ci: Share cache between loadtest and other tests

This puts all those development tools that depend on the dynamically linked postgrestPackage
into a single cache group. Notably this now includes the loadtest, but does not include the
style/lint job anymore.

This also improves the creation of cache keys and their restore prefixes. The cache key
now depends on default.nix and shell.nix in the root folder and all .patch files in the
nix folder. Those may change the output of our nix derivations, so must be included. At
the same time, there is no reason to include the actions/setup-nix folder. This would
only lead to new caches being created every time we update one of the depndent actions
in this file. Finally, restoring caches from a different toolset makes zero sense, so
we remove that again. There is no point in having the style job fall back to the static
cache for example.

.github/actions/setup-nix/action.yaml

@@ -5,26 +5,24 @@ description: Installs nix, sets up cachix and installs a subset of tooling.
 inputs:
   authToken:
     description: Token to pass to cachix
+  cache:
+    description: Cache id to use for cache-nix-action
   tools:
     description: Tools to install with nix-env -iA <tools>
-  cache-id:
-    description: Cache id to use for cache-nix-action
-    default: "default"
 
 runs:
   using: composite
   steps:
     - uses: nixbuild/nix-quick-install-action@v26
       with:
         nix_version: '2.13.6'
-    - name: Restore and cache Nix store
+    - name: Restore and save /nix/store cache
+      if: ${{ inputs.cache }}
       uses: nix-community/[email protected]
       with:
-        key: cache-nix-${{ runner.os }}-id-${{ inputs.cache-id }}-${{ hashFiles('nix/**/*.nix', '.github/actions/setup-nix/*') }}
+        key: cache-nix-${{ runner.os }}-${{ inputs.cache }}-${{ hashFiles('**/*.nix', 'nix/**/*.patch') }}
         restore-keys: |
-          cache-nix-${{ runner.os }}-id-${{ inputs.cache-id }}-
-          cache-nix-${{ runner.os }}-id-common-
-          cache-nix-${{ runner.os }}-
+          cache-nix-${{ runner.os }}-${{ inputs.cache }}-
     - uses: cachix/cachix-action@v14
       with:
         name: postgrest

.github/workflows/ci.yaml

@@ -19,16 +19,16 @@ concurrency:
 
 jobs:
   Prepopulate-Nix-Cache-Linux:
-    name: Prepopulate Nix cache for Linux runners
+    name: Prepopulate Nix "test" cache for Linux runners
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
       - name: Setup Nix Environment
         uses: ./.github/actions/setup-nix
         with:
           authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
-          cache-id: common
-          tools: style withTools memory tests release postgrestPackage
+          cache: test
+          tools: loadtest memory postgrestPackage tests withTools
 
   Lint-Style:
     name: Lint & check code style
@@ -40,8 +40,8 @@ jobs:
         uses: ./.github/actions/setup-nix
         with:
           authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+          cache: style
           tools: style
-          cache-id: common
       - name: Run linter (check locally with `nix-shell --run postgrest-lint`)
         run: postgrest-lint
       - name: Run style check (auto-format with `nix-shell --run postgrest-style`)
@@ -63,8 +63,8 @@ jobs:
         uses: ./.github/actions/setup-nix
         with:
           authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+          cache: test
           tools: tests
-          cache-id: common
 
       - name: Run coverage (IO tests and Spec tests against PostgreSQL 15)
         run: postgrest-coverage
@@ -101,8 +101,8 @@ jobs:
         uses: ./.github/actions/setup-nix
         with:
           authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+          cache: test
           tools: tests withTools
-          cache-id: common 
 
       - name: Run spec tests
         if: always()
@@ -123,8 +123,8 @@ jobs:
         uses: ./.github/actions/setup-nix
         with:
           authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+          cache: test
           tools: memory
-          cache-id: common
       - name: Run memory tests
         run: postgrest-test-memory
 
@@ -139,8 +139,8 @@ jobs:
       - name: Setup Nix Environment
         uses: ./.github/actions/setup-nix
         with:
+          cache: test
           tools: loadtest
-          cache-id: test-loadtest
       - uses: actions-ecosystem/action-get-latest-tag@v1
         id: get-latest-tag
         with:
@@ -166,6 +166,7 @@ jobs:
         uses: ./.github/actions/setup-nix
         with:
           authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+          cache: static
 
       - name: Build static executable
         run: nix-build -A postgrestStatic
@@ -194,6 +195,7 @@ jobs:
         uses: ./.github/actions/setup-nix
         with:
           authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+          cache: all
 
       - name: Build everything
         run: |
@@ -503,11 +505,13 @@ jobs:
       ISPRERELEASE: ${{ needs.Prepare-Release.outputs.isprerelease }}
     steps:
       - uses: actions/checkout@v4
-      - name: Setup Nix Environment
-        uses: ./.github/actions/setup-nix
-        with:
-          authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
-          tools: release
+# Only used for dockerhub description?
+#      - name: Setup Nix Environment
+#        uses: ./.github/actions/setup-nix
+#        with:
+#          authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+#          cache: release
+#          tools: release
       - name: Download Docker image
         uses: actions/download-artifact@v4
         with: