Create a home app (#1032)

Create a home app using Go & Gin with templated HTML and minimal JS. 

This PR mimics the style of the original home app as much as possible.
However, it updates the UI to use Bootstrap 5. I did add a favicon & a
page title as well to make the MATS landing page look more official.

I've done a few additional things as they were easy to do now that we
have a Go server:
- I added a `/health` endpoint to the application so that we can use
[automated health
checks](https://kubernetes.io/docs/tasks/configure-pod-container/configure-liveness-readiness-startup-probes/)
in Kubernetes.
- I added some basic Prometheus metrics so we can tell if the app is up
and if it's taking longer than expected to respond to users. In the
future we may be able to instrument the app links so we can tell how
often certain apps are used. Otherwise, we could implement something
like Google Analytics to get that info.
- Added containerization and CI around the project so we can deploy it.

This is intended to slot into our current docker-compose stacks and
replace `matsapps/production:mats-http` which is this Go file server:
https://github.com/halverneus/static-file-server. Obviously, we could
also deploy this in Kubernetes.

This PR is stacked on top of #1031 and under #1037.

.github/dependabot.yml

@@ -5,10 +5,23 @@
 
 version: 2
 updates:
+  # Maintain dependencies for GitHub Actions
   - package-ecosystem: "github-actions" # See documentation for possible values
     directory: "/" # Location of package manifests
     schedule:
       interval: "weekly"
     pull-request-branch-name:
       separator: "-" # Use "-" instead of "/" in branch names to avoid issues with docker registries
     target-branch: "development" # raise PRs for version updates to GHA against the `development` branch
+    assignees:
+      - "ian-noaa"
+
+  # Maintain dependencies for Go
+  - package-ecosystem: "gomod"
+    directory: "/home"
+    schedule:
+      interval: "weekly"
+    pull-request-branch-name:
+      separator: "-" # Use "-" instead of "/" in branch names to avoid issues with docker registries
+    assignees:
+      - "ian-noaa"

.github/workflows/build.yml

@@ -1,12 +1,15 @@
-name: "Build"
+name: "Build MATS Apps"
 on:
   push:
     branches: [main, development]
     tags:
       - 'v[0-9]+.[0-9]+.[0-9]+'
       - 'v[0-9]+.[0-9]+.[0-9]+-rc[0-9]+'
+    paths-ignore:
+      - "home/**"
   pull_request:
-    branches: [main, development]
+    paths-ignore:
+      - "home/**"
   workflow_dispatch:
 env:
   DEV_REGISTRY: ghcr.io/noaa-gsl/mats/development

