Hi,
It works even with the READ_REQUEST_HOOK! Kudos to you sir. Just to understand
what is going on as there is not much documentation about this.
1. We are adding a header in the client request header if the query parameter
is present.
> cond %{QUERY} /(^|&)a=true(&|$)/
> add-header @QueryPresent TRUE [L]
2. Check wether the flag (@QueryPresent) exists in the client request header.
> cond %{SEND_RESPONSE_HDR_HOOK} [AND]
> cond %{CLIENT-HEADER:@QueryPresent} =TRUE
> add-header TestHeader 1234 [L]
is that correct?
Thank you so much!
Best regards.
> On 18 Feb 2015, at 20:17, Sudheer Vinukonda <[email protected]> wrote:
>
> Sorry, the hook name READ_REQUEST_HOOK is incorrect - the below config is
> sufficient (as this is being added on a remap hook anyway).
>
> % cat rules.config
> cond %{QUERY} /(^|&)a=true(&|$)/
> add-header @QueryPresent TRUE [L]
> cond %{SEND_RESPONSE_HDR_HOOK} [AND]
> cond %{CLIENT-HEADER:@QueryPresent} =TRUE
> add-header TestHeader 1234 [L]
>
> %cat remap.config
> map http://cache.server:8080
> <http://cache.server:8080/>http://web.server:8080 <http://web.server:8080/>
> @plugin=header_rewrite.so @pparam=rules.config
> From: Sudheer Vinukonda <[email protected]>
> To: "[email protected]" <[email protected]>
> Sent: Wednesday, February 18, 2015 10:50 AM
> Subject: Re: Header rewrite rule based on query string
>
> The below config seems to do what you need:
>
> % cat rules.config
> cond %{READ_REQUEST_HOOK} [AND]
> cond %{QUERY} /(^|&)a=true(&|$)/
> add-header @QueryPresent TRUE [L]
> cond %{SEND_RESPONSE_HDR_HOOK} [AND]
> cond %{CLIENT-HEADER:@QueryPresent} =TRUE
> add-header TestHeader 1234 [L]
>
> %cat remap.config
> map http://cache.server:8080
> <http://cache.server:8080/>http://web.server:8080 <http://web.server:8080/>
> @plugin=header_rewrite.so @pparam=rules.config
>
>
> Thanks,
>
> Sudheer
>
>
>
>
> From: Ezequiel Foncubierta <[email protected]>
> To: [email protected]
> Sent: Wednesday, February 18, 2015 6:35 AM
> Subject: Header rewrite rule based on query string
>
> Hi,
>
> I am trying to rewrite the response header using the header_rewrite.so plugin.
>
> My remap.config file:
> map http://cache.server:8080
> <http://cache.server:8080/>http://web.server:8080
> <http://web.server:8080/>@plugin=header_rewrite.so @pparam=rules.conf
> reverse_map http://web.server:8080
> <http://web.server:8080/>http://cache.server:8080 <http://cache.server:8080/>
>
> My rules.conf file:
> cond %{SEND_RESPONSE_HDR_HOOK}
> cond %{QUERY} /(^|&)a=true(&|$)/
> add-header TestHeader 1234
>
> What I am expecting with this configuration so far is that if the request URL
> has a query parameter "a=true”, then the TestHeader 1234 will be added to the
> response header. However, I get the following message in the debug traces.
>
> vagrant@cache <mailto:vagrant@cache>:~/trafficserver$ sudo traffic_server
> -T"header"
> traffic_server: using root directory '/usr/local'
> traffic_server: using root directory '/usr/local'
> [Feb 18 14:05:04.450] Server {0x7fd4f5454740} DIAG: (header_rewrite) Remap
> plugin is successfully initialized
> [Feb 18 14:05:04.451] Server {0x7fd4f5454740} DIAG: (header_rewrite)
> Instantiating a new remap.config plugin rule
> [Feb 18 14:05:04.451] Server {0x7fd4f5454740} DIAG: (header_rewrite) Loading
> remap configuration file rules.conf
> [Feb 18 14:05:04.451] Server {0x7fd4f5454740} DIAG: (header_rewrite)
> Adding condition: %{QUERY} with arg: /(^|&)a=true(&|$)/
> [Feb 18 14:05:04.452] Server {0x7fd4f5454740} DIAG: (header_rewrite) Regex
> precompiled successfully
> [Feb 18 14:05:04.452] Server {0x7fd4f5454740} DIAG: (header_rewrite)
> Adding operator: add-header(TestHeader)
> [Feb 18 14:05:04.452] Server {0x7fd4f5454740} DIAG: (header_rewrite)
> Succesfully loaded remap config file rules.conf
> [Feb 18 14:05:04.453] Server {0x7fd4f5454740} DIAG: (header_rewrite) Adding
> remap ruleset to hook=TS_HTTP_SEND_RESPONSE_HDR_HOOK
> [Feb 18 14:05:23.841] Server {0x7fd4f1819700} DIAG: (header_rewrite) Added
> remapped TXN hook=TS_HTTP_SEND_RESPONSE_HDR_HOOK
> [Feb 18 14:05:23.841] Server {0x7fd4f1819700} DIAG: (header_rewrite) Building
> resources, hook=(null)
> [Feb 18 14:05:23.841] Server {0x7fd4f1819700} DIAG: (header_rewrite)
> Adding TXN client request header buffers
> [Feb 18 14:05:23.841] Server {0x7fd4f1819700} DIAG: (header_rewrite)
> Adding TXN client request header buffers for remap instance
> [Feb 18 14:05:23.896] Server {0x7fd4f1819700} DIAG: (header_rewrite) Building
> resources, hook=TS_HTTP_SEND_RESPONSE_HDR_HOOK
> [Feb 18 14:05:23.896] Server {0x7fd4f1819700} DIAG: (header_rewrite)
> Adding TXN client request header buffers
> [Feb 18 14:05:23.896] Server {0x7fd4f1819700} DIAG: (header_rewrite)
> Adding TXN client response header buffers
> [Feb 18 14:05:23.896] Server {0x7fd4f1819700} DIAG: (header_rewrite) QUERY
> requires remap initialization! Evaluating to false!
