Find missing (#269)

Solves #160 

* Implements check on whether index.txt/changes.csv and directory listings exist. Also fixes minor grammatical mistakes

* Adds missing else to prevent defaulting to missing-error handling even if another error was found

* Removes comment

* test whether changes.csv or index.txt is empty

* Fixed type mismatching, undeclared variable

* Fixes typo in variable

* Fixes another typo in variable

* Fixes formatting error

* Removed reminder comments

* Fixes formatting errors

* Added check for missing directories

* Moved empty dirlistcheck to the right position

* fixes typo

* fixes typo

* Add info if files are found

* Cleans up code

* simplified check for empty changes.csv and index.txt

Co-authored-by: Jan Höfelmeyer <Jan Höfelmeyer jhoefelmeyer@intevation.de>
Co-authored-by: Sascha L. Teichmann <sascha.teichmann@intevation.de>

cmd/csaf_checker/processor.go

@@ -586,6 +586,7 @@ func (p *processor) integrity(
 func (p *processor) processROLIEFeed(feed string) error {
 	client := p.httpClient()
 	res, err := client.Get(feed)
+	p.badDirListings.use()
 	if err != nil {
 		p.badProviderMetadata.error("Cannot fetch feed %s: %v", feed, err)
 		return errContinue
@@ -700,7 +701,6 @@ func (p *processor) processROLIEFeed(feed string) error {
 
 		files = append(files, file)
 	})
-
 	if err := p.integrity(files, base, rolieMask, p.badProviderMetadata.add); err != nil &&
 		err != errContinue {
 		return err
@@ -744,9 +744,12 @@ func (p *processor) checkIndex(base string, mask whereType) error {
 		if res.StatusCode != http.StatusNotFound {
 			p.badIndices.error("Fetching %s failed. Status code %d (%s)",
 				index, res.StatusCode, res.Status)
+		} else {
+			p.badIndices.warn("Fetching index.txt failed: %v not found.", index)
 		}
 		return errContinue
 	}
+	p.badIndices.info("Found %v", index)
 
 	files, err := func() ([]csaf.AdvisoryFile, error) {
 		defer res.Body.Close()
@@ -766,6 +769,9 @@ func (p *processor) checkIndex(base string, mask whereType) error {
 		p.badIndices.error("Reading %s failed: %v", index, err)
 		return errContinue
 	}
+	if len(files) == 0 {
+		p.badIntegrities.warn("index.txt contains no URLs")
+	}
 
 	return p.integrity(files, base, mask, p.badIndices.add)
 }
@@ -798,9 +804,12 @@ func (p *processor) checkChanges(base string, mask whereType) error {
 			// It's optional
 			p.badChanges.error("Fetching %s failed. Status code %d (%s)",
 				changes, res.StatusCode, res.Status)
+		} else {
+			p.badChanges.warn("Fetching changes.csv failed: %v not found.", changes)
 		}
 		return errContinue
 	}
+	p.badChanges.info("Found %v", changes)
 
 	times, files, err := func() ([]time.Time, []csaf.AdvisoryFile, error) {
 		defer res.Body.Close()
@@ -841,6 +850,14 @@ func (p *processor) checkChanges(base string, mask whereType) error {
 		return errContinue
 	}
 
+	if len(files) == 0 {
+		var filtered string
+		if p.ageAccept != nil {
+			filtered = " (maybe filtered out by time interval)"
+		}
+		p.badChanges.warn("no entries in changes.csv found" + filtered)
+	}
+
 	if !sort.SliceIsSorted(times, func(i, j int) bool {
 		return times[j].Before(times[i])
 	}) {
@@ -953,7 +970,7 @@ func (p *processor) checkMissing(string) error {
 	return nil
 }
 
-// checkInvalid wents over all found adivisories URLs and checks
+// checkInvalid goes over all found adivisories URLs and checks
 // if file name confirms to standard.
 func (p *processor) checkInvalid(string) error {
 
@@ -975,7 +992,7 @@ func (p *processor) checkInvalid(string) error {
 	return nil
 }
 
-// checkListing wents over all found adivisories URLs and checks
+// checkListing goes over all found adivisories URLs and checks
 // if their parent directory is listable.
 func (p *processor) checkListing(string) error {
 
@@ -987,6 +1004,10 @@ func (p *processor) checkListing(string) error {
 
 	badDirs := map[string]struct{}{}
 
+	if len(p.alreadyChecked) == 0 {
+		p.badDirListings.info("No directory listings found.")
+	}
+
 	for f := range p.alreadyChecked {
 		found, err := pgs.listed(f, p, badDirs)
 		if err != nil && err != errContinue {