Hi Team Wonder if you can advise I am new to golang and Pulu

Question

Hi Team Wonder if you can advise I am new to golang and Pulumi creating multiple EC2 multiple instances with following Code I would like to export publicip ec2name hostname for each ec2 machine in a separate record I am creating a ec2 Instance slice and then exporting their value What would be the best way to get the output in the following format desired output ```Machine 1 hostname Public ip 15 161 152 141 Machine2 hostname Public ip 15 160 154 234``` Current Code ```var nodeList ec2 Instance for i = 1 i lt = args NumberOfNodes i++ vm Instance err = ec2 NewInstance ctx fmt Sprintf machine d i amp ec2 InstanceArgs Tags pulumi StringMap Name pulumi String fmt Sprintf kafka d i InstanceType pulumi String t3 large InstanceType args InstanceType VpcSecurityGroupIds pulumi StringArray vm SecurityGroup ID Ami pulumi String ami 0f8ce9c417115413d UserData userData KeyName deployer KeyName if err = nil panic error creating ec2 instance nodeList = append nodeList vm Instance for k v = range nodeList ctx Export publicIp +strconv Itoa k v PublicIp ctx Export publicHostName +strconv Itoa k v PublicDns ``` Current Outputs ``` publicHostName0 publicHostName1 publicIp0 15 161 152 141 publicIp1 15 160 154 234 ```

bored-table-20691 · Answer

What s the issue with your current code

late-energy-66663 · Answer

Hi < bored table 20691> Currently there is no issue However Each ec2 machine information its Public ip hostname public not coordinating as being on the slice I am looking to output in the following format as our plan is to store each individual Ec2 information in database ```Machine 1 hostname Public ip 15 161 152 141 Machine2 hostname Public ip 15 160 154 234```

bored-table-20691 · Answer

I m not sure I really follow You can choose how you want to export it so it can just be ```ctx Export machine 1 hostname ctx Export machine 1 public ip ctx Export machine 2 hostname ctx Export machine 2 public ip ```

bored-table-20691 · Answer

You can do that in a loop if you want over your values

late-energy-66663 · Answer

I am already looping over the slice using following code Also I want to be more Dynamic way for exporting the value The code I pasted on my first post uses a loop for create multiple Ec2 machine User could create 100 of ec2 machines with one request and we want to capture each machine information I am thinking if I could use map instead of slice to export machine information ``` for k v = range nodeList ctx Export publicIp +strconv Itoa k v PublicIp ctx Export publicHostName +strconv Itoa k v PublicDns ```

late-energy-66663 · Answer

So Idea is to export the value in the following format for each machine and store in nosql db ``` Machine 1 hostname Public ip 15 161 152 141 Machine 2 hostname Public ip 15 161 152 142 ```

bored-table-20691 · Answer

I see In which case your best bet will be to marshal it to a JSON string and export that

late-energy-66663 · Answer

agree any idea how i can export is there any example I can follow Sorry still newbie to golang and pulumi

bored-table-20691 · Answer

This is very much pseudo code but should give you the idea ``` var nodeList ec2 Instance var ips pulumi StringOutput var dns pulumi StringOutput for node = range nodeList ips = append ips node PublicIp dns = append ips node PublicDns jsonOut = pulumi All ips dns ApplyT func args interface string error length = len args 2 var output map string string for idx = range args ip = args idx string dns = args idx+length string output = append output map string string ip ip dns dns outputBytes err = json Marshal output if err = nil return nil err return string outputBytes nil ctx Export machine info jsonOut ```

late-energy-66663 · Answer

Thanks very much < bored table 20691> Much appreciated pray

late-energy-66663 · Answer

Hi < bored table 20691> I have used the above script and getting following error it creates machine but when it want execute above code the I get following error + pulumi pulumi Stack prod prod dev creating + virtual machine ec2 vms creating + aws ec2 KeyPair deployer creating + aws ec2 SecurityGroup web secgrp creating + aws ec2 KeyPair deployer created + aws ec2 SecurityGroup web secgrp created + aws ec2 Instance machine 1 creating + aws ec2 Instance machine 2 creating + aws ec2 Instance machine 3 creating + aws ec2 Instance machine 1 created + aws ec2 Instance machine 2 created + aws ec2 Instance machine 3 created `panic interface conversion interface is pulumi StringOutput not string` `goroutine 160 running `

