feat: Pass OTEL_* environment variables through to PHP 8.4/8.5 containers

Opt-in producer-side configuration for OpenTelemetry: empty defaults keep
telemetry inert until a developer sets the OTEL_* values in their .env
file (see .env.dist), pointing at the otel-lgtm collector.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: 2 people

.env.dist

@@ -63,3 +63,12 @@ REMOTE_SRC=/var/www/totara/src
 REMOTE_DATA=/var/www/totara/data
 MYSQL_ROOT_PW=root
 MSSQL_SA_PW=Totara.Mssql1
+
+# OpenTelemetry export from the PHP 8.4/8.5 containers (opt-in).
+# Start the backend with 'tup otel-lgtm' (Grafana UI: http://localhost:3000), then uncomment:
+#OTEL_PHP_AUTOLOAD_ENABLED=true
+#OTEL_SERVICE_NAME=totara
+#OTEL_EXPORTER_OTLP_ENDPOINT=http://otel-lgtm:4318
+#OTEL_TRACES_EXPORTER=otlp
+#OTEL_LOGS_EXPORTER=otlp
+#OTEL_METRICS_EXPORTER=otlp

compose/php.yml

@@ -330,6 +330,13 @@ services:
       DISABLE_AUTO_UPDATE: "true" # disables oh-my-zsh update message
       USE_ZSH_NERDFONT: ${USE_ZSH_NERDFONT:-0}
       XDEBUG_MODE: off
+      # OpenTelemetry export (opt-in): set the OTEL_* values in your .env file, see .env.dist.
+      OTEL_PHP_AUTOLOAD_ENABLED: ${OTEL_PHP_AUTOLOAD_ENABLED:-}
+      OTEL_SERVICE_NAME: ${OTEL_SERVICE_NAME:-}
+      OTEL_EXPORTER_OTLP_ENDPOINT: ${OTEL_EXPORTER_OTLP_ENDPOINT:-}
+      OTEL_TRACES_EXPORTER: ${OTEL_TRACES_EXPORTER:-}
+      OTEL_LOGS_EXPORTER: ${OTEL_LOGS_EXPORTER:-}
+      OTEL_METRICS_EXPORTER: ${OTEL_METRICS_EXPORTER:-}
     volumes:
       - ${LOCAL_SRC}:${REMOTE_SRC}
       - totara-data:${REMOTE_DATA}
@@ -359,6 +366,13 @@ services:
       HIST_FILE: /root/.bash_history
       DISABLE_AUTO_UPDATE: "true" # disables oh-my-zsh update message
       USE_ZSH_NERDFONT: ${USE_ZSH_NERDFONT:-0}
+      # OpenTelemetry export (opt-in): set the OTEL_* values in your .env file, see .env.dist.
+      OTEL_PHP_AUTOLOAD_ENABLED: ${OTEL_PHP_AUTOLOAD_ENABLED:-}
+      OTEL_SERVICE_NAME: ${OTEL_SERVICE_NAME:-}
+      OTEL_EXPORTER_OTLP_ENDPOINT: ${OTEL_EXPORTER_OTLP_ENDPOINT:-}
+      OTEL_TRACES_EXPORTER: ${OTEL_TRACES_EXPORTER:-}
+      OTEL_LOGS_EXPORTER: ${OTEL_LOGS_EXPORTER:-}
+      OTEL_METRICS_EXPORTER: ${OTEL_METRICS_EXPORTER:-}
     volumes:
       - ${LOCAL_SRC}:${REMOTE_SRC}
       - totara-data:${REMOTE_DATA}
@@ -382,6 +396,13 @@ services:
       DISABLE_AUTO_UPDATE: "true" # disables oh-my-zsh update message
       USE_ZSH_NERDFONT: ${USE_ZSH_NERDFONT:-0}
       XDEBUG_MODE: off
+      # OpenTelemetry export (opt-in): set the OTEL_* values in your .env file, see .env.dist.
+      OTEL_PHP_AUTOLOAD_ENABLED: ${OTEL_PHP_AUTOLOAD_ENABLED:-}
+      OTEL_SERVICE_NAME: ${OTEL_SERVICE_NAME:-}
+      OTEL_EXPORTER_OTLP_ENDPOINT: ${OTEL_EXPORTER_OTLP_ENDPOINT:-}
+      OTEL_TRACES_EXPORTER: ${OTEL_TRACES_EXPORTER:-}
+      OTEL_LOGS_EXPORTER: ${OTEL_LOGS_EXPORTER:-}
+      OTEL_METRICS_EXPORTER: ${OTEL_METRICS_EXPORTER:-}
     volumes:
       - ${LOCAL_SRC}:${REMOTE_SRC}
       - totara-data:${REMOTE_DATA}
@@ -411,6 +432,13 @@ services:
       HIST_FILE: /root/.bash_history
       DISABLE_AUTO_UPDATE: "true" # disables oh-my-zsh update message
       USE_ZSH_NERDFONT: ${USE_ZSH_NERDFONT:-0}
+      # OpenTelemetry export (opt-in): set the OTEL_* values in your .env file, see .env.dist.
+      OTEL_PHP_AUTOLOAD_ENABLED: ${OTEL_PHP_AUTOLOAD_ENABLED:-}
+      OTEL_SERVICE_NAME: ${OTEL_SERVICE_NAME:-}
+      OTEL_EXPORTER_OTLP_ENDPOINT: ${OTEL_EXPORTER_OTLP_ENDPOINT:-}
+      OTEL_TRACES_EXPORTER: ${OTEL_TRACES_EXPORTER:-}
+      OTEL_LOGS_EXPORTER: ${OTEL_LOGS_EXPORTER:-}
+      OTEL_METRICS_EXPORTER: ${OTEL_METRICS_EXPORTER:-}
     volumes:
       - ${LOCAL_SRC}:${REMOTE_SRC}
       - totara-data:${REMOTE_DATA}