Selective Compression on BIG-IP
BIG-IP provides Local Traffic Policies that simplify the way in which you can manage traffic associated with a virtual server. You can associate a BIG-IP local traffic policy to support selective compression for types of content that can benefit from compression, like HTML, XML, and CSS stylesheets. These file types can realize performance improvements, especially across slow connections, by compressing them. You can easily configure your BIG-IP system to use a simple Local Traffic Policy that selectively compresses these file types. In order to use a policy, you will want to create and configure a draft policy, publish that policy, and then associate the policy with a virtual server in BIG-IP v12. Alright, let’s log into a BIG-IP The first thing you’ll need to do is create a draft policy. On the main menu select Local Traffic>Policies>Policy List and then the Create or + button. This takes us to the create policy config screen. We’ll name the policy SelectiveCompression, add a description like ‘This policy compresses file types,’ and we’ll leave the Strategy as the default of Execute First matching rule. This is so the policy uses the first rule that matches the request. Click Create Policy which saves the policy to the policies list. When saved, the Rules search field appears but has no rules. Click Create under Rules. This brings us to the Rules General Properties area of the policy. We’ll give this rule a name (CompressFiles) and then the first settings we need to configure are the conditions that need to match the request. Click the + button to associate file types. We know that the files for compression are comprised of specific file types associated with a content type HTTP Header. We choose HTTP Header and select Content-Type in the Named field. Select ‘begins with’ next and type ‘text/’ for the condition and compress at the ‘response’ time. We’ll add another condition to manage CPU usage effectively. So we click CPU Usage from the list with a duration of 1 minute with a conditional operator of ‘less than or equal to’ 5 as the usage level at response time. Next under Do the following, click the create + button to create a new action when those conditions are met. Here, we’ll enable compression at the response time. Click Save. Now the draft policy screen appears with the General Properties and a list of rules. Here we want to click Save Draft. Now we need to publish the draft policy and associate it with a virtual server. Select the policy and click Publish. Next, on the main menu click Local Traffic>Virtual Servers>Virtual Server List and click the name of the virtual server you’d like to associate for the policy. On the menu bar click Resources and for Policies click Manage. Move SelectiveCompression to the Enabled list and click Finished. The SelectiveCompression policy is now listed in the policies list which is now associated with the chosen virtual server. The virtual server with the SelectiveCompression Local Traffic Policy will compress the file types you specified. Congrats! You’ve now added a local traffic policy for selective compression! You can also watch the full video demo thanks to our TechPubs team. psAppDynamics EUM JavaScript Injection for Selective URLs
Problem this snippet solves: This code allows for the adrum.js agent to be dynamically injected into an application to support collecting EUM metrics. With this code, you can select from any number of HTTP Request headers and/or POST parameters. Additional EUM features in use: Custom GeoIP mappings based on a DataGroup User Data for Browser Snapshots, currently APM SID and Username How to use this snippet: This sample iRule assumes that the TCL variables $username and $sid have been previously created to support the UserData injection. If you don't have this information or APM available then these lines should be commented out or changed to meet your needs. Import the ltm profiles and iRule via tmsh load sys config merge <from-terminal> On your virtual, attache the Head-HTML profile as well as the iRule. Code : LTM Profiles Required: ltm html-rule tag-raise-event HTMLEvent-HeadStart-HTMLRule { description "Match an HTML tag for " match { tag-name head } } ltm profile html Head-HTML { app-service none content-detection disabled content-selection { text/html text/xhtml } defaults-from html description none rules { HTMLEvent-HeadStart-HTMLRule } } iRule to be attached to the Virtual: ltm rule SND-AppDynamics-HTML-Rule { when CLIENT_ACCEPTED { set APPDYNAMICS_EUM_DEBUG 0; } when HTTP_REQUEST { set APPDYNAMICS_EUM_APP_ID "AD-xxx-xxx-xxx-xxx" if { $APPDYNAMICS_EUM_DEBUG > 0 } {set uri [HTTP::uri]} if {[HTTP::uri] starts_with "/my/HomePage.do"} { # set enableEum 1 if { [HTTP::header Content-Type] eq "application/x-www-form-urlencoded" } { # HTTP::collect [HTTP::header Content-Length] # Only collect the first 200 bytes which should be enough to capture eventSource HTTP::collect 200 } else { if {[HTTP::uri] starts_with "/my/defaultPage"} { set enableEum 1 } } } elseif {[HTTP::uri] starts_with "/app1"} { set enableEum 1 } elseif {[HTTP::uri] starts_with "/app2"} { set enableEum 1 } when HTTP_REQUEST_DATA { set namevals [split [HTTP::payload] "&"] for {set i 0} {$i < [llength $namevals]} {incr i} { set params [split [lindex $namevals $i] "="] # log local0. " [lindex $params 0] : [lindex $params 1]" if {[lindex $params 0] equals "eventSource"} { switch -glob [lindex $params 1] { "PostParm1" - "PostParm2" - "PostParm3" { set enableEum 1 if { $APPDYNAMICS_EUM_DEBUG > 0 } { log local0. "FOUND HTTP DATA [lindex $params 1] TO ENABLE APPDYNAMICS EUM"; } } } break; } unset params } unset namevals } when HTTP_RESPONSE { if {[info exists enableEum]} { if { ($enableEum == 1) && ([HTTP::header "Content-Type"] starts_with "text/html") } { HTML::enable set enableEum 0 } else { HTML::disable } } else { HTML::disable } } when HTML_TAG_MATCHED { if { $APPDYNAMICS_EUM_DEBUG > 0 } { log local0. "uri = $uri element = [HTML::tag name] attribute id = [HTML::tag attribute id]"} switch [HTML::tag name] { "head" { if { $APPDYNAMICS_EUM_DEBUG > 0 } { log local0. "$uri info username [info exists username] info sid [info exists sid]"} if {([info exists username]) && ([info exists sid])} { # Send custom GeoIP Data to with the adrum beacon if we are on the private network set geoData [split [class match -value [IP::client_addr] equals Branch-Address-DataGroup ] "/"] if { $geoData != "" } { HTML::tag append [subst { window\["adrum-app-key"\] = "$APPDYNAMICS_EUM_APP_ID"; window\["adrum-start-time"\] = new Date().getTime(); window\["adrum-geo-resolver-url"\] = "thisdoesnotmatter"; window\["adrum-config"\] = { geo: { "country": "United States", "region": "[lindex $geoData 0]", "city": "[lindex $geoData 1]", "localIP": "[IP::client_addr]" } }; if (ADRUM) { ADRUM.command ("addUserData", "User", "$username"); } { ADRUM.command ("addUserData", "LastMRH_Session", "$sid"); } } ] } else { HTML::tag append [subst { window\["adrum-app-key"\] = "$APPDYNAMICS_EUM_APP_ID"; window\["adrum-start-time"\] = new Date().getTime(); if (ADRUM) { ADRUM.command ("addUserData", "User", "$username"); } { ADRUM.command ("addUserData", "LastMRH_Session", "$sid"); } } ] } unset geoData } } } } } Tested this on version: 11.5
HTML Comment Scrubber
Problem this snippet solves: HTML Commenting is very useful for documenting your site content. Unfortunately, that information can sometimes be private and it is not a desired situation to let everyone viewing your website to be able to access those comments. This iRule will perform a regular expression search on the HTTP response content and if it finds a HTML comment in the form of "!(ws)...(ws)" (ws - whitespace), it will replace all the characters with a space. I could have removed the characters from the reponse, thus shortening the payload, but by keeping the size the same that reduces the need to configure your virtual server to rechunk responses. How to use this snippet: Keep in mind that this will remove any and all content in between "!--" and "--". That includes javascript code inside a script block. I'll leave it to you all out there to modify the regexp to account for non javascript commented code blocks... Code : when HTTP_REQUEST { # Don't allow data to be chunked if { [HTTP::version] eq "1.1" } { if { [HTTP::header is_keepalive] } { HTTP::header replace "Connection" "Keep-Alive" } HTTP::version "1.0" } } when HTTP_RESPONSE { if { [HTTP::header exists "Content-Length"] && [HTTP::header "Content-Length"] < 1000000} { set content_length [HTTP::header "Content-Length"] } else { set content_length 1000000 } if { $content_length > 0 } { HTTP::collect $content_length } } when HTTP_RESPONSE_DATA { # Find the HTML comments set indices [regexp -all -inline -indices {} [HTTP::payload]] # Replace the comments with spaces in the response #log local0. "Indices: $indices" foreach idx $indices { set start [lindex $idx 0] set len [expr {[lindex $idx 1] - $start + 1}] log local0. "Start: $start, Len: $len" HTTP::payload replace $start $len [string repeat " " $len] } }
Remove the Select Client popup from VMware Horizon iApp
Due to security controls, we must have all users use web based HTML (BLAST) access to VDI sessions. The iApp works great, except when you launch a desktop it show a popup to requesting the user select a client (either VMware Horizon or HTML5 Client). I have gone though the iApp template () and cannot find any reference to the popup. I have looked through the APM policy, session-policy and Webtops to see if it there, but I can't seem to find it. Any ideas how to disable this popup?
HTML Comment Scrubber with Stream Profile
Problem this snippet solves: This example uses similar logic to scrub out HTML comments as the Html Comment Scrubber rule. Instead of collecting the HTTP response payloads, it uses the stream filter to replace the strings inline. This should be more efficient than buffering the entire payload with the HTTP::collect command. How to use this snippet: The iRule requires a blank stream profile and a custom HTTP profile with Chunking set to Rechunk if you change the response content length. Code : when HTTP_REQUEST { # Prevent the server from sending chunked response data if { [HTTP::version] eq "1.1" } { # Force downgrade to HTTP 1.0, but still allow keep-alive connections. # Since HTTP 1.1 is keep-alive by default, and 1.0 is not, # we need make sure the headers reflect the keep-alive status. if { [HTTP::header is_keepalive] } { HTTP::header replace "Connection" "Keep-Alive" } } # Disable the stream filter by default STREAM::disable } when HTTP_RESPONSE { # Check if the response is HTML if {[HTTP::header "Content-Type"] contains html{ # Set the stream expression to match HTML comments and replace them with nothing STREAM::expression {###} STREAM::enable } } # STREAM_MATCHED is triggered when the stream filter find string is found when STREAM_MATCHED { # Log the string which matched the stream profile log local0. "[IP::client_addr]:[TCP::client_port]: Removed comment: [STREAM::match]" } Tested this on version: 10.0
