dockcheck/README.md

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<h2 align="center">CLI tool to automate docker image updates or notifying when updates are available.</h2>
<h3 align="center">Features:</h3>
<h3 align="center">selective updates, exclude containers, custom labels, notification plugins, prune when done and more.</h3>

<h4 align="center">For Podman - see the fork <a href="https://github.com/sudo-kraken/podcheck">sudo-kraken/podcheck</a>!</h4>

<h4 align="center">:whale: Docker Hub pull limit :chart_with_downwards_trend: not an issue for checks but for actual pulls - <a href="#whale-docker-hub-pull-limit-chart_with_downwards_trend-not-an-issue-for-checks-but-for-actual-pulls">read more</a></h4>

___
## :bell: Changelog

- **v0.5.7.0**: Rewritten templates - now with a function to notify when there's a new Dockcheck release.
    - Manually migrate your current `notify.sh` settings to a new template for new functionality.
- **v0.5.6.1**: Async xargs hotfix - due to errors `failed to request manifest head ... context canceled`
    - Defaulted subprocess to 1 with `MaxAsync=1`, increase to find a stable value in your environment.
    - Added `-x N` option to pass `MaxAsync` value at runtime.
    - To disable xargs `-P` flag (max processes) all together, set `MaxAsync` to 0.
- **v0.5.6.0**: Heavily improved performance due to async checking for updates.
- **v0.5.5.0**: osx and bsd compatibility changes + rewrite of dependency installer
- **v0.5.4.0**: Added support for a Prometheus+node_exporter metric collection through a file collector.
- **v0.5.3.0**: Local image check changed (use imageId instead of name) and Gotify-template fixed (whale icon removed).
- **v0.5.2.1**: Rewrite of dependency downloads, jq can be installed with package manager or static binary.
___


![](extras/example.gif)

## :mag_right: `dockcheck.sh`
```
$ ./dockcheck.sh -h
Syntax:     dockcheck.sh [OPTION] [part of name to filter]
Example:    dockcheck.sh -y -d 10 -e nextcloud,heimdall

Options:"
-a|y   Automatic updates, without interaction.
-c D   Exports metrics as prom file for the prometheus node_exporter. Provide the collector textfile directory.
-d N   Only update to new images that are N+ days old. Lists too recent with +prefix and age. 2xSlower.
-e X   Exclude containers, separated by comma.
-f     Force stack restart after update. Caution: restarts once for every updated container within stack.
-h     Print this Help.
-i     Inform - send a preconfigured notification.
-l     Only update if label is set. See readme.
-m     Monochrome mode, no printf color codes.
-n     No updates, only checking availability.
-p     Auto-Prune dangling images after update.
-r     Allow updating images for docker run, wont update the container.
-s     Include stopped containers in the check. (Logic: docker ps -a).
-t     Set a timeout (in seconds) per container for registry checkups, 10 is default.
-v     Prints current version.
```

### Basic example:
```
$ ./dockcheck.sh
. . .
Containers on latest version:
glances
homer

Containers with updates available:
1) adguardhome
2) syncthing
3) whoogle-search

Choose what containers to update:
Enter number(s) separated by comma, [a] for all - [q] to quit:
```
Then it proceeds to run `pull` and `up -d` on every container with updates.  
After the updates are complete, you'll get prompted if you'd like to prune dangling images.

___

## :nut_and_bolt: Dependencies
- Running docker (duh) and compose, either standalone or plugin. (see [Podman fork](https://github.com/sudo-kraken/podcheck)  
- Bash shell or compatible shell of at least v4.3
  - POSIX `xargs`, usually default but can be installed with the `findutils` package - to enable async.
- [jq](https://github.com/jqlang/jq)
  - User will be prompted to install with package manager or download static binary.
- [regclient/regctl](https://github.com/regclient/regclient) (Licensed under [Apache-2.0 License](http://www.apache.org/licenses/LICENSE-2.0))  
  - User will be prompted to download `regctl` if not in `PATH` or `PWD`.  
  - regctl requires `amd64/arm64` - see [workaround](#roller_coaster-workaround-for-non-amd64--arm64) if other architecture is used.

