ci: use btrfs for all Nix builds

Previously, we had to perform specific Nix builds which didn't work on ext*-fileysstems in a tmpfs. Due to the memory constraints in GH Actions runners, this is not feasible for all CI workloads. Therefore, this switches all Nix-using CI to perform Nix builds in a btrfs.

.github/actions/setup_nix/action.yml

@@ -19,3 +19,14 @@ runs:
       with:
         name: edgelesssys
         authToken: ${{ inputs.cachixToken }}
+    - name: use btrfs for nix builds
+      shell: bash
+      run: |
+        sudo mkdir /nixbld
+        truncate -s 3G btrfs.img
+        sudo mkfs.btrfs -f btrfs.img
+        sudo mount btrfs.img /nixbld
+        sudo mkdir -p /etc/systemd/system/nix-daemon.service.d
+        echo -e "[Service]\nEnvironment=TMPDIR=/nixbld" | sudo tee /etc/systemd/system/nix-daemon.service.d/btrfs.conf
+        sudo systemctl daemon-reload
+        sudo systemctl restart nix-daemon

.github/workflows/e2e_openssl.yml

@@ -59,7 +59,6 @@ jobs:
           echo "SYNC_ENDPOINT=http://$sync_ip:8080" | tee -a "$GITHUB_ENV"
           sync_uuid=$(kubectl get configmap sync-server-fifo -o jsonpath='{.data.uuid}')
           echo "SYNC_FIFO_UUID=$sync_uuid" | tee -a "$GITHUB_ENV"
-      - uses: ./.github/actions/nix_tmpfs
       - name: Build and prepare deployments
         run: |
           just coordinator initializer openssl port-forwarder node-installer

.github/workflows/e2e_policy.yml

@@ -59,7 +59,6 @@ jobs:
           echo "SYNC_ENDPOINT=http://$sync_ip:8080" | tee -a "$GITHUB_ENV"
           sync_uuid=$(kubectl get configmap sync-server-fifo -o jsonpath='{.data.uuid}')
           echo "SYNC_FIFO_UUID=$sync_uuid" | tee -a "$GITHUB_ENV"
-      - uses: ./.github/actions/nix_tmpfs
       - name: Build and prepare deployments
         run: |
           just coordinator initializer openssl port-forwarder node-installer

.github/workflows/e2e_regression.yml

@@ -58,7 +58,6 @@ jobs:
       - name: Get credentials for CI cluster
         run: |
           just get-credentials
-      - uses: ./.github/actions/nix_tmpfs
       - name: Build and prepare deployments
         run: |
           just node-installer

.github/workflows/e2e_servicemesh.yml

@@ -59,7 +59,6 @@ jobs:
           echo "SYNC_ENDPOINT=http://$sync_ip:8080" | tee -a "$GITHUB_ENV"
           sync_uuid=$(kubectl get configmap sync-server-fifo -o jsonpath='{.data.uuid}')
           echo "SYNC_FIFO_UUID=$sync_uuid" | tee -a "$GITHUB_ENV"
-      - uses: ./.github/actions/nix_tmpfs
       - name: Build and prepare deployments
         run: |
           just coordinator initializer port-forwarder service-mesh-proxy node-installer

.github/workflows/static.yml

@@ -25,6 +25,15 @@ jobs:
     runs-on: ubuntu-22.04
     timeout-minutes: 25
     steps:
+      # This job needs quite some space, so we remove some unnecessary things.
+      - uses: easimon/maximize-build-space@fc881a613ad2a34aca9c9624518214ebc21dfc0c # v10
+        with:
+          root-reserve-mb: 20000
+          remove-dotnet: 'true'
+          remove-android: 'true'
+          remove-haskell: 'true'
+          remove-codeql: 'true'
+          remove-docker-images: 'true'
       - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
         with:
           ref: ${{ !github.event.pull_request.head.repo.fork && github.head_ref || '' }}