Add ensure-rust role

Add a role to install Rust via the rustup tool.  It defaults to
installing globally, which avoids having to worry too much about
setting paths for follow-on jobs.

Packaged Rust and the upstream rustup install tool can live together,
and there's various documentation about it.  Thus I've made this such
that we can expand it with packaged Rust support if there is a need,
but I have not implemented that yet.

Change-Id: I32f9b285904a7036f9a80ada8a49fa9cf31b5163

doc/source/roles.rst

@@ -25,5 +25,6 @@ Roles
    launchpad-roles
    puppet-roles
    python-roles
+   rust-roles
    system-roles
    translation-roles

doc/source/rust-roles.rst

@@ -0,0 +1,4 @@
+Rust Roles
+==========
+
+.. zuul:autorole:: ensure-rust

roles/ensure-rust/README.rst

@@ -0,0 +1,28 @@
+Install Rust
+
+Install the Rust toolchain
+
+**Role Variables**
+
+.. zuul:rolevar:: ensure_rust_rustup
+   :default: True
+
+   Install Rust via the ``rustup`` installer.
+
+.. zuul:rolevar:: ensure_rust_rustup_toolchain
+   :default: stable
+
+   The Rust toolchain to install with ``rustup``.
+
+.. zuul:rolevar:: ensure_rust_rustup_path
+   :default: /usr
+
+   Where to install Rust/Cargo with ``rustup``.  ``/usr`` provides the
+   tools globally.  This may conflict with distribution Rust packages
+   if installed.
+
+.. zuul:rolevar:: ensure_rust_packages
+   :default: False
+
+   Install Rust via system packages.  This role does not currently
+   support package install.

roles/ensure-rust/defaults/main.yaml

@@ -0,0 +1,4 @@
+ensure_rust_rustup: true
+ensure_rust_packages: false
+ensure_rust_rustup_toolchain: stable
+ensure_rust_rustup_path: /usr

roles/ensure-rust/tasks/main.yaml

@@ -0,0 +1,8 @@
+- name: Use rustup
+  include_tasks: 'rustup.yaml'
+  when: ensure_rust_rustup
+
+- name: Install packages
+  fail:
+    msg: 'Packaged rust install not yet implemented'
+  when: ensure_rust_packages

roles/ensure-rust/tasks/rustup.yaml

@@ -0,0 +1,13 @@
+- name: Install Rust
+  shell: |  # noqa 303
+      set -o pipefail
+      curl -sSf https://sh.rustup.rs | sh -s -- -y --no-modify-path --default-toolchain {{ ensure_rust_rustup_toolchain }}
+  environment:
+    RUSTUP_HOME: '{{ ensure_rust_rustup_path }}'
+    CARGO_HOME: '{{ ensure_rust_rustup_path }}'
+  args:
+    executable: /bin/bash
+  become: yes
+
+- name: Use as selected Rust toolchain
+  command: rustup default {{ ensure_rust_rustup_toolchain }}

test-playbooks/rust/ensure-rust.yaml

@@ -0,0 +1,21 @@
+- hosts: all
+  tasks:
+
+    - include_role:
+        name: ensure-rust
+
+    - name: Test cargo run
+      shell: |
+        cargo new foo
+
+    - name: Copy hello world
+      copy:
+        src: hello.rs
+        dest: hello.rs
+        mode: 0644
+
+    - name: Compile hello world
+      command: rustc hello.rs
+
+    - name: Run hello world
+      command: ./hello

