Question

这是我用来配置httpd服务器的proplist_file：

[
  {modules, [
    mod_alias,
    mod_actions,
    mod_cgi,
    mod_get,
    mod_esi,
    mod_log
  ]},
  {bind_address, "localhost"}, 
  {port,0},
  {server_name,"httpd_test"},
  {server_root,"/Users/7stud/erlang_programs/inets_proj"},
  {document_root,"./htdocs"},
  {script_alias, {"/cgi-bin/", "/Users/7stud/erlang_programs/inets_proj/cgi-bin/"} },
  {erl_script_alias, {"/cgi-bin/example", [httpd_example]} },
  {erl_script_nocache, true},
  {error_log, "./errors.log"},
  {transfer_log, "./requests.log"}
].

对于esi脚本，关键属性是：

  {erl_script_alias, {"/cgi-bin/example", [httpd_example]} }

根据inets docs：

ESI属性 - 需要mod_esi

{erl_script_alias，{URLPath，[AllowedModule]}}
  URLPath = string（）和AllowedModule = atom（）。 erl_script_alias标记所有URL   将url-path匹配为erl方案脚本。匹配的URL映射到   特定的模块和功能，例如：
 {erl_script_alias, {"/cgi-bin/example", [httpd_example]}}
请求 http://your.server.org/cgi-bin/example/httpd_example:yahoo会提及到httpd_example:yahoo/3或者，如果不存在， httpd_example：yahoo / 2和 http://your.server.org/cgi-bin/example/other:yahoo不会允许执行。

我的目录结构是：

~/erlang_programs$ tree inets_proj/
inets_proj/
├── cgi-bin
│   ├── 1.pl
│   ├── example
│   │   ├── httpd_example.beam
│   │   └── httpd_example.erl
│   ├── httpd_example.beam
│   └── httpd_example.erl
├── cl.beam
├── cl.erl
├── errors.log
├── htdocs
│   └── file1.txt
├── httpd_example.beam
├── httpd_example.erl
├── mylog.log
├── requests.log
├── s.beam
├── s.erl
└── server.conf

我不确定将httpd_example模块放在哪里，所以我把它放在几个地方。

esi_mod.erl：

-module(esi_mod).
-compile(export_all).

log(Data) ->
    {ok, IoDevice} = file:open(
        "/Users/7stud/erlang_programs/inets_proj/mylog.log",
        [append]
    ),

    ok = file:write(IoDevice, Data),
    file:close(IoDevice).

get_data(SessionID, _Env, _Input) ->
    Headers = "Content-Type: text/html\r\n\r\n",
    Data = "Hello, esi",

    log(["--Inside esi_mod:get_data() ~n"]),

    ok = mod_esi:deliver(SessionID, Headers),  %Headers must be a string.
    ok = mod_esi:deliver(SessionID, Data).     %Data can be an iolist.

以下是shell中报告的服务器信息：

$ erl
Erlang/OTP 20 [erts-9.2] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:10] [hipe] [kernel-poll:false]
Eshell V9.2  (abort with ^G)

1> c(s).         
s.erl:2: Warning: export_all flag enabled - all functions will be exported
{ok,s}
2> S = s:start().
<0.86.0>
3> httpd:info(S).
[{mime_types,[{"htm","text/html"},{"html","text/html"}]},
 {server_name,"httpd_test"},
 {erl_script_nocache,true},
 {script_alias,{"/cgi-bin/",
                "/Users/7stud/erlang_programs/inets_proj/cgi-bin/"}},
 {bind_address,{127,0,0,1}},
 {modules,[mod_alias,mod_actions,mod_cgi,mod_get,mod_esi,
           mod_log]},
 {server_root,"/Users/7stud/erlang_programs/inets_proj"},
 {erl_script_alias,{"/cgi-bin/example",[httpd_example]}},
 {port,64470},
 {transfer_log,<0.93.0>},
 {error_log,<0.92.0>},
 {document_root,"./htdocs"}]
4>

