feat: enable all snmp versions

[pc-ahrens]

Example usage v3:

  - collection: pollect
    tickTime: 120
    timeout: 1
    sources:
      - type: SnmpGet
        name: dev
        host: github.somedomain.com
        snmpVersion: 3
        username: ghes-snmp
        authKeyName: GH_SNMP_AUTHKEY_DEV
        authProtocol: SHA
        privKeyName: GH_SNMP_PRIVKEY_DEV
        privProtocol: AES
        metrics:
          - name: hrMemorySize
            oid: iso.3.6.1.2.1.25.2.2.0

The secrets GH_SNMP_AUTHKEY_DEV and GH_SNMP_PRIVKEY_DEV must be available as environment variables inside the container.

Example usage v2c:

  - collection: pollect
    tickTime: 120
    timeout: 1
    sources:
      - type: SnmpGet
        name: dev
        host: github.somedomain.com
        communityString: public
        snmpVersion: 2c
        metrics:
          - name: hrMemorySize
            oid: iso.3.6.1.2.1.25.2.2.0

[AdrianDsg]

This would resolve #31.

@davidgiga1993 please consider looking into this.

[AdrianDsg]

Also including snmp and netcat in the docker image would be a great idea.

[AdrianDsg]

@davidgiga1993 please consider looking into this

[davidgiga1993]

Also including snmp and netcat in the docker image would be a great idea.

The pollect docker image is supposed to be lightweight, it explicitly does not include all dependencies, nor all required binaries. If you need them you can create your own image.

For simplicity I've rebased this MR in #41 and refactored the config as this did not comply with the pollect config provider as well as added the required documentation to go with it