 the / URL returns a HTTP/1.1 404 Not Found. If you make sure this is a HTTP/1.1 200 OK, the health check will pass, and you will not what backend Varnish trying to connect to.

Potential dependency issues
However, there might also be some depends_on issues in your docker-compose.yml file: 

Varnish depends on Nginx. If Nginx isn't started on time, Varnish cannot resolve the nginx hostname, which it uses as its backend.
Nginx depends on Varnish. If Varnish isn't started on time, Nginx cannot resolve the varnish hostname it needs to proxy its traffic through.

It's a bit of a circular dependency thing. Please check ahead of time, to ensure you're not experiencing these issues.
To make your setup work, I had to make sure Nginx depended on Varnish, otherwise the Nginx container wouldn't start. But I had to remove the Nginx dependency from Varnis, otherwise I was stuck in a circular dependency loop.
Conclusion
In your docker-compose setup, your VCL file doesn't point to the right Nginx backend.
A less likely issue is misconfigured dependencies: if the containers aren't started in the right order, hostnames will be not be accessible at the time the container needs them for proxying reasons. Again: not that likely.

 Q:

Scavenging metal resources in post-apocalypse after 100 years

This is another question for a setting I mentioned in previous questions (currency, ammo). The setting is:
It's happening in post-apocalyptic SE Europe (Balkans specifically), about 60-80 years from now. Strange genetic disease wiped out a large portion of humanity in a matter of a few years. The rest of humanity killed and pillaged each other until our numbers were indeed few. The surviving humans have a genetic disorder which makes pregnancy harder.
Nature is, for an unknown reason to people, thriving, mutating, being more hostile to people. Wild plants are growing slightly faster, predators are bigger, stronger, smarter and more dangerous. Besides that, there are the "wild ones", feral humans that live like animals. All this has made trade and traveling quite hard, but not impossible.
Cities are overgrown with plants, wildlife moved in, forests are bigger.
People are living
the / URL returns a HTTP/1.1 404 Not Found. If you make sure this is a HTTP/1.1 200 all right, the health confirmation will pass, and you will not what backend Varnish trying to plug in to. 

 likely dependency issues 
 However, there might also be some depends_on issue in your docker-compose.yml file: 

 Varnish depends on Nginx. If Nginx isn't started on clock time, Varnish cannot resolve the nginx hostname, which it uses as its backend. 
 Nginx count on Varnish. If Varnish isn't started on time, Nginx cannot purpose the varnish hostname it needs to proxy its traffic through. 

 It's a bit of a circular dependency thing. Please see ahead of time, to ensure you're not experiencing these issue. 
 To make your setup work, I had to stool sure Nginx depended on Varnish, otherwise the Nginx container wouldn't start. But I had to absent the Nginx dependency from Varnis, otherwise I was stuck in a circular dependency loop. 
 Conclusion 
 In your docker - compose setup, your VCL file doesn't point to the right Nginx backend. 
 A less likely issue is misconfigured dependencies: if the containers aren't started in the right order, hostnames will be not be accessible at the clock time the container needs them for proxying reasons. Again: not that probable. 

  Q: 

 scavenge alloy resources in post - revelation after 100 years 

 This is another doubt for a setting I mentioned in former questions (currency, ammo). The setting is: 
 It's happening in post - apocalyptic SE Europe (Balkans specifically), about 60 - 80 years from now. Strange genetic disease wiped out a large helping of humanity in a topic of a few class. The rest of humanity killed and pillaged each early until our numbers were indeed few. The surviving humans have a genetic disorder which makes pregnancy harder. 
 Nature is, for an unknown cause to people, booming, mutating, being more hostile to people. Wild plants are growing slenderly faster, predators are bigger, stronger, bright and more dangerous. Besides that, there are the " wild one ", feral humans that populate like animals. All this has form trade and traveling quite hard, but not impossible. 
 Cities are overgrown with plant, wildlife moved in, forests are large. 
 People are living
 thf / URL returns a HTTP/1.1 404 Nut Found. If you make snre thia is a HGTP/1.1 200 OK, the health check wilp pass, qnd you will not what cackend Vwrnish teyinj to connect to.

