Parameterize nginx-proxy and docker-gen container labels

app/entrypoint.sh

@@ -181,14 +181,16 @@ if [[ "$*" == "/bin/bash /app/start.sh" ]]; then
         echo "Error: can't get nginx-proxy container ID !" >&2
         echo "Check that you are doing one of the following :" >&2
         echo -e "\t- Use the --volumes-from option to mount volumes from the nginx-proxy container." >&2
-        echo -e "\t- Set the NGINX_PROXY_CONTAINER env var on the letsencrypt-companion container to the name of the nginx-proxy container." >&2
-        echo -e "\t- Label the nginx-proxy container to use with 'com.github.nginx-proxy.nginx'." >&2
+        echo -e "\t- Set the NGINX_PROXY_CONTAINER env var on the acme-companion container to the name of the nginx-proxy container." >&2
+        echo -e "\t- Label the nginx-proxy container to use with '${default_nginx_proxy_container_label}'." >&2
+        echo -e "\t- Label the nginx-proxy container with a custom label and set NGINX_PROXY_CONTAINER_LABEL env var on the acme-companion container to match the custom label." >&2
         exit 1
     elif [[ -z "$(get_docker_gen_container)" ]] && ! is_docker_gen_container "$(get_nginx_proxy_container)"; then
         echo "Error: can't get docker-gen container id !" >&2
         echo "If you are running a three containers setup, check that you are doing one of the following :" >&2
-        echo -e "\t- Set the NGINX_DOCKER_GEN_CONTAINER env var on the letsencrypt-companion container to the name of the docker-gen container." >&2
-        echo -e "\t- Label the docker-gen container to use with 'com.github.nginx-proxy.docker-gen'." >&2
+        echo -e "\t- Set the NGINX_DOCKER_GEN_CONTAINER env var on the acme-companion container to the name of the docker-gen container." >&2
+        echo -e "\t- Label the docker-gen container to use with '${default_nginx_docker_gen_container_label}'." >&2
+        echo -e "\t- Label the docker-gen container with a custom label and set NGINX_DOCKER_GEN_CONTAINER_LABEL env var on the acme-companion container to match the custom label." >&2
         exit 1
     fi
     check_writable_directory '/etc/nginx/certs'

app/functions.sh

@@ -10,6 +10,11 @@ if [[ "$DEBUG" == true ]]; then
   DEBUG=1 && export DEBUG
 fi
 
+default_nginx_docker_gen_container_label=com.github.nginx-proxy.docker-gen
+default_nginx_proxy_container_label=com.github.nginx-proxy.nginx
+runtime_nginx_docker_gen_container_label=${NGINX_DOCKER_GEN_CONTAINER_LABEL:-$default_nginx_docker_gen_container_label}
+runtime_nginx_proxy_container_label=${NGINX_PROXY_CONTAINER_LABEL:-$default_nginx_proxy_container_label}
+
 function parse_true() {
 	case "$1" in
 
@@ -284,7 +289,7 @@ function is_docker_gen_container {
 function get_docker_gen_container {
     # First try to get the docker-gen container ID from the container label.
     local legacy_docker_gen_cid; legacy_docker_gen_cid="$(labeled_cid com.github.jrcs.letsencrypt_nginx_proxy_companion.docker_gen)"
-    local new_docker_gen_cid; new_docker_gen_cid="$(labeled_cid com.github.nginx-proxy.docker-gen)"
+    local new_docker_gen_cid; new_docker_gen_cid="$(labeled_cid $runtime_nginx_docker_gen_container_label)"
     local docker_gen_cid; docker_gen_cid="${new_docker_gen_cid:-$legacy_docker_gen_cid}"
 
     # If the labeled_cid function dit not return anything and the env var is set, use it.
@@ -300,7 +305,7 @@ function get_nginx_proxy_container {
     local volumes_from
     # First try to get the nginx container ID from the container label.
     local legacy_nginx_cid; legacy_nginx_cid="$(labeled_cid com.github.jrcs.letsencrypt_nginx_proxy_companion.nginx_proxy)"
-    local new_nginx_cid; new_nginx_cid="$(labeled_cid com.github.nginx-proxy.nginx)"
+    local new_nginx_cid; new_nginx_cid="$(labeled_cid $runtime_nginx_proxy_container_label)"
     local nginx_cid; nginx_cid="${new_nginx_cid:-$legacy_nginx_cid}"
 
