etcdctl lease keep-alive & timetolive return success (0) even on failure

[chrislalos]

Bug report criteria

• This bug report is not security related, security issues should be disclosed privately via etcd maintainers.
• This is not a support request or question, support requests or questions should be raised in the etcd discussion forums.
• You have read the etcd bug reporting guidelines.
• Existing open issues along with etcd frequently asked questions have been checked and this is not a duplicate.

What happened?

Calling etcdctl lease keep-alive or timetolive with an expired or non-existent lease id returns a status code of 0. A human-readable error message is printed, but the status code of 0 indicates success to a shell script or any other programmatic invocation.

etcdctl --discovery-srv redacted.domain.dev lease keep-alive 0bad1d0; echo $?
lease 0000000000bad1d0 expired or revoked.
0 

etcdctl --discovery-srv redcated.domain.dev lease timetolive 0bad1d0; echo $?
lease 0000000000bad1d0 already expired
0

This is inconsistent withetcdctl lease revoke, which does return a non-zero status code indicating an error

etcdctl --discovery-srv redcated.domain.dev lease revoke 0bad1d0; echo $?
{"level":"warn","ts":"2025-01-22T16:52:15.600772-0600","logger":"etcd-client","caller":"[email protected]/retry_interceptor.go:63","msg":"retrying of unary invoker failed","target":"etcd-endpoints://0x14000112000/etcd0.dylt.dev.:2379","attempt":0,"error":"rpc error: code = NotFound desc = etcdserver: requested lease not found"}
Error: failed to revoke lease (etcdserver: requested lease not found)
1

What did you expect to happen?

A non-zero status code was expected, to indicate an error.

How can we reproduce it (as minimally and precisely as possible)?

etcdctl --discovery-srv valid.domain.dev lease keep-alive 0bad1d0; echo $?

Anything else we need to know?

timetolive seems like an odd subcommand, as opposed to a get, show, display etc subcommand that would display all suitable information about the lease, including timetolive, which could then be parsed out of output as desired. Perhaps such a subcommand could be introduced, and the new subcommand could return non-zero status for non-existent or expired lease id. That would avoid backward compatiblity issues with changing behavior of existing subcommands.

Etcd version (please run commands below)

$ etcd --version
etcd Version: 3.5.17
Git SHA: 507c0de87
Go Version: go1.23.3
Go OS/Arch: darwin/arm64

$ etcdctl version
etcdctl version: 3.5.17
API version: 3.5

Etcd configuration (command line flags or environment variables)

paste your configuration here

Etcd debug information (please run commands below, feel free to obfuscate the IP address or FQDN in the output)

$ etcdctl member list -w table
+------------------+---------+----------------+----------------------------+-----------------------------+------------+
|        ID        | STATUS  |      NAME      |         PEER ADDRS         |        CLIENT ADDRS         | IS LEARNER |
+------------------+---------+----------------+----------------------------+-----------------------------+------------+
| 8f1bc71338fcf7b7 | started | etcd0.xxxxxxxx.dev | http://etcd0.xxxxxxxx.dev:2380 |   http://x.x.x.x:2379 |      false |
| ab7cc91583cb4bd9 | started | etcd1.xxxxxxxx.dev | http://etcd1.xxxxxxxx.dev:2380 |    http://x.x.x.x:2379 |      false |
| eb0a61a295ac4f04 | started | etcd2.xxxxxxx.dev | http://etcd2.xxxxxxxx.dev:2380 | http://x.x.x.x:2379 |      false |
+------------------+---------+----------------+----------------------------+-----------------------------+------------+


$ etcdctl --endpoints=<member list> endpoint status -w table
+---------------------+------------------+---------+---------+-----------+------------+-----------+------------+--------------------+--------+
|      ENDPOINT       |        ID        | VERSION | DB SIZE | IS LEADER | IS LEARNER | RAFT TERM | RAFT INDEX | RAFT APPLIED INDEX | ERRORS |
+---------------------+------------------+---------+---------+-----------+------------+-----------+------------+--------------------+--------+
| etcd0.xxxxxxxx.dev:2379 | 8f1bc71338fcf7b7 |  3.5.16 |   20 MB |     false |      false |        78 |       1065 |               1065 |        |
| etcd1.xxxxxxxx.dev:2379 | ab7cc91583cb4bd9 |  3.5.16 |   21 MB |     false |      false |        78 |       1065 |               1065 |        |
| etcd2.xxxxxxxx.dev:2379 | eb0a61a295ac4f04 |  3.5.16 |   21 MB |      true |      false |        78 |       1065 |               1065 |        |
+---------------------+------------------+---------+---------+-----------+------------+-----------+------------+--------------------+--------+

Relevant log output