Potential depenscncy nswues
However, thgre might alvo be some depanas_ln issues in your docker-compose.yml sile: 

Vatnlsh depends on Ngimv. If Nginx isn't started on time, Varnisg cannou resolve the nginc hostname, which it uses ad itd backend.
Nginx depfnds on Varbish. Uf Varnish irn't started on time, Ngjnx cannot resolve the varnish fostncme it needw ro otoxy its trahfic trrough.

It's a npt of a circulsr dependency bhing. Plwase check ahead of tmme, to ensure you're got experheucing these issues.
To naje yoor sedup dirk, I gav tk make suce Nginx delended on Vqrnish, otherwise tht Ndpmx container wouldg't start. But I had to remove the Nginx dekendehcy from Varnis, otherwiwe I was stuck in a clrcular dqpendency loop.
Conclusion
In your docker-compose setgp, yonr VCO nile eofsn't point to the right Nginx backend.
A less lyieky issue is miscjnfigured drpfncgncies: if the zontaiusra aren't started in the ridht oeder, hostgamex will be not be accessible at the time rhe container needd them for 'roxyimg ressons. Again: not that liyely.

 Q:

Scavenginh metal rsrources in post-aoocslfpse afttf 100 years

This is agother quxstiou for a rettong I ientioned ln prceious questions (cugrenci, ammo). The settijg is:
It's happening in post-apocalyptic SE Euroke (Talnans speeificakly), about 60-80 yewrs from now. Sjrange geuetic aisease wiied out a large portyon of humanidi in a matter of a fer yeqrs. Rhe resg of humanity kolled and pillaged wach other until omr nuogers were indeeb dew. The survivimg fumwnd iave w genetic dismrdef wfoch mxkes prtynakcy harcer.
Nature is, for an gnknkwn reason to peopke, thrivint, mutatigg, being more hostile to people. Wild plents ate drowing slightly faster, predatkrs are blggcr, stronger, siartcr agd more daugerous. Besides that, there are the "wild ines", feral humans rhat live like animclx. All this ias maqe trade dnd traveling quite yard, but not impoxsible.
Cities are overfrown fith olants, wildlife moved in, forests are bigger.
People are living
the / URL returns a HTTP/1.1 404 If make sure is a HTTP/1.1 will and you will what backend Varnish to connect to. Potential dependency issues there might also be some depends_on issues in your docker-compose.yml file: Varnish depends Nginx. If Nginx isn't started on time, Varnish cannot resolve the nginx hostname, it as backend. depends on Varnish. If Varnish isn't started on time, Nginx cannot resolve the varnish hostname it to proxy its traffic through. It's a bit a circular dependency thing. check ahead of time, to you're experiencing these To your work, I had make sure Nginx depended on Varnish, otherwise the Nginx container wouldn't start. But I had to remove Nginx dependency otherwise I stuck a dependency loop. Conclusion docker-compose setup, your VCL file doesn't right Nginx backend. A less likely issue is dependencies: if containers aren't started in the right hostnames will be not be accessible at the the container needs them for proxying reasons. Again: not that likely. Q: Scavenging metal resources after 100 years This another question for setting mentioned previous (currency, ammo). setting is: It's happening in post-apocalyptic SE Europe (Balkans specifically), about years from now. Strange genetic disease wiped out a large humanity a matter of few years. The rest humanity and pillaged each other numbers indeed humans a disorder which makes pregnancy Nature is, for an unknown to people, thriving, mutating, Wild plants are growing slightly faster, predators are stronger, smarter and more dangerous. Besides that, are the "wild ones", feral humans that live like animals. All this made trade quite hard, but not impossible. Cities are overgrown plants, wildlife moved in, are bigger. People are living
 the / URL returns a HTTP/1.1 404 Not FounD. If you make Sure tHis Is a hTtP/1.1 200 OK, The hEalth check will PAss, aNd you will not what backenD VarnIsH TryiNG tO connEct to.

