prereq check (mattermost#8151)

Makefile

@@ -300,6 +300,9 @@ update-zoom-plugin: ## Updates Zoom plugin.
 check-licenses: ## Checks license status.
 	./scripts/license-check.sh $(TE_PACKAGES) $(EE_PACKAGES)
 
+check-prereqs: ## Checks prerequisite software status.
+	./scripts/prereq-check.sh
+
 check-style: govet gofmt check-licenses ## Runs govet and gofmt against all packages.
 
 test-te-race: ## Checks for race conditions in the team edition.
@@ -400,7 +403,7 @@ run-client-fullmap: ## Runs the webapp with source code mapping (slower; better
 
 	cd $(BUILD_WEBAPP_DIR) && $(MAKE) run-fullmap
 
-run: run-server run-client ## Runs the server and webapp.
+run: check-prereqs run-server run-client ## Runs the server and webapp.
 
 run-fullmap: run-server run-client-fullmap ## Same as run but with a full sourcemap for client.
 

scripts/prereq-check.sh

@@ -0,0 +1,49 @@
+#!/bin/bash
+check_version()
+{
+    local version=$1 check=$2
+    local winner=$(echo -e "$version\n$check" | sed '/^$/d' | sort -nr | head -1)
+    [[ "$winner" = "$version" ]] && return 0
+    return 1
+}
+
+check_prereq()
+{
+    if [ ! $# == 3 ]; then
+        echo "Unable to determine '$1' version! Ensure that '$1' is in your path and try again." && exit 1
+    fi
+
+    local dependency=$1 required_version=$2 installed_version=$3
+
+    type $dependency >/dev/null 2>&1 || { echo >&2 "Mattermost requires '$dependency' but it doesn't appear to be installed.  Aborting."; exit 1; }
+
+    if check_version $installed_version $required_version; then
+        echo "$dependency minimum requirement met. Required: $required_version, Found: $installed_version"
+    else 
+        echo "WARNING! Mattermost did not find the minimum supported version of '$dependency' installed. Required: $required_version, Found: $installed_version"
+        echo "We highly recommend stopping installation and updating dependencies before continuing"
+        read -p "Enter Y to continue anyway (not recommended)." -n 1 -r
+        echo
+        if [[ ! $REPLY =~ ^[Yy]$ ]]
+        then
+            exit 1
+        fi
+    fi
+}
+
+echo "Checking prerequisites"
+
+REQUIREDNODEVERSION=8.9.0
+REQUIREDNPMVERSION=5.6.0
+REQUIREDGOVERSION=1.9.2
+REQUIREDDOCKERVERSION=17.0
+
+NODEVERSION=$(sed 's/v//' <<< $(node -v))
+NPMVERSION=$(npm -v)
+GOVERSION=$(sed -ne 's/[^0-9]*\(\([0-9]\.\)\{0,4\}[0-9][^.]\).*/\1/p' <<< $(go version))
+DOCKERVERSION=$(docker version --format '{{.Server.Version}}' | sed 's/[a-z-]//g')
+
+check_prereq 'node' $REQUIREDNODEVERSION $NODEVERSION
+check_prereq 'npm' $REQUIREDNPMVERSION $NPMVERSION
+check_prereq 'go' $REQUIREDGOVERSION $GOVERSION
+check_prereq 'docker' $REQUIREDDOCKERVERSION $DOCKERVERSION