func (*environSuite) TestSetConfigAllowsChangingNilAgentNameToEmptyString(c *gc.C) {
oldCfg := getSimpleTestConfig(c, nil)
newCfgTwo := getSimpleTestConfig(c, coretesting.Attrs{"maas-agent-name": ""})
env, err := maas.NewEnviron(oldCfg)
c.Assert(err, gc.IsNil)
err = env.SetConfig(newCfgTwo)
c.Assert(err, gc.IsNil)
c.Check(maas.MAASAgentName(env), gc.Equals, "")
}
func (*environSuite) TestSetConfigRefusesChangingAgentName(c *gc.C) {
oldCfg := getSimpleTestConfig(c, coretesting.Attrs{"maas-agent-name": "agent-one"})
newCfgTwo := getSimpleTestConfig(c, coretesting.Attrs{"maas-agent-name": "agent-two"})
env, err := maas.NewEnviron(oldCfg)
c.Assert(err, gc.IsNil)
// SetConfig() fails, even though both the old and the new config are
// individually valid.
err = env.SetConfig(newCfgTwo)
c.Assert(err, gc.NotNil)
c.Check(err, gc.ErrorMatches, ".*cannot change maas-agent-name.*")
// The old config is still in place. The new config never took effect.
c.Check(maas.MAASAgentName(env), gc.Equals, "agent-one")
// It also refuses to set it to the empty string:
err = env.SetConfig(getSimpleTestConfig(c, coretesting.Attrs{"maas-agent-name": ""}))
c.Check(err, gc.ErrorMatches, ".*cannot change maas-agent-name.*")
// And to nil
err = env.SetConfig(getSimpleTestConfig(c, nil))
c.Check(err, gc.ErrorMatches, ".*cannot change maas-agent-name.*")
}