## :tent: Install Instructions
Download the script to a directory in **PATH**, I'd suggest using `~/.local/bin` as that's usually in **PATH**.  
For OSX/macOS preferably use `/usr/local/bin`.
```sh
# basic example with curl:
curl -L https://raw.githubusercontent.com/mag37/dockcheck/main/dockcheck.sh -o ~/.local/bin/dockcheck.sh
chmod +x ~/.local/bin/dockcheck.sh

# or oneliner with wget:
wget -O ~/.local/bin/dockcheck.sh "https://raw.githubusercontent.com/mag37/dockcheck/main/dockcheck.sh" && chmod +x ~/.local/bin/dockcheck.sh

# OSX or macOS version with curl:
 curl -L https://raw.githubusercontent.com/mag37/dockcheck/main/dockcheck.sh -o /usr/local/bin/dockcheck.sh && chmod +x /usr/local/bin/dockcheck.sh
```
Then call the script anywhere with just `dockcheck.sh`.
Add preferred `notify.sh`-template to the same directory - this will not be touched by the scripts self-update function.


## :loudspeaker: Notifications
Trigger with the `-i` flag.  
Run it scheduled with `-ni` to only get notified when there's updates available!  
Will also send a notification when `dockcheck.sh` itself has an update. 

Use a `notify_X.sh` template file from the **notify_templates** directory, copy it to `notify.sh` alongside the script, modify it to your needs! (notify.sh is added to .gitignore)  
**Current templates:**
- Synology [DSM](https://www.synology.com/en-global/dsm)
- Email with [mSMTP](https://wiki.debian.org/msmtp) (or deprecated alternative [sSMTP](https://wiki.debian.org/sSMTP))
- Apprise (with it's [multitude](https://github.com/caronc/apprise#supported-notifications) of notifications)
  - both native [caronc/apprise](https://github.com/caronc/apprise) and the standalone [linuxserver/docker-apprise-api](https://github.com/linuxserver/docker-apprise-api)
  - Read the [QuickStart](extras/apprise_quickstart.md)
- [ntfy.sh](https://ntfy.sh/) - HTTP-based pub-sub notifications.
- [Gotify](https://gotify.net/) - a simple server for sending and receiving messages.
- [Pushbullet](https://www.pushbullet.com/) - connecting different devices with cross-platform features.
- [Telegram](https://telegram.org/) - Telegram chat API.
- [Matrix-Synapse](https://github.com/element-hq/synapse) - [Matrix](https://matrix.org/), open, secure, decentralised communication.
- [Pushover](https://pushover.net/) - Simple Notifications (to your phone, wearables, desktops)
- [Discord](https://support.discord.com/hc/en-us/articles/228383668-Intro-to-Webhooks) - Discord webhooks.

Further additions are welcome - suggestions or PR!  
<sub><sup>Initiated and first contributed by [yoyoma2](https://github.com/yoyoma2).</sup></sub>  

### :date: Release notes addon to Notifications
There's a function to use a lookup-file to add release note URL's to the notification message.  
Copy the notify_templates/`urls.list` file to the script directory, it will be used automatically if it's there.   Modify it as necessary, the names of interest in the left column needs to match your container names.  
The output of the notification will look something like this:
```
Containers on hostname with updates available:
apprise-api  ->  https://github.com/linuxserver/docker-apprise-api/releases
homer  ->  https://github.com/bastienwirtz/homer/releases
nginx  ->  https://github.com/docker-library/official-images/blob/master/library/nginx
...
```
The `urls.list` file is just an example and I'd gladly see that people contribute back when they add their preferred URLs to their lists.

## :fast_forward: Asyncronous update checks with **xargs**; `-x N` option. (default=1)
Pass `-x N` where N is number of subprocesses allowed, experiment in your environment to find a suitable max!   
Change the default value by editing the `MaxAsync=N` variable in `dockcheck.sh`. To disable the subprocess function set `MaxAsync=0`.


