[CES-607] Add pm2 support to AppService modules

[Krusty93]

List of changes

Override app startup command if PM2 entry point file is provided in AppService modules

Motivation and context

More teams are using PM2 to exploit full hardware capacity

Type of changes

• Add new resources
• Update configuration to existing resources
• Remove existing resources

Does this introduce a change to production resources with possible user impact?

• Yes, users may be impacted applying this change
• No

Other information

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[BurnedMarshal]

LGTM, maybe we can add a validation limiting the property pm2_startup_file_name with node stack

[gunzip]

Why not allow users to define any startup command instead of binding it specifically to PM2?

[Krusty93]

Why not allow users to define any startup command instead of binding it specifically to PM2?

To keep things simple. I don't know if we ever need to add custom commands. What are your thoughts?

[gunzip]

Why do you want to constraint users to a peculiar usage of pm2 ? One user may have a pm2.json configuration in its own codebase for example

[Krusty93]

Why do you want to constraint users to a peculiar usage of pm2 ? One user may have a pm2.json configuration in its own codebase for example

What's your proposal then? Wrapping the TF property? Because I liked the idea where devs don't need to know anything about it, but just saying "here's the file". However, I could be wrong and going against devs preferences

[gunzip]

I vote to just forward the TF command_line property without constraint it to pm2. Consider that this module works for java as well.

[BurnedMarshal]

I vote to just forward the TF command_line property without constraint it to pm2. Consider that this module works for java as well.

I understand your point, but the use of PM2 is not a suggestion it's recommended by Microsoft. You what to shift the responsibility to the team to use it or the capability to configure it, but they don't use it. A good module handle the resources on the good way giving awareness to the team.

[gunzip]

@BurnedMarshal that's right, but in this case, if we want to make pm2 mandatory on every NodeJS App Service, then we should make pm2_startup_file_name mandatory, with a default value, when NodeJS is specified as runtime.

[Krusty93]

@BurnedMarshal that's right, but in this case, if we want to make pm2 mandatory on every NodeJS App Service, then we should make pm2_startup_file_name mandatory, with a default value, when NodeJS is specified as runtime.

@BurnedMarshal Are we confident to enable PM2 everywhere? Consider that developers will find a drift in the terraform configuration and they will be more interested in fixing the breaking change rather than doing tests and fine tuning on the PM2 configuration