Replace distro type (#742)

* remove strong distro type Signed-off-by: Alex Goodman <alex.goodman@anchore.com> * bump json schema to v3 (breaking distro shape) Signed-off-by: Alex Goodman <alex.goodman@anchore.com> * fix linting Signed-off-by: Alex Goodman <alex.goodman@anchore.com> * allow for v2 decoding of distro idLikes field in v3 json decoder Signed-off-by: Alex Goodman <alex.goodman@anchore.com> * fix casing in simple linux release name Signed-off-by: Alex Goodman <alex.goodman@anchore.com> * use discovered name as pretty name in simple linux release Signed-off-by: Alex Goodman <alex.goodman@anchore.com>
2026-11-01 23:16:30 +01:00 · 2022-01-12 12:13:42 -05:00
parent dfefd2ea4e
commit 706f291679
74 changed files with 2452 additions and 1136 deletions
@@ -0,0 +1,184 @@
+package linux
+
+import (
+	"fmt"
+	"io/ioutil"
+	"regexp"
+	"strings"
+
+	"github.com/acobaugh/osrelease"
+	"github.com/anchore/syft/internal"
+	"github.com/anchore/syft/internal/log"
+	"github.com/anchore/syft/syft/source"
+	"github.com/google/go-cmp/cmp"
+)
+
+// returns a distro or nil
+type parseFunc func(string) (*Release, error)
+
+type parseEntry struct {
+	path string
+	fn   parseFunc
+}
+
+var identityFiles = []parseEntry{
+	{
+		// most distros provide a link at this location
+		path: "/etc/os-release",
+		fn:   parseOsRelease,
+	},
+	{
+		// standard location for rhel & debian distros
+		path: "/usr/lib/os-release",
+		fn:   parseOsRelease,
+	},
+	{
+		// check for centos:6
+		path: "/etc/system-release-cpe",
+		fn:   parseSystemReleaseCPE,
+	},
+	{
+		// last ditch effort for determining older centos version distro information
+		path: "/etc/redhat-release",
+		fn:   parseRedhatRelease,
+	},
+	// /////////////////////////////////////////////////////////////////////////////////////////////////////
+	// IMPORTANT! checking busybox must be last since other distros contain the busybox binary
+	{
+		// check for busybox
+		path: "/bin/busybox",
+		fn:   parseBusyBox,
+	},
+	// /////////////////////////////////////////////////////////////////////////////////////////////////////
+}
+
+// IdentifyRelease parses distro-specific files to discover and raise linux distribution release details.
+func IdentifyRelease(resolver source.FileResolver) *Release {
+	for _, entry := range identityFiles {
+		locations, err := resolver.FilesByPath(entry.path)
+		if err != nil {
+			log.Warnf("unable to get path locations from %s: %+v", entry.path, err)
+			continue
+		}
+
+		for _, location := range locations {
+			contentReader, err := resolver.FileContentsByLocation(location)
+			if err != nil {
+				log.Debugf("unable to get contents from %s: %s", entry.path, err)
+				continue
+			}
+
+			content, err := ioutil.ReadAll(contentReader)
+			internal.CloseAndLogError(contentReader, location.VirtualPath)
+			if err != nil {
+				log.Warnf("unable to read %q: %+v", location.RealPath, err)
+				break
+			}
+
+			release, err := entry.fn(string(content))
+			if err != nil {
+				log.Warnf("unable to parse %q", location.RealPath)
+			}
+
+			if release != nil {
+				return release
+			}
+		}
+	}
+
+	return nil
+}
+
+func parseOsRelease(contents string) (*Release, error) {
+	values, err := osrelease.ReadString(contents)
+	if err != nil {
+		return nil, fmt.Errorf("unable to read os-release file: %w", err)
+	}
+
+	var idLike []string
+	for _, s := range strings.Split(values["ID_LIKE"], " ") {
+		s = strings.TrimSpace(s)
+		if s == "" {
+			continue
+		}
+		idLike = append(idLike, s)
+	}
+
+	r := Release{
+		PrettyName:       values["PRETTY_NAME"],
+		Name:             values["NAME"],
+		ID:               values["ID"],
+		IDLike:           idLike,
+		Version:          values["VERSION"],
+		VersionID:        values["VERSION_ID"],
+		Variant:          values["VARIANT"],
+		VariantID:        values["VARIANT_ID"],
+		HomeURL:          values["HOME_URL"],
+		SupportURL:       values["SUPPORT_URL"],
+		BugReportURL:     values["BUG_REPORT_URL"],
+		PrivacyPolicyURL: values["PRIVACY_POLICY_URL"],
+		CPEName:          values["CPE_NAME"],
+	}
+
+	// don't allow for empty contents to result in a Release object being created
+	if cmp.Equal(r, Release{}) {
+		return nil, nil
+	}
+
+	return &r, nil
+}
+
+var busyboxVersionMatcher = regexp.MustCompile(`BusyBox v[\d.]+`)
+
+func parseBusyBox(contents string) (*Release, error) {
+	matches := busyboxVersionMatcher.FindAllString(contents, -1)
+	for _, match := range matches {
+		parts := strings.Split(match, " ")
+		version := strings.ReplaceAll(parts[1], "v", "")
+
+		return simpleRelease(match, "busybox", version, ""), nil
+	}
+	return nil, nil
+}
+
+// example CPE: cpe:/o:centos:linux:6:GA
+var systemReleaseCpeMatcher = regexp.MustCompile(`cpe:\/o:(.*?):.*?:(.*?):.*?$`)
+
+// parseSystemReleaseCPE parses the older centos (6) file to determine distro metadata
+func parseSystemReleaseCPE(contents string) (*Release, error) {
+	matches := systemReleaseCpeMatcher.FindAllStringSubmatch(contents, -1)
+	for _, match := range matches {
+		if len(match) < 3 {
+			continue
+		}
+		return simpleRelease(match[1], strings.ToLower(match[1]), match[2], match[0]), nil
+	}
+	return nil, nil
+}
+
+// example: "CentOS release 6.10 (Final)"
+var redhatReleaseMatcher = regexp.MustCompile(`(.*?)\srelease\s(\d\.\d+)`)
+
+// parseRedhatRelease is a fallback parsing method for determining distro information in older redhat versions
+func parseRedhatRelease(contents string) (*Release, error) {
+	matches := redhatReleaseMatcher.FindAllStringSubmatch(contents, -1)
+	for _, match := range matches {
+		if len(match) < 3 {
+			continue
+		}
+		return simpleRelease(match[1], strings.ToLower(match[1]), match[2], ""), nil
+	}
+	return nil, nil
+}
+
+func simpleRelease(prettyName, name, version, cpe string) *Release {
+	return &Release{
+		PrettyName: prettyName,
+		Name:       name,
+		ID:         name,
+		IDLike:     []string{name},
+		Version:    version,
+		VersionID:  version,
+		CPEName:    cpe,
+	}
+}