kafka: fix consumer (#8491)

Fixes: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=51338

projects/kafka/Dockerfile

@@ -16,7 +16,7 @@
 
 FROM gcr.io/oss-fuzz-base/base-builder-python
 
-RUN apt-get update -y && apt-get install wget 
+RUN apt-get update -y && apt-get install -y wget software-properties-common
 RUN wget -qO - https://packages.confluent.io/deb/7.0/archive.key | apt-key add -
 RUN add-apt-repository "deb https://packages.confluent.io/clients/deb $(lsb_release -cs) main"
 RUN apt-get update -y && apt-get install librdkafka-dev software-properties-common lsb-release gcc make python3-dev libsasl2-modules-gssapi-mit krb5-user -y

projects/kafka/fuzz_consumer.py

@@ -15,8 +15,8 @@
 
 import atheris
 import sys
-with atheris.instrument_imports():
-    from confluent_kafka import Consumer, KafkaException
+from confluent_kafka import Consumer, KafkaException, TopicPartition
+
 
 def TestInput(data):
     fdp = atheris.FuzzedDataProvider(data)
@@ -24,20 +24,36 @@ def TestInput(data):
     def dummy_callback(err, partitions):
         pass
 
-    c = Consumer({
-        'group.id': fdp.ConsumeString(10),
-        'socket.timeout.ms': fdp.ConsumeIntInRange(10,2000),
-        'session.timeout.ms': fdp.ConsumeIntInRange(10,2000),
-        'on_commit': dummy_callback})
+    try:
+        c = Consumer({
+            'group.id': fdp.ConsumeString(10),
+            'socket.timeout.ms': fdp.ConsumeIntInRange(10,2000),
+            'session.timeout.ms': fdp.ConsumeIntInRange(10,2000),
+            'on_commit': dummy_callback})
+    except Exception as e:
+        # If the consumer fails, we just retry
+        return
 
     try:
-        c.subscribe([fdp.ConsumeString(10)], on_assign=dummy_callback, on_revoke=dummy_callback)
+        c.subscribe(
+            [fdp.ConsumeString(10)],
+            on_assign=dummy_callback,
+            on_revoke=dummy_callback
+        )
         c.unsubscribe()
 
         msg = c.poll(timeout=0.001)
-        msglist = c.consume(num_messages=fdp.ConsumeIntInRange(1,10), timeout=0.001)
+        msglist = c.consume(
+            num_messages=fdp.ConsumeIntInRange(1,10),
+            timeout=0.001
+        )
 
-        partitions = list(map(lambda part: TopicPartition(fdp.ConsumeString(10), part), range(0, 100, 3)))
+        partitions = list(
+            map(
+                lambda part: TopicPartition(fdp.ConsumeString(10), part),
+                range(0, 100, 3)
+            )
+        )
         c.assign(partitions)
         c.unassign()
 
@@ -51,9 +67,12 @@ def TestInput(data):
 
     c.close()
 
+
 def main():
+    atheris.instrument_all()
     atheris.Setup(sys.argv, TestInput, enable_python_coverage=True)
     atheris.Fuzz()
 
+
 if __name__ == "__main__":
     main()