Merge updates from public repo

README.md

@@ -1,5 +1,7 @@
 # Manage AWS EC2 SSH access with IAM
 
+> You might want to checkout the newly launched [AWS Systems Manager Session Manager for Shell Access to EC2 Instances](https://aws.amazon.com/de/blogs/aws/new-session-manager/)
+
 Use your IAM user's public SSH key to get access via SSH to an **EC2 instance** running
 * Amazon Linux 2017.09
 * Amazon Linux 2 2017.12
@@ -54,7 +56,7 @@ A picture is worth a thousand words:
    4. Click the **Upload SSH public key** button at the bottom of the page
    5. Paste your public SSH key into the text-area and click the **Upload SSH public key** button to save
 2. Attach the IAM permissions defined in [`iam_ssh_policy.json`](./iam_ssh_policy.json) to the EC2 instances (by creating an IAM role and an Instance Profile)
-3. Install the RPM<sup>1</sup>: `rpm -i https://s3-eu-west-1.amazonaws.com/widdix-aws-ec2-ssh-releases-eu-west-1/aws-ec2-ssh-1.7.0-1.el7.centos.noarch.rpm`
+3. Install the RPM<sup>1</sup>: `rpm -i https://s3-eu-west-1.amazonaws.com/widdix-aws-ec2-ssh-releases-eu-west-1/aws-ec2-ssh-1.9.2-1.el7.centos.noarch.rpm`
 4. The configuration file is placed into `/etc/aws-ec2-ssh.conf`
 5. The RPM creates a crontab file to run import_users.sh every 10 minutes. This file is placed in `/etc/cron.d/import_users`
 
@@ -102,7 +104,7 @@ one or more of the following lines:
 ```
 ASSUMEROLE="IAM-role-arn"                      # IAM Role ARN for multi account. See below for more info
 IAM_AUTHORIZED_GROUPS="GROUPNAMES"             # Comma separated list of IAM groups to import
-SUDOERS_GROUPS="GROUPNAMES"                    # Comma seperated list of IAM groups that should have sudo access
+SUDOERS_GROUPS="GROUPNAMES"                    # Comma seperated list of IAM groups that should have sudo access or `##ALL##` to allow all users
 IAM_AUTHORIZED_GROUPS_TAG="KeyTag"             # Key Tag of EC2 that contains a Comma separated list of IAM groups to import - IAM_AUTHORIZED_GROUPS_TAG will override IAM_AUTHORIZED_GROUPS, you can use only one of them 
 SUDOERS_GROUPS_TAG="KeyTag"                    # Key Tag of EC2 that contains a Comma separated list of IAM groups that should have sudo access - SUDOERS_GROUPS_TAG will override SUDOERS_GROUPS, you can use only one of them
 SUDOERSGROUP="GROUPNAME"                       # Deprecated! IAM group that should have sudo access. Please use SUDOERS_GROUPS as this variable will be removed in future release.

authorized_keys_command.sh

@@ -5,7 +5,7 @@ if [ -z "$1" ]; then
 fi
 
 # check if AWS CLI exists
-if ! which aws; then
+if ! [ -x "$(which aws)" ]; then
     echo "aws executable not found - exiting!"
     exit 1
 fi

aws-ec2-ssh.conf

@@ -6,5 +6,5 @@ ASSUMEROLE=""
 
 # Remove or set to 0 if you are done with configuration
 # To change the interval of the sync change the file
-# /etc/cron.d/aws-ec2-ssh
+# /etc/cron.d/import_users
 DONOTSYNC=0

aws-ec2-ssh.spec

@@ -46,7 +46,7 @@ chmod 0644 ${RPM_BUILD_ROOT}%{_sysconfdir}/cron.d/import_users
 %include install_configure_sshd.sh
 %include install_configure_selinux.sh
 %include install_restart_sshd.sh
-echo "To configure the aws-ec2-ssh package, edit /etc/aws-ec-ssh.conf. No users will be synchronized before you did this."
+echo "To configure the aws-ec2-ssh package, edit /etc/aws-ec2-ssh.conf. No users will be synchronized before you did this."
