Re: [pmg-devel] [PATCH pmg-log-tracker] fix #3657: allow parsing mail.log files

[Thomas Lamprecht <t.lamprecht@proxmox.com>]

On 06.10.21 13:46, Oguz Bektas wrote:
> with an optional "--maillog" parameter, we parse /var/log/mail.log.*
> instead of /var/log/syslog.*

--mail-log

and it may make sense to allow passing a base path to that, that would also allow easier
evaluation like copy of the logs from the production system and run queries on another,
not so important, system.

> 
> Signed-off-by: Oguz Bektas <o.bektas@proxmox.com>
> ---
>  src/main.rs | 49 ++++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 48 insertions(+), 1 deletion(-)
> 
> diff --git a/src/main.rs b/src/main.rs
> index b1d4f8c..13ca63b 100644
> --- a/src/main.rs
> +++ b/src/main.rs
> @@ -39,6 +39,11 @@ fn main() -> Result<(), Error> {
>                  .help("Input file to use instead of /var/log/syslog, or '-' for stdin")
>                  .value_name("INPUTFILE"),
>          )
> +        .arg(
> +            Arg::with_name("maillog")
> +                .long("maillog")
> +                .help("Use /var/log/mail.log* files instead of /var/log/syslog")
> +        )
>          .arg(
>              Arg::with_name("host")
>                  .short("h")
> @@ -1816,7 +1821,11 @@ impl Parser {
>              let filecount = self.count_files_in_time_range();
>              for i in (0..filecount).rev() {
>                  self.current_month = 0;
> -                if let Ok(file) = File::open(LOGFILES[i]) {
> +                let mut target_files = LOGFILES;
> +                if self.options.maillog {
> +                    target_files = MAILLOGFILES;
> +                }

that can be done nicer in rust avoiding mut completely, either use the fact
that if statements can return expressions or the match feature, e.g. the former:

let target_files = if self.options.maillog { MAILLOGFILES } else { LOGFILES };

avoiding mut is nicer for saner programs and allows often better optimizations.

> +                if let Ok(file) = File::open(target_files[i]) {
>                      self.current_file_index = i;
>                      if i > 1 {
>                          let gzdecoder = read::GzDecoder::new(file);
> @@ -1988,6 +1997,8 @@ impl Parser {
>              self.options.inputfile = inputfile.to_string();
>          }
>  
> +        self.options.maillog = args.is_present("maillog");
> +
>          if let Some(start) = args.value_of("start") {
>              if let Ok(res) = time::strptime(&start, "%F %T") {
>                  self.options.start = mkgmtime(&res);
> @@ -2121,6 +2132,7 @@ struct Options {
>      end: libc::time_t,
>      limit: u64,
>      verbose: u32,
> +    maillog: bool,
>      exclude_greylist: bool,
>      exclude_ndr: bool,
>  }
> @@ -2208,6 +2220,41 @@ fn mkgmtime(tm: &time::Tm) -> libc::time_t {
>      res
>  }
>  
> +const MAILLOGFILES: [&str; 32] = [
> +    "/var/log/mail.log",
> +    "/var/log/mail.log.1",
> +    "/var/log/mail.log.2.gz",
> +    "/var/log/mail.log.3.gz",
> +    "/var/log/mail.log.4.gz",
> +    "/var/log/mail.log.5.gz",
> +    "/var/log/mail.log.6.gz",
> +    "/var/log/mail.log.7.gz",
> +    "/var/log/mail.log.8.gz",
> +    "/var/log/mail.log.9.gz",
> +    "/var/log/mail.log.10.gz",
> +    "/var/log/mail.log.11.gz",
> +    "/var/log/mail.log.12.gz",
> +    "/var/log/mail.log.13.gz",
> +    "/var/log/mail.log.14.gz",
> +    "/var/log/mail.log.15.gz",
> +    "/var/log/mail.log.16.gz",
> +    "/var/log/mail.log.17.gz",
> +    "/var/log/mail.log.18.gz",
> +    "/var/log/mail.log.19.gz",
> +    "/var/log/mail.log.20.gz",
> +    "/var/log/mail.log.21.gz",
> +    "/var/log/mail.log.22.gz",
> +    "/var/log/mail.log.23.gz",
> +    "/var/log/mail.log.24.gz",
> +    "/var/log/mail.log.25.gz",
> +    "/var/log/mail.log.26.gz",
> +    "/var/log/mail.log.27.gz",
> +    "/var/log/mail.log.28.gz",
> +    "/var/log/mail.log.29.gz",
> +    "/var/log/mail.log.30.gz",
> +    "/var/log/mail.log.31.gz",
> +];


could be an iterator (good if we want to allow an arbitrary base) or using a
const fn (for a fixed one like here)...

> +
>  const LOGFILES: [&str; 32] = [
>      "/var/log/syslog",
>      "/var/log/syslog.1",
>