这是我的要求：

~$ curl -vv "http://localhost:64470/cgi-bin/example/httpd_example:get_data"
*   Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 64470 (#0)
> GET /cgi-bin/example/httpd_example:get_data HTTP/1.1
> Host: localhost:64470
> User-Agent: curl/7.58.0
> Accept: */*
> 
< HTTP/1.1 404 Object Not Found
< Date: Wed, 28 Feb 2018 10:22:38 GMT
< Server: inets/6.4.5
< Content-Type: text/html
< Content-Length: 245
< 
<HTML>
       <HEAD>
           <TITLE>Object Not Found</TITLE>
      </HEAD>
      <BODY>
      <H1>Object Not Found</H1>
The requested URL &#47;cgi-bin&#47;example&#47;httpd_example:get_data was not found on this server.
</BODY>
      </HTML>
* Connection #0 to host localhost left intact
~$

errors.log：

[时间戳]访问权限 / cgi-bin / example / httpd_example：127.0.0.1的get_data失败，原因：＆＃34; httpd_file：无法打开 ./htdocs/cgi-bin/example/httpd_example:get_data：找不到文件＆＃34;

根据错误消息，请求路径：

/cgi-bin/example/httpd_example:get_data

转换为：

./htdocs/cgi-bin/example/httpd_example:get_data

表示请求路径已添加到./htdocs。咦??

Answer 1

好的，我把事情搞定了。首先，当我在四处寻找时，我碰巧遇到了：

10 Essential Erlang Tools for Erlang Developers

其中有一个我用过的最好的二郎“工具”：

退出erlang shell时未删除的命令历史记录。

您可以按照此处的说明安装/启用它：https://github.com/ferd/erlang-history

回到手头的问题：

1）我发现httpd模块的顺序很重要。 mod_esi需要在mod_get之前：

server.conf中：

[
  {modules, [
    mod_alias,
    mod_actions,
    mod_esi,
    mod_cgi,
    mod_get,
    mod_log
  ]},
  {bind_address, "localhost"}, 
  {port,0},
  {server_name,"httpd_test"},
  {server_root,"/Users/7stud/erlang_programs/inets_proj"},
  {document_root,"./htdocs"},
  {script_alias, {"/cgi-bin/", "/Users/7stud/erlang_programs/inets_proj/cgi-bin/"} },
  {erl_script_alias, {"/erl", [mymod]} },
  {erl_script_nocache, true},
  {error_log, "./errors.log"},
  {transfer_log, "./requests.log"}
].

在获得正确的模块顺序之后，由于奇怪的转换路径，我停止了“找不到文件”错误。

2）esi模块的代码必须位于server_root目录中。我的esi模块的名称是mymod.erl：

~/erlang_programs$ tree inets_proj/
inets_proj/
├── cgi-bin
│   ├── 1.pl
│   ├── example
│   │   ├── httpd_example.beam
│   │   └── httpd_example.erl
│   ├── httpd_example.beam
│   └── httpd_example.erl
├── cl.beam
├── cl.erl
├── errors.log
├── htdocs
│   └── file1.txt
├── mylog.log
├── mymod.beam
├── mymod.erl
├── requests.log
├── s.beam
├── s.erl
├── server.conf
├── xhttpd_example.beam
└── xhttpd_example.erl

3）因为我指定了：

{erl_script_alias, {"/erl", [mymod]} }

我需要使用的网址是：

http://localhost:57867/erl/mymod:get_data

端口必须与服务器端口匹配。正确的路径是您在erl_script_alias属性中指定的任何路径以及/modulename:funcname或/modulename/funcname。

这是mymod.erl：

-module(mymod).
-export([get_data/3]).

log(Data) ->
    {ok, IoDevice} = file:open(
        "/Users/7stud/erlang_programs/inets_proj/mylog.log",
        [append]
    ),

    file:write(IoDevice, Data),
    file:close(IoDevice).

get_data(SessionID, Env, Input) ->
    Headers = "Content-Type: text/html\r\n\r\n",
    Data = [
        <<"Hello, ">>, 
        "esi!\n"
    ],

    log(io_lib:format(
        "Inside mymod:get_data()\nSessionId=~p\nEnv=~p\nInput=~p\n", 
        [SessionID, Env, Input]
    )),

    mod_esi:deliver(SessionID, Headers),  %Headers must be a string.
    mod_esi:deliver(SessionID, Data).     %Data can be an iolist.

