Added Divers

Divers/Docker container update.md

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+# Update Docker Containers
+
+```bash
+sudo vim /mnt/data/docker/update_all_docker_containers.sh
+```
+
+#### 1. Automatic updates
+
+```bash
+#!/usr/bin/env bash
+set -e
+
+# Our function to update containers based on their base image
+update_container() {
+    local image=$1
+    docker pull $image
+    local updated_containers=0
+
+    # Loop through all running containers
+    for container in $(docker ps --format "{{.Names}}"); do
+        local container_image=$(docker inspect --format '{{.Config.Image}}' "$container")
+        
+        # We check if the current container's image matches the updated image
+        if [[ "$container_image" == "$image" ]]; then
+            local latest=$(docker inspect --format "{{.Id}}" $image)
+            local running=$(docker inspect --format "{{.Image}}" $container)
+
+            if [[ "$running" != "$latest" ]]; then
+                echo "Upgrading $container"
+                docker rm -f $container
+                docker run --name $container $image
+                ((updated_containers++))
+            fi
+        fi
+    done
+
+    if [[ $updated_containers -eq 0 ]]; then
+        echo "No containers updated for $image"
+    else
+        echo "$updated_containers container(s) updated for $image"
+    fi
+}
+
+# Our main script starts here
+# Check for updates to all images used by running containers
+for image in $(docker ps --format '{{.Image}}' | sort | uniq); do
+    echo "Checking updates for $image"
+    update_container $image
+done
+
+echo "Container update check complete."
+```
+
+#### 2. Preserving configurations during automatic updates
+
+```bash
+#!/usr/bin/env bash
+set -e
+
+# Function to preserve and update container
+preserve_and_update_container() {
+    local container=$1
+    local image=$(docker inspect --format '{{.Config.Image}}' "$container")
+    
+    # Pull the latest image version
+    docker pull $image
+
+    # Compare image IDs to determine if an update is needed
+    local latest_image_id=$(docker inspect --format '{{.Id}}' $image)
+    local container_image_id=$(docker inspect --format '{{.Image}}' "$container")
+
+    if [[ "$latest_image_id" != "$container_image_id" ]]; then
+        echo "Updating $container..."
+        
+        # Capture current configurations
+        local env_vars=$(docker inspect $container --format '{{range .Config.Env}}{{println .}}{{end}}')
+        local volumes=$(docker inspect $container --format '{{range .Mounts}}{{println .Source ":" .Destination}}{{end}}')
+        local network=$(docker network ls --filter id=$(docker inspect $container --format '{{.HostConfig.NetworkMode}}') --format '{{.Name}}')
+        
+        # Remove the outdated container
+        docker rm -f $container
+        
+        # Recreate the container with the same configurations
+        docker run -d --name $container $(echo "$env_vars" | xargs -I {} echo --env '{}') $(echo "$volumes" | xargs -I {} echo -v '{}') --network="$network" $image
+        echo "$container updated successfully."
+    else
+        echo "$container is already up to date."
+    fi
+}
+
+# Iterate over all running containers
+for container in $(docker ps --format "{{.Names}}"); do
+    preserve_and_update_container $container
+done
+
+echo "Container update check complete while preserving existing container configurations."
+```
+
+```bash
+sudo chmod +x update_all_docker_containers.sh
+
+./update_all_docker_containers.sh
+```
+
+#### 3. Crontab
+
+##### Option 1
+
+```bash
+crontab -e
+```
+
+```
+0 3 * * * /mnt/data/docker/update_all_docker_containers.sh
+```
+
+##### Option 2
+
+```bash
+crontab -e
+```
+
+```
+0 0 * * * /usr/bin/docker system prune -af
+```
+
+##### Option 3
+
+```bash
+cd /etc/cron.daily
+sudo vim docker-prune
+```
+
+```
+#!/bin/bash
+docker system prune -af  --filter "until=$((30*24))h"
+```
+
+```bash
+sudo chmod +x /etc/cron.daily/docker-prune
+```
+
+#### Test
+
+```bash
+run-parts /etc/cron.daily
+```