     # If the labeled_cid function dit not return anything ...

docs/Getting-containers-IDs.md

@@ -6,6 +6,8 @@ There are three methods to inform the **acme-companion** container of the **ngin
 
 * `label` method: add the label `com.github.nginx-proxy.nginx` to the **nginx**/**nginx-proxy** container.
 
+  * Optional. Using a custom `label`: add a custom label, e.g. :`custom.label.nginx` to the **nginx**/**nginx-proxy** container and set the environment variable `NGINX_PROXY_CONTAINER_LABEL` to match the custom label.
+
 * `environment variable` method: assign a fixed name to the **nginx**/**nginx-proxy** container with `container_name:` and set the environment variable `NGINX_PROXY_CONTAINER` to this name on the **acme-companion** container.
 
 * `volumes_from` method. Using this method, the **acme-companion** container will get the **nginx**/**nginx-proxy** container ID from the volumes it got using the `volumes_from` option.
@@ -14,6 +16,8 @@ And two methods to inform the **acme-companion** container of the **docker-gen**
 
 * `label` method: add the label `com.github.nginx-proxy.docker-gen` to the **docker-gen** container.
 
+  * Optional. Using a custom `label`: add a custom label, e.g. :`custom.label.docker-gen` to the **docker-gen** container and set the environment variable `NGINX_DOCKER_GEN_CONTAINER_LABEL` to match the custom label.
+
 * `environment variable` method: assign a fixed name to the **docker-gen** container with `container_name:` and set the environment variable `NGINX_DOCKER_GEN_CONTAINER` to this name on the **acme-companion** container.
 
 The methods for each container are sorted by order of precedence, meaning that if you use both the label and the volumes_from method, the ID of the **nginx**/**nginx-proxy** container that will be used will be the one found using the label. **There is no point in using more than one method at a time for either the nginx/nginx-proxy or docker-gen container beside potentially confusing yourself**.
@@ -39,6 +43,25 @@ $ docker run --detach \
     nginxproxy/acme-companion
 ```
 
+`label` method with custom label.
+```
+$ docker run --detach \
+    [...]
+    --label custom.label.nginx \
+    nginx
+
+$ docker run --detach \
+    [...]
+    --label custom.label.docker-gen \
+    nginxproxy/docker-gen
+
+$ docker run --detach \
+    [...]
+    --env NGINX_PROXY_CONTAINER_LABEL=custom.label.nginx
+    --env NGINX_DOCKER_GEN_CONTAINER_LABEL=custom.label.docker-gen
+    nginxproxy/acme-companion
+```
+
 `environment variable` method
 ```
 $ docker run --detach \

test/tests/docker_api/run.sh

@@ -5,8 +5,10 @@
 nginx_vol='nginx-volumes-from'
 nginx_env='nginx-env-var'
 nginx_lbl='nginx-label'
+nginx_cstm_lbl='nginx-custom-label'
 docker_gen='docker-gen-no-label'
 docker_gen_lbl='docker-gen-label'
+docker_gen_cstm_lbl='docker-gen-custom-label'
 
 case $SETUP in
 
@@ -20,6 +22,7 @@ case $SETUP in
       "$nginx_vol" \
       "$nginx_env" \
       "$nginx_lbl" \
+      "$nginx_cstm_lbl" \
       &> /dev/null
   }
   trap cleanup EXIT
@@ -78,13 +81,31 @@ case $SETUP in
     "$1" \
     bash -c "$commands" 2>&1
 
