Shellcheck fixes

5dbc74af · R. van Elst · 3374cdd8 · 3374cdd8 · 5dbc74af · 5dbc74af
Commit 5dbc74af authored Dec 27, 2020 by R. van Elst
--- a/screenshots/fail.png
+++ b/screenshots/fail.png
--- a/srvmon.sh
+++ b/srvmon.sh
@@ -28,33 +28,46 @@ statuscode[gist.github.com]=302
 # How many curl checks to run at the same time
 maxConcurrentCurls=12

-# Start of script. Do not edit below
-
+# Max timeout of a check in seconds
+defaultTimeOut=10

-# We're writing the status code to a file, reading that later on. Why? 
-# Because an array cannot be filled via a subprocess (curl ... &).
+# Start of script. Do not edit below
+# Exit immediately if a command exits with a non-zero status.
 set -e
+# patterns which match no files expand to a null string, otherwise later on we'd have *.status as a file...
 shopt -s nullglob

+# start of the function definitions
+
 # This function allows the script to execute all the curl calls in paralell. 
 # Otherwise, if one would timeout or take long, the rest after that would be
-# slower.
+# slower. We're writing the status code to a file, reading that later on. Why? 
+# Because an array cannot be filled via a subprocess (curl ... &)
 doRequest() {
  name="${1}"
  url="${2}"
-  checkStartTimeMs=$(date +%s%3N) # epoch in microseconds, but stripped so it's milliseconds
-  checkStatusCode=$(curl --max-time 10 --silent --show-error --insecure --output /dev/null --write-out "%{http_code}" "$url" 2>${tempfolder}/FAIL/${name}.error)
-  checkEndTimeMs=$(date +%s%3N)
-  timeCheckTook=$((checkEndTimeMs-checkStartTimeMs))
-  
-  if [[ ! -z ${statuscode[${name}]} ]]; then
-    defaultExpectedStatusCode=${statuscode[${name}]}
+  checkStartTimeMs="$(date +%s%3N)" # epoch in microseconds, but last chars stripped so it's milliseconds
+  set +e # curl errors don't count for early exit, turn off e
+  checkStatusCode="$(curl --max-time "${defaultTimeOut}" --silent --show-error --insecure --output /dev/null --write-out "%{http_code}" "$url" --stderr "${tempfolder}/FAIL/${name}.error")"
+  set -e # turn e back on
+  checkEndTimeMs="$(date +%s%3N)"
+  timeCheckTook="$((checkEndTimeMs-checkStartTimeMs))"
+
+  expectedStatusCode=${defaultExpectedStatusCode}
+  # check if there is a specific status code for this domain
+  if [[ -n "${statuscode[${name}]}" ]]; then
+    expectedStatusCode="${statuscode[${name}]}"
  fi 

-  if [[ ${defaultExpectedStatusCode} -eq ${checkStatusCode} ]]; then
-    echo ${timeCheckTook} > ${tempfolder}/OK/${name}.duration
+  if [[ ${expectedStatusCode} -eq ${checkStatusCode} ]]; then
+    echo "${timeCheckTook}" > "${tempfolder}/OK/${name}.duration"
  else
-    echo ${checkStatusCode} > ${tempfolder}/FAIL/${name}.status
+    echo "${checkStatusCode}" > "${tempfolder}/FAIL/${name}.status"
+  fi
+
+  # if the error file is empty, remove it.
+  if [[ ! -s "${tempfolder}/FAIL/${name}.error" ]]; then
+    rm "${tempfolder}/FAIL/${name}.error" 
  fi
 }

