fix(examples): Replace env-vars in some sdkconfigs

Author: david-cermak

.github/workflows/examples_build-host-test.yml

@@ -57,9 +57,15 @@ jobs:
       - name: Checkout esp-protocols
         uses: actions/checkout@v4
       - name: Build with IDF-${{ matrix.idf_ver }}
+        env:
+          MQTT_BROKER_URI: ${{ secrets.MQTT_BROKER_URI }}
         shell: bash
         run: |
           . ${IDF_PATH}/export.sh
+          cat examples/mqtt/sdkconfig.defaults.linux
+          echo "MQTT_BROKER_URI=${MQTT_BROKER_URI}"
+          ./ci/replace.sh examples/mqtt/sdkconfig.defaults.linux
+          cat examples/mqtt/sdkconfig.defaults.linux
           python -m pip install idf-build-apps
           python ./ci/build_apps.py examples/mqtt -l -t linux
           timeout 25 ./examples/mqtt/build_linux_default/esp_mqtt_demo.elf | tee test.log  || true

ci/replace.sh

@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+if [ -z "${IDF_PATH:-}" ]; then
+    echo "Error: IDF_PATH is not set" >&2
+    exit 1
+fi
+
+ENVSUBST="$IDF_PATH/tools/ci/envsubst.py"
+
+if [ ! -x "$ENVSUBST" ]; then
+    echo "Error: envsubst.py not found or not executable at $ENVSUBST" >&2
+    exit 1
+fi
+
+for file in "$@"; do
+    if [ ! -f "$file" ]; then
+        echo "Warning: $file does not exist, skipping" >&2
+        continue
+    fi
+
+    # Create a temporary file to hold the output
+    tmpfile=$(mktemp)
+
+    # Process the file
+    cat "$file" | "$ENVSUBST" > "$tmpfile"
+
+    # Overwrite the original file with the processed content
+    mv "$tmpfile" "$file"
+
+    echo "Processed: $file"
+done

examples/mqtt/sdkconfig.defaults.linux

@@ -1,2 +1,3 @@
 CONFIG_IDF_TARGET="linux"
 # CONFIG_ESP_EVENT_POST_FROM_ISR is not set
+CONFIG_BROKER_URL="mqtt://${MQTT_BROKER_URI}"