Nginx : Invalid condition "yes" in nginx.conf

Question

I have an environment variable set as

vod_enable_encryption = yes

which I'm attempting to check using an If block in nginx.conf.

Nginx isn't able to resolve the condition and throwing the following error :

invalid condition "yes"

The error is thrown at the following 2 location blocks:

The 1st block where The variable is checked is within the location block as follows:

location ~ ^/vod/([^/]+)/.+\.(m3u8|ts)$ {
 vod_mode local;
 vod hls;
 vod_base_url "";
 if ($vod_enable_encryption = "yes") {
 set $stream_uuid 1ドル;
 vod_hls_encryption_method aes-128;
 vod_secret_key "$rtmp_secret $stream_uuid";
 set_hmac_sha1 $sig $rtmp_secret "$cookie_sessionid $stream_uuid";
 if ($http_authorization) {
 set_hmac_sha1 $sig $rtmp_secret "$http_authorization $stream_uuid";
 }
 set_encode_base64 $sig $sig;
 vod_hls_encryption_key_uri "~ ^/vod/([^/]+)/encryption.key?s=$sig";
 } 
 }

The 2nd block where The variable is checked is outside the location block as follows:

if ($vod_enable_encryption = "yes") {
 location ~ ^/vod/([^/]+)/encryption\.key$ {
 vod_mode local;
 vod hls;
 vod_base_url "";
 set $stream_uuid 1ドル;
 set $user_sig $arg_s;
 set_hmac_sha1 $sig $rtmp_secret "$cookie_sessionid $stream_uuid";
 if ($http_authorization) {
 set_hmac_sha1 $sig $rtmp_secret "$http_authorization $stream_uuid";
 }
 set_encode_base64 $sig $sig;
 if ($sig != $user_sig) {
 return 403;
 }
 auth_request /authorize;
 vod_hls_encryption_method aes-128;
 vod_secret_key "$rtmp_secret $stream_uuid";
 }
 }

I'm unable to solve the issue above and spent quite sometime on it. Upon reading more, I realized that One must try avoiding using If conditions in nginx as much as possible. I couldn't figure an alternative implementation. Help appreciated.

• Ted Lyngmo: Could it be the double quotes that causes the failure? What does it say if you make it if ($vod_enable_encryption = yes) {?
• Ted Lyngmo: Is the ngx_http_rewrite_module loaded?
• Ananth: Hi. Removing the quotes produces the same error.
• Ananth: Hi. How do i check if the module is loaded ?. I'm using a docker Alpine image. Do I need to install it separately ?
• Ted Lyngmo: No idea, I just read the nginx config documentation for conditions but I don't know how to load the necessary module or check if it's loaded. Where do you assign yes to vod_enable_encryption? You mention "environment variable", but I don't think environment variables are accessible from ngnix config files. I could be wrong though.