Currently testing the following code:
def db_check
begin
schema_call = ActiveRecord::Base.establish_connection(
:adapter => 'mysql2',
:host => 'localhost',
:database => 'dev_db',
:username => 'dev_user',
:password => 'dev_pw').connection.execute("SELECT * FROM schema_migrations LIMIT 1")
if schema_call
render :status => 200, :file => "public/success.html"
else
render :status => 500, :file => "public/query_fail.html"
end
rescue Exception => e
puts "#{e.class} ;; #{e.message}"
logger.debug "#{e.class}"
render :status => 500, :file => "public/500.html"
end
end
The eventual goal is to have a call to a MySQL server to see if 1) the server is still up and 2) if the database is available. If the connection doesn't work, an Error is thrown, so I put the code in a rescue block. Unfortunately, even when I use rescue Exception, which I understand to be advised against, I still get a Mysql2::Error message in the browser (I also tried rescue Mysql2:Error, which had no effect).
The duplication of error logging in the rescue is extra attempts to get additional information to work with, but nothing has worked so far. Anyone know how to catch this error?
UPDATE: also, for additional context, testing the code with MySQL not running currently (condition if the DB server is down), get back the following:
Mysql2::Error
Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)
which makes partial sense, given the server is off, but I still don't understand why it isn't rescuing the error.
The reason the rescue isn't catching the Mysql2::Error is that the error isn't coming from the ActiveRecord::Base code, but rather is Rails throwing an error because it can't connect to the MySQL server that it expects (which I had turned off to test the above code).
Related
I am using RestClient to make a network call in the ruby class. I am getting a SocketError whenever I am not connected to the internet. I have added a rescue block to catch the exception still I am not able to do so.
the error message is:
SocketError (Failed to open TCP connection to api.something.com:443 (getaddrinfo: Name or service not known))
module MyProject
class Client
def get_object(url, params={})
response = RestClient.get(url, {params: params})
rescue SocketError => e
puts "In Socket errror"
rescue => e
puts (e.class.inspect)
end
end
end
The broad rescue gets called and print SocketError, but why the previous rescue SocketError is not triggered!
Do you see something that I am missing?
There are a couple of exceptions you'll need to rescue in case you want to fail gracefully.
require 'rest-client'
def get_object(url, params={})
response = RestClient.get(url, {params: params})
rescue RestClient::ResourceNotFound => e
p e.class
rescue SocketError => e
p e.class
rescue Errno::ECONNREFUSED => e
p e.class
end
get_object('https://www.google.com/missing')
get_object('https://dasdkajsdlaadsasd.com')
get_object('dasdkajsdlaadsasd.com')
get_object('invalid')
get_object('127.0.0.1')
Because you can have problems regarding the uri being a 404 destination, or be a domain that doesn't existing, an IP, and so on.
As you can see above, you can have different scenarios that you may encounter when dealing with connecting to a remote uri. The code above rescue from the most common scenarios.
The first one the URL is missing, which is handled by RestClient itself.
The the following three below are invalid domains, which will fail with SocketError (basically a DNS error in this case).
Finally in the last call we try to connect to an IP that has no server running on it - therefore it throws an ERRNO::ECONNREFUSED
On my rails application, I am receiving an error on production(heroku) but not on my localhost. All of my migrations are done and I can add it through the console, but I cannot get this to work in the controller.
So the area where the error is occuring is here:
respond_to do |format|
if #registration.save
EventMailer.new_registration_notification(#registration, #current_event).deliver
Recipient.create :first_name => #registration.first_name, :last_name => #registration.last_name, :email => #registration.email, :netID => #registration.netID, :event_id => #registration.event_id, :mailing_id => nil
format.html { redirect_to event_path(#current_event), notice: 'Registration was successful' }
Again, I am not getting an error in my development local environment but I am in production. They are both using Postgres. So my registrations ARE saving but Recipient is never created and I get an error. I've checked the heroku logs by running:
herkou logs
but there are no errors shown. On the front end, you see an error that says "Something went wrong. If you're the application owner please check your logs".
Fixed my problem, the problem was with sending the mailer. I did not notice that the mailer wasn't sending and just assumed it was an issue creating the Recipient. I needed to fix some configurations in the production.rb file to use the SMTP server. After fixing that the issue went away
I have the following code:
begin
site = RedirectFollower.new(url).resolve
rescue => e
puts e.to_s
return false
end
Which throws errors like:
the scheme http does not accept registry part: www.officedepot.com;
the scheme http does not accept registry part: ww2.google.com/something;
Operation timed out - connect(2)
How can I add in another rescue for all errors that are like the scheme http does not accept registry part?
