TSRemapInit

Traffic Server remap plugin entry points.

概要

#include <ts/ts.h>
#include <ts/remap.h>

TSReturnCode TSRemapInit(TSRemapInterface *api_info, char *errbuff, int errbuff_size)

void TSRemapPreConfigReload(void)

void TSRemapPostConfigReload(TSReturnCode reloadStatus)

void TSRemapDone(void)

TSRemapStatus TSRemapDoRemap(void *ih, TSHttpTxn rh, TSRemapRequestInfo *rri)

TSReturnCode TSRemapNewInstance(int argc, char *argv[], void **ih, char *errbuff, int errbuff_size)

void TSRemapDeleteInstance(void*)

void TSRemapOSResponse(void *ih, TSHttpTxn rh, int os_response_type)

void *TSRemapDLHandleGet(TSRemapPluginInfo plugin_info)

解説

Traffic Server の remap インターフェースはプラグインが HTTP トランザクションを操作するための簡素な仕組みを提供します。remap プラグインは大域的ではありません。それは remap ルール毎に設定され、 remap.config ファイル内の個々のルールに基づいて URL がどのようにリダイレクトされるかをカスタマイズできるようにしています。一つ以上の remap エントリーポイントを満たすことと、トランザクションがプラグインを通るように remap.config を設定することから remap プラグインを書くことは成り立っています。複数の remap プラグインが一つの remap ルールに指定されることもあり、HTTP トランザクションを検査する機会が各プラグインに与えられる remap プラグインチェーンとなります。

TSRemapInit() は必須のエントリーポイントです。この関数は Traffic Serverがプラグインをロードする際に一度だけ呼ばれます。省略可能な TSRemapDone() 関数がある場合、Traffic Server は remap プラグインをアンロードするときにそれを呼び出します。

A remap plugin may be invoked for different remap rules. Traffic Server will call the entry point each time a plugin is specified in a remap rule. When a remap plugin instance is no longer required, Traffic Server will call TSRemapDeleteInstance(). At that point, it's safe to remove any data or continuations associated with that instance.

The function TSRemapDLHandleGet() will return the handle created for the loaded plugin, as returned by dlopen().

TSRemapDoRemap() は各 HTTP トランザクションで呼び出されます。これは必須のエントリーポイントです。この関数では remap プラグインが HTTP トランザクションを検査し変更するかもしれません。

TSRemapPreConfigReload() is called before the parsing of a new remap configuration starts to notify plugins of the coming configuration reload. It is called on all already loaded plugins, invoked by current and all previous still used configurations. This is an optional entry point.

TSRemapPostConfigReload() is called to indicate the end of the new remap configuration load. It is called on the newly and previously loaded plugins, invoked by the new, current and previous still used configurations. It also indicates whether the configuration reload was successful by passing TSREMAP_CONFIG_RELOAD_FAILURE in case of failure and to notify the plugins if they are going to be part of the new configuration by passing TSREMAP_CONFIG_RELOAD_SUCCESS_PLUGIN_USED or TSREMAP_CONFIG_RELOAD_SUCCESS_PLUGIN_UNUSED. This is an optional entry point.

Generally speaking, calls to these functions are mutually exclusive. The exception is for functions which take an HTTP transaction as a parameter. Calls to these transaction-specific functions for different transactions are not necessarily mutually exclusive of each other.

For further information, see Remap Plugins.

Types

enum TSRemapStatus

Status return value for remap callback.

enumerator TSREMAP_DID_REMAP

The remap callback modified the request.

enumerator TSREMAP_DID_REMAP_STOP

The remap callback modified the request and that no more remapping callbacks should be invoked.

enumerator TSREMAP_NO_REMAP

The remap callback did not modify the request.

enumerator TSREMAP_NO_REMAP_STOP

The remap callback did not modify the request and that no further remapping callbacks should be invoked.

enumerator TSREMAP_ERROR

The remapping attempt in general failed and the transaction should fail with an error return to the user agent.

enum TSRemapReloadStatus

enumerator TSREMAP_CONFIG_RELOAD_FAILURE

Notify the plugin that configuration parsing failed.

enumerator TSREMAP_CONFIG_RELOAD_SUCCESS_PLUGIN_USED

Configuration parsing succeeded and plugin was used by the new configuration.

enumerator TSREMAP_CONFIG_RELOAD_SUCCESS_PLUGIN_UNUSED

Configuration parsing succeeded but plugin was NOT used by the new configuration.

Return Values

TSRemapInit() and TSRemapNewInstance() should return TS_SUCCESS on success, and TS_ERROR otherwise. A return value of TS_ERROR is unrecoverable.

TSRemapDoRemap() returns a status code that indicates whether the HTTP transaction has been modified and whether Traffic Server should continue to evaluate the chain of remap plugins. If the transaction was modified, the plugin should return TSREMAP_DID_REMAP or TSREMAP_DID_REMAP_STOP; otherwise it should return TSREMAP_NO_REMAP or TSREMAP_NO_REMAP_STOP. If Traffic Server should not send the transaction to subsequent plugins in the remap chain, return TSREMAP_NO_REMAP_STOP or TSREMAP_DID_REMAP_STOP. Returning TSREMAP_ERROR causes Traffic Server to stop evaluating the remap chain and respond with an error.

参照

TSAPI(3ts)