Snap notes (#1929)

.github/workflows/release-snap.yaml

@@ -0,0 +1,26 @@
+name: Release
+on: 
+  push:
+    tags:
+      - v*
+  workflow_dispatch:
+
+jobs:
+  snap:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Build snap
+        uses: snapcore/action-build@v1
+        id: build
+
+      - name: Publish to Snap Store
+        uses: snapcore/action-publish@v1
+        env:
+          SNAPCRAFT_STORE_CREDENTIALS: ${{ secrets.SNAPCRAFT_TOKEN }}
+        with:
+          snap: ${{ steps.build.outputs.snap }}
+          # release: stable  # or edge, beta, candidate
+          release: stable

snap/README.md

@@ -0,0 +1,150 @@
+# Failed attempts to create a snap interactively
+
+2026-01-02 I used an Ubuntu 24.04 EC2 instance. I followed https://documentation.ubuntu.com/snapcraft/stable/. Error messages said things like
+
+```
+A network related operation failed in a context of no network access.
+Recommended resolution: Verify that the environment has internet connectivity; see https://canonical-craft-providers.readthedocs-hosted.com/en/latest/explanation/ for further reference.
+Full execution log: '/home/ubuntu/.local/state/snapcraft/log/snapcraft-20260102-170252.488632.log'
+```
+
+when there was in fact no network problem. I remained confused.
+
+```
+$ sudo snapcraft pack
+
+$ lxc list
+
+$ snapcraft pack --destructive-mode
+
+$ snapcraft pack --use-multipass
+
+$ sudo snap install multipass
+
+$ snapcraft pack --use-multipass
+
+$ sudo lxd init --auto
+
+$ lxc network list
+
+$ sudo snapcraft pack
+
+$ sudo snap set snapcraft provider=multipass
+
+$ sudo snapcraft pack --destructive-mode
+
+[This created miller_6.15.0_arm64.snap]
+
+$ snapcraft upload --release=stable *.snap
+No keyring found to store or retrieve credentials from.
+Recommended resolution: Ensure the keyring is working or SNAPCRAFT_STORE_CREDENTIALS is correctly exported into the environment
+For more information, check out: https://documentation.ubuntu.com/snapcraft/stable/how-to/publishing/authenticate
+Full execution log: '/home/ubuntu/.local/state/snapcraft/log/snapcraft-20260102-172357.599171.log'
+
+$ ll *.snap
+-rw-r--r-- 1 root root 8994816 Jan  2 17:22 miller_6.15.0_arm64.snap
+
+$ snap install *.snap
+error: access denied (try with sudo)
+
+$ sudo snap install *.snap
+error: cannot find signatures with metadata for snap/component "miller_6.15.0_arm64.snap"
+```
+
+Conclusion:
+
+* I got cryptic error messages with various permutations.
+* Through trial and error I got a `.snap` file with `sudo` and `multipass` and `--destructive-mode`.
+* Even then, I got a `.snap` file only for the current machine's arch, and the resulting `.snap` file was not locally installable.
+* This led me to try a GitHub Action.
+
+# Info from Claude about auto-releasing
+
+Here's how to set up automatic Snap publishing from GitHub releases:
+
+## 1. Create snapcraft.yaml
+
+First, ensure you have a proper `snapcraft.yaml` in your repo root (or in a `snap/` directory):
+
+```yaml
+name: your-app-name
+base: core22  # or core24 for Ubuntu 24.04
+version: git  # automatically uses git tags
+summary: Single-line summary
+description: |
+  Longer description of your application
+
+grade: stable  # or devel
+confinement: strict  # or classic, devmode
+
+apps:
+  your-app-name:
+    command: bin/your-binary
+    plugs:
+      - home
+      - network
+
+parts:
+  your-app:
+    plugin: nil  # change based on your build system (go, python, etc.)
+    source: .
+    # Add build steps as needed
+```
+
+## 2. Get Snapcraft credentials
+
+Export your Snapcraft login credentials:
+
+```bash
+snapcraft export-login --snaps=miller --channels=stable,candidate,beta,edge snapcraft-token.txt
+```
+
+This creates a token file with limited permissions for just your snap.
+
+## 3. Add token to GitHub Secrets
+
+1. Go to your GitHub repo → Settings → Secrets and variables → Actions
+2. Click "New repository secret"
+3. Name: `SNAPCRAFT_TOKEN`
+4. Value: Paste the entire contents of `snapcraft-token.txt`
+
+## 4. Create GitHub Action workflow
+
+Create `.github/workflows/release.yml`:
+
+```yaml
+name: Release to Snap Store
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  snap:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Build snap
+        uses: snapcore/action-build@v1
+        id: build
+
+      - name: Publish to Snap Store
+        uses: snapcore/action-publish@v1
+        env:
+          SNAPCRAFT_STORE_CREDENTIALS: ${{ secrets.SNAPCRAFT_TOKEN }}
+        with:
+          snap: ${{ steps.build.outputs.snap }}
+          # release: stable  # or edge, beta, candidate
+          release: edge
+```
+
+## Tips
+
+- **Version handling**: Using `version: git` in snapcraft.yaml automatically uses your git tag as the version
+- **Channels**: Start with `edge` channel for testing, then promote to `stable` once confident
+- **Multiple architectures**: Add a build matrix if you need to support arm64, etc.
+- **Testing before stable**: Consider publishing to `candidate` or `beta` first, then manually promote to `stable` after testing
+
+Now when you create a GitHub release with a tag (e.g., `v1.0.0`), the workflow will automatically build and publish your snap!

snap/snapcraft.yaml

@@ -1,17 +1,21 @@
 name: miller
-adopt-info: miller
+base: core24
+version: git
 summary: Miller is like awk, sed, cut, join and sort
 description: |
   Miller is like awk, sed, cut, join, and sort for data formats such as CSV, TSV, JSON, JSON Lines, and positionally-indexed.
 
+grade: stable
+confinement: strict
+
+adopt-info: miller
+
+website: https://github.com/johnkerl/miller/issues
 contact: https://github.com/johnkerl/miller/issues
 issues: https://github.com/johnkerl/miller/issues
 source-code: https://github.com/johnkerl/miller
 
 license: BSD-2-Clause
-base: core24
-grade: stable
-confinement: strict
 compression: lzo
 
 platforms: