Access bracket notation items in snippet

[rinseaid]

Hello,

I am using Pangolin as my reverse proxy, which allows defining resources using docker labels, similar to traefik. I'd like to set up a snippet to reuse existing label values, but struggling to access the array items in bracket notation.

Example labels of a pangolin resource:

- pangolin.proxy-resources.uptime-kuma.name=uptime-kuma
- pangolin.proxy-resources.uptime-kuma.full-domain=uptime-kuma.domain.com
- pangolin.proxy-resources.uptime-kuma.protocol=http
- pangolin.proxy-resources.uptime-kuma.targets[0].method=http
- pangolin.proxy-resources.uptime-kuma.targets[0].port=3001
- pangolin.proxy-resources.uptime-kuma.targets[0].healthcheck.hostname=uptime-kuma
- pangolin.proxy-resources.uptime-kuma.targets[0].healthcheck.port=3001

I've tried accessing the 'port' property using the below snippet:

{% set label = container.Labels %}
{% set port = label["pangolin.proxy-resources.uptime-kuma.targets[0].port"] %}
{% set domain = label["pangolin.proxy-resources.uptime-kuma.full-domain"] %}
{{ container_name }}_http.http.name: {{ container_name }}
{{ container_name }}_http.http.url: https://{{ domain }}:{{ port }}

But receive the error:

autokuma  | 2026-02-10 00:23:36.491 [autokuma::entity] WARN: Error while parsing snippet: Error while trying to parse labels: 
autokuma  | Caused by: Failed to render '{% set label = container.Labels %}
autokuma  | {% set port = label["pangolin.proxy-resources.uptime-kuma.targets[0].port"] %}
autokuma  | {% set domain = label["pangolin.proxy-resources.uptime-kuma.full-domain"] %}
autokuma  | {{ container_name }}_http.http.name: {{ container_name }}
autokuma  | {{ container_name }}_http.http.url: https://{{ domain }}:{{ port }}'
autokuma  | Caused by: Variable `label["pangolin.proxy-resources.uptime-kuma.targets[0].port"]` not found in context while rendering '{% set label = container.Labels %}
autokuma  | {% set port = label["pangolin.proxy-resources.uptime-kuma.targets[0].port"] %}
autokuma  | {% set domain = label["pangolin.proxy-resources.uptime-kuma.full-domain"] %}
autokuma  | {{ container_name }}_http.http.name: {{ container_name }}
autokuma  | {{ container_name }}_http.http.url: https://{{ domain }}:{{ port }}': the evaluated version was `label."pangolin.proxy-resources.uptime-kuma.targets.0.port"`. Maybe the index is out of bounds?

I also tried the below formats, with the same error:

{% set port = label["pangolin.proxy-resources.uptime-kuma.targets.0.port"] %}
{% set port = label["pangolin.proxy-resources.uptime-kuma.targets.port"] %}

Any guidance would be appreciated.