## :chart_with_upwards_trend: Prometheus and node_exporter
Dockcheck can be used together with [Prometheus](https://github.com/prometheus/prometheus) and [node_exporter](https://github.com/prometheus/node_exporter) to export metrics via the file collector, scheduled with cron or likely.
This is done with the `-c` option, like this:
```
dockcheck.sh -c /path/to/exporter/directory
```

See the [README.md](./addons/prometheus/README.md) for more detailed information on how to set it up!

<sub><sup>Contributed by [tdralle](https://github.com/tdralle).</sup></sub>  

## :bookmark: Labels
Optionally add labels to compose-files. Currently these are the usable labels:
```
    labels:
      mag37.dockcheck.restart-stack: true
      mag37.dockcheck.update: true
```
- `mag37.dockcheck.restart-stack: true` works instead of the `-f` option, forcing stop+restart on the whole compose-stack (Caution: Will restart on every updated container within stack).
- `mag37.dockcheck.update: true` will when used with the `-l` option only update containers with this label and skip the rest. Will still list updates as usual.

## :roller_coaster: Workaround for non **amd64** / **arm64**
`regctl` provides binaries for amd64/arm64, to use on other architecture you could try this workaround.
Run regctl in a container wrapped in a shell script. Copied from [regclient/docs/install.md](https://github.com/regclient/regclient/blob/main/docs/install.md):

```sh
cat >regctl <<EOF
#!/bin/sh
opts=""
case "\$*" in
  "registry login"*) opts="-t";;
esac
docker container run \$opts -i --rm --net host \\
  -u "\$(id -u):\$(id -g)" -e HOME -v \$HOME:\$HOME \\
  -v /etc/docker/certs.d:/etc/docker/certs.d:ro \\
  ghcr.io/regclient/regctl:latest "\$@"
EOF
chmod 755 regctl
```
Test it with `./regctl --help` and then either add the file to the same path as *dockcheck.sh* or in your path (eg. `~/.local/bin/regctl`).

## :whale: Docker Hub pull limit :chart_with_downwards_trend: not an issue for checks but for actual pulls
Due to recent changes in [Docker Hub usage and limits](https://docs.docker.com/docker-hub/usage/)
>Unauthenticated users: 10 pulls/hour  
>Authenticated users with a free account: 100 pulls/hour

This is not an issue for registry checks. But if you have a large stack and pull more than 10 updates at once consider updating more often or to create a free account.
You could use/modify the login-wrapper function in the example below to automate the login prior to running `dockcheck.sh`.

### :guardsman: Function to auth with docker hub before running
**Example** - Change names, paths, and remove cat+password flag if you rather get prompted:
```sh
function dchk {
  cat ~/pwd.txt | docker login --username YourUser --password-stdin
  ~/dockcheck.sh "$@"
}
```

## :hammer: Known issues
- No detailed error feedback (just skip + list what's skipped).
- Not respecting `--profile` options when re-creating the container.
- Not working well with containers created by **Portainer**.
- **Watchtower** might cause issues due to retagging images when checking for updates (and thereby pulling new images).

## :warning: `-r flag` disclaimer and warning
**Wont auto-update the containers, only their images. (compose is recommended)**  
`docker run` dont support using new images just by restarting a container.  
Containers need to be manually stopped, removed and created again to run on the new image.

## :wrench: Debugging
If you hit issues, you could check the output of the `extras/errorCheck.sh` script for clues.
Another option is to run the main script with debugging in a subshell `bash -x dockcheck.sh` - if there's a particular container/image that's causing issues you can filter for just that through `bash -x dockcheck.sh nginx`.

## :scroll: License
dockcheck is created and released under the [GNU GPL v3.0](https://www.gnu.org/licenses/gpl-3.0-standalone.html) license.

## :heartpulse: Sponsorlist

- [avegy](https://github.com/avegy)

___

### :floppy_disk: The [story](https://mag37.org/posts/project_dockcheck/) behind it. 1 year in retrospect.