[jars] new plugin: get information about installed JARs

This plugin collects information about JAR files installed in the
standard locations. The information can be later used when debugging
problems with missing/different than expected classes on classpath.

Signed-off-by: Michal Srb <msrb@redhat.com>

1 files changed, 138 insertions, 0 deletions

diff --git a/sos/plugins/jars.py b/sos/plugins/jars.py
new file mode 100644
index 00000000..b5506ef4
--- /dev/null
+++ b/sos/plugins/jars.py
@@ -0,0 +1,138 @@
+# Copyright (C) 2016 Red Hat, Inc., Michal Srb <michal@redhat.com>
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+import hashlib
+import json
+import os
+import re
+import zipfile
+from functools import partial
+from sos.plugins import Plugin, RedHatPlugin
+
+
+class Jars(Plugin, RedHatPlugin):
+    """Collect information about available Java archives."""
+
+    plugin_name = "jars"
+    version = "1.0.0"
+    profiles = ("java",)
+    option_list = [("append_locations",
+                    "colon-separated list of additional JAR locations",
+                    "fast",
+                    "")]
+
+    # There is no standard location for JAR files and scanning
+    # the whole filesystem could be very slow. Therefore we only
+    # scan directories in which JARs can be typically found.
+    jar_locations = (
+        "/usr/share/java",  # common location for JARs
+        "/usr/lib/java",    # common location for JARs containing native code
+        "/opt",             # location for RHSCL and 3rd party software
+        "/usr/local",       # used by sysadmins when installing SW locally
+        "/var/lib"          # Java services commonly explode WARs there
+    )
+
+    def setup(self):
+        results = {"jars": []}
+        jar_paths = []
+
+        locations = list(Jars.jar_locations)
+        extra_locations = self.get_option("append_locations")
+        if extra_locations:
+            locations += extra_locations.split(":")
+
+        # find all JARs in given locations
+        for location in locations:
+            for dirpath, _, filenames in os.walk(location):
+                for filename in filenames:
+                    path = os.path.join(dirpath, filename)
+                    if Jars.is_jar(path):
+                        jar_paths.append(path)
+
+        # try to extract information about found JARs
+        for jar_path in jar_paths:
+            maven_id = Jars.get_maven_id(jar_path)
+            jar_id = Jars.get_jar_id(jar_path)
+            if maven_id or jar_id:
+                record = {"path": jar_path,
+                          "sha1": jar_id,
+                          "maven_id": maven_id
+                          }
+                results["jars"].append(record)
+
+        results_str = json.dumps(results, indent=4, separators=(",", ": "))
+        self.add_string_as_file(results_str, "jars.json")
+
+    @staticmethod
+    def is_jar(path):
+        """Check whether given file is a JAR file.
+
+        JARs are ZIP files which usually include a manifest
+        at the canonical location 'META-INF/MANIFEST.MF'.
+        """
+        if os.path.isfile(path) and zipfile.is_zipfile(path):
+            try:
+                with zipfile.ZipFile(path) as f:
+                    if "META-INF/MANIFEST.MF" in f.namelist():
+                        return True
+            except IOError:
+                pass
+        return False
+
+    @staticmethod
+    def get_maven_id(jar_path):
+        """Extract Maven coordinates from a given JAR file, if possible.
+
+        JARs build by Maven (most popular Java build system) contain
+        'pom.properties' file. We can extract Maven coordinates
+         from there.
+        """
+        props = {}
+        try:
+            with zipfile.ZipFile(jar_path) as f:
+                r = re.compile("META-INF/maven/[^/]+/[^/]+/pom.properties$")
+                result = [x for x in f.namelist() if r.match(x)]
+                if len(result) != 1:
+                    return None
+                with f.open(result[0]) as props_f:
+                    for line in props_f.readlines():
+                        line = line.strip()
+                        if not line.startswith("#"):
+                            try:
+                                (key, value) = line.split("=")
+                                props[key.strip()] = value.strip()
+                            except ValueError:
+                                return None
+        except IOError:
+            pass
+        return props
+
+    @staticmethod
+    def get_jar_id(jar_path):
+        """Compute JAR id.
+
+        Returns sha1 hash of a given JAR file.
+        """
+        jar_id = ""
+        try:
+            with open(jar_path, mode="rb") as f:
+                m = hashlib.sha1()
+                for buf in iter(partial(f.read, 4096), b''):
+                    m.update(buf)
+            jar_id = m.hexdigest()
+        except IOError:
+            pass
+        return jar_id