Adds 3 resources that will properly setup the RBAC:
1. service account, which is also assigned to the pods of the cluster, so that they use those particular permissions
2. a role, which holds only the necessary permissions that patroni members need to interact with k8s cluster
3. a rolebinding, which connects two two former things together to use.
The role and rolebinding was created using this tool https://github.com/liggitt/audit2rbac which looks at [audit logs](https://kubernetes.io/docs/tasks/debug-application-cluster/audit/#advanced-audit) provided by the api server.
Output exception trace to the logs when http status code == 403, something is wrong with permissions.
When http status code == 409 -- such error could be ignored, because object probably was created or updated by another process.
For all other http status codes it will also produce stack traces.
I hope it will help to debug issues similar to the https://github.com/zalando/patroni/issues/606
It is very easy to get current timeline on the master by executing
```sql
SELECT ('x' || SUBSTR(pg_walfile_name(pg_current_wal_lsn()), 1, 8))::bit(32)::int
```
Unfortunately the same method doesn't work when postgres is_in_recovery. Therefore we will use replication connection for that on the replicas. In order to avoid opening and closing replication connection on every HA loop we will cache the result if its value matches with the timeline of the master.
Also this PR introduces a new key in DCS: `/history`. It will contain a json serialized object with timeline history in a format similar to the usual history files. The differences are:
* Second column is the absolute wal position in bytes, instead of LSN
* Optionally there might be a fourth column - timestamp, (mtime of history file)
Every iteration of HA loop Patroni needs to call pg_is_in_recovery() and calcualte absolute wal_position. It was doing two separate SELECT statements for that. In case of master it was doing even three queries (wal_position two times).
We will issue one SELECT for every HA loop and cache the results.
* Use scope from config file when listing members
* Add version command to patronictl
* Only delete leader on shutdown when we have the lock to avoid exceptions when leader key does not exist
* Add a timestamp option to list command.
* YAML format for patronictl output
* Fix API request to get version
Make it possible to cancel a running task if you want to reinitialize replica.
There are two possible ways to trigger it:
1. patronictl will ask whether you want to cancel already running task if an attempt to trigger reinitialize has failed
2. if you are using `--force` argument with `patronictl reinit`
This list will be used for initial discovery of etcd cluster members.
If for some reason during work this list of hosts has been exhausted (during work), Patroni will return to initial list.
In addition to that improve ipv6 compatibility by using a special function for splitting host and port.
Fixes https://github.com/zalando/patroni/issues/523
* Use ConfigMaps or Endpoins for leader elections and to keep cluster state
* Label pods with a postgres role
* change behavior of pip install. From now on it will not install all dependencies, you have to specify explicitly DCS you want to use Patroni with: `pip install patroni[etcd,zookeeper,kubernetes]`
* Show information about scheduled failover and maintenance mode when showing list of cluster members. Fixes https://github.com/zalando/patroni/issues/557
* Fix postgres version check functions (postgres 10 and above compatibility) and apply pep8 formatting to the tests.
* Bump some configuration parameters to match with postgres 10 defaults.
* Fix name of contributor in release notes.
Introduces a PostmasterProcess object that identifies a running process via pid and start time.
When pid file is parsed and the correct process identified this object is passed around.
When the process goes away we try to find a new one in case somebody restarted postgres behind our back.
After a crash that doesn't clean up postmaster.pid there could be a new process with the same pid resulting in a false positive for is_running(), which will lead to all kinds of bad behavior.
Fixes#548
It could happen that ttl provided in Patroni configuration is smaller
than minimum supported by Consul. In such case Consul agent fails to
create a new session and responds with 500 Internal Server Error and
http body contains something like: "Invalid Session TTL '3000000000',
must be between [10s=24h0m0s]". Without session Patroni is not able to
create member and leader keys in the Consul KV store and it means that
cluster becomes completely unhealthy.
As a workaround we will handle such exception, adjust ttl to the minimum
possible and retry session creation.
In addition to that make it possible to define custom log format via environment variable `PATRONI_LOGFORMAT`
If list of checks is not specified, Consul will use "serfHealth" in addition to TTL based created by Patroni.
There are some cases when people want to sacrifice fast detection of network partitioning in favor of ability to tolerate network lags.
Fixes https://github.com/zalando/patroni/issues/522
When Patroni does calculation whether it should run pg_rewind or not, it relies on pg_controldata output or gets necessary information from replication connection.
On some cases (when for example postgres running as a master was killed), we can't use pg_controldata output immediately, but trying to start postgres. Such start could fail with the following errror:
```
LOG,00000,"ending log output to stderr",,"Future log output will go to log destination ""csvlog"".",,,,,,,""
LOG,00000,"database system was interrupted; last known up at 2017-09-16 22:35:22 UTC",,,,,,,,,""
LOG,00000,"restored log file ""00000006.history"" from archive",,,,,,,,,""
LOG,00000,"entering standby mode",,,,,,,,,"" 2017-09-18 08:00:39.433 UTC,,,57,,59bf7d26.39,4,,2017-09-18 08:00:38 UTC,,0,LOG,00000,"restored log file ""00000006.history"" from archive",,,,,,,,,""
FATAL,XX000,"requested timeline 6 is not a child of this server's history","Latest checkpoint is at 29/1A000178 on timeline 5, but in the history of the requested timeline, the server forked off from that timeline at 29/1A000140.",,,,,,,,""
LOG,00000,"startup process (PID 57) exited with exit code 1",,,,,,,,,""
LOG,00000,"aborting startup due to startup process failure",,,,,,,,,""
LOG,00000,"database system is shut down",,,,,,,,,""
```
In this case controldata will still have `Database cluster state: in production`
All further attempts to start postgres will fail. Such situation could be fixed only if we start not in recovery. For safety we will do it in a single user mode.
The second problems is: if postgres was running as master, but later we started it and stopped, than pg_controldata will report:
```
Database cluster state: shut down in recovery
Minimum recovery ending location: 0/0
Min recovery ending loc's timeline: 0
```
And this info can't be used for calculations. In this case we should use
`Latest checkpoint location` and `Latest checkpoint's TimeLineID`
A misunderstanding of the ioctl() call interface. If mutable=False then fcntl.ioctl() actually returns the arg buffer back.
This accidentally worked on Python2 because int and str comparison did not return an error.
Error reporting is actually done by raising IOError on Python2 and OSError on Python3.
* Properly handle errors in set_timeout(), have them result in only a warning if watchdog support is not required.
* Improve watchdog device driver name display on Python3
* Eliminate race condition in watchdog feature tests.
The pinged/closed states were not getting reset properly if the checks ran too quickly.
Add explicit reset points in feature test so the check is unambiguous.
