How best to accomplish HTTP redirection for specific URLs?

I'd go with the data group method. It's by far the easiest to manage and requires no subsequent changes to the iRule. Example.

Data group - string-based (ex. my_uri_dg)

"/uri1"
"/uri2"
"/uri3"
"/uri4"

iRule:

when HTTP_REQUEST {
   if { not ( [class match [string tolower [HTTP::uri]] starts_with my_uri_dg] ) } {
      HTTP::redirect "https://[HTTP::host][HTTP::uri]"
   }
}

So as long as the requested URI pattern (starts_with) is in the data group, the request will pass through. Otherwise, for everything else, it gets redirected. It doesn't appear that the host name changes, so you shouldn't have to evaluate that. Also note that we're just looking for data the group key, so the corresponding values can be empty.

Can you use regex in these data groups? I will want to match a common 3 digit string in each URI but the digits will change over time. Also I would want to ignore case on these URIs.

what about this?

e.g.

root@(ve11a)(cfg-sync Changes Pending)(Active)(/Common)(tmos) list ltm virtual bar
ltm virtual bar {
    destination 172.28.20.111:80
    ip-protocol tcp
    mask 255.255.255.255
    pool foo
    profiles {
        http { }
        tcp { }
    }
    rules {
        myrule
    }
    source 0.0.0.0/0
    source-address-translation {
        type automap
    }
    vs-index 23
}
root@(ve11a)(cfg-sync Changes Pending)(Active)(/Common)(tmos) list ltm rule myrule
ltm rule myrule {
    when HTTP_REQUEST {
  set path [string tolower [HTTP::path]]
  switch -glob $path {
    "/slowcomputer/is/slow/index.html" -
    "/notso/fastcomputer/is/notfast.html" -
    "slownotebook/is/slow/nossl/index.html" -
    "/slow[0-9][0-9][0-9][0-9][0-9]/nossl/is/slow/myhome.svc" {
       do nothing
    }
    default {
      HTTP::redirect "https://[HTTP::host][HTTP::uri]"
    }
  }
}
}

[root@ve11a:Active:Changes Pending] config  curl -I http://172.28.20.111/slowcomputer/is/slow/index.html
HTTP/1.1 404 Not Found
Date: Sun, 25 Aug 2013 01:28:50 GMT
Server: Apache/2.2.3 (CentOS)
Content-Type: text/html; charset=iso-8859-1

[root@ve11a:Active:Changes Pending] config  curl -I http://172.28.20.111/SLOW54321/nossl/is/slow/myhome.svc
HTTP/1.1 404 Not Found
Date: Sun, 25 Aug 2013 01:31:45 GMT
Server: Apache/2.2.3 (CentOS)
Content-Type: text/html; charset=iso-8859-1

[root@ve11a:Active:Changes Pending] config  curl -I http://172.28.20.111/somethingelse
HTTP/1.0 302 Found
Location: https://172.28.20.111/somethingelse
Server: BigIP
Connection: Keep-Alive
Content-Length: 0

Can you use regex in these data groups? I will want to match a common 3 digit string in each URI but the digits will change over time. Also I would want to ignore case on these URIs.

what about this?

e.g.

root@(ve11a)(cfg-sync Changes Pending)(Active)(/Common)(tmos) list ltm virtual bar
ltm virtual bar {
    destination 172.28.20.111:80
    ip-protocol tcp
    mask 255.255.255.255
    pool foo
    profiles {
        http { }
        tcp { }
    }
    rules {
        myrule
    }
    source 0.0.0.0/0
    source-address-translation {
        type automap
    }
    vs-index 23
}
root@(ve11a)(cfg-sync Changes Pending)(Active)(/Common)(tmos) list ltm rule myrule
ltm rule myrule {
    when HTTP_REQUEST {
  set path [string tolower [HTTP::path]]
  switch -glob $path {
    "/slowcomputer/is/slow/index.html" -
    "/notso/fastcomputer/is/notfast.html" -
    "slownotebook/is/slow/nossl/index.html" -
    "/slow[0-9][0-9][0-9][0-9][0-9]/nossl/is/slow/myhome.svc" {
       do nothing
    }
    default {
      HTTP::redirect "https://[HTTP::host][HTTP::uri]"
    }
  }
}
}

[root@ve11a:Active:Changes Pending] config  curl -I http://172.28.20.111/slowcomputer/is/slow/index.html
HTTP/1.1 404 Not Found
Date: Sun, 25 Aug 2013 01:28:50 GMT
Server: Apache/2.2.3 (CentOS)
Content-Type: text/html; charset=iso-8859-1

[root@ve11a:Active:Changes Pending] config  curl -I http://172.28.20.111/SLOW54321/nossl/is/slow/myhome.svc
HTTP/1.1 404 Not Found
Date: Sun, 25 Aug 2013 01:31:45 GMT
Server: Apache/2.2.3 (CentOS)
Content-Type: text/html; charset=iso-8859-1

[root@ve11a:Active:Changes Pending] config  curl -I http://172.28.20.111/somethingelse
HTTP/1.0 302 Found
Location: https://172.28.20.111/somethingelse
Server: BigIP
Connection: Keep-Alive
Content-Length: 0

Okay, this is a little hacky, but there is technically a way to achieve "regex-like" behavior with data groups. I'll start with the data group.

/slow1234/nossl/is/
/fast1234/nossl/is/
... 

The digits in the URI aren't important and I'm purposely limiting the URIs to three-levels deep, but yours should be limited to the lowest common denominator for your matched URIs. Now the iRule:

when HTTP_REQUEST {
     limit the request URI to three levels
     Example: /slow1234/nossl/is/slow/ becomes /slow1234/nossl/is/
    set uri [string range [HTTP::uri] 0 [string first "/" [HTTP::uri] [expr [string first "/" [HTTP::uri] [expr [string first "/" [HTTP::uri] 1] +1]]+1]]]

     Turn the URI into a glob pattern based on numeric values
     Example: /slow1234/nossl/is/slow becomes /slow*/nossl/is/slow
    regsub -all -nocase {\d+} $uri "*" globuri
    append globuri "*"

     Search for the glob pattern in the data group
    if { not ( [lindex [class get -nocase glob_datagrouop $globuri] 1] eq "" ) } {
        log local0. "no match"
         perform redirects
    } 
}

The idea here is that I'm using the [class get ] command with a glob pattern - not truly a regex itself, but the regsub command above makes sure that only digits are affected. So to illustrate what's happening:

1. The URI is first truncated to three levels. That'll make more sense in a moment.

2. The regsub command replaces any instance of a sequential digits in the URI with a glob "*" character, and then an additional "*" is appended to the end.

3. This pattern is fed into the [class get ] command, which produces a list. If the pattern matches a single data group entry, then it's flagged as a match. Otherwise all or multiple records are returned and it's not a match. Of course you want to make sure that your URI patterns cannot produce multiple results in the search.

The reason for limiting the data group URI is that you can't really do a "starts_with" expression like you can with other class commands. So, for example, if the data group URI was something like "/slow1234/nossl/is/" and the request URI was "/slow3454/nossl/is/slow/test/foo/bar", the glob pattern would become "/slow*/nossl/is/slow/test/foo/bar" - and this wouldn't match the data group.