Don't overwrite FMA outputs with latest manifest if input has "frozen" set to true (#30044)

Resolves #29218. No changes file as this is internal/FMA-related.

# Checklist for submitter

If some of the following don't apply, delete the relevant line.

<!-- Note that API documentation changes are now addressed by the
product design team. -->

- [x] Input data is properly validated, `SELECT *` is avoided, SQL
injection is prevented (using placeholders for values in statements)
- [x] Manual QA for all new/changed functionality

cmd/maintained-apps/main.go

@@ -13,6 +13,7 @@ import (
 	maintained_apps "github.com/fleetdm/fleet/v4/ee/maintained-apps"
 	"github.com/fleetdm/fleet/v4/ee/maintained-apps/ingesters/homebrew"
 	"github.com/fleetdm/fleet/v4/ee/maintained-apps/ingesters/winget"
+	"github.com/fleetdm/fleet/v4/pkg/file"
 	"github.com/fleetdm/fleet/v4/server/contexts/ctxerr"
 	kitlog "github.com/go-kit/log"
 	"github.com/go-kit/log/level"
@@ -38,8 +39,8 @@ func main() {
 		"ee/maintained-apps/inputs/winget":   winget.IngestApps,
 	}
 
-	for p, i := range ingesters {
-		apps, err := i(ctx, logger, p, *slugPtr)
+	for inputDir, ingest := range ingesters {
+		apps, err := ingest(ctx, logger, inputDir, *slugPtr)
 		if err != nil {
 			level.Error(logger).Log("msg", "failed to ingest apps", "error", err)
 		}
@@ -74,15 +75,23 @@ func processOutput(ctx context.Context, app *maintained_apps.FMAManifestApp) err
 		return ctxerr.Wrap(ctx, err, "marshaling output app manifest")
 	}
 
-	// Overwrite the file, since right now we're only caring about 1 version (latest). If we
-	// care about previous data, it will be in our Git history.
-	outPath := path.Join(maintained_apps.OutputPath, app.SlugAppName())
+	outDir := path.Join(maintained_apps.OutputPath, app.SlugAppName())
 
-	if err := os.MkdirAll(outPath, os.ModePerm); err != nil {
+	if err := os.MkdirAll(outDir, os.ModePerm); err != nil {
 		return ctxerr.Wrap(ctx, err)
 	}
-	if err := os.WriteFile(path.Join(maintained_apps.OutputPath, fmt.Sprintf("%s.json", app.Slug)), outBytes, 0o644); err != nil {
-		return ctxerr.Wrap(ctx, err, "writing output json file")
+	outFilePath := path.Join(maintained_apps.OutputPath, fmt.Sprintf("%s.json", app.Slug))
+	outFileExists, err := file.Exists(outFilePath)
+	if err != nil {
+		return ctxerr.Wrap(ctx, err, "checking if output json file exists")
+	}
+
+	// Overwrite the file unless frozen, since right now we're only caring about 1 version (latest). If we
+	// care about previous data, it will be in our Git history.
+	if !app.Frozen || !outFileExists {
+		if err := os.WriteFile(outFilePath, outBytes, 0o644); err != nil {
+			return ctxerr.Wrap(ctx, err, "writing output json file")
+		}
 	}
 
 	return nil
@@ -90,13 +99,13 @@ func processOutput(ctx context.Context, app *maintained_apps.FMAManifestApp) err
 
 func updateAppsListFile(ctx context.Context, outApp *maintained_apps.FMAManifestApp) error {
 	appListFilePath := path.Join(maintained_apps.OutputPath, "apps.json")
-	file, err := os.ReadFile(appListFilePath)
+	inputJson, err := os.ReadFile(appListFilePath)
 	if err != nil {
 		return ctxerr.Wrap(ctx, err, "reading output apps list file")
 	}
 
 	var outputAppsFile maintained_apps.FMAListFile
-	if err := json.Unmarshal(file, &outputAppsFile); err != nil {
+	if err := json.Unmarshal(inputJson, &outputAppsFile); err != nil {
 		return ctxerr.Wrap(ctx, err, "unmarshaling output apps list file")
 	}
 

ee/maintained-apps/README.md

@@ -1,5 +1,14 @@
 # Fleet-maintained apps (FMA)
 
+## Freezing an existing app
+
+Add `"frozen": true` to the appropriate input JSON file to pause automated updates to the corresponding output manifest.
+To aid in testing, manifests will still be generated for frozen inputs if the output file doesn't exist.
+
+Apps should be frozen when updating the manifest would introduce regressions on ability to install/uninstall the app.
+Frozen apps should have bugs filed, and fixes for those bugs should unfreeze the app and bump it to the latest version
+as part of the fix PR.
+
 ## Adding a new app
 
 1. Decide on a source for the app's metadata. We currently support homebrew as a source for macOS apps.

ee/maintained-apps/ingesters/homebrew/ingester.go

@@ -166,6 +166,7 @@ func (i *brewIngester) ingestOne(ctx context.Context, app inputApp) (*maintained
 
 	out.UninstallScriptRef = maintained_apps.GetScriptRef(out.UninstallScript)
 	out.InstallScriptRef = maintained_apps.GetScriptRef(out.InstallScript)
+	out.Frozen = app.Frozen
 
 	return out, nil
 }
@@ -184,6 +185,7 @@ type inputApp struct {
 	PreUninstallScripts  []string `json:"pre_uninstall_scripts"`
 	PostUninstallScripts []string `json:"post_uninstall_scripts"`
 	DefaultCategories    []string `json:"default_categories"`
+	Frozen               bool     `json:"frozen"`
 }
 
 type brewCask struct {

ee/maintained-apps/ingesters/winget/ingester.go

@@ -299,6 +299,7 @@ func (i *wingetIngester) ingestOne(ctx context.Context, input inputApp) (*mainta
 	out.UninstallScript = preProcessUninstallScript(uninstallScript, productCode)
 	out.InstallScriptRef = maintained_apps.GetScriptRef(out.InstallScript)
 	out.UninstallScriptRef = maintained_apps.GetScriptRef(out.UninstallScript)
+	out.Frozen = input.Frozen
 
 	return &out, nil
 }
@@ -354,6 +355,7 @@ type inputApp struct {
 	// Whether to use "no_check" instead of the app's hash (e.g. for non-pinned download URLs)
 	IgnoreHash        bool     `json:"ignore_hash"`
 	DefaultCategories []string `json:"default_categories"`
+	Frozen            bool     `json:"frozen"`
 }
 
 type installerManifest struct {

ee/maintained-apps/maintained_apps.go

@@ -34,6 +34,7 @@ type FMAManifestApp struct {
 	Slug               string     `json:"-"`
 	Name               string     `json:"-"`
 	DefaultCategories  []string   `json:"default_categories"`
+	Frozen             bool       `json:"-"`
 }
 
 func (a *FMAManifestApp) Platform() string {