How do I set Expires: header when using send_data - ruby-on-rails

I have a method in my controller which uses send_data like this:
def show
expires_in 10.hours, :public => true
send_data my_image_generator, :filename => "image.gif", :type => "image/gif"
end
Using expires_in results in headers being sent like this:
HTTP/1.1 200 OK
Connection: close
Date: Fri, 25 Jun 2010 10:41:22 GMT
ETag: "885d75258e9306c46a5dbfe3de44e581"
Content-Transfer-Encoding: binary
X-Runtime: 143
Content-Type: image/gif
Content-Disposition: inline; filename="image.gif"
Content-Length: 1277
Cache-Control: max-age=36000, public
What I would like to do is add an header like Expires: (some exact date) to keep the user agent from revalidating. But I don't see how to make send_data set that header?
I guess I could set it explicitly in the response.headers hash, but surely there must be a wrapper for that (or something)?

I came across this syntax and I like it :-)
response.headers["Expires"] = 1.year.from_now.httpdate

Apparently there seems to be no way to pass expires to send_data - instead you must set it yourself in response.headers and take care of formatting the date appropriately:
response.headers["Expires"] = CGI.rfc1123_date(Time.now + period)
Note that the max-age directive in the Cache-Control header overrides the Expires header if both are present. See RFC2616 Section 14.9.3 for more details.

The code in your question should actually work on recent Rails:
`expires_in 10.hours, :public => true`

Related

Does ruby strip headers from response?

I am fetching html content directly from my blog as:
response = Net::HTTP.get_response(uri)
respond_to do |format|
format.html { render :text => response.body }
end
Although at the blog engine (WordPress) I am adding header Access-Control-Allow-Origin: * how ever I noticed that its not passed within the response.
However, if I use postman to get the page or view the page into browser directly, I can see that the header is there.
EDIT
I can see other headers passed, ex:
cache-control: no-cache, must-revalidate, max-age=0
content-type: text/html; charset=UTF-8
date: Tue, 24 Jul 2018 06:37:57 GMT
expires: Wed, 11 Jan 1984 05:00:00 GMT
Any idea?
response.body will return you body part not header part. you can convert response to hash and check header like below:
> url = "https://stackoverflow.com/questions/51492025/does-ruby-strip-headers-from-response"
> uri = URI.parse(url)
> response = Net::HTTP.get_response(uri)
#=> #<Net::HTTPOK 200 OK readbody=true>
> response.to_hash
#=> {"cache-control"=>["private"], "content-type"=>["text/html; charset=utf-8"], "last-modified"=>["Tue, 24 Jul 2018 07:04:00 GMT"], "x-frame-options"=>["SAMEORIGIN"], "x-request-guid"=>["22a4b6b6-3039-46e2-b4de-c8af7cad6659"], "strict-transport-security"=>["max-age=15552000"], "content-security-policy"=>["upgrade-insecure-requests"], "accept-ranges"=>["bytes", "bytes"], "age"=>["0", "0"], "content-length"=>["31575"], "date"=>["Tue, 24 Jul 2018 07:04:46 GMT"], "via"=>["1.1 varnish"], "connection"=>["keep-alive"], "x-served-by"=>["cache-bom18221-BOM"], "x-cache"=>["MISS"], "x-cache-hits"=>["0"], "x-timer"=>["S1532415886.990199,VS0,VE280"], "vary"=>["Accept-Encoding,Fastly-SSL"], "x-dns-prefetch-control"=>["off"], "set-cookie"=>["prov=a7dfe911-76a1-f1c1-093b-3fc8fe79af65; domain=.stackoverflow.com; expires=Fri, 01-Jan-2055 00:00:00 GMT; path=/; HttpOnly"]}
You can access specific header as below by passing header name:
> response['Cache-Control']
#=> "private"
for more details read: https://ruby-doc.org/stdlib-2.5.1/libdoc/net/http/rdoc/Net/HTTP.html
If you want to pass through headers that are being served from the host that you're fetching from, you first need to stash the response from your blog in a different variable name. Let's call it blog_response (this is because response is a preexisting special method name in a rails controller instance.).
blog_response = Net::HTTP.get_response(uri)
Then you need to grab the header you care about from the blog_response like this:
header_name, header_value = blog_response.each_header.find do |name, value|
name =~ /pattern-matching-a-header-name-i-care-about/i #case insensitive regex matching recommended for http headers
end
Then you need to set them in your controller before you render the response, e.g.:
response.headers[header_name] = header_value
respond_to do |format|
format.html { render :text => blog_response.body }
end
This example is obviously only for one header, but you can copy multiple headers by just iterating through, matching and setting them in your response like so:
blog_response.each_header.select do |name, value|
if name =~ /pattern-matching-header-names-i-care-about|some-other-pattern-i-care-about/i #case insensitive regex matching recommended for http headers
response.headers[name] = value
end
end
If you want to pass all headers through just do this:
blog_response.each_header do |name, value|
response.headers[name] = value
end
respond_to do |format|
format.html { render :text => blog_response.body }
end
Net::HTTPResponse (that is your response) mixes in Net::HTTPHeader. Thus, you can get an individual header as response['Access-Control-Allow-Origin'], iterate over them with response.each_header, or even get them all as a hash using response.to_hash.

