send_email.sh (or SNDEM for short)

Script to send an email in bare-bone environments with minimal requirements

Depends only on:

• coreutils (base64, numfmt, stat)
• bash
• curl

Aimed at sending emails from within continuous integration runners and other feature-limited light environments

Usage

send_mail is flexible and supports supplying information through environment variable (useful in CIs) and on the command line:

$ ./send_email -s 'smtp://smtp.gmail.com:587' -t 'username:password' -a '[email protected]' -r '[email protected],[email protected]' -R 'Your Name,Team Name'

OR

$ export SNDEM_EMAIL_SERVER='smtp://smtp.gmail.com:587'
$ export SNDEM_EMAIL_AUTH='username:password'
$ export SNDEM_FROM_EMAIL='[email protected]'
$ export SNDEM_RCPNT_EMAILS='[email protected],[email protected]'
$ export SNDEM_RCPNT_NAMES='Your Name,Team Name'
$ ./send_email

It has another feature to also accept either raw or base64 encoded strings for its input arguments/variables. e.g.:

# it can run like this
$ ./send_email -s 'smtp://smtp.gmail.com:587' -t 'username:password' -a '[email protected]' -r '[email protected]'
# or like this
$ ./send_email -s 'c210cDovL3NtdHAuZ21haWwuY29tOjU4Nwo=' -t 'dXNlcm5hbWU6cGFzc3dvcmQK' -a 'bXlAZW1haWwuY29tCg==' -r 'eW91ckBlbWFpbC5jb20K'

Moreover, you can mix and match as needed:

# like this
$ ./send_email -s 'smtp://smtp.gmail.com:587' -t 'dXNlcm5hbWU6cGFzc3dvcmQK' -a '[email protected]' -r 'eW91ckBlbWFpbC5jb20K'
# or even like this
$ env SNDEM_EMAIL_AUTH='dXNlcm5hbWU6cGFzc3dvcmQK' ./send_email -s 'smtp://smtp.gmail.com:587' -a 'bXlAZW1haWwuY29tCg==' -r 'eW91ckBlbWFpbC5jb20K'

The last one is especially useful as some CI environments only allow masked variables if they are base64 encoded strings. This way, you can easily hide your email credentials from logs.

You can go wild and even include things like your commit message or attachments or both:

$ env SNDEM_EMAIL_SERVER='smtp://smtp.gmail.com:587' SNDEM_EMAIL_AUTH='dXNlcm5hbWU6cGFzc3dvcmQK' \
      SNDEM_FROM_EMAIL='[email protected]' \
      SNDEM_RCPNT_EMAILS='[email protected]' \
      SNDEM_RCPNT_NAMES='Some One' \
      SNDEM_CI_COMMIT_MESSAGE='My commit message' \
      ./send_email -M \
        -b 'Hey,\na new CI build completed for the commit: __CMTMSG_POS__\nHave a look.\nRegards\nCI Runner' \
        -s 'Awesome Subject' \
        -c '[email protected],[email protected]' \
        -b '[email protected]' \
        -A artifacts.zip

The above shows a custom email body with a positional argument for where the commit message is to be placed. The resulting email will look like:

Hey,
a new CI build completed for the commit: My commit message
Have a look.
Regards
CI Runner

and artifacts.zip will be attached to the email

For more options run send_email -h.

Examples

GitLab CI

Add send_mail.sh to your project as a git submodule.

$ cd my_gitlab_project
$ git submodule add -b stable https://github.com/kgizdov/send_email.sh.git sndem

configure your .gitlab-ci.yaml:

variables:
  GIT_SUBMODULE_STRATEGY: recursive

build_my_project:
  stage: build
  script:
    - make
  artifacts:
    paths:
      - artifact.zip

update_me:
  stage: deploy
  needs: ["build_my_project"]
  script:
    # assuming configuration is done through
    # GitLab CI settings
    - sndem/send_email -M -A 'artifact.zip'