 
 
 %postun

iam_crossaccount_policy.json

@@ -6,5 +6,9 @@
     "Resource": [
       "arn:aws:iam::<YOUR_USERS_ACCOUNT_ID_HERE>:role/<YOUR_USERS_ACCOUNT_ROLE_NAME_HERE>"
     ]
+  },{
+    "Effect": "Allow",
+    "Action": "ec2:DescribeTags",
+    "Resource": "*"
   }]
 }

import_users.sh

@@ -1,8 +1,12 @@
 #!/bin/bash -e
 
+function log() {
+    /usr/bin/logger -i -p auth.info -t aws-ec2-ssh "$@"
+}
+
 # check if AWS CLI exists
-if ! which aws; then
-    echo "aws executable not found - exiting!"
+if ! [ -x "$(which aws)" ]; then
+    log "aws executable not found - exiting!"
     exit 1
 fi
 
@@ -14,7 +18,7 @@ fi
 
 if [ ${DONOTSYNC} -eq 1 ]
 then
-    echo "Please configure aws-ec2-ssh by editing /etc/aws-ec2-ssh.conf"
+    log "Please configure aws-ec2-ssh by editing /etc/aws-ec2-ssh.conf"
     exit 1
 fi
 
@@ -54,10 +58,6 @@ fi
 INSTANCE_ID=$(curl -s http://169.254.169.254/latest/meta-data/instance-id)
 REGION=$(curl -s http://169.254.169.254/latest/dynamic/instance-identity/document | grep region | awk -F\" '{print $4}')
 
-function log() {
-    /usr/bin/logger -i -p auth.info -t aws-ec2-ssh "$@"
-}
-
 function setup_aws_credentials() {
     local stscredentials
     if [[ ! -z "${ASSUMEROLE}" ]]
@@ -171,7 +171,7 @@ function create_or_update_local_user() {
     # check that username contains only alphanumeric, period (.), underscore (_), and hyphen (-) for a safe eval
     if [[ ! "${username}" =~ ^[0-9a-zA-Z\._\-]{1,32}$ ]]
     then
-        echo "Local user name ${username} contains illegal characters"
+        log "Local user name ${username} contains illegal characters"
         exit 1
     fi
 
@@ -227,16 +227,13 @@ function clean_iam_username() {
 function sync_accounts() {
     if [ -z "${LOCAL_MARKER_GROUP}" ]
     then
-        echo "Please specify a local group to mark imported users. eg iam-synced-users"
+        log "Please specify a local group to mark imported users. eg iam-synced-users"
         exit 1
     fi
 
     # Check if local marker group exists, if not, create it
     /usr/bin/getent group "${LOCAL_MARKER_GROUP}" >/dev/null 2>&1 || /usr/sbin/groupadd "${LOCAL_MARKER_GROUP}"
 
-    # setup the aws credentials if needed
-    setup_aws_credentials
-
     # declare and set some variables
     local iam_users
     local sudo_users
@@ -249,8 +246,23 @@ function sync_accounts() {
     get_iam_groups_from_tag
     get_sudoers_groups_from_tag
 
+    # setup the aws credentials if needed
+    setup_aws_credentials
+
     iam_users=$(get_clean_iam_users | sort | uniq)
+    if [[ -z "${iam_users}" ]]
+    then
+      log "we just got back an empty iam_users user list which is likely caused by an IAM outage!"
+      exit 1
+    fi
+
     sudo_users=$(get_clean_sudoers_users | sort | uniq)
+    if [[ ! -z "${SUDOERS_GROUPS}" ]] && [[ ! "${SUDOERS_GROUPS}" == "##ALL##" ]] && [[ -z "${sudo_users}" ]]
+    then
+      log "we just got back an empty sudo_users user list which is likely caused by an IAM outage!"
+      exit 1
+    fi
+
     local_users=$(get_local_users | sort | uniq)
 
     intersection=$(echo ${local_users} ${iam_users} | tr " " "\n" | sort | uniq -D | uniq)
@@ -262,7 +274,7 @@ function sync_accounts() {
         then
             create_or_update_local_user "${user}" "$sudo_users"
         else
-            echo "Can not import IAM user ${user}. User name is longer than 32 characters."
+            log "Can not import IAM user ${user}. User name is longer than 32 characters."
         fi
     done
 

install.sh

@@ -2,7 +2,7 @@
 
 show_help() {
 cat << EOF
-Usage: ${0##*/} [-hv] [-a ARN] [-i GROUP,GROUP,...] [-l GROUP,GROUP,...] [-s GROUP] [-p PROGRAM] [-u "ARGUMENTS"]
+Usage: ${0##*/} [-hv] [-a ARN] [-i GROUP,GROUP,...] [-l GROUP,GROUP,...] [-s GROUP] [-p PROGRAM] [-u "ARGUMENTS"] [-r RELEASE]
 Install import_users.sh and authorized_key_commands.
 
     -h                 display this help and exit
@@ -23,6 +23,9 @@ Install import_users.sh and authorized_key_commands.
                        Defaults to '/usr/sbin/useradd'
     -u "useradd args"  Specify arguments to use with useradd.
                        Defaults to '--create-home --shell /bin/bash'
+    -r release         Specify a release of aws-ec2-ssh to download from GitHub. This argument is
+                       passed to \`git clone -b\` and so works with branches and tags.
+                       Defaults to 'master'
 
 
 EOF
@@ -39,8 +42,9 @@ LOCAL_GROUPS=""
 ASSUME_ROLE=""
 USERADD_PROGRAM=""
 USERADD_ARGS=""
+RELEASE="master"
 
-while getopts :hva:i:l:s: opt
+while getopts :hva:i:l:s:p:u:r: opt
 do
     case $opt in
         h)
@@ -68,6 +72,9 @@ do
         u)
             USERADD_ARGS="$OPTARG"
             ;;
+        r)
+            RELEASE="$OPTARG"
+            ;;
         \?)
             echo "Invalid option: -$OPTARG" >&2
             show_help
@@ -88,16 +95,22 @@ export USERADD_PROGRAM
 export USERADD_ARGS
 
 # check if AWS CLI exists
-if ! which aws; then
+if ! [ -x "$(which aws)" ]; then
     echo "aws executable not found - exiting!"
     exit 1
 fi
 
+# check if git exists
+if ! [ -x "$(which git)" ]; then
+    echo "git executable not found - exiting!"
+    exit 1
+fi
+
 tmpdir=$(mktemp -d)
 
 cd "$tmpdir"
 
-git clone -b master https://github.com/widdix/aws-ec2-ssh.git
+git clone -b "$RELEASE" https://github.com/widdix/aws-ec2-ssh.git
 
 cd "$tmpdir/aws-ec2-ssh"
 

install_configure_sshd.sh

@@ -1,17 +1,14 @@
 #!/bin/bash -e
 
-if grep -q '#AuthorizedKeysCommand none' "$SSHD_CONFIG_FILE"; then
-  sed -i "s:#AuthorizedKeysCommand none:AuthorizedKeysCommand ${AUTHORIZED_KEYS_COMMAND_FILE}:g" "$SSHD_CONFIG_FILE"
-else
-  if ! grep -q "AuthorizedKeysCommand ${AUTHORIZED_KEYS_COMMAND_FILE}" "$SSHD_CONFIG_FILE"; then
-    echo "AuthorizedKeysCommand ${AUTHORIZED_KEYS_COMMAND_FILE}" >> "$SSHD_CONFIG_FILE"
-  fi
+# add new line if file does not end with new line
+if [ -n "$(tail -c1 ${SSHD_CONFIG_FILE})" ]; then
+	echo >> ${SSHD_CONFIG_FILE}
 fi
 
-if grep -q '#AuthorizedKeysCommandUser nobody' "$SSHD_CONFIG_FILE"; then
-  sed -i "s:#AuthorizedKeysCommandUser nobody:AuthorizedKeysCommandUser nobody:g" "$SSHD_CONFIG_FILE"
-else
-  if ! grep -q 'AuthorizedKeysCommandUser nobody' "$SSHD_CONFIG_FILE"; then
-    echo "AuthorizedKeysCommandUser nobody" >> "$SSHD_CONFIG_FILE"
-  fi
+if ! grep -q '^AuthorizedKeysCommand /opt/authorized_keys_command.sh' ${SSHD_CONFIG_FILE}; then
+	sed -e '/AuthorizedKeysCommand / s/^#*/#/' -i ${SSHD_CONFIG_FILE}; echo "AuthorizedKeysCommand ${AUTHORIZED_KEYS_COMMAND_FILE}" >> ${SSHD_CONFIG_FILE}
+fi
+
+if ! grep -q '^AuthorizedKeysCommandUser nobody' ${SSHD_CONFIG_FILE}; then
+	sed -e '/AuthorizedKeysCommandUser / s/^#*/#/' -i ${SSHD_CONFIG_FILE}; echo 'AuthorizedKeysCommandUser nobody' >> ${SSHD_CONFIG_FILE}
 fi

showcase-rpm.yaml

@@ -1,4 +1,13 @@
 ---
+# The MIT License (MIT)
+# 
+# Copyright (c) 2016 widdix GmbH
+# 
+# Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+# 
+# The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+# 
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 AWSTemplateFormatVersion: '2010-09-09'
 Description: 'AWS EC2 SSH access with IAM showcase using RPM'
 Parameters:
@@ -35,16 +44,19 @@ Mappings:
     AmazonLinux:
       RegionMap: RegionMapAmazonLinux
       UserData: |
