Create devcontainer.json [skip ci]

Instantiates a development environment with the Nix flake supplied from the repo

Author: NickHu

.devcontainer/Dockerfile

@@ -0,0 +1,5 @@
+# https://github.com/xtruder/nix-devcontainer-python-jupyter/blob/main/.devcontainer/Dockerfile
+FROM ghcr.io/xtruder/nix-devcontainer:v1
+
+# cache /nix
+VOLUME /nix

.devcontainer/devcontainer.json

@@ -0,0 +1,35 @@
+// Adapted from https://github.com/xtruder/nix-devcontainer-python-jupyter/blob/main/.devcontainer/devcontainer.json
+// For format details, see https://aka.ms/vscode-remote/devcontainer.json or the definition README at
+// https://github.com/microsoft/vscode-dev-containers/tree/master/containers/docker-existing-dockerfile
+{
+  "name": "nix-devcontainer-homotopy-rs",
+  "dockerFile": "Dockerfile",
+  "context": "${localWorkspaceFolder}",
+  "build": {
+    "args": {
+      "USER_UID": "${localEnv:USER_UID}",
+      "USER_GID": "${localEnv:USER_GID}"
+    },
+  },
+
+  "runArgs": [
+    "--security-opt", "label=disable"
+  ],
+
+  "mounts": [
+    "source=nix-devcontainer-homotopy-rs_nix,target=/nix,type=volume"
+  ],
+
+  "userEnvProbe": "loginShell",
+  "overrideCommand": false,
+  "updateRemoteUserUID": false,
+
+  // build development environment on creation
+  "onCreateCommand": "nix profile install nixpkgs#nix-direnv && ln -s $HOME/.nix-profile/share/nix-direnv/direnvrc $HOME/.direnvrc",
+
+  // Use 'forwardPorts' to make a list of ports inside the container available locally.
+  "forwardPorts": [8080],
+
+  // Use 'postCreateCommand' to run commands after the container is created.
+  // "postCreateCommand": "rustc --version",
+}

.github/workflows/nix.yml

@@ -27,3 +27,21 @@ jobs:
         env:
           PR_URL: ${{github.event.pull_request.html_url}}
           GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}
+  devshell:
+    name: Build and cache devShell
+    runs-on: ubuntu-latest
+    needs: lockfile
+    steps:
+      - name: Install Nix
+        uses: cachix/install-nix-action@v18
+        with:
+          extra_nix_config: |
+            access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
+      - name: Setup cachix
+        uses: cachix/cachix-action@v12
+        with:
+          name: homotopy-io
+          authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+      - name: Build devShell
+        run: |
+          nix develop --build github:homotopy-io/homotopy-rs/update_flake_lock_action