Set default logging config for Docker daemon (#157)

Co-authored-by: Steven Briscoe <me@stevenbriscoe.com>

scripts/update/01-run.sh

@@ -122,6 +122,9 @@ cd "$UMBREL_ROOT"
   }
 }
 
+# Add default logging configuration to Docker daemon
+"${UMBREL_ROOT}/.umbrel-${RELEASE}/scripts/update/steps/docker-add-logging-config.sh"
+
 # Restart Docker to resolve:
 # - This error could happen when pulling new images:
 #   ERROR: Get "https://registry-1.docker.io/v2/": net/http: TLS handshake timeout

scripts/update/steps/docker-add-logging-config.sh

@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+DOCKER_DAEMON_CONF_FILE="/etc/docker/daemon.json"
+DOCKER_DAEMON_BACKUP_CONF_FILE="/etc/docker/daemon.json.bak"
+
+if [[ ! -f "${DOCKER_DAEMON_CONF_FILE}" ]]; then
+	echo "{}" > "${DOCKER_DAEMON_CONF_FILE}"
+fi
+
+# Check if a 'log-driver' is already set
+has_log_driver=$(cat "${DOCKER_DAEMON_CONF_FILE}" | jq '. | has("log-driver")')
+
+if [[ "${has_log_driver}" == "true" ]]; then
+  echo "Docker daemon 'log-driver' already set"
+  exit
+fi
+
+echo "Adding logging config. to Docker daemon"
+
+# Make a backup of daemon.json
+cp --archive "${DOCKER_DAEMON_CONF_FILE}" "${DOCKER_DAEMON_BACKUP_CONF_FILE}"
+
+output=$(jq '. + {"log-driver": "json-file", "log-opts": {"max-size": "50m", "max-file": "1"}}' "${DOCKER_DAEMON_CONF_FILE}")
+echo "${output}" > "${DOCKER_DAEMON_CONF_FILE}"
+
+has_log_driver_after=$(cat "${DOCKER_DAEMON_CONF_FILE}" 2> /dev/null | jq -r '. | has("log-driver")' || true)
+
+# If an explicit 'true' does not come back
+# Then something has gone wrong, and we'll restore
+if [[ "${has_log_driver_after}" != "true" ]]; then
+  echo "The Docker daemon.json now looks bad. Restoring..."
+
+  mv "${DOCKER_DAEMON_BACKUP_CONF_FILE}" "${DOCKER_DAEMON_CONF_FILE}"
+
+  exit
+fi
+
+rm --force "${DOCKER_DAEMON_BACKUP_CONF_FILE}"
+
+echo "Successfully added default logging config to Docker daemon"