Add redis symlinks at the same place as the installed binaries

[vitahlin]

Adds a new make variable called USE_REDIS_SYMLINKS, with default value yes. If yes, then make install creates additional symlinks to the installed binaries:

• valkey-server
• valkey-cli
• valkey-benchmark
• valkey-check-rdb
• valkey-check-aof
• valkey-sentinel

The names of the symlinks are the legacy redis binary names (redis-server, etc.). The purpose is to provide backward compatibility for scripts expecting the these filenames. The symlinks are installed in the same directory as the binaries (typically /usr/local/bin/ or similar).

Similarly, make uninstall removes these symlinks if USE_REDIS_SYMLINKS is yes.

This is described in a note in README.md.

Fixes #147

[madolson]

I think the approach makes sense, just some minor comments

[vitahlin]

I think the approach makes sense, just some minor comments

Solved the language expression problem you suggested and the space problem in Makefile.
Thanks for your help.

[zuiderkwast]

Yeah, this is the behaviour we want. Some comments on details.

[zuiderkwast]

One more thing: The symlinks valkey-check-rdb -> valkey-server and valkey-check-aof -> valkey-server work by conditional code in server.c looking for the exec name, i.e. which symlink was used for starting it. Please also check that it works for redis-check-rdb etc.

Code in server.c:

    /* Check if we need to start in redis-check-rdb/aof mode. We just execute
     * the program main. However the program is part of the Redis executable
     * so that we can easily execute an RDB check on loading errors. */
    if (strstr(exec_name,"valkey-check-rdb") != NULL)
        redis_check_rdb_main(argc,argv,NULL);
    else if (strstr(exec_name,"valkey-check-aof") != NULL)
        redis_check_aof_main(argc,argv);

[zuiderkwast]

Disclaimer: The suggestions are untested. :)

[vitahlin]

One more thing: The symlinks valkey-check-rdb -> valkey-server and valkey-check-aof -> valkey-server work by conditional code in server.c looking for the exec name, i.e. which symlink was used for starting it. Please also check that it works for redis-check-rdb etc.

Code in server.c:

    /* Check if we need to start in redis-check-rdb/aof mode. We just execute
     * the program main. However the program is part of the Redis executable
     * so that we can easily execute an RDB check on loading errors. */
    if (strstr(exec_name,"valkey-check-rdb") != NULL)
        redis_check_rdb_main(argc,argv,NULL);
    else if (strstr(exec_name,"valkey-check-aof") != NULL)
        redis_check_aof_main(argc,argv);

I will test it next.

[zuiderkwast]

Good. Just a few minor suggestions.

[vitahlin]

My first PR that wasn't about typo. Thank you for your patience and help, have a nice day. 😀

[zuiderkwast]

Thanks @vitahlin! I edited the top comment to match what was finally implemented.

[furai]

For me this change causes issues when using TLS. When I switch off symlinks for redis then installation fails cause it can't find libhiredis_ssl.a. Could this implementation be revisited?

[zuiderkwast]

@furai Yes, of course we can revise it. Why is libhiredis_ssl.a affected by this?

[furai]

I haven't had time to dig into it. What I'm doing is pretty simple, e.g.:

 make BUILD_TLS=yes USE_SYSTEMD=yes 
 make PREFIX=custom/usr USE_REDIS_SYMLINKS=no install

And then it fails with error because it can't find the aforementioned file. I was building from prepackaged version 7.2.5 available here on github.