[squid-dev] To make squid works in snap world.

[Alex Rousskov]

On 03/14/2017 08:44 AM, Gary Wang wrote:
>     About the DEFAULT_STATEDIR,
>     ...
>     DEFS += -DDEFAULT_STATEDIR=\"$(localstatedir)/run/squid\"    
>     ...
>     According to the above share memory namespace in snap world, it
> couldn't help on this either.

Here is how I [mis]interpret the above:

1. Squid has a DEFAULT_STATEDIR compile-time constant that provides the
right control knob you need but uses the wrong hard-coded value.

2. You are adding a compile-time variable DEFAULT_IPC_PREFIX that does
what DEFAULT_STATEDIR does but can be changed at ./configure time.

This raises an obvious question: Why not make DEFAULT_STATEDIR
configurable instead?  (If we do make it configurable, we may need to
renamed it to STATEDIR, IPCDIR, or something like that but that is a
separate and minor issue.)


AFAICT, DEFAULT_STATEDIR is also used for IPC communications in
src/ipc/Port.cc. Your patch does not change that code. This means that

* either you forgot to change src/ipc/Port.cc to honor the new
DEFAULT_IPC_PREFIX

* or src/ipc/Port.cc cannot use DEFAULT_IPC_PREFIX for some reason (and,
hence, DEFAULT_IPC_PREFIX is the wrong name because the parameter does
not apply to some of the IPC code).

Alex.



> === modified file 'configure.ac'
> --- configure.ac	2017-01-28 03:54:15 +0000
> +++ configure.ac	2017-03-02 03:51:46 +0000
> @@ -311,6 +311,15 @@
>  ])
>  AC_SUBST(DEFAULT_SWAP_DIR)
>  
> +DEFAULT_IPC_PREFIX=""
> +AC_ARG_WITH(ipcprefix,
> +  AS_HELP_STRING([--with-ipcprefix=NAME],
> +    [Default namespace prefix for shared memory object for ipc communication. 
> +     Default is empty string and the share memory object name will be specified by squid. ]), [
> +   DEFAULT_IPC_PREFIX="$withval"
> +])
> +AC_SUBST(DEFAULT_IPC_PREFIX)
> +
>  if test "$squid_cv_compiler" = "gcc"; then
>    GCCVER=`$CC -v 2>&1 | awk '$2 ==  "version" {print $3}'`
>    GCCVER2=`echo $GCCVER | awk '{print $1 * 100}'`
> 
> === modified file 'src/ipc/Makefile.am'
> --- src/ipc/Makefile.am	2017-01-01 00:16:45 +0000
> +++ src/ipc/Makefile.am	2017-03-02 03:51:46 +0000
> @@ -68,7 +68,7 @@
>  	mem/Segment.cc \
>  	mem/Segment.h
>  
> -DEFS += -DDEFAULT_STATEDIR=\"$(localstatedir)/run/squid\"
> +DEFS += -DDEFAULT_STATEDIR=\"$(localstatedir)/run/squid\" -DDEFAULT_IPC_PREFIX=\"$(DEFAULT_IPC_PREFIX)\"
>  
>  install-data-local:
>  	$(mkinstalldirs) $(DESTDIR)$(localstatedir)/run/squid;
> 
> === modified file 'src/ipc/mem/Segment.cc'
> --- src/ipc/mem/Segment.cc	2017-01-01 00:16:45 +0000
> +++ src/ipc/mem/Segment.cc	2017-03-02 03:51:46 +0000
> @@ -30,6 +30,8 @@
>  #include <unistd.h>
>  #endif
>  
> +#define DEFAULT_SQUID_IPC_PREFIX  "/" DEFAULT_IPC_PREFIX
> +
>  // test cases change this
>  const char *Ipc::Mem::Segment::BasePath = DEFAULT_STATEDIR;
>  
> @@ -229,9 +231,9 @@
>      if (nameIsPath) {
>          name.append(BasePath);
>          if (name[name.size()-1] != '/')
> -            name.append('/');
> +            name.append(DEFAULT_SQUID_IPC_PREFIX);
>      } else {
> -        name.append('/');
> +        name.append(DEFAULT_SQUID_IPC_PREFIX);
>          name.append(service_name.c_str());
>          name.append('-');
>      }