feat: add support for common v2 endpoints (ping/metrics/version/config)

[siggiskulason]

feat: add support for common v2 endpoints (ping/metrics/version/config)

This commit adds v2 (Ireland/Jakarta) support for four common endpoints:

• version
• metrics
• ping
• config

For information about the available commands, use edgex-cli -h

There are a number of ways to use the commands:

1. edgex-cli version displays version of each active microservice.
   The version commands just shows the version string. The other commands
   use a pretty-printed JSON structure (config) or a table (metrics).

$ edgex-cli version
EdgeX CLI version:  1.0.0-dev.9
core-metadata: 2.0.0-2
core-data: 2.0.0-2
core-command: 2.0.0-2

$ edgex-cli metrics
Service       CpuBusyAvg MemAlloc MemFrees MemLiveObjects MemMallocs MemSys   MemTotalAlloc
core-command  14         1572240  50446    8839           59285      75318280 11463128
core-metadata 14         1757440  56371    9918           66289      75318280 12001840
core-data     14         1691984  56145    9551           65696      75318280 11903936

$ edgex-cli config
core-metadata:
{
    "Clients": {
        "core-data": {
            "Host": "localhost",
            "Port": 59880,
            "Protocol": "http"
        },
...

2. edgex-cli version -d shows debug output - the URL used and the result

$ edgex-cli ping -d
core-metadata: http://localhost:59881/api/v2/ping: {"apiVersion":"v2","timestamp":"Fri Sep 10 16:17:44 BST 2021"}
core-data: http://localhost:59880/api/v2/ping: {"apiVersion":"v2","timestamp":"Fri Sep 10 16:17:44 BST 2021"}
core-command: http://localhost:59882/api/v2/ping: {"apiVersion":"v2","timestamp":"Fri Sep 10 16:17:44 BST 2021"}
core-scheduler: : Get "http://localhost:59861/api/v2/ping": dial tcp 127.0.0.1:59861: connect: connection refused
core-notification: : Get "http://localhost:59860/api/v2/ping": dial tcp 127.0.0.1:59860: connect: connection refused
device-modbus: : Get "http://localhost:59901/api/v2/ping": dial tcp 127.0.0.1:59901: connect: connection refused
device-camera: : Get "http://localhost:59985/api/v2/ping": dial tcp 127.0.0.1:59985: connect: connection refused
device-mqtt: : Get "http://localhost:59982/api/v2/ping": dial tcp 127.0.0.1:59982: connect: connection refused
device-rest: : Get "http://localhost:59986/api/v2/ping": dial tcp 127.0.0.1:59986: connect: connection refused
rules-engine: : Get "http://localhost:59701/api/v2/ping": dial tcp 127.0.0.1:59701: connect: connection refused
http-export: : Get "http://localhost:59704/api/v2/ping": dial tcp 127.0.0.1:59704: connect: connection refused
mqtt-export: : Get "http://localhost:59703/api/v2/ping": dial tcp 127.0.0.1:59703: connect: connection refused
functional-tests: : Get "http://localhost:59705/api/v2/ping": dial tcp 127.0.0.1:59705: connect: connection refused
push-to-core: : Get "http://localhost:59702/api/v2/ping": dial tcp 127.0.0.1:59702: connect: connection refused

3. edgex-cli version -j gets the raw JSON output for one service (by default core-data)

$ edgex-cli metrics -j
{"apiVersion":"v2","metrics":{"memAlloc":1755096,"memFrees":1008594,"memLiveObjects":9980,"memMallocs":1018574,"memSys":75580424,"memTotalAlloc":327693144,"cpuBusyAvg":11}}

It's possible to specify the service to use: -m/--metadata, -c/--command, -n/--notification, -s/--scheduler or --data (which is the default). This can also be combined with -j or -d

$ edgex-cli metrics -j -m
{"apiVersion":"v2","metrics":{"memAlloc":1709440,"memFrees":1008937,"memLiveObjects":9468,"memMallocs":1018405,"memSys":75580424,"memTotalAlloc":327792520,"cpuBusyAvg":10}}

$ edgex-cli ping -d -c
core-command: http://localhost:59882/api/v2/ping: {"apiVersion":"v2","timestamp":"Fri Sep 10 16:20:55 BST 2021"}

Help is available with

$ edgex-cli help
$ edgex-cli version --help
$ edgex-cli version --h

PR Checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

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

What is the current behavior?

edgex-cli does not currently support the V2 API.

Issue Number:

What is the new behavior?

This PR adds support in edgex-cli for the common V2 endpoints.

Does this PR introduce a breaking change?

• Yes
• No

New Imports

• Yes
• No

Specific Instructions

Are there any specific instructions or things that should be known prior to reviewing?

Other information

[siggiskulason]

Thank you very much @lenny-intel for the helpful comments. I have responded to them inline, updated the code, force-pushed an update and marked the comments as resolved.

[siggiskulason]

Hi @lenny-intel - thanks again for your review. I have responded to all your comments and made some changes - I removed the format package and also for metrics added the SDK method to get the metrics - which I then print out in a table, rather than printing out the JSON result. I still print out the config as a JSON for now at least, as that can have an hierarchical structure - and I just get the raw JSON for version/ping. For the other methods I'm now starting to add I'm using the SDK functions. I've force-pushed the changes and marked your comments as resolved.

[lenny-goodell]

LGTM