Automate release generation from tags and refactor CI

.github/environment.yml

@@ -0,0 +1,15 @@
+name: build
+channels:
+  - conda-forge
+dependencies:
+  - conda
+  - mamba
+  - compilers
+  - ninja
+  - cmake
+  - proj
+  - ccache
+  - libtiff
+  - zlib
+  - libjpeg-turbo
+

.github/workflows/test.yml

@@ -0,0 +1,134 @@
+
+name: Build
+on: [push, pull_request]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+    name: ${{ matrix.os }} with BUILD_SHARED_LIBS=${{matrix.shared}}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [macos-latest, windows-latest, ubuntu-latest]
+        shared: [ON, OFF]
+    permissions:
+      contents: write
+      attestations: write
+      id-token: write
+    steps:
+     - uses: actions/checkout@v4
+     - uses: ilammy/msvc-dev-cmd@v1
+       if: matrix.os == 'windows-latest'
+     - name: Support longpaths
+       run: git config --system core.longpaths true
+       if: matrix.os == 'windows-latest'
+     - uses: mamba-org/setup-micromamba@v1
+       with:
+           init-shell: bash
+           environment-file: ./.github/environment.yml
+           environment-name: "build"
+           cache-environment: true
+           cache-downloads: true
+
+     - name: Setup
+       shell: bash -l {0}
+       run: |
+           mkdir build
+       working-directory: ./libgeotiff
+
+     - name: CMake
+       shell: bash -l {0}
+       env:
+        BUILD_SHARED_LIBS: ${{ matrix.shared }}
+
+       run: |
+
+        if [ "$RUNNER_OS" == "Windows" ]; then
+        export CC=cl.exe
+        export CXX=cl.exe
+        fi
+
+        cmake   -G "Ninja"  \
+              -DCMAKE_BUILD_TYPE=RelWithDebInfo \
+              -DBUILD_SHARED_LIBS=$BUILD_SHARED_LIBS \
+              -DBUILD_TESTING=ON \
+              -DCMAKE_INSTALL_PREFIX=${CONDA_PREFIX} \
+              -DWITH_ZLIB=ON \
+              -DWITH_JPEG=ON \
+              -DWITH_TIFF=ON \
+              -DTIFF_NAMES=tiff \
+              -DPROJ_NAMES=proj \
+              -DJPEG_NAMES=libjpeg \
+              ..
+
+
+       working-directory: ./libgeotiff/build
+
+     - name: Compile
+       shell: bash -l {0}
+       run: |
+          ninja
+       working-directory: ./libgeotiff/build
+
+     - name: Generate source distribution
+       shell: bash -l {0}
+       if: matrix.os == 'ubuntu-latest'
+       run: |
+          cmake --build .  --config Release --target package_source
+          extensions=".tar.gz .tar.bz2"
+          for ext in $extensions
+          do
+              for filename in $(ls *$ext)
+              do
+
+                  `md5sum $filename > $filename.md5`
+                  `sha256sum $filename > $filename.sha256sum`
+                  `sha512sum $filename > $filename.sha512sum`
+              done
+          done
+       working-directory: ./libgeotiff/build
+     - name: Attest
+       uses: actions/attest-build-provenance@v1
+       if: matrix.os == 'ubuntu-latest' && matrix.shared == 'ON' && startsWith(github.ref, 'refs/tags/') && github.repository_owner == 'OSGeo'
+       with:
+          subject-path: './libgeotiff/build/libgeotiff-*'
+     - uses: actions/upload-artifact@v4
+       if: matrix.os == 'ubuntu-latest' && matrix.shared == 'ON'
+       name: Gather source distribution artifact
+       with:
+         name: source-package-${{matrix.os}}
+         if-no-files-found: error
+         path: |
+          ./libgeotiff/build/libgeotiff-*
+
+  release:
+    name: Gather and attach release
+    runs-on: ubuntu-latest
+    needs: build
+    permissions:
+      contents: write
+      id-token: write
+      attestations: write
+    steps:
+     - uses: actions/download-artifact@v4
+       name: Download release artifact
+       with:
+         name: source-package-ubuntu-latest
+         path: release
+
+     - uses: softprops/action-gh-release@v2
+       if: startsWith(github.ref, 'refs/tags/')
+       name: Publish release as draft
+       with:
+         make_latest: false
+         fail_on_unmatched_files: true
+         prerelease: true
+         generate_release_notes: true
+         draft: true
+         files: |
+          release/libgeotiff-*
+
+