OpenSMTPD Docker Container Image

Docker images

Use image revision tags such as wodby/opensmtpd:7-rN to select a Wodby image revision. Major and minor tags use the repository release number, starting at r0. Full-version tags such as wodby/opensmtpd:7.8.0-r0 start at r0 for each exact upstream version. Every published versioned revision tag has a matching annotated Git tag pointing to its release commit. Existing tags remain available after support for their major or minor version ends. See release tags for available revisions and the image revision policy for upgrade guidance. Previously published image tags remain available.

Overview:

• All images are based on Alpine Linux
• Base image: wodby/alpine
• GitHub actions builds
• Docker Hub

Supported tags and respective Dockerfile links:

• 7, 7.8, latest (Dockerfile)

All images built for linux/amd64 and linux/arm64

Environment variables

Variable	Default Value	Description
OPENSMTPD_BOUNCE_WARN	1h, 6h, 2d
OPENSMTPD_EXPIRE	4d
OPENSMTPD_MAX_MESSAGE_SIZE	35M
RELAY_HOST
RELAY_PROTO	smtp+tls
RELAY_USER
RELAY_USER_FILE		A file where the user can be found
RELAY_PASSWORD
RELAY_PASSWORD_FILE		A file where the password can be found
RELAY_PORT	587

The XXX_FILE environment variables allow to put the authentication credentials in files rather than environment variables directly. This is typically used to deploy the authentication password using docker secret.

If you store the password in docker secret, e.g.

$ echo 'my secret' | docker secret create smtp_relay_password -

then you can use it setting the RELAY_PASSWORD_FILE environment variable in your container like:

RELAY_PASSWORD_FILE=/run/secrets/smtp_relay_password

Note that you cannot specify both the XXX and XXX_FILE environment variables.

Orchestration actions

Usage:

make COMMAND [params ...]

commands:
    check-ready [host max_try wait_seconds delay_seconds]
 
default params values:
    host localhost
    max_try 1
    wait_seconds 1
    delay_seconds 0

Deployment

Deploy OpenSMTPD to your own server via Wodby.

Building with pinned base images

Build with the Makefile to use the base image digests in base-images.mk. Local builds and CI resolve the same version and variant to the same multi-platform image. A version without a pin fails before the build starts.

When adding a supported base version or variant, add its image index digest to base-images.mk. For a custom build, override BASE_IMAGE with a complete repository:tag@sha256:... reference.