initial commit

.gitignore

+awscert
+*.tar.gz
+*.tgz

README

+AWSCERT
+
+A work in progress.
+
+awscert(1) reads an awscert file and prints the certificate and its
+owner if the certificate should be renewed soon. This is currently
+hardcoded to 60 days. 
+
+An awscert file is a newline-delimited list of certificate
+declarations. A certificate declaration starts with the keyword
+"cert", followed by the type of certificate, who it belongs to, and
+finally the date when the certificate was obtained.
+
+Here is the simplest example:
+
+	cert SAA of Oliver valid from 2018-03-01
+
+This is listing the certificate "SAA", short for "Solutions Architect
+Associate", obtained by Oliver on the 1st of March 2018.
+
+Certificates do not have to be cryptic acronyms:
+
+	cert "Developer Associate" of Farid valid from 2018-01-01
+
+Note the double quotes. Values with whitespace need to be quoted:
+
+	cert "DevOps Professional" of "Walter Heck" valid from 2018-02-01
+
+The date format is rigid (for now). It must have the form YYYY-MM-dd.
+
+The command-line usage is very simple. The synopsis:
+
+	usage: awscert [-v] file
+
+From the source repository, build awscert(1). awscert(1) is written
+in Go with no external dependencies, so a standard installation of go
+is fine. Set the test file "certificates" as the argument to
+awscert(1) to run it:
+
+	go build
+	./awscert certificates
+
+Set the flag "v" to add verbosity. awscert(1) will print information
+about each certificate it finds to standard error.
+
+	./awscert -v certificates

awscert.go

+package main
+
+import (
+	"fmt"
+	"flag"
+	"os"
+	"text/scanner"
+	"time"
+	"strings"
+)
+
+const dateLayout string = "2006-01-02"
+const validDuration time.Duration = time.Hour*24*365*2 // 2 years
+const validWarn time.Duration = time.Hour*24*60 // 60 days
+
+func usage() {
+	fmt.Printf("usage: awscert [-v] file\n")
+	os.Exit(1)
+}
+
+type cert struct {
+	Type string
+	Owner string
+	Start time.Time
+}
+
+func (c *cert) Clear() error {
+	c.Type = ""
+	c.Owner = ""
+	c.Start = time.Now()
+	return nil
+}
+
+func main() {
+	if len(os.Args) < 2 {
+		usage()
+	}
+	
+	verbose := flag.Bool("v", false, "")
+	flag.Parse()
+	
+	file, err := os.Open(flag.Args()[0])
+	if err != nil {
+		fmt.Printf("cannot open certificates file: %v\n", err)
+		os.Exit(1)
+	}
+	defer file.Close()
+	
+	var c cert
+	var s scanner.Scanner
+	s.Init(file)
+	s.Filename = file.Name()
+	for tok := s.Scan(); tok != scanner.EOF; tok = s.Scan() {
+		if s.TokenText() == "cert" {
+			if err = c.Clear(); err != nil {
+				fmt.Printf("%v\n", err)
+				os.Exit(1)
+			}
+			s.Scan()
+			c.Type = s.TokenText()
+
+			s.Scan()
+			if s.TokenText() != "of" {
+				fmt.Fprintf(os.Stderr, "%s: syntax error: ", s.Position)
+				fmt.Fprintf(os.Stderr, "unexpected %s, ", s.TokenText())
+				fmt.Fprintf(os.Stderr, "expected of\n")
+				os.Exit(1)
+			}
+			s.Scan()
+			c.Owner = s.TokenText()
+
+			s.Scan()
+			if s.TokenText() != "valid" {
+				fmt.Fprintf(os.Stderr, "%s: syntax error: ", s.Position)
+				fmt.Fprintf(os.Stderr, "unexpected %s, ", s.TokenText())
+				fmt.Fprintf(os.Stderr, "expected valid\n")
+				os.Exit(1)
+			}
+			s.Scan()
+			if s.TokenText() == "from" {
+				var dates []string
+				var datestr string
+				// scan until we hit a newline
+				for s.Peek() != 0x000A {
+					s.Scan()
+					dates = append(dates, s.TokenText())
+				}
+				datestr = strings.Join(dates, "")
+				t, err := time.Parse(dateLayout, datestr)
+				if err != nil {
+					fmt.Fprintf(os.Stderr, "%s: error reading certificate start date: ", s.Position)
+					fmt.Fprintf(os.Stderr, "%v\n", err)
+				} else {
+					c.Start = t
+				}
+			} else {
+				fmt.Fprintf(os.Stderr, "%s: syntax error: ", s.Position)
+				fmt.Fprintf(os.Stderr, "unexpected %s, ", s.TokenText())
+				fmt.Fprintf(os.Stderr, "expected from or to\n")
+				os.Exit(1)
+			}
+
+			expiry := c.Start.Add(validDuration)
+			remaining := expiry.Sub(time.Now())
+			if remaining < validWarn {
+				fmt.Printf("%s needs to review their certs\n", c.Owner)
+			}
+
+			if *verbose {
+				fmt.Fprintf(os.Stderr, "type: %s, owner: %s, ", c.Type, c.Owner)
+				fmt.Fprintf(os.Stderr, "valid from: %s\n", c.Start.String())
+			}
+		}
+	}
+}
+

certificates

+// Good records, including values with quoted whitespace
+cert SA of Oliver valid from 2018-03-01
+cert "Developer Associate" of Farid valid from 2018-01-01
+cert "DevOps professional" of "Walter Heck" valid from 2018-02-01
+
+cert "old AWS cert" of "Oliver Lowe" valid from 2014-01-01
+
+// Bad records
+cert spaces without quotes of Oliver valid from 2018-01-01
+cert badowner of Oliver L valid from 2018-01-01
+cert baddate of Oliver valid from 1st January 2018
+cert baddate2 of Oliver valid from 01/1/2018
+cert baddate3 of Oliver valid from 01-01-2018