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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
commit | 26a029d407be480d791972afb5975cf62c9360a6 (patch) | |
tree | f435a8308119effd964b339f76abb83a57c29483 /testing/geckodriver/doc/TraceLogs.md | |
parent | Initial commit. (diff) | |
download | firefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz firefox-26a029d407be480d791972afb5975cf62c9360a6.zip |
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'testing/geckodriver/doc/TraceLogs.md')
-rw-r--r-- | testing/geckodriver/doc/TraceLogs.md | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/testing/geckodriver/doc/TraceLogs.md b/testing/geckodriver/doc/TraceLogs.md new file mode 100644 index 0000000000..fb4e298c44 --- /dev/null +++ b/testing/geckodriver/doc/TraceLogs.md @@ -0,0 +1,206 @@ +# Enabling trace logs + +geckodriver provides different bands of logs for different audiences. +The most important log entries are shown to everyone by default, +and these include which port geckodriver provides the WebDriver +API on, as well as informative warnings, errors, and fatal exceptions. + +The different log bands are, in ascending bandwidth: + +1. `fatal` is reserved for exceptional circumstances when geckodriver + or Firefox cannot recover. This usually entails that either + one or both of the processes will exit. + +2. `error` messages are mistakes in the program code which it is + possible to recover from. + +3. `warn` shows warnings of more informative nature that are not + necessarily problems in geckodriver. This could for example happen + if you use the legacy `desiredCapabilities`/`requiredCapabilities` + objects instead of the new `alwaysMatch`/`firstMatch` structures. + +4. `info` (default) contains information about which port geckodriver + binds to, but also all messages from the lower-bandwidth levels + listed above. + +5. `config` additionally shows the negotiated capabilities after + matching the `alwaysMatch` capabilities with the sequence of + `firstMatch` capabilities. + +6. `debug` is reserved for information that is useful when programming. + +7. `trace`, where in addition to itself, all previous levels + are included. The trace level shows all HTTP requests received + by geckodriver, packets sent to and from the remote protocol in + Firefox, and responses sent back to your client. + +In other words this means that the configured level will coalesce +entries from all lower bands including itself. If you set the log +level to `error`, you will get log entries for both `fatal` and `error`. +Similarly for `trace`, you will get all the logs that are offered. + +To help debug a problem with geckodriver or Firefox, the trace-level +output is vital to understand what is going on. This is why we ask +that trace logs are included when filing bugs gainst geckodriver. +It is only under very special circumstances that a trace log is +not needed, so you will normally find that our first action when +triaging your issue will be to ask you to include one. Do yourself +and us a favour and provide a trace-level log right away. + +To silence geckodriver altogether you may for example either redirect +all output to append to some log files: + +```shell +% geckodriver >>geckodriver.log 2>>geckodriver.err.log +``` + +Or a black hole somewhere: + +```shell +% geckodriver >/dev/null 2>&1 +``` + +The log level set for geckodriver is propagated to the Marionette +logger in Firefox. Marionette is the remote protocol that geckodriver +uses to implement WebDriver. This means enabling trace logs for +geckodriver will also implicitly enable them for Marionette. + +The log level is set in different ways. Either by using the +`--log <LEVEL>` option, where `LEVEL` is one of the log levels +from the list above, or by using the `-v` (for debug) or `-vv` +(for trace) shorthands. For example, the following command will +enable trace logs for both geckodriver and Marionette: + +```shell +% geckodriver -vv +``` + +The second way of setting the log level is through capabilities. +geckodriver accepts a Mozilla-specific configuration object +in [`moz:firefoxOptions`]. This JSON Object, which is further +described in the [README] can hold Firefox-specific configuration, +such as which Firefox binary to use, additional preferences to set, +and of course which log level to