.github/workflows/home.yml

@@ -0,0 +1,118 @@
+name: "Build Home App"
+
+on:
+  push:
+    branches: ["main", "development"]
+    paths:
+        - "home/**"
+  pull_request:
+    paths:
+        - "home/**"
+  workflow_dispatch:
+env:
+    DEV_REGISTRY: ghcr.io/noaa-gsl/mats/development
+
+# Update the working directory for any job steps with "run" components.
+# Note this doesn't apply to "uses" steps - those will need to have
+# their working directory updated manually, if they support it.
+defaults:
+  run:
+    working-directory: "home"
+
+jobs:
+  golangci:
+    name: lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-go@v4
+        with:
+          go-version: "1.20"
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v3
+        with:
+            working-directory: "home"
+
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-go@v4
+        with:
+          go-version: "1.20"
+      - name: Build
+        run: go build -v ./...
+      - name: Test
+        run: go test -v -shuffle=on -cover ./...
+
+  build:
+    name: Build Docker image
+    runs-on: ubuntu-latest
+    permissions:
+        actions: read
+        contents: read
+        packages: write
+        security-events: write
+    steps:
+        - uses: actions/checkout@v3
+
+        - name: Set env variables
+          shell: bash
+        # Note - this doesn't support branch names with "/" in them
+          run: |
+            DATE=$(git show -s --format=%cd --date=format:'%Y-%m-%d.%H:%M:%S.%z' ${{ github.sha }})
+            if [[ "${GITHUB_EVENT_NAME}" == "pull_request" ]]; then
+            # PR build
+            echo "BRANCH=${GITHUB_HEAD_REF}" >> $GITHUB_ENV
+            echo "VERSION=dev-${{ github.sha }}-$DATE" >> $GITHUB_ENV
+            elif [[ "${GITHUB_EVENT_NAME}" == "push" ]]; then
+            # Handle differences between branches/tags
+            if [[ "${GITHUB_REF}" == *"heads"* ]]; then
+                # Branch build
+                echo "BRANCH=${GITHUB_REF#refs/heads/}" >> $GITHUB_ENV
+                echo "VERSION=dev-${{ github.sha }}-$DATE" >> $GITHUB_ENV
+            elif [[ "${GITHUB_REF}" == *"tags"* ]]; then
+                # Tag build
+                echo "BRANCH=${GITHUB_REF#refs/tags/}" >> $GITHUB_ENV
+                echo "VERSION=${GITHUB_REF#refs/tags/}" >> $GITHUB_ENV
+            else
+                echo "ERROR: Unanticipated Git Ref"
+                exit 1
+            fi
+            else
+            echo "ERROR: Unanticipated GitHub Event"
+            exit 1
+            fi
+
+        - name: Build image
+          run: |
+            docker build \
+            --build-arg BUILDVER="${{ env.VERSION }}" \
+            --build-arg COMMITBRANCH=${{ env.BRANCH }} \
+            --build-arg COMMITSHA=${{ github.sha }} \
+            -t ${{ env.DEV_REGISTRY }}/home:${{ env.BRANCH }} \
+            .
+
+        - name: Scan image with Trivy
+          uses: aquasecurity/trivy-action@master
+          with:
+            image-ref: '${{ env.DEV_REGISTRY }}/home:${{ env.BRANCH }}'
+            format: 'sarif'
+            output: 'trivy-results-home.sarif'
+            ignore-unfixed: true
+
+        - name: Upload Trivy scan results to GitHub Security tab
+          uses: github/codeql-action/upload-sarif@v2
+          with:
+            sarif_file: 'trivy-results-home.sarif'
+
+        - name: Login to GitHub Container Registry
+          uses: docker/login-action@v2
+          with:
+            registry: ghcr.io
+            username: ${{ github.actor }}
+            password: ${{ secrets.GITHUB_TOKEN }}
+
+        - name: Push image to dev registry
+          run: |
+            docker push ${{ env.DEV_REGISTRY }}/home:${{ env.BRANCH }}

.prettierignore

@@ -6,6 +6,7 @@ kubernetes
 scripts
 server_configuration_files
 static
+!home/static
 **/.meteor
 **/met-*
 **/README.md

home/.dockerignore

@@ -0,0 +1,18 @@
+# Tooling artifacts
+.git/
+.github/
+.idea/
+.vscode/
+.gitignore
+
+# Home app
+docs/
+.golangci.yml
+Dockerfile
+docker-compose.yml
+**/*.md
+LICENSE
+home
+main
+coverage.out
+settings.json

