feat(snap): use updated environment variable injection

[siggiskulason]

Signed-off-by: Siggi Skulason [email protected]

This PR updates edgex-go to use the new environment variable injection.

apps.<app>.config.<my.env.var> -> setting env var MY_ENV_VAR for an app (e.g. apps.core-data.config.service.port=1000)
config.<my.env.var> -> setting env variable for all apps (e.g. config.service.host=localhost)

If your build fails due to your commit message not passing the build checks, please review the guidelines here: https://github.com/edgexfoundry/edgex-go/blob/main/.github/Contributing.md

PR Checklist

Please check if your PR fulfills the following requirements:

• I am not introducing a breaking change (if you are, flag in conventional commit message with BREAKING CHANGE: describing the break)
• I am not introducing a new dependency (add notes below if you are)
• I have added unit tests for the new feature or bug fix (if not, why?) N/A - they are in the imported module
• I have fully tested (add details below) this the new feature or bug fix (if not, why?)
• I have opened a PR for the related docs change (if not, why?) N/A

Testing Instructions

Do

sudo snap set edgexfoundry env.core-data.service.host=localhost
sudo snap set edgexfoundry apps.core-data.config.service.port=8080
sudo snap set edgexfoundry config.debug=true

1. Confirm that all .env files have DEBUG=true
2. Confirm that the core-data .env file also has both the SERVICE_HOST and SERVICE_PORT settings

$ more /var/snap/edgexfoundry/current/config/core-data/res/core-data.env 
export SERVICE_HOST=localhost
export DEBUG=true
export SERVICE_PORT=8080
$ more /var/snap/edgexfoundry/current/config/core-command/res/core-command.env 
export DEBUG=true

New Dependency Instructions (If applicable)

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
0.0% Duplication

[siggiskulason]

@farshidtz - this is now ready for review- it uses version v2.2.0-beta.2 of the snap hooks.

[farshidtz]

It works according to the given instructions:

$ sudo snap set edgexfoundry env.core-data.service.host=localhost
$ sudo snap set edgexfoundry apps.core-data.config.service.port=8080
$ sudo snap set edgexfoundry config.debug=true

$ cat /var/snap/edgexfoundry/current/config/core-data/res/core-data.env 
export SERVICE_HOST=localhost
export DEBUG=true
export SERVICE_PORT=8080

$ cat /var/snap/edgexfoundry/current/config/core-command/res/core-command.env
export DEBUG=true

But there is a bug for services that don't have env.* legacy options and only the new ones:

1. env vars keep getting appended to the env files:

$ sudo snap set edgexfoundry apps.core-command.config.x=true
$ sudo snap set edgexfoundry apps.core-command.config.x=true
$ sudo snap set edgexfoundry apps.core-command.config.x=true
$ cat /var/snap/edgexfoundry/current/config/core-command/res/core-command.env
export DEBUG=true
export X=true
export X=true
export X=true

2. unset does not remove the env var:

$ sudo snap unset edgexfoundry apps.core-command.config.x
$ cat /var/snap/edgexfoundry/current/config/core-command/res/core-command.env
export DEBUG=true
export X=true
export X=true
export X=true

As discussed with @siggiskulason, this is because the new functions try to be backwards compatible by appending to env files, while the old functions always read all snap options and write the env file from scratch.

[farshidtz]

Thanks @siggiskulason for this addition. I've added a new PR (#3986) with some fixes and additions.

I'm going to close this in favor of the other PR.