Fix deployment timestamp always showing 'less than a minute ago' in k8s

Previously, the deployment timestamp was set to DateTime.utc_now() when
the application started, which meant it would always show as recent in
k8s environments where pods are recreated on each deployment.

This commit:
- Updates Release.init() to check for DEPLOYED_AT environment variable
- Falls back to current time if env var is not set (backwards compatible)
- Adds proper ISO8601 timestamp parsing with error handling
- Updates GitHub Actions deploy workflow to set DEPLOYED_AT during deployment
- Creates k8s patch file for future manual deployments

The deployment timestamp will now persist across pod restarts in k8s,
showing the actual deployment time rather than pod startup time.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

.github/workflows/deploy.yml

@@ -74,7 +74,32 @@ jobs:
 
       - name: Deploy to K3s
         run: |
+          # Get current timestamp in ISO8601 format
+          DEPLOYED_AT=$(date -u +"%Y-%m-%dT%H:%M:%SZ")
+          
+          # Create a temporary patch file with the deployment timestamp
+          cat > /tmp/deployed-at-patch.yaml <<EOF
+          apiVersion: apps/v1
+          kind: StatefulSet
+          metadata:
+            name: aprs
+            namespace: aprs
+          spec:
+            template:
+              spec:
+                containers:
+                - name: aprs
+                  env:
+                  - name: DEPLOYED_AT
+                    value: "$DEPLOYED_AT"
+          EOF
+          
+          # Apply the patch to set the deployment timestamp
+          kubectl patch statefulset aprs -n aprs --patch-file=/tmp/deployed-at-patch.yaml
+          
+          # Update the image
           kubectl set image statefulset/aprs aprs=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest -n aprs
+          
           # Force a rollout to ensure latest image is pulled
           kubectl rollout restart statefulset/aprs -n aprs
-          echo "Deployment initiated - not waiting for rollout to complete"
+          echo "Deployment initiated with timestamp $DEPLOYED_AT - not waiting for rollout to complete"

Dockerfile

@@ -57,9 +57,8 @@ ENV LANG=en_US.UTF-8 LANGUAGE=en_US:en LC_ALL=en_US.UTF-8
 
 WORKDIR /app
 
-# Create deployment timestamp before switching users
+# Ensure proper ownership
-RUN date -u +"%Y-%m-%dT%H:%M:%SZ" > /app/deployed_at.txt && \
+RUN chown -R elixir:root /app
-    chown elixir:root /app/deployed_at.txt
 
 COPY --from=builder --chown=elixir:root /app/_build/prod/rel/aprsme ./
 

k8s/statefulset-deployed-at-patch.yaml

@@ -0,0 +1,13 @@
+apiVersion: apps/v1
+kind: StatefulSet
+metadata:
+  name: aprs
+  namespace: aprs
+spec:
+  template:
+    spec:
+      containers:
+      - name: aprs
+        env:
+        - name: DEPLOYED_AT
+          value: "TIMESTAMP_PLACEHOLDER"

lib/aprsme/application.ex

@@ -9,6 +9,9 @@ defmodule Aprsme.Application do
 
   @impl true
   def start(_type, _args) do
+    # Initialize deployment timestamp
+    Aprsme.Release.init()
+
     # Run migrations on startup
     migrate()
 

lib/aprsme/release.ex

@@ -75,10 +75,29 @@ defmodule Aprsme.Release do
   This is called during application startup.
   """
   def init do
-    # Read deployment timestamp from file
+    # Check if deployment timestamp is provided via environment variable
-    deployed_at = read_deployment_timestamp()
+    # This allows k8s deployments to set a persistent timestamp
+    deployed_at =
+      case System.get_env("DEPLOYED_AT") do
+        nil ->
+          # Fallback to current time for local development or non-k8s deployments
+          DateTime.utc_now()
 
-    # Add to application config
+        timestamp_str ->
+          # Parse the ISO8601 timestamp from environment variable
+          case DateTime.from_iso8601(timestamp_str) do
+            {:ok, datetime, _offset} ->
+              datetime
+
+            {:error, _} ->
+              require Logger
+
+              Logger.warning("Invalid DEPLOYED_AT timestamp: #{timestamp_str}, using current time")
+              DateTime.utc_now()
+          end
+      end
+
+    # Store in application config
     Application.put_env(:aprsme, :deployed_at, deployed_at)
 
     deployed_at
@@ -88,7 +107,16 @@ defmodule Aprsme.Release do
   Get the deployment timestamp.
   """
   def deployed_at do
-    Application.get_env(:aprsme, :deployed_at) || DateTime.utc_now()
+    case Application.get_env(:aprsme, :deployed_at) do
+      nil ->
+        # If not initialized yet, initialize now
+        timestamp = DateTime.utc_now()
+        Application.put_env(:aprsme, :deployed_at, timestamp)
+        timestamp
+
+      timestamp ->
+        timestamp
+    end
   end
 
   defp run_migrations_with_timeout(timeout) do
@@ -113,18 +141,4 @@ defmodule Aprsme.Release do
         timeout: timeout
       )
   end
-
-  defp read_deployment_timestamp do
-    case File.read("/app/deployed_at.txt") do
-      {:ok, timestamp} ->
-        case DateTime.from_iso8601(String.trim(timestamp)) do
-          {:ok, datetime, _} -> datetime
-          _ -> DateTime.utc_now()
-        end
-
-      _ ->
-        # Fallback to current time if file doesn't exist
-        DateTime.utc_now()
-    end
-  end
 end