根据mod_esi docs：

mod_esi：deliver / 2 将用于生成对客户端的响应，SessionID是一个在调用时应使用的标识符这个函数，不假设有关数据类型的任何内容。这个可以多次调用函数来对响应数据进行分块。请注意，发送到客户端的第一个数据块必须至少包含响应将生成的所有HTTP标头字段。如果第一个块不包含HTTP头的末尾，即 “\ r \ n \ r \ n”，服务器假定没有HTTP头字段生成。

4）编译mymod.erl：

~/erlang_programs/inets_proj$ erlc mymod.erl 
~/erlang_programs/inets_proj$

您必须在对mymod.erl进行的每次更改后重新编译，然后重新启动服务器。如果这样做会更简单：

5> httpd:reload_config("server.conf", disturbing).
{error,{missing_property,server_name}}

但即使我的配置文件确实指定了server_name属性，我也会收到该错误。

5）我建议您通过在模块列表中包含mod_log并指定属性来执行错误记录：

{error_log, "./errors.log"}

然后检查该文件是否有关于请求失败时发生的事情的任何反馈。

6）当我调用自定义log（）方法（为了将一些信息写入文件）时，我不知道log（）方法导致异常，导致服务器拒绝请求并输入{ error.log中的{1}}消息：

module traverse failed

7）这是我用来启动服务器的模块：

[Timestamp], module traverse failed: mod_esi:do => 
   Error Type:  exit
   Error:       {mod_esi_linked_process_died,<0.97.0>,normal}
   Stack trace: [{mod_esi,receive_headers,1,[{file,"mod_esi.erl"},{line,428}]},
                 {mod_esi,deliver_webpage_chunk,3,
                     [{file,"mod_esi.erl"},{line,389}]},
                 {mod_esi,erl_scheme_webpage_chunk,5,
                     [{file,"mod_esi.erl"},{line,380}]},
                 {mod_esi,generate_webpage,7,
                     [{file,"mod_esi.erl"},{line,314}]},
                 {httpd_response,traverse_modules,2,
                     [{file,"httpd_response.erl"},{line,77}]},
                 {httpd_response,generate_and_send_response,1,
                     [{file,"httpd_response.erl"},{line,44}]},
                 {httpd_request_handler,handle_response,1,
                     [{file,"httpd_request_handler.erl"},{line,655}]},
                 {gen_server,try_dispatch,4,
                     [{file,"gen_server.erl"},{line,616}]}]

8）以下是一些使用curl的示例请求...

shell中的服务器信息：

-module(s).
-compile(export_all).

%Need to look up port with httpd:info(Server)

ensure_inets_start() ->
    case inets:start() of
        ok -> ok;
        {error,{already_started,inets}} -> ok
    end.


start() ->
    ok = s:ensure_inets_start(),

    {ok, Server} = inets:start(httpd, 
        [{proplist_file, "./server.conf"}]
    ),
    Server.


stop(Server) ->
    ok = inets:stop(httpd, Server).

请求1（esi get request）：

~/erlang_programs/inets_proj$ erl
Erlang/OTP 20 [erts-9.2] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:10] [hipe] [kernel-poll:false]

Eshell V9.2  (abort with ^G)
1> c(s).         
s.erl:2: Warning: export_all flag enabled - all functions will be exported
{ok,s}
2> S = s:start().
<0.86.0>
3> httpd:info(S).
[{mime_types,[{"htm","text/html"},{"html","text/html"}]},
 {server_name,"httpd_test"},
 {erl_script_nocache,true},
 {script_alias,{"/cgi-bin/",
                "/Users/7stud/erlang_programs/inets_proj/cgi-bin/"}},
 {bind_address,{127,0,0,1}},
 {modules,[mod_alias,mod_actions,mod_esi,mod_cgi,mod_get,
           mod_log]},
 {server_root,"/Users/7stud/erlang_programs/inets_proj"},
 {erl_script_alias,{"/erl",[mymod]}},
 {port,59202},
 {transfer_log,<0.93.0>},
 {error_log,<0.92.0>},
 {document_root,"./htdocs"}]
4>

mylog.log：

~$  curl -v "http://localhost:57867/erl/mymod:get_data"
*   Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 57867 (#0)
> GET /erl/mymod:get_data HTTP/1.1
> Host: localhost:57867
> User-Agent: curl/7.58.0
> Accept: */*
> 
< HTTP/1.1 200 OK
< Date: Wed, 28 Feb 2018 13:28:09 GMT
< Server: inets/6.4.5
< Cache-Control: no-cache
< Pragma: no-cache
< Expires: Wed, 28 Feb 2018 13:28:09 GMT
< Transfer-Encoding: chunked
< Content-Type: text/html
< 
Hello, esi!
* Connection #0 to host localhost left intact
~$

请求2（带查询字符串的esi get请求）：

~/erlang_programs/inets_proj$ cat mylog.log
...
...
Inside mymod:get_data()
SessionId=<0.99.0>
Env=[{server_software,"inets/6.4.5"},
     {server_name,"httpd_test"},
     {host_name,"ChristophersMBP"},
     {gateway_interface,"CGI/1.1"},
     {server_protocol,"HTTP/1.1"},
     {server_port,59202},
     {request_method,"GET"},
     {remote_addr,"127.0.0.1"},
     {peer_cert,undefined},
     {script_name,"/erl/mymod:get_data"},
     {http_host,"localhost:59202"},
     {http_user_agent,"curl/7.58.0"},
     {http_accept,"*/*"}]
Input=[]
-------

mylog.log：

~$  curl -v "http://localhost:59202/erl/mymod:get_data?a=1&b=2"
*   Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 59202 (#0)
> GET /erl/mymod:get_data?a=1&b=2 HTTP/1.1
> Host: localhost:59202
> User-Agent: curl/7.58.0
> Accept: */*
> 
< HTTP/1.1 200 OK
< Date: Wed, 28 Feb 2018 13:47:41 GMT
< Server: inets/6.4.5
< Cache-Control: no-cache
< Pragma: no-cache
< Expires: Wed, 28 Feb 2018 13:47:41 GMT
< Transfer-Encoding: chunked
< Content-Type: text/html
< 
Hello, esi!
* Connection #0 to host localhost left intact

请求3（esi post request）：

~/erlang_programs/inets_proj$ cat mylog.log
...
...
Inside mymod:get_data()
SessionId=<0.105.0>
Env=[{server_software,"inets/6.4.5"},
     {server_name,"httpd_test"},
     {host_name,"ChristophersMBP"},
     {gateway_interface,"CGI/1.1"},
     {server_protocol,"HTTP/1.1"},
     {server_port,59202},
     {request_method,"GET"},
     {remote_addr,"127.0.0.1"},
     {peer_cert,undefined},
     {script_name,"/erl/mymod:get_data?a=1&b=2"},
     {http_host,"localhost:59202"},
     {http_user_agent,"curl/7.58.0"},
     {http_accept,"*/*"},
     {query_string,"a=1&b=2"}]
Input="a=1&b=2"

mylog.log：

~$  curl -v --data "a=1&b=2" "http://localhost:59202/erl/mymod:get_data"
*   Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 59202 (#0)
> POST /erl/mymod:get_data HTTP/1.1
> Host: localhost:59202
> User-Agent: curl/7.58.0
> Accept: */*
> Content-Length: 7
> Content-Type: application/x-www-form-urlencoded
> 
* upload completely sent off: 7 out of 7 bytes
< HTTP/1.1 200 OK
< Date: Wed, 28 Feb 2018 13:51:44 GMT
< Server: inets/6.4.5
< Cache-Control: no-cache
< Pragma: no-cache
< Expires: Wed, 28 Feb 2018 13:51:44 GMT
< Transfer-Encoding: chunked
< Content-Type: text/html
< 
Hello, esi!
* Connection #0 to host localhost left intact

请求4（cgi get request）：

Inside mymod:get_data()
SessionId=<0.108.0>
Env=[{server_software,"inets/6.4.5"},
     {server_name,"httpd_test"},
     {host_name,"ChristophersMBP"},
     {gateway_interface,"CGI/1.1"},
     {server_protocol,"HTTP/1.1"},
     {server_port,59202},
     {request_method,"POST"},
     {remote_addr,"127.0.0.1"},
     {peer_cert,undefined},
     {script_name,"/erl/mymod:get_data"},
     {http_host,"localhost:59202"},
     {http_user_agent,"curl/7.58.0"},
     {http_accept,"*/*"},
     {http_content_length,"7"},
     {http_content_type,"application/x-www-form-urlencoded"}]
Input="a=1&b=2"
-------

请求5（从document_root目录获取常规文件的请求）：

~$  curl -v "http://localhost:59202/cgi-bin/1.pl"
*   Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 59202 (#0)
> GET /cgi-bin/1.pl HTTP/1.1
> Host: localhost:59202
> User-Agent: curl/7.58.0
> Accept: */*
> 
< HTTP/1.1 200 OK
< Date: Wed, 28 Feb 2018 13:41:43 GMT
< Server: inets/6.4.5
< Transfer-Encoding: chunked
< Content-Type: text/html
< 
Hello, Perl.
* Connection #0 to host localhost left intact

inets httpd：无法使用简单的esi脚本

1 个答案: