Merge pull request #97 from hashicorp/quick-improv

Fix: Retry downloading consul on install script

modules/install-consul/README.md

@@ -44,7 +44,7 @@ example](https://github.com/hashicorp/terraform-aws-consul/tree/master/examples/
 The `install-consul` script accepts the following arguments:
 
 * `version VERSION`: Install Consul version VERSION. Optional if download-url is provided.
-* `dowload-url URL`: Install the Consul package hosted in this url. Optional if version is provided.
+* `download-url URL`: Install the Consul package hosted in this url. Optional if version is provided.
 * `path DIR`: Install Consul into folder DIR. Optional.
 * `user USER`: The install dirs will be owned by user USER. Optional.
 * `ca-file-path PATH`: Path to a PEM-encoded certificate authority used to encrypt and verify authenticity of client and server connections. Optional.

modules/install-consul/install-consul

@@ -41,30 +41,30 @@ function print_usage {
 }
 
 function log {
-  local readonly level="$1"
-  local readonly message="$2"
-  local readonly timestamp=$(date +"%Y-%m-%d %H:%M:%S")
+  local -r level="$1"
+  local -r message="$2"
+  local -r timestamp=$(date +"%Y-%m-%d %H:%M:%S")
   >&2 echo -e "${timestamp} [${level}] [$SCRIPT_NAME] ${message}"
 }
 
 function log_info {
-  local readonly message="$1"
+  local -r message="$1"
   log "INFO" "$message"
 }
 
 function log_warn {
-  local readonly message="$1"
+  local -r message="$1"
   log "WARN" "$message"
 }
 
 function log_error {
-  local readonly message="$1"
+  local -r message="$1"
   log "ERROR" "$message"
 }
 
 function assert_not_empty {
-  local readonly arg_name="$1"
-  local readonly arg_value="$2"
+  local -r arg_name="$1"
+  local -r arg_value="$2"
 
   if [[ -z "$arg_value" ]]; then
     log_error "The value for '$arg_name' cannot be empty"
@@ -74,10 +74,10 @@ function assert_not_empty {
 }
 
 function assert_either_or {
-  local readonly arg1_name="$1"
-  local readonly arg1_value="$2"
-  local readonly arg2_name="$3"
-  local readonly arg2_value="$4"
+  local -r arg1_name="$1"
+  local -r arg1_value="$2"
+  local -r arg2_name="$3"
+  local -r arg2_value="$4"
 
   if [[ -z "$arg1_value" && -z "$arg2_value" ]]; then
     log_error "Either the value for '$arg1_name' or '$arg2_name' must be passed, both cannot be empty"
@@ -86,6 +86,30 @@ function assert_either_or {
   fi
 }
 
+# A retry function that attempts to run a command a number of times and returns the output
+function retry {
+  local -r cmd="$1"
+  local -r description="$2"
+
+  for i in $(seq 1 5); do
+    log_info "$description"
+
+    # The boolean operations with the exit status are there to temporarily circumvent the "set -e" at the
+    # beginning of this script which exits the script immediatelly for error status while not losing the exit status code
+    output=$(eval "$cmd") && exit_status=0 || exit_status=$?
+    log_info "$output"
+    if [[ $exit_status -eq 0 ]]; then
+      echo "$output"
+      return
+    fi
+    log_warn "$description failed. Will sleep for 10 seconds and try again."
+    sleep 10
+  done;
+
+  log_error "$description failed after 5 attempts."
+  exit $exit_status
+}
+
 # Install steps are based on: http://unix.stackexchange.com/a/291098/215969
 function install_supervisord_debian {
   sudo apt-get install -y supervisor
@@ -166,12 +190,12 @@ function install_dependencies {
 }
 
 function user_exists {
-  local readonly username="$1"
+  local -r username="$1"
   id "$username" >/dev/null 2>&1
 }
 
 function create_consul_user {
-  local readonly username="$1"
+  local -r username="$1"
 
   if $(user_exists "$username"); then
     echo "User $username already exists. Will not create again."
@@ -182,8 +206,8 @@ function create_consul_user {
 }
 
 function create_consul_install_paths {
-  local readonly path="$1"
-  local readonly username="$2"
+  local -r path="$1"
+  local -r username="$2"
 
   log_info "Creating install dirs for Consul at $path"
   sudo mkdir -p "$path"
@@ -198,24 +222,25 @@ function create_consul_install_paths {
 }
 
 function fetch_binary {
-  local readonly version="$1"
+  local -r version="$1"
   local download_url="$2"
 
   if [[ -z "$download_url" && -n "$version" ]];  then
     download_url="https://releases.hashicorp.com/consul/${version}/consul_${version}_linux_amd64.zip"
   fi
 