home/.gitignore

@@ -0,0 +1,3 @@
+# Go binaries for this project
+home
+main

home/.golangci.yml

@@ -0,0 +1,198 @@
+run:
+  tests: true
+
+output:
+  uniq-by-line: false
+  sort-results: true
+  print-linter-name: true
+
+issues:
+  # Show all issues in the project
+  max-issues-per-linter: 0
+  max-same-issues: 0
+  new: false
+
+
+# Linters & linter-settings inspired by https://olegk.dev/go-linters-configuration-the-right-version
+linters:
+  enable:
+    # Check for passing []any as any in variadic func(...any).
+    - asasalint
+
+    # Prefer plain ASCII identifiers.
+    # I.e. - use `delta` in place of `∆`
+    # TODO - enable
+    # - asciicheck
+
+    # Checks for dangerous unicode character sequences.
+    - bidichk
+
+    # Check that HTTP response bodies are closed
+    - bodyclose
+
+    # Check whether the function uses a non-inherited context.
+    - contextcheck
+
+    # Check for two durations multiplied together.
+    - durationcheck
+
+    # Forces to not skip error check.
+    - errcheck
+
+    # Checks `Err-` prefix for var and `-Error` suffix for error type.
+    - errname
+
+    # Suggests to use `%w` for error-wrapping.
+    - errorlint
+
+    # Checks for pointers to enclosing loop variables.
+    - exportloopref
+
+    - gocritic
+
+    # lint comments
+    # TODO - enable
+    # - godot
+
+    # Make sure everything's auto-formatted
+    - gofmt
+    - gofumpt
+    - goimports
+
+    # Handle replace, retract, exclude directives in go.mod 
+    - gomoddirectives
+
+    # Security-oriented linter
+    # TODO - enable
+    # - gosec
+
+    # Simplify code
+    - gosimple
+
+    # Official go linter
+    - govet
+
+    # Detects when assignments to existing variables are unused
+    - ineffassign
+
+    # Check for misspellings
+    - misspell
+
+    # Finds naked/bare returns
+    - nakedret
+
+    # Both require a bit more explicit returns.
+    - nilerr
+    - nilnil
+
+    # Finds sending HTTP request without context.Context.
+    - noctx
+
+    # Forces comment why another check is disabled.
+    # Better not to have //nolint: at all ;)
+    - nolintlint
+
+    # Finds slices that could potentially be pre-allocated.
+    # - prealloc
+
+    # Finds shadowing of Go's predeclared identifiers.
+    # I hear a lot of complaints from junior developers.
+    # But after some time they find it very useful.
+    - predeclared
+
+    # Lint your Prometheus metrics name.
+    - promlinter
+
+    # Checks that package variables are not reassigned.
+    # Super rare case but can catch bad things (like `io.EOF = nil`)
+    - reassign
+
+    # Drop-in replacement of `golint`
+    - revive
+
+    # Somewhat similar to `bodyclose` but for `database/sql` package.
+    - rowserrcheck
+    - sqlclosecheck
+
+    - staticcheck
+
+    # Checks function and package cyclomatic complexity
+    # Cyclomatic complexity is a measurement, not a goal.
+    # TODO - enable
+    # - cyclop
+
+    - typecheck
+
+    # Is a replacement for `golint`, similar to `revive`.
+    - stylecheck
+
+    # Check struct tags.
+    - tagliatelle
+
+    # Test-related checks.
+    - tenv
+    - testableexamples
+    - thelper
+    - tparallel
+
+    # Remove unnecessary type conversions, make code cleaner
+    - unconvert
+
+    # Might be noisy but better to know what is unused
+    # TODO - enable
+    # - unparam
+
+    # Must have. Finds unused declarations.
+    - unused
+
+    # Detect the possibility to use variables/constants from stdlib.
+    # TODO - enable
+    - usestdlibvars
+
+    # Finds wasted assignment statements.
+    - wastedassign
+
+linters-settings:
+  # See https://go-critic.com/overview.html
+  gocritic:
+    enabled-tags:
+      - diagnostic
+      # - experimental
+      - opinionated
+      - performance
+      - style
+    disabled-checks:
+      # These 3 detect many cases and are mostly useful for helping optimize for
+      # performance oriented code
+      - hugeParam
+      - rangeExprCopy
+      - rangeValCopy
+
+  errcheck:
+    # Report `a := b.(MyStruct)` when `a, ok := ...` should be.
+    # TODO - enable
+    # check-type-assertions: true # Default: false
+
+    # Report skipped checks:`num, _ := strconv.Atoi(numStr)`.
+    # TODO - enable
+    # check-blank: true # Default: false
+
+    # Function to skip.
+    exclude-functions:
+      - io/ioutil.ReadFile
+      - io.Copy(*bytes.Buffer)
+      - io.Copy(os.Stdout)
+
+  nakedret:
+    # No naked returns
+    max-func-lines: 1 # Default: 30
+
+  tagliatelle:
+    case:
+      rules:
+        json: snake
+        yaml: snake
+        xml: camel
+        bson: camel
+        avro: snake
+        mapstructure: kebab