Log outgoing HTTP requests made from your application. Helps with debugging pesky API error responses, or just generally understanding what's going on under the hood.
Requires ruby >= 2.5
This gem works with the following ruby modules and libraries:
These libraries are at least partially supported, where they use one of the above as adapters, but not explicitly tested - YMMV:
In theory, it should also work with any library built on top of these. But the difference between theory and practice is bigger in practice than in theory.
This is very much a development and debugging tool; it is not recommended to use this in a production environment as it is monkey-patching the respective HTTP implementations. You have been warned - use at your own risk.
Httplog is kindly sponsored by Bearer.sh - go check them out please!
gem install httplog
require 'httplog' # require this *after* your HTTP gem of choice
By default, this will log all outgoing HTTP requests and their responses to $stdout on DEBUG level.
- Binary data from response bodies (as indicated by the
Content-Type
header)is not logged. - Text data (
text/*
and mostapplication/*
types) is encoded as UTF-8, with invalid characters replaced. If you need to inspect raw non-UTF data exactly as sent over the wire, this tool is probably not for you.
You can override the following default options:
HttpLog.configure do |config|
# Enable or disable all logging
config.enabled = true
# You can assign a different logger or method to call on that logger
config.logger = Logger.new($stdout)
config.logger_method = :log
# I really wouldn't change this...
config.severity = Logger::Severity::DEBUG
# Tweak which parts of the HTTP cycle to log...
config.log_connect = true
config.log_request = true
config.log_headers = false
config.log_data = true
config.log_status = true
config.log_response = true
config.log_benchmark = true
# ...or log all request as a single line by setting this to `true`
config.compact_log = false
# You can also log in JSON format
config.json_log = false
# Prettify the output - see below
config.color = false
# Limit logging based on URL patterns
config.url_whitelist_pattern = nil
config.url_blacklist_pattern = nil
# Mask sensitive information in request and response JSON data.
# Enable global JSON masking by setting the parameter to `/.*/`
config.url_masked_body_pattern = nil
# You can specify any custom JSON serializer that implements `load` and `dump` class methods
# to parse JSON responses
config.json_parser = JSON
# When using graylog, you can supply a formatter here - see below for details
config.graylog_formatter = nil
# Mask the values of sensitive request parameters
config.filter_parameters = %w[password]
end
If you want to use this in a Rails app, I'd suggest configuring this specifically for each environment. A global initializer is not a good idea since HttpLog
will be undefined in production. Because you're not using this in production, right? :)
# config/environments/development.rb
HttpLog.configure do |config|
config.logger = Rails.logger
end
If you're running a (hopefully patched) legacy Rails 3 app, you may need to set
config.logger_method = :add
due to its somewhat unusual logger.
You can colorize the output to make it stand out in your logfile, either with a single color for the text:
HttpLog.configure do |config|
config.color = :red
end
Or with a color hash for text and background:
HttpLog.configure do |config|
config.color = {color: :black, background: :yellow}
end
For more color options please refer to the rainbow documentation
If you use Graylog and want to use its search features such as "benchmark:>1 AND method:PUT", you can use this configuration:
FORMATTER = Lograge::Formatters::KeyValue.new
HttpLog.configure do |config|
config.logger = <your GELF::Logger>
config.logger_method = :add
config.severity = GELF::Levels::DEBUG
config.graylog_formatter = FORMATTER
end
You also can use GELF Graylog format this way:
class Lograge::Formatters::Graylog2HttpLog < Lograge::Formatters::Graylog2
def short_message data
data[:response_body] = data[:response_body].to_s.byteslice(0, 32_766) unless data[:response_body].blank?
"[httplog] [#{data[:response_code]}] #{data[:method]} #{data[:url]}"
end
end
FORMATTER = Lograge::Formatters::Graylog2HttpLog.new
Or define your own class that implements the call
method
If the log is too noisy for you, but you don't want to completely disable it either, set the compact_log
option to true
. This will log each request in a single line with method, request URI, response status and time, but no data or headers. No need to disable any other options individually.
If you want to log HTTP requests in a JSON format, set the json_log
option to true
. You can combine this with compact_log
to only log the basic request metrics without headers and bodies.
Just like in Rails, you can filter the values of sensitive parameters by setting the filter_parameters
to an array of (lower case) keys. The value for "password" is filtered by default.
Please note that this will only filter the request data with well-formed parameters (in the URL, the headers, and the request data) but not the response. It does not currently filter JSON request data either, just standard "key=value" pairs in the request body.
With the default configuration, the log output might look like this:
[httplog] Connecting: localhost:80
[httplog] Sending: GET http://localhost:9292/index.html
[httplog] Status: 200
[httplog] Benchmark: 0.00057 seconds
[httplog] Response:
<html>
<head>
<title>Test Page</title>
</head>
<body>
<h1>This is the test page.</h1>
</body>
</html>
With log_headers = true
and a parameter 'password' in the request query and headers:
[httplog] Connecting: localhost:80
[httplog] Sending: GET http://localhost:9292/index.html?password=[FILTERED]
[httplog] Header: accept: *.*
[httplog] Header: password=[FILTERED]
[httplog] Status: 200
[httplog] Benchmark: 0.00057 seconds
[httplog] Response:
<html>
<head>
<title>Test Page</title>
</head>
<body>
<h1>This is the test page.</h1>
</body>
</html>
With compact_log
enabled, the same request might look like this:
[httplog] GET http://localhost:9292/index.html completed with status code 200 in 0.00057 seconds
With json_log
enabled:
[httplog] {"method":"GET","url":"localhost:80","request_body":null, "request_headers":{"foo":"bar"}, "response_code":200,"response_body":"<html>\n <head>\n <title>Test Page</title>\n </head>\n <body>\n <h1>This is the test page.</h1>\n </body>\n </html>","response_headers":{"foo":"bar"},"benchmark":0.00057}
And with json_log
and compact_log
enabled:
[httplog] {"method":"GET","url":"localhost:80","response_code":200,"benchmark":0.00057}
Following are some known quirks and issues with particular libraries. If you know a workaround or have a suggestion for a fix, please open an issue or, even better, submit a pull request!
-
Requests types other than GET and POST have not been explicitly tested. They may or may not be logged, depending on the implementation details of the underlying library. If they are not for a particular library, please feel free to open an issue with the details.
-
When using OpenURI, the reading of the HTTP response body is deferred, so it is not available for logging. This will be noted in the logging statement:
[httplog] Connecting: localhost:80 [httplog] Sending: GET http://localhost:9292/index.html [httplog] Status: 200 [httplog] Benchmark: 0.000617 seconds [httplog] Response: (not available yet)
-
When using HTTPClient, the TCP connection establishment will be logged after the HTTP request and headers, due to the way HTTPClient is organized.
[httplog] Sending: GET http://localhost:9292/index.html [httplog] Header: accept: */* [httplog] Header: foo: bar [httplog] Connecting: localhost:9292 [httplog] Status: 200 [httplog] Benchmark: 0.001562 seconds
-
Also when using HTTPClient, make sure you include
httplog
afterhttpclient
in yourGemfile
. -
When using Ethon or Patron, and any library based on them (such as Typhoeus), the TCP connection is not logged (since it's established by libcurl).
-
Benchmarking only covers the time between starting the HTTP request and receiving the response. It does not cover the time it takes to establish the TCP connection.
Make sure you have the necessary dependencies installed by running bundle install
.
Then simply run bundle exec rspec spec
.
This will launch a simple rack server on port 9292 and run all tests locally against that server.
If you have any issues with or feature requests for httplog, please open an issue on GitHub or fork the project and send a pull request. Please include passing specs with all pull requests.