For registering vault as a service you will have to do the following steps

1. Create a file and write this {"service": {"name": "vault", "tags": ["vault-tag"], "port": 8200}} into it. Name it as vault.json
2. Now, enter this command consul services register vault.json
3. You can now see that vault is registered as a service

Vault will automatically register with consul when using consul as a backend datastorage. If you are using one of the other storage options you have 2 ways to do it:

Vault >1.4

If you have vault 1.4 or newer, you can add the following to the vault config to automatically register the vault service in consul

service_registration "consul" {  address      = "127.0.0.1:8500"}

Vault < 1.4

Assuming you are running vault with https on port 8200

{  "service": {    "checks": [      {        "http": "https://vault1.example.com:8200/v1/sys/health",        "id": "port",        "interval": "10s",        "name": "vault running on port 8200",        "timeout": "1s"      }    ],    "enable_tag_override": false,    "id": "vault",    "meta": {      "meta": "Vault"    },    "name": "vault",    "port": 8200,    "tags": []  }}

Note This won't provide the dynamic tags like active or standby that you get automatically with the other options.https://www.vaultproject.io/docs/configuration/service-registration/consul