Redis [BUG] Redis sentinel can not run in k8s with environment variables in config file

Describe the bug

I try to run a redis sentinel in k8s that there is a environgment variables in config file to set the master's hostname. Then I will show a error "Can't resolve master instance hostname";

To reproduce

Version: 5.0.12

Some of yaml:

....
        env:
          - name: REDIS_MASTER_IP
            value: "alink-redis" 
        ports:
        - containerPort: 6379
.....

alink-redis is a name of svc which is point to this deployment.

My sentinel config file:

port 6380
daemonize yes
protected-mode no

pidfile "/data/redis/sentinel.pid"
dir "/data/redis"
logfile "/data/redis/sentinel.log"

sentinel myid 577f953b52f42c08e85ffb2b48024520154209a9
sentinel deny-scripts-reconfig yes

sentinel monitor mymaster $REDIS_MASTER_IP 6379 2
sentinel auth-pass mymaster rrDs5KYV3
sentinel config-epoch mymaster 0
sentinel leader-epoch mymaster 0
sentinel current-epoch 0

When I use echo $REDIS_MASTER_IP it can print alink-redis. When I use ping alink-redis and it reutn the ip of this svc.

But when I run redis-server it print:

 *** FATAL CONFIG FILE ERROR ***
Reading the configuration file, at line 27
>>> 'sentinel monitor mymaster $REDIS_MASTER_IP 6379 2'
Can't resolve master instance hostname.

But if I change $REDIS_MASTER_IP to alink-redis in config file. It can run successfully.

Expected behavior

support variables

Additional information

Any additional information that is relevant to the problem.

Comment From: yossigo

Hi @lystormenvoy, this is not a bug - Redis configuration files don't support expansion of environment variables.

Comment From: lystormenvoy

Hi @lystormenvoy, this is not a bug - Redis configuration files don't support expansion of environment variables.

ok I get it.