Add Expires header to rails assets

I am currently building a rails application and trying to improve its page speed insight mark. The only remaining warning would be my assets headers.
After looking at rails documentation and some articles on the internet, here's what I came up with in my production.rb file:
config.public_file_server.headers = {
'Cache-Control' => 'public, s-maxage=31536000, max-age=86400',
'Expires' => "#{1.day.from_now.httpdate}"
}
Now, here's what appears in my chrome network tab for my js/css file:
cache-control:public, max-age=86400
content-encoding:gzip
content-length:90444
content-type:application/javascript
date:Tue, 22 Aug 2017 10:49:05 GMT
last-modified:Tue, 22 Aug 2017 08:49:06 GMT
server:...
The cache-control appears as it should but there's no expires header.
I also use cloudfront on top of that but I'm not sure I should/can alter the headers from there.
Am I doing it wrong?
If you are using Rails 4, then only Cache-Control response header can be set for assets served by Rails. That’s a limitation.
Your solution is working for Rails 5
There is a test in Rails 5 source code, which ensures that custom header is included in response:
def test_serves_files_with_headers
headers = {
"Access-Control-Allow-Origin" => "http://rubyonrails.org",
"Cache-Control" => "public, max-age=60",
"X-Custom-Header" => "I'm a teapot"
}
app = ActionDispatch::Static.new(DummyApp, #root, headers: headers)
response = Rack::MockRequest.new(app).request("GET", "/foo/bar.html")
assert_equal "http://rubyonrails.org", response.headers["Access-Control-Allow-Origin"]
assert_equal "public, max-age=60", response.headers["Cache-Control"]
assert_equal "I'm a teapot", response.headers["X-Custom-Header"]
end
Also, even if you add Expires header somehow, max-age will take precedence anyway.
config.public_file_server.headers = {
'Cache-Control' => 'public, s-maxage=31536000, max-age=86400',
'Expires' => "#{1.day.from_now.to_formatted_s(:rfc822)}"
}
try this

Attachment not sent properly in rails using ActionMailer

I am trying to send xls file via ActionMailer.
mailer = ActionMailer::Base.mail(:to => "reciever#gmail.com", :from => "sender#gmail.com", :content_type=>"application/vnd.ms-excel", :body=> '')
mailer.attachments['filename.xls']= {mime_type: 'application/vnd.ms-excel', content: File.read("filePath.xls")}
mailer.deliver!
I am able to receive the mail as well.
But somehow the attachment is not correct, it shows up as noname and below is the content I get in the file (I am copy pasting the exact contents)
--
Date: Wed, 04 Jun 2014 23:33:48 +0530
Mime-Version: 1.0
Content-Type: application/vnd.ms-excel;
charset=UTF-8
Content-Transfer-Encoding: base64
Content-Disposition: inline;
filename=filename.xls
Content-ID: <538f5f82836992#C02L2178FFT3.gmail>
PGgzIHN0eWxlPSJmb250LXdlaWdodDpib2xkIj4gCiAgICBTaG93aW5nCiAg
ICBvcGVuCiAgICByZXF1ZXN0cwogICAgZnJvbQogICAgTm92IDIxLCAyMDEz
....
I am sure I am missing something simple, I am unable to figure out what. Can someone help?
Try this:--
mailer = ActionMailer::Base.mail(:to => "reciever#gmail.com", :from => "sender#gmail.com", :content_type=>"application/vnd.ms-excel", :body=> '')
mailer.attachments["filename.xls"]= File.read("filePath.xls")
mailer.deliver!

