ci: build the Espressif examples weekly

A weekly scheduled job builds both ESP-IDF example projects, so a break
in the Espressif port surfaces on its own instead of waiting for a user
to report it.

- compileAllExamples.sh builds every project under examples/, pointing
  the local components at WOLFSSH_ROOT and WOLFSSL_ROOT
- the workflow covers ESP-IDF release-v5.5 and release-v5.1, built
  against wolfSSL v5.9.1-stable
- a scheduled failure opens or comments on an issue labelled
  espressif-build-failure

.github/workflows/espressif.yml

@@ -0,0 +1,97 @@
+name: wolfSSH Espressif Build Test
+
+on:
+  schedule:
+    # Weekly: Mondays at 07:00 UTC
+    - cron: '0 7 * * 1'
+  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+env:
+  WOLFSSL_REF: v5.9.1-stable
+
+jobs:
+  build_examples:
+    name: ESP-IDF ${{ matrix.idf-ref }}
+    strategy:
+      fail-fast: false
+      matrix:
+        # release-v5.5 is the current stable line; release-v5.1 is the version
+        # the example READMEs and VisualGDB projects document.
+        idf-ref: [ release-v5.5, release-v5.1 ]
+    runs-on: ubuntu-latest
+    container:
+      image: espressif/idf:${{ matrix.idf-ref }}
+    timeout-minutes: 30
+    steps:
+      - name: Checkout wolfSSH
+        uses: actions/checkout@v6
+        with:
+          path: wolfssh
+
+      - name: Checkout wolfSSL
+        uses: actions/checkout@v6
+        with:
+          repository: wolfssl/wolfssl
+          ref: ${{ env.WOLFSSL_REF }}
+          path: wolfssl
+
+      - name: Build the Espressif examples
+        env:
+          WOLFSSH_ROOT: ${{ github.workspace }}/wolfssh
+          WOLFSSL_ROOT: ${{ github.workspace }}/wolfssl
+        run: |
+          # The image sets IDF_PATH, but the ESP-IDF tool paths come from
+          # export.sh, which a job step does not get from the entrypoint.
+          . "${IDF_PATH}/export.sh"
+          "${WOLFSSH_ROOT}/ide/Espressif/ESP-IDF/compileAllExamples.sh"
+
+  notify_failure:
+    name: Open issue on scheduled failure
+    needs: [build_examples]
+    if: failure() && github.event_name == 'schedule'
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    permissions:
+      issues: write
+    steps:
+      - uses: actions/github-script@v7
+        with:
+          script: |
+            const label = 'espressif-build-failure';
+            const runUrl = `${context.serverUrl}/${context.repo.owner}/` +
+              `${context.repo.repo}/actions/runs/${context.runId}`;
+            const body = [
+              'The weekly Espressif example build failed.',
+              '',
+              `Run: ${runUrl}`,
+              `Commit: ${context.sha}`,
+            ].join('\n');
+            const existing = await github.rest.issues.listForRepo({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              state: 'open',
+              labels: label,
+            });
+            if (existing.data.length > 0) {
+              await github.rest.issues.createComment({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: existing.data[0].number,
+                body: body,
+              });
+            } else {
+              await github.rest.issues.create({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                title: 'Weekly Espressif example build failed',
+                body: body,
+                labels: [label],
+              });
+            }

ide/Espressif/ESP-IDF/compileAllExamples.sh

@@ -0,0 +1,89 @@
+#!/usr/bin/env bash
+
+# Build every wolfSSH ESP-IDF example project under ./examples/
+#
+# The examples carry local wolfssh and wolfssl components that compile the
+# library sources in place, so both source trees have to be on disk. Their
+# CMakeLists find them through the WOLFSSH_ROOT and WOLFSSL_ROOT environment
+# variables, which this script fills in when they are not already set.
+#
+# Run from an ESP-IDF environment:
+#
+#   . /opt/esp/idf/export.sh
+#   WOLFSSL_ROOT=/path/to/wolfssl ide/Espressif/ESP-IDF/compileAllExamples.sh
+#
+# WOLFSSH_ROOT defaults to the tree holding this script, WOLFSSL_ROOT to a
+# wolfssl checkout beside it. IDF_TARGET selects the chip; default esp32.
+
+if [ -z "${IDF_PATH}" ]; then
+    echo "ERROR: IDF_PATH is not set. Source the ESP-IDF export.sh first."
+    exit 1
+fi
+
+SCRIPT_DIR=$(cd "$(dirname "$0")" && pwd)
+
+if [ -z "${WOLFSSH_ROOT}" ]; then
+    WOLFSSH_ROOT=$(cd "${SCRIPT_DIR}/../../.." && pwd)
+fi
+
+if [ -z "${WOLFSSL_ROOT}" ]; then
+    WOLFSSL_ROOT="$(dirname "${WOLFSSH_ROOT}")/wolfssl"
+fi
+
+export WOLFSSH_ROOT
+export WOLFSSL_ROOT
+export IDF_TARGET="${IDF_TARGET:-esp32}"
+
+if [ ! -f "${WOLFSSH_ROOT}/wolfssh/ssh.h" ]; then
+    echo "ERROR: no wolfSSH source in WOLFSSH_ROOT=${WOLFSSH_ROOT}"
+    exit 1
+fi
+
+if [ ! -f "${WOLFSSL_ROOT}/wolfssl/ssl.h" ]; then
+    echo "ERROR: no wolfSSL source in WOLFSSL_ROOT=${WOLFSSL_ROOT}"
+    echo "Clone wolfssl beside wolfssh or set WOLFSSL_ROOT."
+    exit 1
+fi
+
+echo "IDF_PATH     = ${IDF_PATH}"
+echo "IDF_TARGET   = ${IDF_TARGET}"
+echo "WOLFSSH_ROOT = ${WOLFSSH_ROOT}"
+echo "WOLFSSL_ROOT = ${WOLFSSL_ROOT}"
+
+BUILT=""
+FAILED=""
+
+for PROJECT in "${SCRIPT_DIR}"/examples/*/; do
+    # A project directory is one with a top level CMakeLists.txt.
+    if [ ! -f "${PROJECT}/CMakeLists.txt" ]; then
+        continue
+    fi
+
+    NAME=$(basename "${PROJECT}")
+
+    echo
+    echo "--------------------------------------------------------------"
+    echo "Building ${NAME} for ${IDF_TARGET}"
+    echo "--------------------------------------------------------------"
+
+    if (cd "${PROJECT}" && idf.py fullclean && idf.py build); then
+        BUILT="${BUILT} ${NAME}"
+    else
+        FAILED="${FAILED} ${NAME}"
+    fi
+done
+
+if [ -z "${BUILT}" ] && [ -z "${FAILED}" ]; then
+    echo "ERROR: no example projects found in ${SCRIPT_DIR}/examples/"
+    exit 1
+fi
+
+echo
+echo "Built: ${BUILT:- none}"
+
+if [ -n "${FAILED}" ]; then
+    echo "Failed:${FAILED}"
+    exit 1
+fi
+
+echo "All wolfSSH Espressif examples built."