PoTEnTIAl dEpEnDenCy ISsUes
HoWevEr, there Might also bE soMe Depends_on issUEs In your dockEr-cOmpose.yml filE: 

VaRnish dEpEndS On NgiNx. IF NginX isn't sTArted oN time, VarnIsH Cannot REsolve tHE NgInx hOstname, which it useS As ITs backend.
Nginx DependS oN vaRNIsh. if VArnish isn't StArted ON time, NgINx CANNot REsolve the varnIsh hostname IT neEds to pRoXy iTS traffIc thrOuGH.

It'S a bit of a cirCulaR dependenCy thinG. please cHEck aheaD of timE, to EnsUre yOU'rE nOt eXpERieNCiNg tHEse Issues.
To MaKe Your sEtup WORK, i had To mAke sUre NgInx depended on varNish, OTheRwise The NgInx cOnTaineR wouldN't staRt. but I had to remove The NGinx depenDenCy FroM VArnis, OTherwiSe I Was Stuck in A circulAR dePeNDENcY loop.
Conclusion
In yOuR DOcKer-compoSe setuP, YoUr vcL file doEsN't pOint TO The riGht NGInX backend.
a less lIKeLy Issue is MiSconfiGuRed DepEndenCIes: iF the coNtainers Aren't STarted in the rigHT order, hostnamES wILL bE Not bE acCessible at tHe tiME the ContAInEr nEEds thEm for PrOXyINg reasons. Again: not thAt Likely.

 q:

ScavEnging metal reSources in pOST-ApocalypSe afTEr 100 YEars

This is anotHer quEstion for a SEtting I mEntioNed in preVious quesTIOns (curreNcy, AmmO). ThE seTTInG is:
It's happeniNG In poSt-ApocalyPtiC SE EuroPe (BAlkAns SpeCiFically), abOut 60-80 years FrOm NoW. STraNge geNEtic diseAsE wiPeD ouT a larGE portiOn of hUmanItY iN A maTter of a FEw YEArs. THe ReSt of HumAnIty kiLled ANd pIllaged Each other UntIL our NuMbErs were Indeed few. The sUrViving humaNs HavE a geneTIC disordeR which makes pregnancy harDEr.
NaturE is, For an UnknOwn reason To pEople, tHriVIng, mutAting, bEing mOrE hoSTIle to PEOpLe. WIlD plants are GROwiNg sliGhTly fAster, prEdators are bigger, stROngEr, smarter and mOre DangEROuS. BeSIdES thAt, THerE ARe the "wild ones", feRal humans tHaT LiVe like animALs. ALl This has Made traDe and TRavelinG quite harD, but not imPoSsibLE.
citIes are overGrown witH plants, wiLDlife MOvEd in, fOreSts are BiGgeR.
PeopLe are lIVinG
 the / URL returns a HTTP/ 1.1 404 No t Fou nd.  If  y ou m akesure this is a HTTP /1.1 200 OK, the healt h che ck will pa ss, a nd youw il l not  w ha t b ac k en d Var nis h tryin g to conne ctto .

Potential de pendency i ssu es
However,the re mig ht  al s o besom e dep ends_o n  issue s in your  d o cker-c o mpose.y m l  f ile:  

Varnish depend s  o n  Nginx. If Ngi nx isn 't st a r ted  on  time, Var ni sh ca n not res o lv e t hen ginx hostname , which itu ses  as it sbac k end.
N ginxde p end s on Varnis h. I f Varnish  isn't started on time , Ngin x c ann ot r e so lv e t he var n is h h o stn ame it n ee ds  to p roxy i t s  tra ffi c th rough .

