Merge branch 'dev' into 'master'

## Adding truststore/keystore to volume

When deploying at first time, you must copy generated stores to `${SECURITY_VOL_NAME}` volume (at root level). NiFi needs these files at startup.

## Adding external service certificate

In processes like `invokeHttp`, if you wish to access to an external service through HTTPS where a certificate is mandatory, you must add it to NiFi's truststore, using these commands:

```sh

echo -n | openssl s_client -connect external_url:443 | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > /tmp/external_name.crt

keytool -import -alias external_name -file /tmp/external_name.crt -keystore truststore.p12

rm tmp/external_name.crt

```

      traefik-net:

      kafka-net:

      elastic-net:

      postgres-net:

      auth-net:

    volumes:

      - log-vol:${NIFI_HOME}/logs

      labels:

        traefik.frontend.rule: Host:${TRAEFIK_SUBDOMAIN}.${PUBLIC_HOSTNAME}

        traefik.frontend.headers.customRequestHeaders: X-ProxyScheme:https||X-ProxyHost:${TRAEFIK_SUBDOMAIN}.${PUBLIC_HOSTNAME}||X-ProxyPort:443||X-ProxyContextPath:/

        traefik.frontend.redirect.regex: ^(.*://${TRAEFIK_SUBDOMAIN}.${PUBLIC_HOSTNAME})/$$

        traefik.frontend.redirect.replacement: $$1/nifi

        traefik.frontend.redirect.permanent: 'true'

        traefik.backend: nifi

        traefik.protocol: https

        traefik.port: '${NIFI_WEB_HTTPS_PORT}'

    driver: ${ELASTIC_NET_DRIVER:-overlay}

    external: true

  postgres-net:

    name: ${POSTGRES_NET_NAME:-postgres-net}

    driver: ${POSTGRES_NET_DRIVER:-overlay}

    external: true

  auth-net:

    name: ${AUTH_NET_NAME:-auth-net}

    driver: ${AUTH_NET_DRIVER:-overlay}