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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_reboot_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.crash()
# 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")
# Restart crashed machine.
server.start()
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.crash()
for server in servers:
server.start()
# 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_reboot_test()")
rolling_reboot_test()
print("all_servers_crash_simultaneously_test()")
all_servers_crash_simultaneously_test()
print("rolling_reboot_test(proper_rolling_procedure=False)")
rolling_reboot_test(proper_rolling_procedure=False)
'';
})
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