use. + +[`moz:firefoxOptions`]: https://searchfox.org/mozilla-central/source/testing/geckodriver/README.md#firefox-capabilities +[README]: https://searchfox.org/mozilla-central/source/testing/geckodriver/README.md + +Each client has its own way of specifying capabilities, and some clients +include “helpers” for providing browser-specific configuration. +It is often advisable to use these helpers instead of encoding the +JSON Object yourself because it can be difficult to get the exact +details right, but if you choose to, it should look like this: + +```json +{"moz:firefoxOptions": {"log": {"level": "trace"}}} +``` + +Note that most known WebDriver clients, such as those provided by +the Selenium project, do not expose a way to actually _see_ the logs +unless you redirect the log output to a particular file (using the +method shown above) or let the client “inherit” geckodriver’s +output, for example by redirecting the stdout and stderr streams to +its own. The notable exceptions are the Python and Ruby bindings, +which surface geckodriver logs in a remarkable easy and efficient way. + +See the client-specific documentation below for the most idiomatic +way to enable trace logs in your language. We want to expand this +documentation to cover all the best known clients people use with +geckodriver. If you find your language missing, please consider +[submitting a patch]. + +[submitting a patch]: Patches.md + +## C-Sharp + +The Selenium [C# client] comes with a [`FirefoxOptions`] helper for +constructing the [`moz:firefoxOptions`] capabilities object: + +```csharp +FirefoxOptions options = new FirefoxOptions(); +options.LogLevel = FirefoxDriverLogLevel.Trace; +IWebDriver driver = new FirefoxDriver(options); +``` + +The log output is directed to stdout. + +[C# client]: https://seleniumhq.github.io/selenium/docs/api/dotnet/ +[`FirefoxOptions`]: https://seleniumhq.github.io/selenium/docs/api/dotnet/html/T_OpenQA_Selenium_Firefox_FirefoxOptions.htm + +## Java + +The Selenium [Java client] also comes with +a [`org.openqa.selenium.firefox.FirefoxOptions`] helper for +constructing the [`moz:firefoxOptions`] capabilities object: + +```java +FirefoxOptions options = new FirefoxOptions(); +options.setLogLevel(FirefoxDriverLogLevel.TRACE); +WebDriver driver = new FirefoxDriver(options); +``` + +The log output is directed to stdout. + +[Java client]: https://seleniumhq.github.io/selenium/docs/api/java/ +[`org.openqa.selenium.firefox.FirefoxOptions`]: https://seleniumhq.github.io/selenium/docs/api/java/org/openqa/selenium/firefox/FirefoxOptions.html + +## Javascript (webdriver.io) + +With the Selenium [JavaScript client] the capabilities object can directly be +constructed: + +```javascript +import WebDriver from 'webdriver' + +const driver = await WebDriver.newSession({ + capabilities: { + browserName: 'firefox', + 'moz:firefoxOptions': { + log: { level: 'trace' }, + } + } +}) +``` + +The log output is directed to stdout, or if geckodriver runs as a wdio plugin +then the generated logs are part of the wdio log system. + +[JavaScript client]: https://webdriver.io/ + +## Python + +The Selenium [Python client] comes with a +[`selenium.webdriver.firefox.options.Options`] helper that can +be used programmatically to construct the [`moz:firefoxOptions`] +capabilities object: + +```python +from selenium.webdriver import Firefox +from selenium.webdriver.firefox.options import Options + +opts = Options() +opts.log.level = "trace" +driver = Firefox(options=opts) +``` + +The log output is stored in a file called _geckodriver.log_ in your +script’s current working directory. + +[Python client]: https://selenium-python.readthedocs.io/ +[`selenium.webdriver.firefox.options.Options`]: https://github.com/SeleniumHQ/selenium/blob/master/py/selenium/webdriver/firefox/options.py + +## Ruby + +The Selenium [Ruby client] comes with an [`Options`] helper to +generate the correct [`moz:firefoxOptions`] capabilities object: + +```ruby +Selenium::WebDriver.logger.level = :debug +opts = Selenium::WebDriver::Firefox::Options.new(log_level: :trace) +driver = Selenium::WebDriver.for :firefox, options: opts +``` + +The log output is directed to stdout. + +[Ruby client]: https://seleniumhq.github.io/selenium/docs/api/rb/ +[`Options`]: https://seleniumhq.github.io/selenium/docs/api/rb/Selenium/WebDriver/Firefox/Options.html |