test-playbooks/rust/files/hello.rs

@@ -0,0 +1,5 @@
+fn main() {
+
+   println!("Hello, World!");
+
+}

zuul-tests.d/rust-jobs.yaml

@@ -0,0 +1,140 @@
+- job:
+    name: zuul-jobs-test-rust
+    description: Test the rust roles
+    tags: all-platforms
+    run: test-playbooks/rust/ensure-rust.yaml
+    files:
+      - playbooks/ensure-rust.yaml
+      - roles/ensure-rust
+      - zuul.d/rust-jobs.yaml
+
+# -* AUTOGENERATED *-
+#  The following project section is autogenerated by
+#    tox -e update-test-platforms
+#  Please re-run to generate new job lists
+
+- job:
+    name: zuul-jobs-test-rust-centos-7
+    description: Test the rust roles on centos-7
+    parent: zuul-jobs-test-rust
+    tags: auto-generated
+    nodeset:
+      nodes:
+        - name: centos-7
+          label: centos-7
+
+- job:
+    name: zuul-jobs-test-rust-centos-8
+    description: Test the rust roles on centos-8
+    parent: zuul-jobs-test-rust
+    tags: auto-generated
+    nodeset:
+      nodes:
+        - name: centos-8
+          label: centos-8
+
+- job:
+    name: zuul-jobs-test-rust-debian-stretch
+    description: Test the rust roles on debian-stretch
+    parent: zuul-jobs-test-rust
+    tags: auto-generated
+    nodeset:
+      nodes:
+        - name: debian-stretch
+          label: debian-stretch
+
+- job:
+    name: zuul-jobs-test-rust-fedora-31
+    description: Test the rust roles on fedora-31
+    parent: zuul-jobs-test-rust
+    tags: auto-generated
+    nodeset:
+      nodes:
+        - name: fedora-31
+          label: fedora-31
+
+- job:
+    name: zuul-jobs-test-rust-gentoo-17-0-systemd
+    description: Test the rust roles on gentoo-17-0-systemd
+    parent: zuul-jobs-test-rust
+    tags: auto-generated
+    nodeset:
+      nodes:
+        - name: gentoo-17-0-systemd
+          label: gentoo-17-0-systemd
+
+- job:
+    name: zuul-jobs-test-rust-opensuse-15
+    description: Test the rust roles on opensuse-15
+    parent: zuul-jobs-test-rust
+    tags: auto-generated
+    nodeset:
+      nodes:
+        - name: opensuse-15
+          label: opensuse-15
+
+- job:
+    name: zuul-jobs-test-rust-opensuse-tumbleweed-nv
+    voting: false
+    description: Test the rust roles on opensuse-tumbleweed
+    parent: zuul-jobs-test-rust
+    tags: auto-generated
+    nodeset:
+      nodes:
+        - name: opensuse-tumbleweed
+          label: opensuse-tumbleweed
+
+- job:
+    name: zuul-jobs-test-rust-ubuntu-bionic
+    description: Test the rust roles on ubuntu-bionic
+    parent: zuul-jobs-test-rust
+    tags: auto-generated
+    nodeset:
+      nodes:
+        - name: ubuntu-bionic
+          label: ubuntu-bionic
+
+- job:
+    name: zuul-jobs-test-rust-ubuntu-xenial
+    description: Test the rust roles on ubuntu-xenial
+    parent: zuul-jobs-test-rust
+    tags: auto-generated
+    nodeset:
+      nodes:
+        - name: ubuntu-xenial
+          label: ubuntu-xenial
+
+- job:
+    name: zuul-jobs-test-rust-ubuntu-focal
+    description: Test the rust roles on ubuntu-focal
+    parent: zuul-jobs-test-rust
+    tags: auto-generated
+    nodeset:
+      nodes:
+        - name: ubuntu-focal
+          label: ubuntu-focal
+
+- project:
+    check:
+      jobs:
+        - zuul-jobs-test-rust-centos-7
+        - zuul-jobs-test-rust-centos-8
+        - zuul-jobs-test-rust-debian-stretch
+        - zuul-jobs-test-rust-fedora-31
+        - zuul-jobs-test-rust-gentoo-17-0-systemd
+        - zuul-jobs-test-rust-opensuse-15
+        - zuul-jobs-test-rust-opensuse-tumbleweed-nv
+        - zuul-jobs-test-rust-ubuntu-bionic
+        - zuul-jobs-test-rust-ubuntu-xenial
+        - zuul-jobs-test-rust-ubuntu-focal
+    gate:
+      jobs:
+        - zuul-jobs-test-rust-centos-7
+        - zuul-jobs-test-rust-centos-8
+        - zuul-jobs-test-rust-debian-stretch
+        - zuul-jobs-test-rust-fedora-31
+        - zuul-jobs-test-rust-gentoo-17-0-systemd
+        - zuul-jobs-test-rust-opensuse-15
+        - zuul-jobs-test-rust-ubuntu-bionic
+        - zuul-jobs-test-rust-ubuntu-xenial
+        - zuul-jobs-test-rust-ubuntu-focal