Using pg1-path, as we were doing previously, could lead to WAL being copied to/from unexpected places. PostgreSQL sets the current working directory to PGDATA so we can use that to resolve relative paths.
Three major changes were required to get this working:
1) Provide the path to pgbackrest in the build directory when running outside a container. Tests in a container will continue to install and run against /usr/bin/pgbackrest.
1) Set a per-test lock path so tests don't conflict on the default /tmp/pgbackrest path. Also set a per-test log-path while we are at it.
2) Use localhost instead of a custom host for TLS test connections. Tests in containers will continue to update /etc/hosts and use the custom host.
Add infrastructure and update harnessCfgLoad*() to get the correct exe and paths loaded for testing.
Since new tests are required to verify that running outside a container works, also rework the tests in Travis CI to provide coverage within a reasonable amount of time. Mainly, break up to doc tests by VM and run an abbreviated unit test suite on co6 and co7.
If the file is compressible (i.e. not encrypted or already compressed) it can be marked as such in storageNewRead()/storageNewWrite(). If the file is being read from/written to a remote it will be compressed in transit using gzip.
Simplify filter group handling by having the IoRead/IoWrite objects create the filter group automatically. This removes the need for a lot of NULL checking and has a negligible effect on performance since a filter group needs to be created eventually unless the source file is missing.
Allow filters to be created using a VariantList so filter parameters can be passed to the remote.
Not all storage types support paths as a physical thing that must be created/destroyed. Add a feature to determine which drivers use paths and simplify the driver API as much as possible given that knowledge and by implementing as much path logic as possible in the Storage object.
Remove the ignoreMissing parameter from pathSync() since it is not used and makes little sense.
Create a standard list of error messages for the drivers to use and apply them where the code was modified -- there is plenty of work still to be done here.
Remove "File" and "Driver" from object names so they are shorter and easier to keep consistent.
Also remove the "driver" directory so storage implementations are visible directly under "storage".
The function pointer casting used when creating drivers made changing interfaces difficult and led to slightly divergent driver implementations. Unit testing caught production-level errors but there were a lot of small issues and the process was harder than it should have been.
Use void pointers instead so that no casts are required. Introduce the THIS_VOID and THIS() macros to make dealing with void pointers a little safer.
Since we don't want to expose void pointers in header files, driver functions have been removed from the headers and the various driver objects return their interface type. This cuts down on accessor methods and the vast majority of those functions were not being used. Move functions that are still required to .intern.h.
Remove the special "C" crypto functions that were used in libc and instead use the standard interface.
These are more efficient than creating buffers in place when needed.
After replacement discovered that bufNewStr() and BufNewZ() were not being used in the core code so removed them. This required using the macros in tests which is not the usual pattern.
The prior behavior on a global error (i.e. not file specific) was to write an individual error file for each WAL file being processed. On retry each of these error files would be removed, and if the error was persistent, they would then be recreated. In a busy environment this could mean tens or hundreds of thousands of files.
Another issue was that the error files could not be written until a list of WAL files to process had been generated. This was easy enough for archive-get but archive-push requires more processing and any errors that happened when generating the list would only be reported in the pgBackRest log rather than the PostgreSQL log.
Instead write a global.error file that applies to any WAL file that does not have an explicit ok or error file. This reduces churn and allows more errors to be reported directly to PostgreSQL.
The C code was assuming that the current PostgreSQL version in archive.info/backup.info was the most recent item in the history, but this is not always the case with some stanza-upgrade scenarios. If a cluster is restored from before the upgrade and stanza-upgrade is run again, it will revert db-id to the original history item.
Instead, load db-id from the db section explicitly as the Perl code does.
This did not affect archive-get since it does a reverse scan through the history versions and does not rely on the current version.
This new implementation should behave exactly like the old Perl code with the exception of a few updated log messages.
Remove as much of the Perl code as possible without breaking other commands.
There was a lot of extra boilerplate involved in setting up pipes so that is now automated.
In some cases testing with multiple children is useful so allow that as well.
