Bring back: derive nix profile changes (#1742)

.github/workflows/cli-tests.yaml

@@ -59,7 +59,7 @@ jobs:
       - name: Build devbox
         run: go build -o dist/devbox ./cmd/devbox
       - name: Upload devbox artifact
-        uses: actions/upload-artifact@v3  
+        uses: actions/upload-artifact@v3
         with:
           name: devbox-${{ runner.os }}-${{ runner.arch }}
           path: ./dist/devbox
@@ -113,7 +113,7 @@ jobs:
         run: |
           chmod +x ./devbox
           sudo mv ./devbox /usr/local/bin/
-          
+
       - run:  devbox run lint
 
   test:
@@ -129,9 +129,8 @@ jobs:
         run-project-tests: ["project-tests", "project-tests-off"]
         # Run tests on:
         # 1. the oldest supported nix version (which is 2.9.0? But determinate-systems installer has 2.12.0)
-        # 2. nix version 2.17.0 which introduces a new code path that minimizes nixpkgs downloads.
-        # 3. latest nix version
-        nix-version: ["2.12.0", "2.17.0", "2.19.2"]
+        # 2. latest nix version
+        nix-version: ["2.12.0", "2.19.2"]
         exclude:
           - is-main: "not-main"
             os: "${{ inputs.run-mac-tests && 'dummy' || 'macos-latest' }}"
@@ -200,7 +199,7 @@ jobs:
           go test -v -timeout $DEVBOX_GOLANG_TEST_TIMEOUT ./...
 
   auto-nix-install: # ensure Devbox installs nix and works properly after installation.
-    needs: build-devbox 
+    needs: build-devbox
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest]

internal/devbox/nixprofile.go

@@ -0,0 +1,86 @@
+package devbox
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"github.com/samber/lo"
+	"go.jetpack.io/devbox/internal/nix"
+	"go.jetpack.io/devbox/internal/nix/nixprofile"
+	"go.jetpack.io/devbox/internal/ux"
+)
+
+// syncNixProfileFromFlake ensures the nix profile has the packages from the buildInputs
+// from the devshell of the generated flake.
+//
+// It also removes any packages from the nix profile that are no longer in the buildInputs.
+func (d *Devbox) syncNixProfileFromFlake(ctx context.Context) error {
+	// Get the computed Devbox environment from the generated flake
+	env, err := d.computeEnv(ctx, false /*usePrintDevEnvCache*/)
+	if err != nil {
+		return err
+	}
+
+	// Get the store-paths of the packages we want installed in the nix profile
+	wantStorePaths := []string{}
+	if env["buildInputs"] != "" {
+		// env["buildInputs"] can be empty string if there are no packages in the project
+		// if buildInputs is empty, then we don't want wantStorePaths to be an array with a single "" entry
+		wantStorePaths = strings.Split(env["buildInputs"], " ")
+	}
+
+	profilePath, err := d.profilePath()
+	if err != nil {
+		return err
+	}
+
+	// Get the store-paths of the packages currently installed in the nix profile
+	items, err := nixprofile.ProfileListItems(d.stderr, profilePath)
+	if err != nil {
+		return fmt.Errorf("nix profile list: %v", err)
+	}
+	gotStorePaths := make([]string, 0, len(items))
+	for _, item := range items {
+		gotStorePaths = append(gotStorePaths, item.StorePaths()...)
+	}
+
+	// Diff the store paths and install/remove packages as needed
+	remove, add := lo.Difference(gotStorePaths, wantStorePaths)
+	if len(remove) > 0 {
+		packagesToRemove := make([]string, 0, len(remove))
+		for _, p := range remove {
+			storePath := nix.NewStorePathParts(p)
+			packagesToRemove = append(packagesToRemove, fmt.Sprintf("%s@%s", storePath.Name, storePath.Version))
+		}
+		if len(packagesToRemove) == 1 {
+			ux.Finfo(d.stderr, "Removing %s\n", strings.Join(packagesToRemove, ", "))
+		} else {
+			ux.Finfo(d.stderr, "Removing packages: %s\n", strings.Join(packagesToRemove, ", "))
+		}
+
+		if err := nix.ProfileRemove(profilePath, remove...); err != nil {
+			return err
+		}
+	}
+	if len(add) > 0 {
+		// We need to install the packages in the nix profile one-by-one because
+		// we do checks for insecure packages.
+		// TODO: move the insecure package check here, and do `nix profile install installables...`
+		// in one command for speed.
+		for _, addPath := range add {
+			if err = nix.ProfileInstall(ctx, &nix.ProfileInstallArgs{
+				Installable: addPath,
+				// Install in offline mode for speed. We know we should have all the files
+				// locally in /nix/store since we have run `nix print-dev-env` prior to this.
+				// Also avoids some "substituter not found for store-path" errors.
+				Offline:     true,
+				ProfilePath: profilePath,
+				Writer:      d.stderr,
+			}); err != nil {
+				return fmt.Errorf("error installing package in nix profile %s: %w", addPath, err)
+			}
+		}
+	}
+	return nil
+}