late-energy-66663 · Answer

Also code does not accept pulumi All ips dns I had to add as pulumi All ips dns

bored-table-20691 · Answer

What s the specific code you ended up running Which line is causing the error

late-energy-66663 · Answer

Hi < bored table 20691> So the code is divided in few sections I am creating the Virtual machine component NewVirtualMachine Then I call this on another function GetDeployVMFunc Then I call deployfunction Virtualmachine Component ```func NewVirtualMachine ctx pulumi Context name string args virtualmachines VirtualMachinesArgs opts pulumi ResourceOption virtualmachines VirtualMachines error vm = amp virtualmachines VirtualMachines err = ctx RegisterComponentResource virtual machine name vm opts if err = nil return nil err stackName = ctx Stack Create a valid webserver security group vm SecurityGroup err = ec2 NewSecurityGroup ctx web secgrp amp ec2 SecurityGroupArgs Ingress ec2 SecurityGroupIngressArray ec2 SecurityGroupIngressArgs Protocol pulumi String tcp Protocol args Protocol FromPort 80 ToPort 80 CidrBlocks pulumi StringArray pulumi String 0 0 0 0 0 if err = nil return nil err userData = pulumi Sprintf ` bin bash echo Hello from stack s gt index html nohup python m SimpleHTTPServer 80 amp ` stackName deployer err = ec2 NewKeyPair ctx deployer amp ec2 KeyPairArgs PublicKey pulumi String ssh rsa key if err = nil return nil err var nodeList ec2 Instance var ips pulumi StringOutput var dns pulumi StringOutput for i = 1 i lt = args NumberOfNodes i++ name = fmt Sprintf Machine d i vm Instance err = ec2 NewInstance ctx name amp ec2 InstanceArgs Tags pulumi StringMap Name pulumi String fmt Sprintf Machine d i InstanceType pulumi String t3 large InstanceType args InstanceType VpcSecurityGroupIds pulumi StringArray vm SecurityGroup ID Ami pulumi String ami 0f8ce9c417115413d UserData userData KeyName deployer KeyName if err = nil panic error creating ec2 instance nodeList = append nodeList vm Instance for node = range nodeList ips = append ips node PublicIp dns = append dns node PublicDns jsonOut = pulumi All ips dns ApplyT func args interface string error length = len args 2 var output map string string for idx = range args ip = args idx string dns = args idx+length string output = append output map string string ip ip dns dns outputBytes err = json Marshal output if err = nil return fmt Sprintf Not able to create json err fmt Println string outputBytes return string outputBytes nil ctx Export machine info jsonOut return vm nil ``` Get Deploy Function ```unc v virtualMachinesService GetDeployVMFunc vm virtualmachines CreateVmReq pulumi RunFunc return func ctx pulumi Context error fmt Println vm Protocol err = NewVirtualMachine ctx ec2 vms amp virtualmachines VirtualMachinesArgs Protocol pulumi String vm Protocol NumberOfNodes vm NumberOfNodes InstanceType pulumi String vm InstanceType if err = nil return err return nil ``` Deploy function ``` set out program for the deployment with the resulting network info w SetProgram VirtualMachinesService GetDeployVMFunc vm fmt Println deploying vm webserver wire up our update to stream progress to stdout stdoutStreamer = optup ProgressStreams os Stdout res err = s Up ctx stdoutStreamer if err = nil fmt Printf Failed to deploy vm stack v n err os Exit 1 time Sleep 60 time Second for key element = range res Outputs fmt Println key key = gt element Value fmt Println Update succeeded ```

late-energy-66663 · Answer

And have the Virtual machine Struct setup like this ```type VirtualMachines struct pulumi ResourceState PublicIP ec2 Eip `pulumi publicip ` NetworkInterface ec2 NetworkInterface VPC ec2 Vpc Instance ec2 Instance `pulumi instance ` Internet gateway ec2 InternetGateway Route ec2 Route GetAvailabilityZones ec2 AvailabilityZoneGroup Subnet ec2 Subnet SecurityGroup ec2 SecurityGroup ```

late-energy-66663 · Answer

I suspect panic is due to the following line ```jsonOut = pulumi All ips dns ApplyT func args interface string error ``` Error `panic interface conversion interface is pulumi StringOutput not string` `goroutine 160 running `

bored-table-20691 · Answer

The goroutine stack will tell you which line specifically is erroring is that the line it says What s the code for the `ApplyT` function