Rails 3.2 Rack::Cache HTTP Headers and Action Caching

Good afternoon,
I've run into some issues trying to combine HTTP caching with Rack::Cache and action caching (on my Heroku-hosted app).
Using them individually, it seems to be working. With action caching enabled, the page loading is snappy, and the log would suggest it is caching. With HTTP caching in the controllers (eTag, last_modified and fresh_when) the proper headers appear to be set.
However, when I try to combine the two, it appears to be action caching, but the HTTP headers are always max_age: 0, must_revalidate. Why is this? Am I doing something wrong?
For example, here's the code in my "home" action:
class StaticPagesController < ApplicationController
layout 'public'
caches_action :about, :contact, ......, :home, .....
......
def home
last_modified = File.mtime("#{Rails.root}/app/views/static_pages/home.html.haml")
fresh_when last_modified: last_modified , public: true, etag: last_modified
expires_in 10.seconds, :public => true
end
For all intents and purposes, this should have a public cache-control tag with max-age 10 no?
$ curl -I http://myapp-staging.herokuapp.com/
HTTP/1.1 200 OK
Cache-Control: max-age=0, private, must-revalidate
Content-Type: text/html; charset=utf-8
Date: Thu, 24 May 2012 06:50:45 GMT
Etag: "997dacac05aa4c73f5a6861c9f5a9db0"
Status: 200 OK
Vary: Accept-Encoding
X-Rack-Cache: stale, invalid
X-Request-Id: 078d86423f234da1ac41b418825618c2
X-Runtime: 0.005902
X-Ua-Compatible: IE=Edge,chrome=1
Connection: keep-alive
Config Info:
# Use a different cache store in production
config.cache_store = :dalli_store
config.action_dispatch.rack_cache = {
:verbose => true,
:metastore => "memcached://#{ENV['MEMCACHE_SERVERS']}",
:entitystore => "memcached://#{ENV['MEMCACHE_SERVERS']}"#,
}
In my mind, you should be able to use action caching as well as a reverse proxy correct? I know that they do fairly similar things (if the page changes, both the proxy and the action cache will be invalid and need to be regenerated), but I feel I should be able to have both in there. Or should I get rid of one?
UPDATE
Thanks for the answer below! It seems to work. But to avoid having to write set_XXX_cache_header methods for every controller action, do you see any reason why this wouldn't work?
before_filter :set_http_cache_headers
.....
def set_http_cache_headers
expires_in 10.seconds, :public => true
last_modified = File.mtime("#{Rails.root}/app/views/static_pages/#{params[:action]}.html.haml")
fresh_when last_modified: last_modified , public: true, etag: last_modified
end
When you use action caching, only the response body and content type is cached. Any other changes to the response will not happen on subsequent requests.
However, action caching will run any before filters even when the action itself is cached.
So, you can do something like this:
class StaticPagesController < ApplicationController
layout 'public'
before_filter :set_home_cache_headers, :only => [:home]
caches_action :about, :contact, ......, :home, .....
......
def set_home_cache_headers
last_modified = File.mtime("#{Rails.root}/app/views/static_pages/home.html.haml")
fresh_when last_modified: last_modified , public: true, etag: last_modified
expires_in 10.seconds, public: true
end

How to STOP caches_page from setting page in cache permanently? -- Rails 3.1

I want to make sure that if the file changes (if cache files are deleted for example), the user's browser shouldn't load the cached version.
Here is the issue I found. Here are the headers when I DON'T use caches_page:
HTTP/1.1 200 OK =>
ETag => "4ff902bc57e1892d7a963e43bf56dcc8"
X-UA-Compatible => IE=Edge,chrome=1
Cache-Control => max-age=0, private, must-revalidate
X-Runtime => 2.710376
X-Rack-Cache => miss
Set-Cookie => _Myapp_session=.....; path=/; HttpOnly
Status => 200
And here are the headers when I do use it:
HTTP/1.1 200 OK =>
ETag => "80003-1ad93-4b44a71a41180"
Last-Modified => Sat, 17 Dec 2011 14:22:14 GMT
Accept-Ranges => bytes
I've removed the common lines for easy comparison.
Are there any issues with these differing headers?
I didn't find any rails way to do this so put in "Header set" directives in apache.conf

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