Add a Spack installation guide (#850)

* Add a Spack installation guide

* Fix link

* Fix doxygen

* Update installation.md

* Fix titles

Author: tpadioleau

README.md

@@ -56,12 +56,7 @@ To use DDC components, one needs the following dependencies:
 
 ## Getting the code and basic configuration
 
-```bash
-git clone --recurse-submodules --jobs 4 https://github.com/CExA-project/ddc.git
-cd ddc
-cmake -D DDC_BUILD_KERNELS_FFT=OFF -D DDC_BUILD_KERNELS_SPLINES=OFF -D DDC_BUILD_PDI_WRAPPER=OFF -B build
-cmake --build build --parallel 4
-```
+Please see [this page](docs/installation.md) for a detailed installation guide.
 
 ## Contributing
 

docs/installation.md

@@ -6,4 +6,91 @@ Copyright (C) The DDC development team, see COPYRIGHT.md file
 SPDX-License-Identifier: MIT
 -->
 
-Under construction
+## Quick start
+
+A quick way to compile DDC is to disable all optional components providing only core features
+
+```bash
+git clone --recurse-submodules --jobs 4 https://github.com/CExA-project/ddc.git
+cmake -D DDC_BUILD_KERNELS_FFT=OFF -D DDC_BUILD_KERNELS_SPLINES=OFF -D DDC_BUILD_PDI_WRAPPER=OFF -B ddc/build
+cmake --build ddc/build --parallel 4
+ctest --test-dir ddc/build
+cmake --install ddc/build --prefix path/to/ddc/install
+```
+
+## Using Spack package manager
+
+\note We are currently working on providing a DDC recipe for the Spack package manager.
+
+In the meantime, as of Spack 0.23.1, we provide a CPU Spack environment that contains almost all dependencies. The rest of the dependencies are provided by the git submodules.
+
+### Spack installation
+
+#### Download
+
+```bash
+wget https://github.com/spack/spack/releases/download/v0.23.1/spack-0.23.1.tar.gz
+tar -xvf spack-0.23.1.tar.gz
+rm spack-0.23.1.tar.gz
+```
+
+#### Activation
+
+One first needs to activate Spack before executing any command.
+
+```bash
+. spack-0.23.1/share/spack/setup-env.sh
+```
+
+#### DDC environment installation
+
+```bash
+spack env create ddc-env ddc-env.yaml
+```
+
+Here is the content of `ddc-env.yaml`:
+
+```yaml
+# ddc-env.yaml
+spack:
+  concretizer:
+    unify: true
+  definitions:
+    - compilers:
+        - 'gcc@10:14'
+    - packages:
+        - 'benchmark@1.8:1 ~performance_counters'
+        - 'cmake@3.22:3'
+        - 'doxygen@1.9.8:1'
+        - 'fftw@3.3:3'
+        - 'ginkgo@1.8:1'
+        - 'googletest@1.14:1 +gmock'
+        - 'kokkos@4.4.1:4'
+  specs:
+    - lapack
+    - matrix:
+        - [$packages]
+        - [$%compilers]
+  view:
+    default:
+      root: .spack-env/view
+      exclude: ['gcc-runtime']
+  packages:
+    all:
+      providers:
+        lapack: [openblas]
+      variants: cxxstd=17
+```
+
+#### Compilation of DDC
+
+```bash
+git clone --recurse-submodules --jobs 4 https://github.com/CExA-project/ddc.git
+cmake -D DDC_BUILD_PDI_WRAPPER=OFF -B ddc/build
+ctest --test-dir ddc/build
+cmake --build ddc/build --parallel 4
+```
+
+#### Installation of DDC
+
+\warning Installing DDC solely using the bundled libraries (provided via git submodules) is currently untested and not recommended. For better stability, we recommend using system-installed or Spack-installed dependencies whenever possible.