podman logs: read journald with passthrough #17502
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I missed a TrimNewline call while refactoring, should be working correctly now. |
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@giuseppe PTAL |
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This seems to work pretty nicely, the only problem compared to regular logging is that systemd does not separate stdout/err: systemd/systemd#5019 /hold |
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[APPROVALNOTIFIER] This PR is APPROVED This pull-request has been approved by: giuseppe, Luap99 The full list of commands accepted by this bot can be found here. The pull request process is described here
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The passthrough driver is designed for use in systemd units. By default we can expect systemd to log the output on journald unless the unit sets differen StandardOutput/StandardError settings. At the moment podman logs just errors out when the passthrough driver is used. With this change we will read the journald for the unit messages. The logic is actually very similar to the existing one, we just need to change the filter. We now filter by SYSTEMD_UNIT wich equals to the contianer cgroup, this allows us the actually filter on a per contianer basis even when multiple contianers are started in the same unit, i.e. via [email protected]. The only difference a user will see is that journald will merge stdout/err into one stream so we loose the separation there. Signed-off-by: Paul Holzinger <[email protected]>
It makes little sense to create a log line string from the entry just to parse it again into a LogLine. We have the typed fields so we can assemble the logLine direclty, this makes things simpler and more efficient. Also entries from the passthrough driver do not use the CONTAINER_ID_FULL field, instead we can just access c.ID() directly. Signed-off-by: Paul Holzinger <[email protected]>
When run with --cgroups=split mode (e.g. quadlet) we do not use the a separate cgroup for the container and just run in the unit cgroup. When we filter logs we thus must match the unit name. Added a small test to the quadlet test to make sure it will work. Signed-off-by: Paul Holzinger <[email protected]>
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The passthrough driver is designed for use in systemd units. By default
we can expect systemd to log the output on journald unless the unit sets
differen StandardOutput/StandardError settings.
At the moment podman logs just errors out when the passthrough driver is
used. With this change we will read the journald for the unit messages.
The logic is actually very similar to the existing one, we just need to
change the filter. We now filter by SYSTEMD_UNIT wich equals to the
contianer cgroup, this allows us the actually filter on a per contianer
basis even when multiple contianers are started in the same unit, i.e.
via [email protected].
The only difference a user will see is that journald will merge
stdout/err into one stream so we loose the separation there.
journald logs: simplify entry parsing
It makes little sense to create a log line string from the entry just to
parse it again into a LogLine. We have the typed fields so we can
assemble the logLine direclty, this makes things simpler and more
efficient.
Also entries from the passthrough driver do not use the CONTAINER_ID_FULL
field, instead we can just access c.ID() directly.
Does this PR introduce a user-facing change?