[pbs-devel] [PATCH proxmox v5 1/1] email: add small function to send multi-part emails using sendmail

[Stoiko Ivanov]

Thanks for the improvements!

I did some rough tests - and LGTM:

Reviewed-By: Stoiko Ivanov <s.ivanov at proxmox.com>
Tested-By: Stoiko Ivanov <s.ivanov at proxmox.com>

On Thu, 27 Aug 2020 12:00:36 +0200
Hannes Laimer <h.laimer at proxmox.com> wrote:

> Signed-off-by: Hannes Laimer <h.laimer at proxmox.com>
> ---
>  proxmox/src/tools/email.rs | 152 +++++++++++++++++++++++++++++++++++++
>  proxmox/src/tools/mod.rs   |   1 +
>  2 files changed, 153 insertions(+)
>  create mode 100644 proxmox/src/tools/email.rs
> 
> diff --git a/proxmox/src/tools/email.rs b/proxmox/src/tools/email.rs
> new file mode 100644
> index 0000000..04a5dc0
> --- /dev/null
> +++ b/proxmox/src/tools/email.rs
> @@ -0,0 +1,152 @@
> +//! Email related utilities.
> +
> +use std::process::{Command, Stdio};
> +use anyhow::{bail, Error};
> +use std::io::Write;
> +use chrono::{DateTime, Local};
> +use crate::tools::time::time;
> +
> +
> +/// Sends multi-part mail with text and/or html to a list of recipients
> +///
> +/// ``sendmail`` is used for sending the mail.
> +pub fn sendmail(mailto: Vec<&str>,
> +                subject: &str,
> +                text: Option<&str>,
> +                html: Option<&str>,
> +                mailfrom: Option<&str>,
> +                author: Option<&str>) -> Result<(), Error> {
> +    let mail_regex = regex::Regex::new(r"^[a-zA-Z\.0-9-]+@[a-zA-Z\.0-9-]+$").unwrap();
> +
> +    if mailto.is_empty() {
> +        bail!("At least one recipient has to be specified!")
> +    }
> +
> +    for recipient in &mailto {
> +        if !mail_regex.is_match(recipient) {
> +            bail!("'{}' is not a valid email address", recipient)
> +        }
> +    }
> +
> +    let mailfrom = mailfrom.unwrap_or("root");
> +    if !mailfrom.eq("root") && !mail_regex.is_match(mailfrom) {
> +        bail!("'{}' is not a valid email address", mailfrom)
> +    }
> +
> +    let recipients = mailto.join(",");
> +    let author = author.unwrap_or("Proxmox Backup Server");
> +
> +    let now: DateTime<Local> = Local::now();
> +
> +    let mut sendmail_process = match Command::new("/usr/sbin/sendmail")
> +        .arg("-B")
> +        .arg("8BITMIME")
> +        .arg("-f")
> +        .arg(mailfrom)
> +        .arg("--")
> +        .arg(&recipients)
> +        .stdin(Stdio::piped())
> +        .spawn() {
> +        Err(err) => bail!("could not spawn sendmail process: {}", err),
> +        Ok(process) => process
> +    };
> +    let mut is_multipart = false;
> +    if let (Some(_), Some(_)) = (text, html) {
> +        is_multipart = true;
> +    }
> +
> +    let mut body = String::new();
> +    let boundary = format!("----_=_NextPart_001_{}", time()?);
> +    if is_multipart {
> +        body.push_str("Content-Type: multipart/alternative;\n");
> +        body.push_str(&format!("\tboundary=\"{}\"\n", boundary));
> +        body.push_str("MIME-Version: 1.0\n");
> +    } else if !subject.is_ascii() {
> +        body.push_str("MIME-Version: 1.0\n");
> +    }
> +    if !subject.is_ascii() {
> +        body.push_str(&format!("Subject: =?utf-8?B?{}?=\n", base64::encode(subject)));
> +    } else {
> +        body.push_str(&format!("Subject: {}\n", subject));
> +    }
> +    body.push_str(&format!("From: {} <{}>\n", author, mailfrom));
> +    body.push_str(&format!("To: {}\n", &recipients));
> +    body.push_str(&format!("Date: {}\n", now.to_rfc2822()));
> +    if is_multipart {
> +        body.push('\n');
> +        body.push_str("This is a multi-part message in MIME format.\n");
> +        body.push_str(&format!("\n--{}\n", boundary));
> +    }
> +    if let Some(text) = text {
> +        body.push_str("Content-Type: text/plain;\n");
> +        body.push_str("\tcharset=\"UTF-8\"\n");
> +        body.push_str("Content-Transfer-Encoding: 8bit\n");
> +        body.push('\n');
> +        body.push_str(text);
> +        if is_multipart {
> +            body.push_str(&format!("\n--{}\n", boundary));
> +        }
> +    }
> +    if let Some(html) = html {
> +        body.push_str("Content-Type: text/html;\n");
> +        body.push_str("\tcharset=\"UTF-8\"\n");
> +        body.push_str("Content-Transfer-Encoding: 8bit\n");
> +        body.push('\n');
> +        body.push_str(html);
> +        if is_multipart {
> +            body.push_str(&format!("\n--{}--", boundary));
> +        }
> +    }
> +
> +    if let Err(err) = sendmail_process.stdin.take().unwrap().write_all(body.as_bytes()) {
> +        bail!("couldn't write to sendmail stdin: {}", err)
> +    };
> +
> +    // wait() closes stdin of the child
> +    if let Err(err) = sendmail_process.wait() {
> +        bail!("sendmail did not exit successfully: {}", err)
> +    }
> +
> +    Ok(())
> +}
> +
> +#[cfg(test)]
> +mod test {
> +    use crate::tools::email::sendmail;
> +
> +    #[test]
> +    fn test1() {
> +        let result = sendmail(
> +            vec!["somenotvalidemail!", "somealmostvalid email"],
> +            "Subject1",
> +            Some("TEXT"),
> +            Some("<b>HTML</b>"),
> +            Some("bim at bam.bum"),
> +            Some("test1"));
> +        assert!(result.is_err());
> +    }
> +
> +    #[test]
> +    fn test2() {
> +        let result = sendmail(
> +            vec![],
> +            "Subject2",
> +            None,
> +            Some("<b>HTML</b>"),
> +            None,
> +            Some("test1"));
> +        assert!(result.is_err());
> +    }
> +
> +    #[test]
> +    fn test3() {
> +        let result = sendmail(
> +            vec!["a at b.c"],
> +            "Subject3",
> +            None,
> +            Some("<b>HTML</b>"),
> +            Some("notv at lid.com!"),
> +            Some("test1"));
> +        assert!(result.is_err());
> +    }
> +}
> \ No newline at end of file
> diff --git a/proxmox/src/tools/mod.rs b/proxmox/src/tools/mod.rs
> index 721e5d1..df6c429 100644
> --- a/proxmox/src/tools/mod.rs
> +++ b/proxmox/src/tools/mod.rs
> @@ -10,6 +10,7 @@ pub mod borrow;
>  pub mod byte_buffer;
>  pub mod common_regex;
>  pub mod constnamemap;
> +pub mod email;
>  pub mod fd;
>  pub mod fs;
>  pub mod io;