fix: confusion when substituting ENV in config file

[zhoujiexiong]

Description

Fixes #11121
Fixes #11239

1. Import environment variables with the same prefix to Nginx using assignment style
2. In the init_by_lua phase
3. There will be confusion issues

use Test::Nginx::Socket 'no_plan';

master_on();
repeat_each(1);

our $prefix = "prefix";
our $longer = "longer";
$ENV{TEST_ENV_SAME_PREFIX} = $prefix;
$ENV{TEST_ENV_SAME_PREFIX_LONGER} = $longer;

add_block_preprocessor(sub {
    my ($block) = @_;

    if (!$block->request) {
        $block->set_value("request", "GET /t");
    }

    my $config = $block->config // "";
    $config .= <<_EOC_;
    location = /t {
    	content_by_lua_block {
            local prefix = os.getenv("TEST_ENV_SAME_PREFIX")                 
            local longer = os.getenv("TEST_ENV_SAME_PREFIX_LONGER")
            assert(prefix == "$::prefix" and longer == "$::longer")
        }
	}
_EOC_

    $block->set_value("config", $config);
});

run_tests();

__DATA__

=== TEST 1: assignment style, the PREFIX 1st - incorrect
--- main_config eval
qq/
env TEST_ENV_SAME_PREFIX=$::prefix;
env TEST_ENV_SAME_PREFIX_LONGER=$::longer;
/
--- http_config eval
qq/
    init_by_lua_block {
        local prefix = os.getenv("TEST_ENV_SAME_PREFIX")                 
        local longer = os.getenv("TEST_ENV_SAME_PREFIX_LONGER")
        assert(prefix == "$::prefix" and longer == "$::prefix")
    }
/



=== TEST 2: assignment style, the LONGER 1st - correct
--- main_config eval
qq/
env TEST_ENV_SAME_PREFIX_LONGER=$::longer;
env TEST_ENV_SAME_PREFIX=$::prefix;
/
--- http_config eval
qq/
    init_by_lua_block {
        local prefix = os.getenv("TEST_ENV_SAME_PREFIX")                 
        local longer = os.getenv("TEST_ENV_SAME_PREFIX_LONGER")
        assert(prefix == "$::prefix" and longer == "$::longer")
    }
/

    

=== TEST 3: declaration style, the LONGER 1st - correct
--- main_config
env TEST_ENV_SAME_PREFIX_LONGER;
env TEST_ENV_SAME_PREFIX;
--- http_config eval
qq/
    init_by_lua_block {
        local prefix = os.getenv("TEST_ENV_SAME_PREFIX")                 
        local longer = os.getenv("TEST_ENV_SAME_PREFIX_LONGER")
        assert(prefix == "$::prefix" and longer == "$::longer")
    }
/
    


=== TEST 4: declaration style, the PREFIX 1st - also correct
--- main_config
env TEST_ENV_SAME_PREFIX;
env TEST_ENV_SAME_PREFIX_LONGER;
--- http_config eval    
qq/
    init_by_lua_block {
        local prefix = os.getenv("TEST_ENV_SAME_PREFIX")                 
        local longer = os.getenv("TEST_ENV_SAME_PREFIX_LONGER")
        assert(prefix == "$::prefix" and longer == "$::longer")
    }
/

Checklist

• I have explained the need for this PR and the problem it solves
• I have explained the changes or the new features added to this PR
• I have added tests corresponding to this change
• I have updated the documentation to reflect this change
• I have verified that this change is backward compatible (If not, please discuss on the APISIX mailing list first)

[shreemaan-abhishek]

LGTM, but the test cases are sophisticated. I would suggest you to simplify if you can, but after a close look I understood them.

[shreemaan-abhishek]

there is a failing test case related to your change: https://github.com/apache/apisix/actions/runs/10667500821/job/29968905933?pr=11545#step:7:4777

[shreemaan-abhishek]

this could lead to a breaking change?

[zhoujiexiong]

No, because when rendering nginx.conf, apisix cli decides to insert the relevant env directives based on whether they exist or are valid. The declarative method is sufficient. The final reading still needs to use os.getenv, env FOO=bar; this method is not necessary and can be replaced by the declarative method to ensure compatibility.

[membphis]

LGTM