+  # Run a nginx-proxy container named nginx-custom-label, with a custom label.
+  # Store the container id in the custom_labeled_nginx_cid variable.
+  custom_labeled_nginx_cid="$(docker run --rm -d \
+    --name "$nginx_cstm_lbl" \
+    -v /var/run/docker.sock:/tmp/docker.sock:ro \
+    --label custom.label.nginx \
+    nginxproxy/nginx-proxy)"
+
+  # This should target the nginx-proxy container with the custom label (nginx-custom-label)
+  docker run --rm \
+    -v /var/run/docker.sock:/var/run/docker.sock:ro \
+    --volumes-from "$nginx_vol" \
+    -e "NGINX_PROXY_CONTAINER_LABEL=custom.label.nginx" \
+    "$1" \
+    bash -c "$commands" 2>&1
+
   cat > "${GITHUB_WORKSPACE}/test/tests/docker_api/expected-std-out.txt" <<EOF
 Container $nginx_vol received exec_start: sh -c /app/docker-entrypoint.sh /usr/local/bin/docker-gen /app/nginx.tmpl /etc/nginx/conf.d/default.conf; /usr/sbin/nginx -s reload
 $nginx_vol
 Container $nginx_env received exec_start: sh -c /app/docker-entrypoint.sh /usr/local/bin/docker-gen /app/nginx.tmpl /etc/nginx/conf.d/default.conf; /usr/sbin/nginx -s reload
 $nginx_env
 Container $nginx_lbl received exec_start: sh -c /app/docker-entrypoint.sh /usr/local/bin/docker-gen /app/nginx.tmpl /etc/nginx/conf.d/default.conf; /usr/sbin/nginx -s reload
 $labeled_nginx_cid
+Container $nginx_cstm_lbl received exec_start: sh -c /app/docker-entrypoint.sh /usr/local/bin/docker-gen /app/nginx.tmpl /etc/nginx/conf.d/default.conf; /usr/sbin/nginx -s reload
+$custom_labeled_nginx_cid
 EOF
   ;;
 
@@ -98,8 +119,10 @@ EOF
       "$nginx_vol" \
       "$nginx_env" \
       "$nginx_lbl" \
+      "$nginx_cstm_lbl" \
       "$docker_gen" \
       "$docker_gen_lbl" \
+      "$docker_gen_cstm_lbl" \
       &> /dev/null
   }
   trap cleanup EXIT
@@ -220,6 +243,30 @@ EOF
     "$1" \
     bash -c "$commands" 2>&1
 
+  # Spawn a nginx container named nginx-custom-label, with a custom label.
+  custom_labeled_nginx2_cid="$(docker run --rm -d \
+    --name "$nginx_cstm_lbl" \
+    --label custom.label.nginx \
+    nginx:alpine)"
+
+  # Spawn a "fake docker-gen" container named docker-gen-custom-label, with a custom label.
+  custom_labeled_docker_gen_cid="$(docker run --rm -d \
+    --name "$docker_gen_cstm_lbl" \
+    --label custom.label.docker-gen \
+    nginx:alpine)"
+
+  # This should target the nginx container whose id or name was obtained with
+  # the custom label (nginx-custom-label)
+  # and the docker-gen container whose id or name was obtained with
+  # the custom label (docker-gen-custom-label)
+  docker run --rm \
+    -v /var/run/docker.sock:/var/run/docker.sock:ro \
+    --volumes-from "$nginx_vol" \
+    -e "NGINX_PROXY_CONTAINER_LABEL=custom.label.nginx" \
+    -e "NGINX_DOCKER_GEN_CONTAINER_LABEL=custom.label.docker-gen" \
+    "$1" \
+    bash -c "$commands" 2>&1
+
     cat > "${GITHUB_WORKSPACE}/test/tests/docker_api/expected-std-out.txt" <<EOF
 Container $docker_gen received signal 1
 Container $nginx_vol received signal 1
@@ -246,7 +293,12 @@ Container $docker_gen_lbl received signal 1
 Container $nginx_lbl received signal 1
 $labeled_docker_gen_cid
 $labeled_nginx2_cid
+Container $docker_gen_cstm_lbl received signal 1
+Container $nginx_cstm_lbl received signal 1
+$custom_labeled_docker_gen_cid
+$custom_labeled_nginx2_cid
 EOF
   ;;
 
 esac
+sleep 60