-  log_info "Downloading Consul to $DOWNLOAD_PACKAGE_PATH"
-  curl -o "$DOWNLOAD_PACKAGE_PATH" "$download_url" --location --silent --fail --show-error
+  retry \
+    "curl -o '$DOWNLOAD_PACKAGE_PATH' '$download_url' --location --silent --fail --show-error" \
+    "Downloading Consul to $DOWNLOAD_PACKAGE_PATH"
 }
 
 function install_binary {
-  local readonly install_path="$1"
-  local readonly username="$2"
+  local -r install_path="$1"
+  local -r username="$2"
 
-  local readonly bin_dir="$install_path/bin"
-  local readonly consul_dest_path="$bin_dir/consul"
-  local readonly run_consul_dest_path="$bin_dir/run-consul"
+  local -r bin_dir="$install_path/bin"
+  local -r consul_dest_path="$bin_dir/consul"
+  local -r run_consul_dest_path="$bin_dir/run-consul"
 
   unzip -d /tmp "$DOWNLOAD_PACKAGE_PATH"
 
@@ -224,7 +249,7 @@ function install_binary {
   sudo chown "$username:$username" "$consul_dest_path"
   sudo chmod a+x "$consul_dest_path"
 
-  local readonly symlink_path="$SYSTEM_BIN_DIR/consul"
+  local -r symlink_path="$SYSTEM_BIN_DIR/consul"
   if [[ -f "$symlink_path" ]]; then
     log_info "Symlink $symlink_path already exists. Will not add again."
   else
@@ -239,14 +264,14 @@ function install_binary {
 }
 
 function install_tls_certificates {
-  local readonly path="$1"
-  local readonly user="$2"
-  local readonly ca_file_path="$3"
-  local readonly cert_file_path="$4"
-  local readonly key_file_path="$5"
-
-  local readonly consul_tls_certs_path="$path/tls"
-  local readonly ca_certs_path="$consul_tls_certs_path/ca"
+  local -r path="$1"
+  local -r user="$2"
+  local -r ca_file_path="$3"
+  local -r cert_file_path="$4"
+  local -r key_file_path="$5"
+
+  local -r consul_tls_certs_path="$path/tls"
+  local -r ca_certs_path="$consul_tls_certs_path/ca"
 
   log_info "Moving TLS certs to $consul_tls_certs_path and $ca_certs_path"
 

modules/install-dnsmasq/install-dnsmasq

@@ -34,30 +34,30 @@ function print_usage {
 }
 
 function log {
-  local readonly level="$1"
-  local readonly message="$2"
-  local readonly timestamp=$(date +"%Y-%m-%d %H:%M:%S")
+  local -r level="$1"
+  local -r message="$2"
+  local -r timestamp=$(date +"%Y-%m-%d %H:%M:%S")
   >&2 echo -e "${timestamp} [${level}] [$SCRIPT_NAME] ${message}"
 }
 
 function log_info {
-  local readonly message="$1"
+  local -r message="$1"
   log "INFO" "$message"
 }
 
 function log_warn {
-  local readonly message="$1"
+  local -r message="$1"
   log "WARN" "$message"
 }
 
 function log_error {
-  local readonly message="$1"
+  local -r message="$1"
   log "ERROR" "$message"
 }
 
 function assert_not_empty {
-  local readonly arg_name="$1"
-  local readonly arg_value="$2"
+  local -r arg_name="$1"
+  local -r arg_value="$2"
 
   if [[ -z "$arg_value" ]]; then
     log_error "The value for '$arg_name' cannot be empty"
@@ -75,7 +75,7 @@ function has_apt_get {
 }
 
 function install_dnsmasq {
-  local readonly consul_ip="$1"
+  local -r consul_ip="$1"
 
   log_info "Installing Dnsmasq"
 
@@ -95,9 +95,9 @@ function install_dnsmasq {
 }
 
 function write_consul_config {
-  local readonly consul_domain="$1"
-  local readonly consul_ip="$2"
-  local readonly consul_port="$3"
+  local -r consul_domain="$1"
+  local -r consul_ip="$2"
+  local -r consul_port="$3"
 
   log_info "Configuring Dnsmasq to forward lookups of the '$consul_domain' domain to $consul_ip:$consul_port in $CONSUL_DNS_MASQ_CONFIG_FILE"
   mkdir -p "$DNS_MASQ_CONFIG_DIR"