late-energy-66663 · Answer

``` + pulumi pulumi Stack prod prod dev creating + virtual machine ec2 vms creating + aws ec2 KeyPair deployer creating + aws ec2 SecurityGroup web secgrp creating + aws ec2 KeyPair deployer created + aws ec2 SecurityGroup web secgrp created + aws ec2 Instance Machine 1 creating + aws ec2 Instance Machine 2 creating + aws ec2 Instance Machine 3 creating + aws ec2 Instance Machine 2 created + aws ec2 Instance Machine 3 created + aws ec2 Instance Machine 1 created panic interface conversion interface is pulumi StringOutput not string goroutine 213 running 0x2 0x2 0x0 0x0 0x0 0x0 Documents github com services virtual machines go 208 +0x489 reflect Value call 0x2869700 0x2d3f6a8 0x13 0x2cda1e6 0x4 0xc000ec4348 0x1 0x1 0x1010f7b 0xc000081a28 usr local go src reflect value go 476 +0x8e7 reflect Value Call 0x2869700 0x2d3f6a8 0x13 0xc000ec4348 0x1 0x1 0x2749b40 0xc000eba888 0xc000081b90 usr local go src reflect value go 337 +0xb9 0x2 0x2 0xc000ec4330 0x2a6ec0 0x2842ea0 Users go pkg mod github com pulumi pulumi sdk v3 v3 19 0 go pulumi types go 362 +0x7c reflect Value call 0xc000dbc300 0xc000c63b90 0x13 0x2cda1e6 0x4 0xc000081f60 0x2 0x2 0x296c2a0 0x2749b40 usr local go src reflect value go 476 +0x8e7 reflect Value Call 0xc000dbc300 0xc000c63b90 0x13 0xc000d31760 0x2 0x2 0xc000ec4300 0x3 0x3 usr local go src reflect value go 337 +0xb9 0x30297d8 0xc0001b4050 0x3043708 0xc0007fa700 0xc000dbc300 0xc000c63b90 0x13 Users go pkg mod github com pulumi pulumi sdk v3 v3 19 0 go pulumi types go 470 +0x2f1 created by Users go pkg mod github com pulumi pulumi sdk v3 v3 19 0 go pulumi types go 458 +0x1f6 exit status 2```

late-energy-66663 · Answer

Above is the full output

bored-table-20691 · Answer

```Documents github com services virtual machines go 208``` This line which line is it And can you share the full function for `ApplyT`

late-energy-66663 · Answer

so the `virtual machines go` file have all the function I mentioned in the above comments

late-energy-66663 · Answer

let me add again

bored-table-20691 · Answer

Ah sorry I see it now

late-energy-66663 · Answer

```func NewVirtualMachine ctx pulumi Context name string args virtualmachines VirtualMachinesArgs opts pulumi ResourceOption virtualmachines VirtualMachines error vm = amp virtualmachines VirtualMachines err = ctx RegisterComponentResource virtual machine name vm opts if err = nil return nil err stackName = ctx Stack Create a valid webserver security group vm SecurityGroup err = ec2 NewSecurityGroup ctx web secgrp amp ec2 SecurityGroupArgs Ingress ec2 SecurityGroupIngressArray ec2 SecurityGroupIngressArgs Protocol pulumi String tcp Protocol args Protocol FromPort 80 ToPort 80 CidrBlocks pulumi StringArray pulumi String 0 0 0 0 0 if err = nil return nil err userData = pulumi Sprintf ` bin bash echo Hello from stack s gt index html nohup python m SimpleHTTPServer 80 amp ` stackName deployer err = ec2 NewKeyPair ctx deployer amp ec2 KeyPairArgs PublicKey pulumi String ssh rsa key if err = nil return nil err var nodeList ec2 Instance var ips pulumi StringOutput var dns pulumi StringOutput for i = 1 i lt = args NumberOfNodes i++ name = fmt Sprintf Machine d i vm Instance err = ec2 NewInstance ctx name amp ec2 InstanceArgs Tags pulumi StringMap Name pulumi String fmt Sprintf Machine d i InstanceType pulumi String t3 large InstanceType args InstanceType VpcSecurityGroupIds pulumi StringArray vm SecurityGroup ID Ami pulumi String ami 0f8ce9c417115413d UserData userData KeyName deployer KeyName if err = nil panic error creating ec2 instance nodeList = append nodeList vm Instance for node = range nodeList ips = append ips node PublicIp dns = append dns node PublicDns ``` `jsonOut = pulumi All ips dns ApplyT func args interface string error ` `length = len args 2` ``` var output map string string for idx = range args ip = args idx string dns = args idx+length string output = append output map string string ip ip dns dns outputBytes err = json Marshal output if err = nil return fmt Sprintf Not able to create json err fmt Println string outputBytes return string outputBytes nil ctx Export machine info jsonOut return vm nil ```

bored-table-20691 · Answer

which line is 208

late-energy-66663 · Answer

