Introduction to Results in LAVA

Results in LAVA

At the lowest level, a result in LAVA is called a Test Case and is a simple flag:

  • pass
  • fail
  • skip
  • unknown

In addition, each test case can include a measurement (integer or floating point), with units.

Test cases are aggregated into a Test Suite. Multiple test suites can be generated for each submitted test job.

Accessing results

LAVA exposes a REST API to provide access to the results from test jobs. The URL is built from the following components:

  1. The instance name
  2. The results directory.
  3. The test job ID

From this point, all the results for the test job can be downloaded as CSV or YAML.

There are also CSV and YAML download links for the complete set of results for the job. The export includes details of the test definition names. For example, if a test job on validation.linaro.org has the job ID 1109234, the CSV download link for all results would be https://validation.linaro.org/results/1109234/csv. The YAML download link for all results would be https://validation.linaro.org/results/1109234/yaml.

Accessing specific test results

Within the results for the entire test job, results are split into test suites, optionally into test sets and finally into test cases.

Test Suite

The name of the Test Suite is determined by the test job definition. The Test Suite is created when results are generated in the running test job.

    auto_login:
      login_prompt: "login:"
      username: root

- test:
    timeout:
      minutes: 5
    definitions:
    - repository: http://git.linaro.org/lava-team/lava-functional-tests.git
      from: git
      path: lava-test-shell/smoke-tests-basic.yaml
      name: smoke-tests
    - repository: https://git.linaro.org/lava-team/lava-functional-tests.git
      from: git
      path: lava-test-shell/single-node/singlenode03.yaml
      name: singlenode-advanced

In this test job definition, there are two entries in the definitions list, so two test suites. The first test suite in the list has the prefix 0_ and the prefix increments for subsequent test suites in the list. The name element is then appended to create the test suite name.

  • 0_smoke-tests
  • 1_singlenode-advanced

Results are only generated when the Lava Test Shell Definition makes at least one call to lava-test-case (including automatic calls made by the MultiNode API).

The test suite can then be appended to the REST API URL for the results to limit the results to just that test suite: /results/1109234/0_smoke-tests/csv or: /results/1109234/0_smoke-tests/yaml.

In addition, every test job has a lava test suite which holds results for the processing of the pipeline itself. This set of results can hold useful information like the commit hash of the test definition when it was cloned to create the overlay, the duration of all actions (including the kernel boot) and other information.

Note

Test definitions will be rejected if the test suite name is set to lava to prevent conflicts with the internal results.

Test Set

Test Set is optional but allows test writers to subdivide individual results within a single Lava Test Shell Definition using an arbitrary label.

Some test definitions run the same test with different parameters. To distinguish between these similar tests, it can be useful to use a test set:

lava-test-set start syscalls
lava-test-case syscalls
# ....
lava-test-set stop syscalls
# change parameters
lava-test-case start math
lava-test-case math
# ....
lava-test-set stop math

This adds a set around those test cases by adding the test set to the URL. /results/JOB_ID/2_smoke-tests/syscall_one_test becomes /results/JOB_ID/2_smoke-tests/syscalls/syscall_one_test

Test Case

A Test Case can be generated in a number of ways:

  • by calling lava-test-case from a Lava Test Shell.
  • during operation of an Action within the pipeline
  • by parsing patterns in the test

Each test case has a name and a result. Optionally, test cases can have measurements and units. The name of the test case must be valid as part of the REST API so whitespace is not allowed.

If a test case has a measurement, the measurement is represented as a python Decimal value as this provides the best way to preserve precision through the various export handlers.

>>> case.measurement
Decimal('112.2510000000')
>>> import decimal
>>> decimal.Decimal(case.measurement)
Decimal('112.2510000000')
>>> decimal.Decimal(case.measurement).normalize()
Decimal('112.251')
>>> float(decimal.Decimal(case.measurement).normalize())
112.251

Representation of some numbers in Decimal can look a little odd but these can be easily converted or compared:

>>> decimal.Decimal(0E-10) == 0
True

See also

The python documentation on Decimal at https://docs.python.org/2.7/library/decimal.html#module-decimal

Note

Since test case name can be generated in such ways that no character validation is viable, the test case URL has been changed and is now generated using the test case ID. Old URL behaviour is still supported when looking up the test case in the results but test case URLs with non supported characters will return a Not Found (404) page. Links within test job log files all use the test case ID.

e.g. http://localhost/results/12020/lava/validate and http://localhost/results/testcase/60534 will both work.

Test Raise

Some test definitions are designed to configure or initialise a service or operation or peripheral device. If this setup task fails, the later test definitions will fail but that will take time and the failure messages may not be obvious.

