nixpkgs/nixos/tests/consul.nix
IndeedNotJames c229a6463e
nixos/tests/consul: stop consul cleanly
This should fix the flakyness of the test.

Forcefully killing the consul process can lead to
a broken `/var/lib/consul/node-id` file, which
will prevent consul from starting on that node again.
See https://github.com/hashicorp/consul/issues/3489

So instead of crashing the whole node, which leads to
this corruption from time to time, we kill the
networking instead, preventing any cluster
communication and then cleanly stop consul.
2023-03-22 19:18:34 +01:00

239 lines
8 KiB
Nix

import ./make-test-python.nix ({pkgs, lib, ...}:
let
# Settings for both servers and agents
webUi = true;
retry_interval = "1s";
raft_multiplier = 1;
defaultExtraConfig = {
inherit retry_interval;
performance = {
inherit raft_multiplier;
};
};
allConsensusServerHosts = [
"192.168.1.1"
"192.168.1.2"
"192.168.1.3"
];
allConsensusClientHosts = [
"192.168.2.1"
"192.168.2.2"
];
firewallSettings = {
# See https://www.consul.io/docs/install/ports.html
allowedTCPPorts = [ 8301 8302 8600 8500 8300 ];
allowedUDPPorts = [ 8301 8302 8600 ];
};
client = index: { pkgs, ... }:
let
ip = builtins.elemAt allConsensusClientHosts index;
in
{
environment.systemPackages = [ pkgs.consul ];
networking.interfaces.eth1.ipv4.addresses = pkgs.lib.mkOverride 0 [
{ address = ip; prefixLength = 16; }
];
networking.firewall = firewallSettings;
services.consul = {
enable = true;
inherit webUi;
extraConfig = defaultExtraConfig // {
server = false;
retry_join = allConsensusServerHosts;
bind_addr = ip;
};
};
};
server = index: { pkgs, ... }:
let
numConsensusServers = builtins.length allConsensusServerHosts;
thisConsensusServerHost = builtins.elemAt allConsensusServerHosts index;
ip = thisConsensusServerHost; # since we already use IPs to identify servers
in
{
networking.interfaces.eth1.ipv4.addresses = pkgs.lib.mkOverride 0 [
{ address = ip; prefixLength = 16; }
];
networking.firewall = firewallSettings;
services.consul =
assert builtins.elem thisConsensusServerHost allConsensusServerHosts;
{
enable = true;
inherit webUi;
extraConfig = defaultExtraConfig // {
server = true;
bootstrap_expect = numConsensusServers;
# Tell Consul that we never intend to drop below this many servers.
# Ensures to not permanently lose consensus after temporary loss.
# See https://github.com/hashicorp/consul/issues/8118#issuecomment-645330040
autopilot.min_quorum = numConsensusServers;
retry_join =
# If there's only 1 node in the network, we allow self-join;
# otherwise, the node must not try to join itself, and join only the other servers.
# See https://github.com/hashicorp/consul/issues/2868
if numConsensusServers == 1
then allConsensusServerHosts
else builtins.filter (h: h != thisConsensusServerHost) allConsensusServerHosts;
bind_addr = ip;
};
};
};
in {
name = "consul";
nodes = {
server1 = server 0;
server2 = server 1;
server3 = server 2;
client1 = client 0;
client2 = client 1;
};
testScript = ''
servers = [server1, server2, server3]
machines = [server1, server2, server3, client1, client2]
for m in machines:
m.wait_for_unit("consul.service")
def wait_for_healthy_servers():
# See https://github.com/hashicorp/consul/issues/8118#issuecomment-645330040
# for why the `Voter` column of `list-peers` has that info.
# TODO: The `grep true` relies on the fact that currently in
# the output like
# # consul operator raft list-peers
# Node ID Address State Voter RaftProtocol
# server3 ... 192.168.1.3:8300 leader true 3
# server2 ... 192.168.1.2:8300 follower true 3
# server1 ... 192.168.1.1:8300 follower false 3
# `Voter`is the only boolean column.
# Change this to the more reliable way to be defined by
# https://github.com/hashicorp/consul/issues/8118
# once that ticket is closed.
for m in machines:
m.wait_until_succeeds(
"[ $(consul operator raft list-peers | grep true | wc -l) == 3 ]"
)
def wait_for_all_machines_alive():
"""
Note that Serf-"alive" does not mean "Raft"-healthy;
see `wait_for_healthy_servers()` for that instead.
"""
for m in machines:
m.wait_until_succeeds("[ $(consul members | grep -o alive | wc -l) == 5 ]")
wait_for_healthy_servers()
# Also wait for clients to be alive.
wait_for_all_machines_alive()
client1.succeed("consul kv put testkey 42")
client2.succeed("[ $(consul kv get testkey) == 42 ]")
def rolling_restart_test(proper_rolling_procedure=True):
"""
Tests that the cluster can tolearate failures of any single server,
following the recommended rolling upgrade procedure from
https://www.consul.io/docs/upgrading#standard-upgrades.
Optionally, `proper_rolling_procedure=False` can be given
to wait only for each server to be back `Healthy`, not `Stable`
in the Raft consensus, see Consul setting `ServerStabilizationTime` and
https://github.com/hashicorp/consul/issues/8118#issuecomment-645330040.
"""
for server in servers:
server.block()
server.systemctl("stop consul")
# Make sure the stopped peer is recognized as being down
client1.wait_until_succeeds(
f"[ $(consul members | grep {server.name} | grep -o -E 'failed|left' | wc -l) == 1 ]"
)
# For each client, wait until they have connection again
# using `kv get -recurse` before issuing commands.
client1.wait_until_succeeds("consul kv get -recurse")
client2.wait_until_succeeds("consul kv get -recurse")
# Do some consul actions while one server is down.
client1.succeed("consul kv put testkey 43")
client2.succeed("[ $(consul kv get testkey) == 43 ]")
client2.succeed("consul kv delete testkey")
server.unblock()
server.systemctl("start consul")
if proper_rolling_procedure:
# Wait for recovery.
wait_for_healthy_servers()
else:
# NOT proper rolling upgrade procedure, see above.
wait_for_all_machines_alive()
# Wait for client connections.
client1.wait_until_succeeds("consul kv get -recurse")
client2.wait_until_succeeds("consul kv get -recurse")
# Do some consul actions with server back up.
client1.succeed("consul kv put testkey 44")
client2.succeed("[ $(consul kv get testkey) == 44 ]")
client2.succeed("consul kv delete testkey")
def all_servers_crash_simultaneously_test():
"""
Tests that the cluster will eventually come back after all
servers crash simultaneously.
"""
for server in servers:
server.block()
server.systemctl("stop --no-block consul")
for server in servers:
# --no-block is async, so ensure it has been stopped by now
server.wait_until_fails("systemctl is-active --quiet consul")
server.unblock()
server.systemctl("start consul")
# Wait for recovery.
wait_for_healthy_servers()
# Wait for client connections.
client1.wait_until_succeeds("consul kv get -recurse")
client2.wait_until_succeeds("consul kv get -recurse")
# Do some consul actions with servers back up.
client1.succeed("consul kv put testkey 44")
client2.succeed("[ $(consul kv get testkey) == 44 ]")
client2.succeed("consul kv delete testkey")
# Run the tests.
print("rolling_restart_test()")
rolling_restart_test()
print("all_servers_crash_simultaneously_test()")
all_servers_crash_simultaneously_test()
print("rolling_restart_test(proper_rolling_procedure=False)")
rolling_restart_test(proper_rolling_procedure=False)
'';
})