ci: add GitHub actions

Adds a GitHub CI action:

    * Uses the rust-toolchain file to install the requested version.
    * Performs a build with default cargo target
    * Runs workspace tests
    * Checks cargo fmt is happy
    * Runs clippy for lints, denying warnings

All commands taken from the existing CircleCI pipeline.

Currently no caching / reuse of build container.

.circleci/config.yml

@@ -7,16 +7,13 @@
 #   pushed to `quay.io/influxdb/rust:ci`. This build image is then used to run
 #   the CI tasks for the day.
 #
-# Each CI run:
-#
-#   Runs tests, fmt, & lints and then compiles binaries using the default cargo
-#   target ("dev").
-#
 # CI runs for git branches ending in `/perf`:
 #
 #   Runs tests, fmt, & lints and then compiles binaries using the "release"
 #   cargo target and pushes a container with the binary to
 #   `quay.io/influxdb/fusion` (see perf_image below).
+#
+# CI for all other branches is performed by the GitHub actions (see .github dir)
 
 version: 2.1
 

.github/workflows/rust.yml

@@ -0,0 +1,87 @@
+# CI Overview
+# -----------
+#
+# All pushes and PRs (including from forks) run:
+#
+#   - cargo build with the default cargo profile ("dev")
+#   - cargo test
+#   - cargo fmt
+#   - clippy (with warnings denied)
+#
+# All workflow actions make use of our build container
+# (`quay.io/influxdb/rust:ci`) to satisfy system dependencies, and is updated
+# nightly.
+#
+# Cargo's build artefacts are cached to reduce the build time, see
+# https://github.com/actions/cache for more info.
+
+on: [push, pull_request]
+
+name: ci
+
+jobs:
+
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    container:
+      image: quay.io/influxdb/rust:ci
+      # Run as the "root" user in the build container to fix workspace & cache
+      # permission errors.
+      options: --user root
+    steps:
+      # Checkout the code
+      - uses: actions/checkout@v2
+
+      # Enable caching of build artefacts
+      - uses: actions/cache@v2
+        with:
+          path: target
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
+      
+      # Build!
+      - name: Run dev build
+        uses: actions-rs/cargo@v1
+        with:
+          command: build
+          args: --workspace
+
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    container:
+      image: quay.io/influxdb/rust:ci
+      options: --user root
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/cache@v2
+        with:
+          path: target
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
+      - name: Run tests
+        uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --workspace
+
+  lints:
+    name: Lints
+    runs-on: ubuntu-latest
+    container:
+      image: quay.io/influxdb/rust:ci
+      options: --user root
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/cache@v2
+        with:
+          path: target
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
+      - name: Run cargo fmt
+        uses: actions-rs/cargo@v1
+        with:
+          command: fmt
+          args: --all -- --check
+      - uses: actions-rs/clippy-check@v1
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          args: --all-targets --workspace -- -D warnings