Since I want to do something other than just printing the error and returning false in that case.
That depends.
I see the three exception descriptions are different. Are the Exception types different as well?
If So you could write your code like this:
begin
site = RedirectFollower.new(url).resolve
rescue ExceptionType1 => e
#do something with exception that throws 'scheme http does not...'
else
#do something with other exceptions
end
If the exception types are the same then you'll still have a single rescue block but will decide what to do based on a regular expression. Perhaps something like:
begin
site = RedirectFollower.new(url).resolve
rescue Exception => e
if e.message =~ /the scheme http does not accept registry part/
#do something with it
end
end
Does this help?
Check what is exception class in case of 'the scheme http does not accept registry part' ( you can do this by puts e.class). I assume that this will be other than 'Operation timed out - connect(2)'
then:
begin
.
rescue YourExceptionClass => e
.
rescue => e
.
end
Important Note: Rescue with wildcard, defaults to StandardError. It will not rescue every error.
For example, SignalException: SIGTERMwill not be rescued with rescue => error. You will have to specifically use rescue SignalException => e.
The following code
purchase = #order.authorize_payment(#credit_card, options)
is_success = purchase.success?
if is_success
...
else
flash[:notice] = "!! " + purchase.message + "" +
purchase.params['missingField'].to_s
redirect_to :action => :payment, :id => #order.id
end
results in "!! Failed with 500 Internal Server Error" in my flash[:notice]. There is no stacktrace, no webserver error, all that I know is that purchase.message is populated and purchase.success? is false.
I am really at a loss to figure out how to troubleshoot this. I think it might be an ssl requirement, but I can't either see the soap request, or test basic connectivity with cybersource (my payment gateway).
I establish my gateway with this code (after config.after_initialize do):
ActiveMerchant::Billing::Base.mode = :production # :test
ActiveMerchant::Billing::CreditCard.require_verification_value = false
ActiveMerchant::Billing::CyberSourceGateway.wiredump_device = File.new(File.join([Rails.root, "log", "cybersource.log"]), "a") # doesn't work (!)
# we need to open an external file to get the password
mypassphrase = File.open('/var/www/foo/shared/passphrase.txt').read
OrderTransaction.gateway = ActiveMerchant::Billing::CyberSourceGateway.new(:login => 'vxxxxxxx',
:password => mypassphrase.to_s,
:test => false,
:vat_reg_number => 'your VAT registration number',
# sets the states/provinces where you have a physical presense for tax purposes
:nexus => "GA OH",
# don‘t want to use AVS so continue processing even if AVS would have failed
:ignore_avs => true,
# don‘t want to use CVV so continue processing even if CVV would have failed
:ignore_cvv => true,
:money_format => :dollars
)
Can I see the soap request? Are there ways to test part of this? Any help greatly appreciated.
Best,
Tim
ActiveMerchant::Billing::CyberSourceGateway.logger = your_logger
So, late response but...
I've done a good amount of work with the Cybersource gateway, and the only way to see the SOAP request/response of the cybersource gateway currently is to open up the gem and edit it.
If you modify the commit method of lib/active_merchant/billing/gateways/cybersource.rb, you can do something like this:
def commit(request, options)
puts "*** POSTING TO: #{test? ? TEST_URL : LIVE_URL}"
request = build_request(request, options)
puts "*** POSTING:"
puts request
begin
post_response = ssl_post(test? ? TEST_URL : LIVE_URL, request)
rescue ActiveMerchant::ResponseError => e
puts "ERROR!"
puts e.response
end
puts post_response
It would be nice if there was a way to get that response without going through that hassle, I'll see if there's a way to pass that information up through the response object that's returned and add it to my fork.
With the launch of Amazon's Relational Database Service today and their 'enforced' maintenance windows I wondered if anyone has any solutions for handling a missing database connection in Rails.
Ideally I'd like to be able to automatically present a maintenance page to visitors if the database connection disappears (i.e. Amazon are doing their maintenance) - has anyone ever done anything like this?
Cheers
Arfon
You can do this with a Rack Middleware:
class RescueFromNoDB < Struct.new(:app)
def call(env)
app.call(env)
rescue Mysql::Error => e
if e.message =~ /Can't connect to/
[500, {"Content-Type" => "text/plain"}, ["Can't get to the DB server right now."]]
else
raise
end
end
end
Obviously you can customize the error message, and the e.message =~ /Can't connect to/ bit may just be paranoia, almost all other SQL errors should be caught inside ActionController::Dispatcher.