@@ -62,7 +75,7 @@ writeOkayChecks() {
  echo "</div></div>"
  echo "<div class=row><div class=col>"
  echo "<h2>Checks</h2>"
-  pushd "${tempfolder}/OK" 2>&1 >/dev/null
+  pushd "${tempfolder}/OK" >/dev/null 2>&1
  okFiles=(*.duration)
  okCount=${#okFiles[@]}
  if [[ okCount -gt 0 ]]; then
@@ -70,20 +83,20 @@ writeOkayChecks() {
      if [[ -r $filename ]]; then
        value="$(cat $filename)"
        filenameWithoutExt=${filename%.*}
-        echo -n '<a href="#" class="btn btn-success disabled" tabindex="-1" role="button" aria-disabled="true" style="margin-top: 10px; padding: 10px;">'
-        echo -n "${filenameWithoutExt}"
-        echo -n "<font color=LightGray> ("
-        echo -n ${value}
-        echo -n " ms)</font>"
-        echo -n "</a> &nbsp;"
+        echo '<a href="#" class="btn btn-success disabled" tabindex="-1" role="button" aria-disabled="true" style="margin-top: 10px; padding: 10px;">'
+        echo "${filenameWithoutExt}"
+        echo "<font color=LightGray> ("
+        echo ${value}
+        echo " ms)</font>"
+        echo "</a> &nbsp;"
      fi
    done
  fi
-  popd 2>&1 >/dev/null
+  popd >/dev/null 2>&1
 }

 writeFailedChecks() {
-  pushd "${tempfolder}/FAIL" 2>&1 >/dev/null
+  pushd "${tempfolder}/FAIL" >/dev/null 2>&1
  failFiles=(*.status)
  failCount=${#failFiles[@]}
  if [[ failCount -gt 0 ]]; then
@@ -99,19 +112,23 @@ writeFailedChecks() {
    for filename in "${failFiles[@]}"; do
      if [[ -r $filename ]]; then
        filenameWithoutExt=${filename%.*}
-        error="$(cat ${filenameWithoutExt}.error)"
+        if [[ -r "${filenameWithoutExt}.error" ]]; then
+          curlError="$(cat "${filenameWithoutExt}.error" 2>/dev/null)"
+        else
+          curlError="Status code does not match expected code"
+        fi
        status="$(cat ${filename})"
-        echo -n "<tr class='table-danger'><td>"
-        echo -n "${filenameWithoutExt}"
-        echo -n "</td><td>"
-        echo -n "${status} / "
-        if [[ -z ${statuscode[${filenameWithoutExt}]} ]]; then
-          echo -n "200"
+        echo "<tr class='table-danger'><td>"
+        echo "${filenameWithoutExt}"
+        echo "</td><td>"
+        echo "${status} / "
+        if [[ -z "${statuscode[${filenameWithoutExt}]}" ]]; then
+          echo "${defaultExpectedStatusCode}"
        else
-          echo -n "${statuscode[${filenameWithoutExt}]}"
+          echo "${statuscode[${filenameWithoutExt}]}"
        fi
-        echo -n "</td><td>"
-        echo -n "${error}"
+        echo "</td><td>"
+        echo "${curlError}"
        echo "</td></tr>"
      fi
    done
@@ -121,11 +138,11 @@ writeFailedChecks() {
    echo "All is well, all services are up."
    echo "</div>"
  fi
-  popd 2>&1 >/dev/null
+  popd >/dev/null 2>&1
 }

 cleanupFailedCheckFiles() {
-  pushd "${tempfolder}/FAIL" 2>&1 >/dev/null
+  pushd "${tempfolder}/FAIL" >/dev/null 2>&1
  errorFiles=(*.error)
  errorCount=${#errorFiles[@]}
  for filename in "${errorFiles[@]}"; do
@@ -141,12 +158,12 @@ cleanupFailedCheckFiles() {
      rm "${filename}"
    fi
  done
-  popd 2>&1 >/dev/null
+  popd >/dev/null 2>&1
  rmdir "${tempfolder}/FAIL"
 }

 cleanupOKCheckFiles() {
-  pushd "${tempfolder}/OK" 2>&1 >/dev/null
+  pushd "${tempfolder}/OK" >/dev/null 2>&1
  okFiles=(*.duration)
  okCount=${#okFiles[@]}
  for filename in "${okFiles[@]}"; do
@@ -154,10 +171,40 @@ cleanupOKCheckFiles() {
      rm "${filename}"
    fi
  done
-  popd 2>&1 >/dev/null
+  popd >/dev/null 2>&1
  rmdir "${tempfolder}/OK"
 }