```for idx = range args ip = args idx string dns = args idx+length string output = append output map string string ip ip dns dns ```

late-energy-66663 · Answer

that 208 line `ip = args idx string `

bored-table-20691 · Answer

Yeah

bored-table-20691 · Answer

I d try something like this instead ``` outputs = pulumi StringOutput for node = range nodeList outputs = append outputs node PublicIp node PublicDns jsonOut = pulumi All outputs ApplyT func args interface string error length = len args for idx = 0 idx lt length idx += 2 ip = args idx string dns = args idx+1 string output = append output map string string ip ip dns dns outputBytes err = json Marshal output if err = nil return fmt Sprintf Not able to create json err fmt Println string outputBytes return string outputBytes nil ctx Export machine info jsonOut return vm nil ```

late-energy-66663 · Answer

thanks very Much Almost came the similar version but was struggling with the getting all the records in slice my version was showing only last record ```for nodes = range nodeList jsonout = pulumi All nodes PublicIp nodes PublicDns ApplyT func args interface string error var output map string string ip = args 0 string dns = args 1 string output = append output map string string ip ip dns dns outputBytes err = json Marshal output if err = nil return fmt Sprintf Not able to create json err return string outputBytes nil fmt Println jsonout ctx Export machine info jsonout ```

late-energy-66663 · Answer

Let me try now

bored-table-20691 · Answer

the JSON piece should not be inside the body of the loop

late-energy-66663 · Answer

Now getting this error complaining about following line ```jsonOut = pulumi All outputs ApplyT func args interface string error ``` Cannot use outputs type pulumi StringOutput as the type interface

late-energy-66663 · Answer

What is the difference between jsonOut = pulumi All outputs ApplyT func args interface string error amp jsonOut = pulumi All outputs ApplyT func args interface string error