>
> If I get rid of the SEND_RESPONSE_HDR_HOOK condition in rules.conf, I get the
> following traces:
>
> vagrant@cache <mailto:vagrant@cache>:~/trafficserver$ sudo traffic_server
> -T"header"
> traffic_server: using root directory '/usr/local'
> traffic_server: using root directory '/usr/local'
> [Feb 18 14:09:49.061] Server {0x7f7d6d42f740} DIAG: (header_rewrite) Remap
> plugin is successfully initialized
> [Feb 18 14:09:49.061] Server {0x7f7d6d42f740} DIAG: (header_rewrite)
> Instantiating a new remap.config plugin rule
> [Feb 18 14:09:49.061] Server {0x7f7d6d42f740} DIAG: (header_rewrite) Loading
> remap configuration file rules.conf
> [Feb 18 14:09:49.061] Server {0x7f7d6d42f740} DIAG: (header_rewrite)
> Adding condition: %{QUERY} with arg: /(^|&)a=true(&|$)/
> [Feb 18 14:09:49.061] Server {0x7f7d6d42f740} DIAG: (header_rewrite) Regex
> precompiled successfully
> [Feb 18 14:09:49.062] Server {0x7f7d6d42f740} DIAG: (header_rewrite)
> Adding operator: add-header(TestHeader)
> [Feb 18 14:09:49.062] Server {0x7f7d6d42f740} DIAG: (header_rewrite)
> Succesfully loaded remap config file rules.conf
> [Feb 18 14:09:55.967] Server {0x7f7d697f4700} DIAG: (header_rewrite) Building
> resources, hook=(null)
> [Feb 18 14:09:55.968] Server {0x7f7d697f4700} DIAG: (header_rewrite)
> Adding TXN client request header buffers
> [Feb 18 14:09:55.968] Server {0x7f7d697f4700} DIAG: (header_rewrite)
> Adding TXN client request header buffers for remap instance
> [Feb 18 14:09:55.968] Server {0x7f7d697f4700} DIAG: (header_rewrite)
> Appending QUERY to evaluation value: a=true
> [Feb 18 14:09:55.968] Server {0x7f7d697f4700} DIAG: (header_rewrite)
> Evaluating QUERY - a=true
> [Feb 18 14:09:55.968] Server {0x7f7d697f4700} DIAG: (header_rewrite) Test
> regular expression (^|&)a=true(&|$) : a=true
> [Feb 18 14:09:55.968] Server {0x7f7d697f4700} DIAG: (header_rewrite)
> Successfully found regular expression match
> [Feb 18 14:09:55.968] Server {0x7f7d697f4700} DIAG: (header_rewrite)
> OperatorAddHeader::exec() invoked on header TestHeader: 1234
> [Feb 18 14:09:55.968] Server {0x7f7d697f4700} DIAG: (header_rewrite)
> Adding header TestHeader
>
> The regular expression is working as it is expected for the QUERY condition
> but, obviously, the TestHeader is added to the HTTP request from cache.server
> to web.server instead of the HTTP response from cache.server to the client.
> On the other hand, the PATH condition works nicely with the
> SEND_RESPONSE_HDR_HOOK condition.
>
> I have tried many different configuration with no luck (i.e. setting the
> plugin in plugin.config). Any help would be really appreciated.
>
> Thank you!
>
> Best regards.
>
>
>
