uptag: Update tags in Dockerfiles.

Tired of manually looking up whether the base images you depend on have been updated?

$ uptag check ./Dockerfile
Report for Dockerfile at `/home/j-maas/Dockerfile`:

1 breaking update(s):
ubuntu:18.03
   -!> 20.10

1 compatible update(s):
ubuntu:18.03
    -> 18.04

/home/j-maas/Dockerfile:

# uptag --pattern "<!>.<>"
FROM ubuntu:18.03

Documentation is available with uptag help. Note that for example uptag fetch -h will give a summary, while uptag fetch --help prints the full documentation.

For an example of how to receive daily update emails, see ./examples.

Installation

Download the binaries from the releases page, available for Linux and Windows. Put them in a convenient location that is included in your PATH, so that uptag is available from everywhere.

Alternatively, you can build the binary for your system yourself. Install rustup, clone this repository, and run cargo build --release in this folder. The binary will be available at ./target/release/uptag.

Pattern syntax

Use <> to match a number. Everything else will be matched literally.

• <>.<>.<> will match 2.13.3 but not 2.13.3a.
• debian-<>-beta will match debian-10-beta but not debian-10.

Specify which numbers indicate breaking changes using <!>. Uptag will report breaking changes separately from compatible changes.

• Given pattern <!>.<>.<> and the current tag 1.4.12
  • compatible updates: 1.6.12 and 1.4.13
  • breaking updates: 2.4.12 and 3.5.13

Specifying patterns

Dockerfiles

Each FROM definition needs to be annotated with a pattern and declare a specific tag that matches that pattern. The pattern must be given as a comment in the line before each FROM <image>:<tag> definition in the following format: # uptag --pattern "<pattern>"

Example Dockerfile:

# uptag --pattern "<!>.<>"
FROM ubuntu:18.04

# uptag --pattern "<!>.<>.<>-slim"
FROM node:14.5.0-slim

docker-compose.yml

Each service must associate a pattern with its images. There are two supported declarations.

A service can specify an image field, pointing to an image on DockerHub. Such an image needs to be annotated with a pattern and declare a specific tag that matches that pattern. The pattern must be given as a comment in the line before the image field in the following format: # uptag --pattern "<pattern>"

Alternatively, a service can point to a folder containing a Dockerfile via its build field. That Dockerfile needs to specify patterns as documented for Dockerfiles.

Example docker-compose.yml:

version: "3.6"

services:
  ubuntu: 
    # uptag --pattern "<!>.<>"
    image: ubuntu:18.04

  alpine:
    build: ./alpine

Maintenance

This project is provided as is. I do not intend to continue working on this, but it works for the purposes it was designed for.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.