bored-table-20691 · Answer

```outputs = interface ```

bored-table-20691 · Answer

change it to that

late-energy-66663 · Answer

sure

bored-table-20691 · Answer

<https pkg go dev github com pulumi pulumi sdk v3 v3 24 1 go pulumi All> `pulumi All` accepts a variable argument list and will wait until they re all resolved If you pass in just `outputs` then it waits for that value to be resolved which it is immediately since it s not a future `outputs ` passes each element as an argument allowing you to wait for each one

late-energy-66663 · Answer

pray thumbsup

late-energy-66663 · Answer

I have another question if you dont mind Since I have return the output to virtualmachines VirtualMachines Struct Why do I need to do ctx Export machine info jsonOut

late-energy-66663 · Answer

Also what is the difference between ctx Export Vs ```ctx RegisterResourceOutputs vm pulumi Map PublicIP vm Instance PublicIp ```

late-energy-66663 · Answer

Why do we have to use `ctx Export` Cant we use `ctx RegisterResourceOutputs` and use the output some where

bored-table-20691 · Answer

`ctx Export` exports it as a stack output so that other stacks can use it as stack references or if you need some other automation otuside your stack to access it

bored-table-20691 · Answer

Your `RegisterResourceOutputs` call registers it as an output of a component resource

late-energy-66663 · Answer

`call registers it as an output of a component resource` so what impact it has on the program as whole

bored-table-20691 · Answer

None it just registers it ofr that component resource

late-energy-66663 · Answer

hmm isee

late-energy-66663 · Answer

would there be a problem if I dont use in my components

bored-table-20691 · Answer

I m not sure what you mean You need to use it in your component resources if you want this to be an output of that resource so reference able by your other things

late-energy-66663 · Answer

ohoo i see

late-energy-66663 · Answer

So to clarify if I use the following code for for virtual machine component i can only reference to PublicIP of that component ```ctx RegisterResourceOutputs vm pulumi Map PublicIP vm Instance PublicIp ```

bored-table-20691 · Answer

I believe so yes

late-energy-66663 · Answer

Just ran the code Working as expected pray Next I am going to look how to push this info to DB ``` + aws ec2 Instance Machine 4 creating + aws ec2 Instance Machine 4 created + aws ec2 Instance Machine 5 created dns ip 15 161 190 245 dns ip 15 161 197 181 dns ip 15 161 107 21 dns ip 15 160 211 73 dns ip 15 161 228 178 virtual machine ec2 vms pulumi pulumi Stack prod prod dev Outputs + machine info dns ip 15 161 190 245 dns ip 15 161 197 181 dns ip 15 161 107 21 dns ip 15 160 211 73 dns ip 15 161 228 178 Resources + 2 created 7 unchanged Duration 16s key machine info = gt dns ip 15 161 190 245 dns ip 15 161 197 181 dns ip 15 161 107 21 dns ip 15 160 211 73 dns ip 15 161 228 178 Update succeeded ```

bored-table-20691 · Answer

thumbsup

late-energy-66663 · Answer

var `jsonOut` is of pulumi Output Can I use it directly to store value to some struct or do I have export it first which we did and can be seen on the output

bored-table-20691 · Answer

It s a future value it won t be known at runtime what it is

late-energy-66663 · Answer

only way I know to print the exported value using range to the res output I take that would be the right place to know the future value ```res err = s Up ctx stdoutStreamer if err = nil fmt Printf Failed to deploy vm stack v n err os Exit 1 time Sleep 60 time Second ``` `for key element = range res Outputs ` `fmt Println key key = gt element Value ` ``` ```

bored-table-20691 · Answer

Yes you can reference it in the automation API

bored-table-20691 · Answer

or via the CLI with `pulumi stack output`

late-energy-66663 · Answer

Thank I do it normally using Automation api

late-energy-66663 · Answer

I am sorry keep asking questions Can `ApplyT` output to some STRUCT which can then be use in the program like using the struct value to some other programs pulumi All outputs ApplyT func args interface `vm struct` error something like above

bored-table-20691 · Answer

No the result of `ApplyT` will always be a future

late-energy-66663 · Answer

I see

late-energy-66663 · Answer

thanks

late-energy-66663 · Answer

Hi < bored table 20691> I did manage to store the info in the DB So Thank you so much for the advise pray once I added the info to Db i noticed that i was looking to store Name of each machine I dont think the name is part of the ec2 InstanceArgs which can be exported using `ctx export` ```for i = 1 i lt = 3 i++ ``` `name = fmt Sprintf Machine d i ` ```vm Instance err = ec2 NewInstance ctx name amp ec2 InstanceArgs Tags pulumi StringMap Name pulumi String fmt Sprintf Machine d i InstanceType pulumi String t3 large InstanceType args InstanceType VpcSecurityGroupIds pulumi StringArray vm SecurityGroup ID Ami pulumi String ami 0f8ce9c417115413d UserData userData KeyName deployer KeyName ``` I have updated the code we discussed last week adding the new slice which picks the name of the node and trying to append it to the output slice interface But some how not getting the desired result where the name is also added as part of dns ip Just wondering where i am missing the trick really Appreciate for the advise ``` nodeName = append nodeName pulumi Sprintf name nodeList = append nodeList vm Instance var outputs pulumi StringOutput outputs = interface for names = range nodeName for node = range nodeList outputs = append outputs node PublicIp node PublicDns names jsonOut = pulumi All outputs ApplyT func args interface string error length = len args fmt Println length var output map string string for idx = 0 idx lt length idx += 3 ip = args idx string dns = args idx+1 string name = args idx+2 string output = append output map string string ip ip dns dns name name outputBytes err = json Marshal output if err = nil return fmt Sprintf Not able to create json err fmt Println string outputBytes return string outputBytes nil ctx Export machine info jsonOut return vm nil ```

bored-table-20691 · Answer

You re loop doesn t look right you re iterating over nodeList for each name rather than once so you basically end up with the same list many times over You want likely something like this since `nodeName` and `nodeList` are the same length ```for idx node = range nodeList outputs = append outputs node PublicIp node PublicDns nodeName idx ``` And then in the `ApplyT` function it would be similar to what you have in your code above

late-energy-66663 · Answer

Thanks Let me try