+        trap '/opt/aws/bin/cfn-signal -e 1 --stack=${STACKNAME} --region=${REGION} --resource=Instance' ERR
         /opt/aws/bin/cfn-init --verbose --stack=${STACKNAME} --region=${REGION} --resource=Instance
         /opt/aws/bin/cfn-signal -e 0 --stack=${STACKNAME} --region=${REGION} --resource=Instance
     AmazonLinux2:
       RegionMap: RegionMapAmazonLinux2
       UserData: |
+        trap '/opt/aws/bin/cfn-signal -e 1 --stack=${STACKNAME} --region=${REGION} --resource=Instance' ERR
         /opt/aws/bin/cfn-init --verbose --stack=${STACKNAME} --region=${REGION} --resource=Instance
         /opt/aws/bin/cfn-signal -e 0 --stack=${STACKNAME} --region=${REGION} --resource=Instance
     SUSELinuxEnterpriseServer:
       RegionMap: RegionMapSUSELinuxEnterpriseServer
       UserData: |
+        trap '/usr/bin/cfn-signal -e 1 --stack=${STACKNAME} --region=${REGION} --resource=Instance' ERR
         mkdir aws-cfn-bootstrap-latest
         curl -s -m 60 https://s3.amazonaws.com/cloudformation-examples/aws-cfn-bootstrap-latest.tar.gz | tar xz -C aws-cfn-bootstrap-latest --strip-components 1
         easy_install aws-cfn-bootstrap-latest
@@ -53,6 +65,7 @@ Mappings:
     RHEL:
       RegionMap: RegionMapRHEL
       UserData: |
+        trap '/bin/cfn-signal -e 1 --stack=${STACKNAME} --region=${REGION} --resource=Instance' ERR
         mkdir aws-cfn-bootstrap-latest
         curl -s -m 60 https://s3.amazonaws.com/cloudformation-examples/aws-cfn-bootstrap-latest.tar.gz | tar xz -C aws-cfn-bootstrap-latest --strip-components 1
         easy_install aws-cfn-bootstrap-latest
@@ -61,6 +74,7 @@ Mappings:
     CentOS:
       RegionMap: RegionMapCentOS
       UserData: |
+        trap '/bin/cfn-signal -e 1 --stack=${STACKNAME} --region=${REGION} --resource=Instance' ERR
         mkdir aws-cfn-bootstrap-latest
         curl -s -m 60 https://s3.amazonaws.com/cloudformation-examples/aws-cfn-bootstrap-latest.tar.gz | tar xz -C aws-cfn-bootstrap-latest --strip-components 1
         easy_install aws-cfn-bootstrap-latest
@@ -299,13 +313,19 @@ Resources:
         prepareSUSELinuxEnterpriseServer: {}
         prepareRHEL:
           packages:
-            rpm:
-              epel: 'http://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm'
             yum:
               git: []
-              python2-pip: []
-            python:
-              awscli: []
+              unzip: []
+          commands:
+            a_download:
+              command: 'curl "https://s3.amazonaws.com/aws-cli/awscli-bundle.zip" -o "awscli-bundle.zip"'
+              cwd: '/tmp'
+            b_extract:
+              command: 'unzip awscli-bundle.zip'
+              cwd: '/tmp'
+            c_install:
+              command: './awscli-bundle/install -i /usr/local/aws -b /bin/aws'
+              cwd: '/tmp'
         prepareCentOS:
           packages:
             rpm:
@@ -330,7 +350,6 @@ Resources:
         'Fn::Base64': !Sub
           - |
               #!/bin/bash -ex
-              trap '/opt/aws/bin/cfn-signal -e 1 --stack=${AWS::StackName} --region=${AWS::Region} --resource=Instance' ERR
               export REGION=${AWS::Region}
               export STACKNAME=${AWS::StackName}
               ${UserData}
@@ -348,7 +367,7 @@ Resources:
     CreationPolicy:
       ResourceSignal:
         Count: 1
-        Timeout: PT15M
+        Timeout: PT20M
 Outputs:
   PublicName:
     Description: 'The public name of the EC2 instance.'