+
+writeHeader() {
+  echo '<!doctype html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">'
+  echo '<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@4.5.3/dist/css/bootstrap.min.css" integrity="sha384-TX8t27EcRE3e/ihU7zmQxVncDAy5uIKz4rEkgIXeMed4M0jlfIDPvg6uqKI2xXr2" crossorigin="anonymous">'
+  echo "<title>Monitoring</title>"
+  echo "</head><body>"
+  echo "<div class=container><div class=row><div class=col>"
+  echo "<h1>Monitoring</h1>"
+  echo "</div></div>"
+  echo "<div class=row><div class=col>"
+}
+
+writeFooter() {
+  echo "</div></div>"
+  echo "<div class=row><div class=col>"
+  echo "<h2>Info</h2>"
+  echo "<p>Last check: "
+  date
+
+  echo "<br>Total duration: ${runtime} ms"
+  echo "<br>Monitoring script by <a href='https://raymii.org/'>Remy van Elst</a>. License: GNU AGPLv3. "
+  echo "<a href='https://github.com/raymiiorg/bash-http-monitoring'>Source code</a>"
+  echo "</p>"
+  echo "</div></div></div>"
+  echo "</body></html>"
+}
+
+
+# script start 
+
 # Total script duration timer
 start=$(date +%s%3N)

@@ -168,7 +215,7 @@ tempfolder=${tmpdir:-/tmp/statusmon/}
 mkdir -p "${tempfolder}/OK" || exit 1
 mkdir -p "${tempfolder}/FAIL" || exit 1

-pushd "${tempfolder}" 2>&1 >/dev/null
+pushd "${tempfolder}" >/dev/null 2>&1

 # Do the checks parallel
 for key in "${!urls[@]}"
@@ -181,20 +228,10 @@ do
 done
 wait 

-# Header
-
-echo '<!doctype html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">'
-echo '<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@4.5.3/dist/css/bootstrap.min.css" integrity="sha384-TX8t27EcRE3e/ihU7zmQxVncDAy5uIKz4rEkgIXeMed4M0jlfIDPvg6uqKI2xXr2" crossorigin="anonymous">'
-
-echo "<title>Monitoring</title>"
-echo "</head><body>"
-echo "<div class=container><div class=row><div class=col>"
-echo "<h1>Monitoring</h1>"
-echo "</div></div>"
-echo "<div class=row><div class=col>"
+writeHeader

 # Failed checks, if any, go on top
-writeFailedChecks;
+writeFailedChecks

 # Okay checks go below the failed checks
 writeOkayChecks
@@ -203,25 +240,12 @@ writeOkayChecks
 cleanupFailedCheckFiles
 cleanupOKCheckFiles

-# Footer
-
-echo "</div></div>"
-echo "<div class=row><div class=col>"
-echo "<h2>Info</h2>"
-echo "<p>Last check: "
-date
-
 # stop the total timer
 end=$(date +%s%3N)
 runtime=$((end-start))
-echo "<br>Total duration: ${runtime} ms"

-echo "<br>Monitoring script by <a href='https://raymii.org/'>Remy van Elst</a>. License: GNU AGPLv3. "
-echo "<a href='https://github.com/raymiiorg/bash-http-monitoring'>Source code</a>"
-echo "</p>"
-echo "</div></div></div>"
-echo "</body></html>"
+writeFooter

-popd 2>&1 >/dev/null
+popd >/dev/null 2>&1

 rmdir "${tempfolder}"
\ No newline at end of file