Can't rely on `lsb_release` for codename on pre-releases, like `buster`

`n/a` is not a helpful bit. This isn't necessary as jobs are release-specific, but it reduces confusion during packaging.

.gitlab-ci.yml

@@ -15,6 +15,8 @@ test_build_script:
 test_build_nginx_buster:
   stage: build
   image: containers.ethitter.com:443/docker/images/debian:buster
+  variables:
+    RELEASE_CODE_NAME: buster
   script:
     - chmod +x ./scripts/build.sh
     - ./scripts/build.sh
@@ -24,6 +26,8 @@ test_build_nginx_buster:
 build_nginx_buster:
   stage: build
   image: containers.ethitter.com:443/docker/images/debian:buster
+  variables:
+    RELEASE_CODE_NAME: buster
   script:
     - chmod +x ./scripts/build.sh
     - ./scripts/build.sh
@@ -37,6 +41,8 @@ build_nginx_buster:
 test_build_nginx_stretch:
   stage: build
   image: containers.ethitter.com:443/docker/images/debian:stretch
+  variables:
+    RELEASE_CODE_NAME: stretch
   script:
     - chmod +x ./scripts/build.sh
     - ./scripts/build.sh
@@ -46,6 +52,8 @@ test_build_nginx_stretch:
 build_nginx_stretch:
   stage: build
   image: containers.ethitter.com:443/docker/images/debian:stretch
+  variables:
+    RELEASE_CODE_NAME: stretch
   script:
     - chmod +x ./scripts/build.sh
     - ./scripts/build.sh
@@ -59,6 +67,8 @@ build_nginx_stretch:
 test_build_nginx_jessie:
   stage: build
   image: containers.ethitter.com:443/docker/images/debian:jessie
+  variables:
+    RELEASE_CODE_NAME: jessie
   script:
     - chmod +x ./scripts/build.sh
     - ./scripts/build.sh
@@ -68,6 +78,8 @@ test_build_nginx_jessie:
 build_nginx_jessie:
   stage: build
   image: containers.ethitter.com:443/docker/images/debian:jessie
+  variables:
+    RELEASE_CODE_NAME: jessie
   script:
     - chmod +x ./scripts/build.sh
     - ./scripts/build.sh

scripts/build.sh

@@ -17,7 +17,7 @@ echo ""
 NGINX_ARTIFACT_PATH="$OG_DIR/artifacts"
 export NGINX_ARTIFACT_PATH
 
-NGINX_BUILT_BINARY_PATH="${NGINX_ARTIFACT_PATH}/nginx_$(lsb_release -sc)_${NGINX_TAG}_${OPENSSL_TAG}"
+NGINX_BUILT_BINARY_PATH="${NGINX_ARTIFACT_PATH}/nginx_${RELEASE_CODE_NAME}_${NGINX_TAG}_${OPENSSL_TAG}"
 export NGINX_BUILT_BINARY_PATH
 
 mkdir -p "$NGINX_ARTIFACT_PATH"