A test shell definition can abort further test operations by calling lava-test-raise MESSAGE which will raise an immediate TestError exception. The current test shell result will be marked as fail and the ${MESSAGE} will be recorded. The test job itself will go Incomplete and the ${MESSAGE} will be recorded as the job failure comment.

Accessing the test job logs from results

There is a link in the test case detail page, directly after the test case name, which links to the point in the log where that test was reported.

Note

To prevent problems with test case names which do not map as a URL, the test case ID is used to link the report of the test case in the test job log file to the actual test case and back again. This database ID is reported in the log file and exported as part of the results data.

In the log file this section looks like:

Received signal: <TESTCASE> TEST_CASE_ID=mysql-show-databases RESULT=pass
case: mysql-show-databases
case_id: 60551
definition: 1_lamp-test
result: pass

Note

The test shell does not wait until the test case entry has been created before moving on, so there can be an offset between the point linked from the result (where the test case entry was created) to the point slightly earlier in the log where the test itself was executed. This wait behaviour caused various bugs as it needs to block at the shell read command which gets confused by other messages on the serial console.

There is a REST API using the name of the test definition and the name of the test case.

The name of the test definition comes from the test job definition:

- repository: http://git.linaro.org/lava-team/lava-functional-tests.git
     from: git
     path: lava-test-shell/single-node/singlenode03.yaml
     name: singlenode-advanced

The digit comes from the sequence of definitions in the list in the test action of the test job definition. For example, a test job with three definitions may result in the test actions: 0_env-dut-inline, 1_smoke_tests and 2_singlenode_advanced.

The test case name comes directly from the call to lava-test-case.

When an inline test definition does not report any test cases (by not calling lava-test-case anywhere, just doing setup or diagnostic calls to put data into the logs) then the metadata shows that test definition as “omitted” and it has no entry in the results table.

omitted.0.inline.name: env-dut-inline

In addition, each test job gets a set of LAVA results containing useful information like the commit hash of the test definition when it was cloned for this test job.

Multiple occurrences

If a test suite or test case occurs more than one in a set of results, those occurrences will show up in the results table. If each occurrence is within the same test definition, there will be one page showing both results (as the test case name is the same, there can only be one URL). Each occurrence links to a different point in the job log.

Accessing associated sections of test job logs

Accessing the test job logs from results allows users to navigate from a result back to the log file at the point where the result was created. It is also useful to allow sections of the test job log file to be downloaded, using the scheduler.jobs.logs(job_id, start=0, end=None) XMLRPC function:

import xmlrpc.client


def main(args):
    server = xmlrpc.client.ServerProxy("http://localhost/RPC2")
    # get lines 809 to 832 for test job 2140 on localhost
    print(str(server.scheduler.jobs.logs(2140, 809, 832)[1]))

The output is a list of dictionaries, one dictionary for each line of the test job log output, as YAML.

See also

Exporting data out of LAVA - the start and end lines are displayed in the UI when viewing a test case and are also exported through the REST API and XMLRPC functions

When a test case is created from a Lava Test Shell, the line number in the log file will be recorded in the TestCase in the following ways:

  • lava-test-case <NAME> --shell includes a start_log_line field and a end_log_line field which match the START_TC and END_TC signals respectively. The lines between the start and end will typically contain the content of the shell executed by the lava-test-case command.
  • lava-test-case <NAME> --result includes only the start_log_line as the line number where the result was reported. Typically, the content relating to how the result was declared will precede this line number, depending on how the Test Shell Definition is written.

Important

If the test shell definition scripts parse a log file and then call lava-test-case, the scripts are responsible for also outputting anything from the log file which relates to the reported test case. LAVA can only react to the signals sent by the DUT and the output can be earlier or later in the file. The test itself would need to be rewritten to not run a pre-existing command but to run each test operation as a separate lava-test-case <NAME> --shell call. This is not necessarily possible for all test suites.

One idea is to deliberately add a lava-test-case <NAME> --result pass before each block of commands to the upstream test suite, then fetch the entire section, from the known starting test case log line to the log line of the upstream test case.

Note that results created in the lava test suite do not create start, end or test case log lines.

