Blob storage would also benefit from stress
testing and concurrency consistency tests.
But these are things that are probably also
worth adding to go-imap-backend-tests instead.
This is a double-edged sword though as blind panic recovery
can lead to consistency issues in program state.
In particular, halting imapsql update push due to panic can lead
to a deadlock in IMAP code.
Panic in MTA-STS cache maintenance routine can lead to degraded
security.
Now imapsql module does not handle authentication. (it was not doing it so well
anyway)
sql_table module was introduced and used in the default configuration as
a replacement for functionality that was implemented by imapsql before.
Parts of maddyctl code were rewritten to make it work transparently with
any IMAP backend or credentials store.
Closes#212.
Several comments were removed since they are not worth the trouble.
A few minor issues were addressed.
Most of remaining comments got corresponding GitHub issues assigned.
The authentication provider can now provide multiple authorization
identities associated with credentials. Protocols that support that
(e.g. JMAP, SASL) can let the client select the wanted identity.
runtime/trace together with 'go tool trace' provides extremely powerful
tooling for performance (latency) analysis. Since maddy prides itself on
being "optimized for concurrency", it is a good idea to actually live up
to this promise.
Closes#144. No need to reinvent the wheel. The original issue
proposed a solution to use in production to detect "performance
anomalies", it is possible to use runtime/trace in production too, but
the corresponding flag to enable profiler endpoint is hidden behind the
'debugflags' build tag at the moment.
For SMTP code, the basic latency information can be obtained from
regular logs since they include timestamps with millisecond granularity.
After the issue is apparent, it is possible to deploy the server
executable compiled with tracing support and obtain more information
... Also add missing context.Context arguments to smtpconn.C.
It is useful to define background tasks lifetimes more precisely,
especially involving timeouts and other cancellation methods.
On top of that, several tracing facilities are context-based (e.g.
runtime/trace), so it is possible to use them now.
Allow to override DNS resolver address via the -debug.dnsoverride flag
and SMTP port via -debug.smtpport.
All flags are not available unless maddy is built using the 'debugflags'
tag.
There is abstraction 'updates pipe' defined for future use with
configuration involving IMAP data replication (e.g. multiple nodes with
maddy instances + PostgreSQL replicas + S3 bucket for messages).
However, for the case of local SQLite3 DB, limited UDS-based
implementation is provided. It solves the problem of maddyctl not being
able to tell the server about modifications it makes. Alternative to
this approach would be to have server actually perform operations and
maddyctl being a dumb API client, but this requires a lot more complex
IPC interface and will not work when the server is down.
The intention is to keep to repo root clean while the list of packages
is slowly growing.
Additionally, a bunch of small (~30 LoC) files in the repo root is
merged into a single maddy.go file, for the same reason.
Most of the internal code is moved into the internal/ directory. Go
toolchain will make it impossible to import these packages from external
applications.
Some packages are renamed and moved into the pkg/ directory in the root.
According to https://github.com/golang-standards/project-layout this is
the de-facto standard to place "library code that's ok to use by
external applications" in.
To clearly define the purpose of top-level directories, README.md files
are added to each.
