFingerPrint())
 		}
@@ -292,7 +302,7 @@ func (s *Solver) Upgrade(checkconflicts bool) (pkg.Packages, PackagesAssertions,
 
 // Uninstall takes a candidate package and return a list of packages that would be removed
 // in order to purge the candidate. Returns error if unsat.
-func (s *Solver) Uninstall(c pkg.Package, checkconflicts bool) (pkg.Packages, error) {
+func (s *Solver) Uninstall(c pkg.Package, checkconflicts, full bool) (pkg.Packages, error) {
 	var res pkg.Packages
 	candidate, err := s.InstalledDatabase.FindPackage(c)
 	if err != nil {
@@ -311,6 +321,16 @@ func (s *Solver) Uninstall(c pkg.Package, checkconflicts bool) (pkg.Packages, er
 	// Build a fake "Installed" - Candidate and its requires tree
 	var InstalledMinusCandidate pkg.Packages
 
+	// We are asked to not perform a full uninstall (checking all the possible requires that could
+	// be removed). Let's only check if we can remove the selected package
+	if !full && checkconflicts {
+		if conflicts, err := s.Conflicts(candidate, s.Installed()); conflicts {
+			return nil, err
+		} else {
+			return pkg.Packages{candidate}, nil
+		}
+	}
+
 	// TODO: Can be optimized
 	for _, i := range s.Installed() {
 		if !i.Matches(candidate) {

pkg/solver/solver_test.go

@@ -547,7 +547,7 @@ var _ = Describe("Solver", func() {
 			}
 			s = NewSolver(dbInstalled, dbDefinitions, db)
 
-			solution, err := s.Uninstall(A, true)
+			solution, err := s.Uninstall(A, true, true)
 			Expect(err).ToNot(HaveOccurred())
 
 			Expect(solution).To(ContainElement(A.IsFlagged(false)))
@@ -573,7 +573,7 @@ var _ = Describe("Solver", func() {
 			}
 			s = NewSolver(dbInstalled, dbDefinitions, db)
 
-			solution, err := s.Uninstall(&pkg.DefaultPackage{Name: "A", Version: ">1.0"}, true)
+			solution, err := s.Uninstall(&pkg.DefaultPackage{Name: "A", Version: ">1.0"}, true, true)
 			Expect(err).ToNot(HaveOccurred())
 
 			Expect(solution).To(ContainElement(A.IsFlagged(false)))
@@ -692,7 +692,7 @@ var _ = Describe("Solver", func() {
 			}
 
 			val, err := s.Conflicts(A, dbInstalled.World())
-			Expect(err).ToNot(HaveOccurred())
+			Expect(err.Error()).To(Equal("\n/B-"))
 			Expect(val).To(BeTrue())
 
 		})
@@ -716,7 +716,7 @@ var _ = Describe("Solver", func() {
 			}
 
 			val, err := s.Conflicts(D, dbInstalled.World())
-			Expect(err).ToNot(HaveOccurred())
+			Expect(err.Error()).To(Equal("\n/A-\n/B-"))
 			Expect(val).To(BeTrue())
 		})
 
@@ -781,7 +781,7 @@ var _ = Describe("Solver", func() {
 				_, err := dbInstalled.CreatePackage(p)
 				Expect(err).ToNot(HaveOccurred())
 			}
-			solution, err := s.Uninstall(A, true)
+			solution, err := s.Uninstall(A, true, true)
 			Expect(err).ToNot(HaveOccurred())
 
 			Expect(solution).To(ContainElement(A.IsFlagged(false)))
@@ -805,7 +805,7 @@ var _ = Describe("Solver", func() {
 				_, err := dbInstalled.CreatePackage(p)
 				Expect(err).ToNot(HaveOccurred())
 			}
-			solution, err := s.Uninstall(A, true)
+			solution, err := s.Uninstall(A, true, true)
 			Expect(err).ToNot(HaveOccurred())
 
 			Expect(solution).To(ContainElement(A.IsFlagged(false)))
@@ -828,7 +828,7 @@ var _ = Describe("Solver", func() {
 				_, err := dbInstalled.CreatePackage(p)
 				Expect(err).ToNot(HaveOccurred())
 			}
-			solution, err := s.Uninstall(A, true)
+			solution, err := s.Uninstall(A, true, true)
 			Expect(err).ToNot(HaveOccurred())
 
 			Expect(solution).To(ContainElement(A.IsFlagged(false)))
@@ -853,7 +853,7 @@ var _ = Describe("Solver", func() {
 				Expect(err).ToNot(HaveOccurred())
 			}
 
-			solution, err := s.Uninstall(A, true)
+			solution, err := s.Uninstall(A, true, true)
 			Expect(err).ToNot(HaveOccurred())
 
 			Expect(solution).To(ContainElement(A.IsFlagged(false)))
@@ -879,7 +879,7 @@ var _ = Describe("Solver", func() {
 				Expect(err).ToNot(HaveOccurred())
 			}
 
-			solution, err := s.Uninstall(A, true)
+			solution, err := s.Uninstall(A, true, true)
 			Expect(err).ToNot(HaveOccurred())
 
 			Expect(solution).To(ContainElement(A.IsFlagged(false)))