Sample output for lava-test-case <NAME> shell

- {'dt': '2018-07-02T10:20:23.238676', 'lvl': 'debug', 'msg': 'Received signal: <STARTTC> linux-linaro-ubuntu-ifconfig'}
- {'dt': '2018-07-02T10:20:23.239618', 'lvl': 'target', 'msg': 'eth0      Link encap:Ethernet  HWaddr 52:54:00:12:34:59  '}
- {'dt': '2018-07-02T10:20:23.240048', 'lvl': 'target', 'msg': '          inet addr:10.0.2.15  Bcast:10.0.2.255  Mask:255.255.255.0'}
- {'dt': '2018-07-02T10:20:23.240583', 'lvl': 'target', 'msg': '          inet6 addr: fe80::5054:ff:fe12:3459/64 Scope:Link'}
- {'dt': '2018-07-02T10:20:23.241201', 'lvl': 'target', 'msg': '          inet6 addr: fec0::5054:ff:fe12:3459/64 Scope:Site'}
- {'dt': '2018-07-02T10:20:23.241931', 'lvl': 'target', 'msg': '          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1'}
- {'dt': '2018-07-02T10:20:23.242807', 'lvl': 'target', 'msg': '          RX packets:3 errors:0 dropped:0 overruns:0 frame:0'}
- {'dt': '2018-07-02T10:20:23.242946', 'lvl': 'target', 'msg': '          TX packets:7 errors:0 dropped:0 overruns:0 carrier:0'}
- {'dt': '2018-07-02T10:20:23.244086', 'lvl': 'target', 'msg': '          collisions:0 txqueuelen:1000 '}
- {'dt': '2018-07-02T10:20:23.244300', 'lvl': 'target', 'msg': '          RX bytes:1290 (1.2 KiB)  TX bytes:1102 (1.0 KiB)'}
- {'dt': '2018-07-02T10:20:23.244445', 'lvl': 'target', 'msg': ''}
- {'dt': '2018-07-02T10:20:23.244571', 'lvl': 'target', 'msg': 'lo        Link encap:Local Loopback  '}
- {'dt': '2018-07-02T10:20:23.245784', 'lvl': 'target', 'msg': '          inet addr:127.0.0.1  Mask:255.0.0.0'}
- {'dt': '2018-07-02T10:20:23.245930', 'lvl': 'target', 'msg': '          inet6 addr: ::1/128 Scope:Host'}
- {'dt': '2018-07-02T10:20:23.246054', 'lvl': 'target', 'msg': '          UP LOOPBACK RUNNING  MTU:65536  Metric:1'}
- {'dt': '2018-07-02T10:20:23.246175', 'lvl': 'target', 'msg': '          RX packets:0 errors:0 dropped:0 overruns:0 frame:0'}
- {'dt': '2018-07-02T10:20:23.247830', 'lvl': 'target', 'msg': '          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0'}
- {'dt': '2018-07-02T10:20:23.247999', 'lvl': 'target', 'msg': '          collisions:0 txqueuelen:0 '}
- {'dt': '2018-07-02T10:20:23.248125', 'lvl': 'target', 'msg': '          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)'}
- {'dt': '2018-07-02T10:20:23.248246', 'lvl': 'target', 'msg': ''}
- {'dt': '2018-07-02T10:20:23.248364', 'lvl': 'target', 'msg': '<LAVA_SIGNAL_ENDTC linux-linaro-ubuntu-ifconfig>'}
- {'dt': '2018-07-02T10:20:23.250065', 'lvl': 'debug', 'msg': 'Received signal: <ENDTC> linux-linaro-ubuntu-ifconfig'}

Note

The command which generates this output is typically not seen and may be several lines earlier in the log output:

- {'dt': '2018-07-02T10:20:23.236887', 'lvl': 'target', 'msg': '+ lava-test-case linux-linaro-ubuntu-ifconfig --shell ifconfig -a'}

In particular, the issuing of the command may be interleaved with the signal handling of other test cases:

- {'dt': '2018-07-02T10:20:23.236887', 'lvl': 'target', 'msg': '+ lava-test-case linux-linaro-ubuntu-ifconfig --shell ifconfig -a'}
- {'dt': '2018-07-02T10:20:23.237428', 'lvl': 'debug', 'msg': 'Received signal: <TESTCASE> TEST_CASE_ID=linux-linaro-ubuntu-vmstat RESULT=pass'}
- {'dt': '2018-07-02T10:20:23.237860', 'lvl': 'results', 'msg': {'case': 'linux-linaro-ubuntu-vmstat', 'definition': '1_smoke-tests', 'result': 'pass'}}
- {'dt': '2018-07-02T10:20:23.238196', 'lvl': 'target', 'msg': '<LAVA_SIGNAL_STARTTC linux-linaro-ubuntu-ifconfig>'}

This is due to the inherent latency between issuing a command in a shell on the DUT and the reception of the signal by the worker across the serial connection.

The problem can be mitigated by loading the YAML output and filtering the lines according to the logging level (lvl) for the DUT, target.

Latency also causes issues if a test outputs a lot of test cases in quick succession. The output of the test will then be many lines above the signal handling and therefore above the associated log line.