Grails plugin for logging HTTP traffic.

It logs:

• request information (url, headers, cookies, method, body),
• grails dispatch information (controller, action, parameters),
• response information (elapsed time and body).
• whatever else you want! (see Configuration section)

It is mostly useful for logging your REST traffic. Full HTTP web pages can be huge to log and generally waste your space.

Add the following to your BuildConfig.groovy

runtime ":httplogger:1.1"

And be sure to enable logging for grails.plugins.httlogger at INFO level in Config.groovy:

info 'grails.plugins.httplogger'

Without any further configuration, all reqeusts are logged. Sample output below:

17:16:00,331 INFO  filters.LogRawRequestInfoFilter  - << #1 GET http://localhost:8080/riddle/rest/index?username=admin&search=foo
17:16:00,340 INFO  filters.LogRawRequestInfoFilter  - << #1 headers Cookie: 'JSESSIONID=DF4EA5725AC4A4990281BD96963739B0; splashShown1.6=1', Accept-Language: 'en-US,en;q=0.8,pl;q=0.6', X-MyHeader: 'null'
17:16:00,342 INFO  filters.LogGrailsUrlsInfoFilter  - << #1 dispatched to rest/index with parsed params [username:[admin], search:[foo]].
17:16:00,731 INFO  filters.LogOutputResponseFilter  - >> #1 returned 200, took 405 ms.
17:16:00,745 INFO  filters.LogOutputResponseFilter  - >> #1 responded with '{count:0}'

17:18:55,799 INFO  filters.LogRawRequestInfoFilter  - << #2 POST http://localhost:8080/riddle/rest/login
17:18:55,799 INFO  filters.LogRawRequestInfoFilter  - << #2 headers Cookie: 'JSESSIONID=DF4EA5725AC4A4990281BD96963739B0; splashShown1.6=1', Accept-Language: 'en-US,en;q=0.8,pl;q=0.6', X-MyHeader: 'null'
17:18:55,800 INFO  filters.LogRawRequestInfoFilter  - << #2 body: 'username=admin&password=password'
17:18:55,801 INFO  filters.LogOutputResponseFilter  - >> #2 returned 404, took 3 ms.
17:18:55,802 INFO  filters.LogOutputResponseFilter  - >> #2 responded with ''

Logging all the requests and responses is quite a lot of logs, so you might want to configure the plugin before running it on production :).

You can configure the plugin in your Config.groovy like this:

grails.plugins.httplogger.enabled = false
//should you wish to disable it temporarily or based on environment

grails.plugins.httplogger.headers = 'Cookie, Accept-Language, X-MyHeader' 
//list of headers to log by the default HttpLogger implementation

grails.plugins.httplogger.includeUrls = ['/rest/**', '/**/*.interesting']
grails.plugins.httplogger.excludeUrls = ['/css/**', '/**/*.js']
// - lists of Ant-style patterns to be included/excluded by the default RequestMatcher implementation
//   (AntPatternRequestMatcher)
// - includes take precedence over excludes
// - if none of them are given - all requests are logged

You can even completely override how the requests are matched and what and how is logged, by providing your own implementations of two simple interfaces. See the following sections.

Just implement grails.plugins.httplogger.RequestMatcher interface and expose it as a bean named loggableRequestMatcher:

//somewhere in resources.groovy
loggableRequestMatcher(MethodBasedRequestMatcher) {
    method = 'POST'
}

You might want your custom implementations to be written is Java, for performance and type-safety reasons (BTW: most of the plugin is Java):

public class MethodBasedRequestMatcher implements RequestMatcher {
    
    String method;

    public void setMethod(String method) {
        this.method = method;
    }

    @Override
    public boolean matches(MultiReadHttpServletRequest requestWrapper) {
        return method.equalsIgnoreCase(requestWrapper.getMethod());
    }
}

But a Groovy class will do as well:

class MethodBasedRequestMatcher implements RequestMatcher {

    String method

    @Override
    boolean matches(MultiReadHttpServletRequest requestWrapper) {
        method.equalsIgnoreCase(requestWrapper.method)
    }
}

Just implement the grails.plugins.httplogger.HttpLogger interface and expose it as a bean named httpLogger.

See the default implementation (grails.plugins.httplogger.DefaultHttpLogger) for details.

Notice how we log request and response body using our MultiRead wrappers' getCopied[Input/Output] methods (these were one of the 'tricky' parts of the plugin ;)).

Be sure to adjust your logging configuration in config groovy.

Many kudos to Marek Maj for his MultiReadHttpServletResponse class.