Bugfix: Heisenbug when parsing console output in entropy check

Resolves #1007.

The login prompt generated by the serial getty service could mess up the output and throw off our primitive parser.

Thanks @garloff for the crucial tip!

Signed-off-by: Matthias Büchse <[email protected]>

Author: mbuechse

Tests/iaas/scs_0101_entropy/entropy_check.py

@@ -32,11 +32,14 @@
 
 TIMEOUT = 5 * 60  # timeout in seconds after which we no longer wait for the VM to complete the run
 MARKER = '_scs-test-'
+# NOTE we mask [email protected] because the login prompt messes up the console output that we want to parse
 SERVER_USERDATA_GENERIC = """
 #cloud-config
 # apt-placeholder
 packages:
   - rng-tools5
+bootcmd:
+  - systemctl mask [email protected]
 runcmd:
   - echo '_scs-test-entropy-avail'; cat /proc/sys/kernel/random/entropy_avail
   - echo '_scs-test-fips-test'; cat /dev/random | rngtest -c 1000
@@ -337,6 +340,8 @@ def compute_canonical_image(all_images):
 def _convert_to_collected(lines, marker=MARKER):
     # parse lines from console output
     # removing any "indent", stuff that looks like '[   70.439502] cloud-init[513]: '
+    # NOTE this logic can fail when something (such as a login prompt) messes up the console output
+    # therefore we disable the corresponding service (see cloud-init)
     section = None
     indent = 0
     collected = {}