Added more info in docs for Vault (#462)

* Added more info in docs for Vault

* Removed misleading info about Vault

docs/VAULT.md

@@ -27,4 +27,36 @@ AWS_SECRET_ACCESS_KEY="[YOUR AWS SECRET ACCESS KEY]" \
 SSH_PRIVATE_KEY=@/vault/file/secrets/jenkins_ssh_key
 ```
 
-Essentially, anything can go into a vault, as long as it's KEY=VALUE formatted. If you work inside a docker container, the above example requires you to have the file `/vault/file/secrets/jenkins_ssh_key` exist inside the docker container.
+Essentially, anything can go into a vault, as long as it's KEY=VALUE formatted. If you work inside a docker container, the above example requires you to have the file `/vault/file/secrets/jenkins_ssh_key` exist inside the docker container.
+
+## Usage 
+
+```bash
+$ vault kv get  kv/jenkins/master
+============= Data =============
+Key                        Value
+---                        -----
+operator_pass        doggo
+operator_userid      catto
+```
+and use them in configuration:
+```yaml
+# config truncated
+credentials:
+  system:
+    domainCredentials:
+      - credentials:
+          - usernamePassword:
+              scope: "GLOBAL"
+              id: "${operator_userid}"
+              username: "${operator_userid}"
+              password: "${operator_pass}"
+              description: "i am catto with doggo pass"
+```
+
+## Current limitations
+
+Due to dependency on BetterCloud's [vault-java-driver](https://github.com/BetterCloud/vault-java-driver), Vault's change default KV backend from v1 to v2 and HTTP endpoints change it's currently unable to use Vault's KV v2 secret store. ([see issue on BetterCloud project](https://github.com/BetterCloud/vault-java-driver/issues/114))
+Be aware which version you use as default dev Vault server, starting from 0.10, it uses KV v2. [See docs](https://www.vaultproject.io/docs/secrets/kv/kv-v2.html)
+
+

plugin/src/main/java/io/jenkins/plugins/casc/impl/secrets/VaultSecretSource.java

@@ -18,8 +18,6 @@ import java.util.logging.Level;
 import java.util.logging.Logger;
 
 /**
- * Replaces secrets from .yaml files with the ${vault.*} prefix
- *
  * Requires either CASC_VAULT_USER and CASC_VAULT_PW, or CASC_VAULT_TOKEN environment variables set
  * alongside with CASC_VAULT_PATH and CASC_VAULT_URL
  */