Hashicorp Vault: "Code: 400. Errors" Error Message - hashicorp-vault

Question

When using Vault Agent with a secret ID file, I received the following error message:
$ ./vault agent --config auth_config.hcl
==> Vault server started! Log data will stream in below:
==> Vault agent configuration:
Api Address 1: http://127.0.0.1:8300
Cgo: disabled
Log Level: info
Version: Vault v1.3.0
2020-02-04T14:08:28.352-0800 [INFO] auth.handler: starting auth handler
2020-02-04T14:08:28.352-0800 [INFO] auth.handler: authenticating
2020-02-04T14:08:28.352-0800 [INFO] sink.server: starting sink server
2020-02-04T14:08:28.352-0800 [INFO] template.server: starting template server
2020-02-04T14:08:28.352-0800 [INFO] template.server: no templates found
2020-02-04T14:08:28.352-0800 [INFO] template.server: template server stopped
2020-02-04T14:08:28.354-0800 [ERROR] auth.handler: error authenticating: error="Error making API request.
URL: PUT http://127.0.0.1:8200/v1/auth/approle/login
Code: 400. Errors:
* invalid secret id" backoff=2.190384035
The command I executed was:
vault agent --config auth_config.hcl
The contents of my auth_config.hcl file is:
vault {
address = "http://127.0.0.1:8200"
}
auto_auth {
method "approle" {
config {
role_id_file_path = "./role_id"
secret_id_file_path = "./secret_id"
remove_secret_id_file_after_reading = false
}
}
}
cache {
use_auto_auth_token = true
}
listener "tcp" {
address = "127.0.0.1:8300"
tls_disable = true
}
My secret ID was generated using the following command:
vault write -f auth/approle/role/payments_service/secret-id -format=json | sed -E -n 's/.*"secret_id": "([^"]*).*/\1/p' > secret_id
Why is this error happening?

Answer 1

I found that the usual reason that this happens because the secret ID file wasn't generated correctly in the first place. See this Github thread for example. Unfortunately, in my case, the file was generated. The file secret_id referenced in auth_config.hcl contained the secret ID.
In my case, the problem was that after I generated the file, secret_id, I executed the command vault write -f auth/approle/role/payments_service/secret-id a second time. This new command didn't write over the original file with a new secret ID. The consequence of this new command was that it respawned a new secret ID which invalidated the previous secret ID which was written to the secret_id file.
My solution was to rerun the command that wrote the secret ID to the file, secret_id, and then immediately run the Vault Agent. Problem solved.

Answer 2

My case was because the app (kes) was trying to use http, instead of https, to connect to vault, while the tls was enabled both in vault and the app (kes). Once it was updated, the app could connect to vault without any issue
Error: failed to connect to Vault: Error making API request.
URL: PUT http://vault.vault:8200/v1/auth/approle/login
Code: 400. Raw Message:
Client sent an HTTP request to an HTTPS server.
Authenticating to Hashicorp Vault 'http://vault.vault:8200'