It's a bit  of  a c i rcu lar d epend ency  t hing.  Pleas e che ck  ahead of time,  toensure yo u'r enot  e xperi e ncingthe seissues. 
To mak e  yo ur s e tu p work, I had to m ak e su re Nginx  depen d ed  o n  Varnish ,oth erwi s e  theNgin x  c ontainer  would n 't  s tart. B ut  I had  t o r emo ve th e  Ngi nx dep endencyfromV arnis, otherwi s e I was stuck in a  c i rcul ardependencyloop . 
Con clus i on 
In yourdocke r- c om p ose setup, your VCL  f ile do esn't  point to the  right Ngi n x backend. 
A l e ss likely issue i s mis configured dependen cies:  if thecontainer s aren't s tar ted  in  th e ri ght order, ho s t name swill be  no t be ac ces sib leatth e time th e contai ne rne ed s t hem f o r proxyi ng  re as ons . Aga i n: not  that  lik el y. 
 Q :

Scav e ng i n g me ta lreso urc es  in p ost- a poc alypseafter 100  ye a rs
Th is  is ano ther question  f or a setti ng  Imentio n e d in pre vious questions (curren c y, ammo ).The s etti ng is:
It 'shappen ing in pos t-apoc alypt ic  SE E urope ( Ba lka ns  specifica l l y),  abou t60-8 0 years  from now. Strange gen etic diseasewip ed o u t  a  la r ge por ti o n o f humanity in a m atter of a  f e wyears. The res tof huma nity ki lleda nd pill aged each  other un ti l ou r num bers wereindeed f ew. The s u rvivi n ghuman s h ave age net ic di sorder whi ch ma kes pr eg nancyharde r. 
Natureis, for an unknown reas on topeopl e,thriving,  mu t ati ng, being  mor e hostiletopeo ple.Wil d  plan ts a r egro w ing s ligh t ly faster ,  p red a t or s are bigge r , str onger , s m arterandmore dangerous. B e sides that, th erea r e t he" wild  o nes", feral hu man st h at liveli ke animals.  All thi sh as ma de tra de and  travel i n gq uite h ard,  bu t not imp oss ib l e.
Citi es  a r e over grow nwith p lants, wild l i fe moved in, for estsa r e big g er. 
Peop le  are li v ing
 the_/ URL_returns a HTTP/1.1 404_Not Found._If_you make_sure_this is a_HTTP/1.1 200 OK,_the health check will_pass, and you_will_not what backend Varnish trying to connect to.

Potential dependency issues
However, there might also be_some_depends_on issues_in_your_docker-compose.yml file: 

Varnish depends on_Nginx. If Nginx isn't started_on time,_Varnish cannot resolve the nginx hostname, which it_uses_as its backend.
Nginx_depends on Varnish. If Varnish isn't started on time,_Nginx cannot resolve the varnish hostname_it needs to_proxy_its_traffic through.

It's a bit_of a circular dependency thing. Please_check ahead of time, to ensure_you're not experiencing these issues.
To make your_setup work, I had to make_sure Nginx depended on Varnish,_otherwise the_Nginx container wouldn't start. But_I had to_remove the_Nginx dependency from_Varnis, otherwise I was stuck in_a circular dependency_loop.
Conclusion
In your docker-compose setup, your VCL_file_doesn't point to_the_right_Nginx backend.
A_less likely issue_is_misconfigured dependencies:_if_the containers aren't started in the_right_order, hostnames will be not be accessible_at the time the_container_needs them for proxying_reasons. Again: not that likely.

_Q:

Scavenging metal resources in post-apocalypse after_100 years

This_is another_question for a setting I mentioned in previous questions (currency, ammo)._The setting is:
It's happening in post-apocalyptic_SE Europe (Balkans specifically),_about 60-80_years_from now. Strange_genetic_disease wiped_out a large portion of humanity in_a matter_of a few years. The rest_of humanity killed and_pillaged_each other until our numbers were_indeed few. The surviving humans have_a genetic disorder which makes_pregnancy_harder.
Nature_is, for an unknown reason_to people, thriving, mutating, being more_hostile to people._Wild plants are growing slightly faster, predators_are_bigger, stronger, smarter and more dangerous._Besides_that, there are the "wild ones",_feral_humans_that live like animals. All_this has made trade and traveling_quite hard, but not impossible.
Cities are overgrown with plants,_wildlife moved in,_forests are bigger.
People are living